Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-30 (of 51 Records) |
Query Trace: Shafer L[original query] |
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Transcriptional responses of Neisseria gonorrhoeae to glucose and lactate: implications for resistance to oxidative damage and biofilm formation
Ayala JC , Balthazar JT , Shafer WM . mBio 2024 e0176124 Understanding how bacteria adapt to different environmental conditions is crucial for advancing knowledge regarding pathogenic mechanisms that operate during infection as well as efforts to develop new therapeutic strategies to cure or prevent infections. Here, we investigated the transcriptional response of Neisseria gonorrhoeae, the causative agent of gonorrhea, to L-lactate and glucose, two important carbon sources found in the host environment. Our study revealed extensive transcriptional changes that gonococci make in response to L-lactate, with 37% of the gonococcal transcriptome being regulated, compared to only 9% by glucose. We found that L-lactate induces a transcriptional program that would negatively impact iron transport, potentially limiting the availability of labile iron, which would be important in the face of the multiple hydrogen peroxide attacks encountered by gonococci during its lifecycle. Furthermore, we found that L-lactate-mediated transcriptional response promoted aerobic respiration and dispersal of biofilms, contrasting with an anaerobic condition previously reported to favor biofilm formation. Our findings suggest an intricate interplay between carbon metabolism, iron homeostasis, biofilm formation, and stress response in N. gonorrhoeae, providing insights into its pathogenesis and identifying potential therapeutic targets.IMPORTANCEGonorrhea is a prevalent sexually transmitted infection caused by the human pathogen Neisseria gonorrhoeae, with ca. 82 million cases reported worldwide annually. The rise of antibiotic resistance in N. gonorrhoeae poses a significant public health threat, highlighting the urgent need for alternative treatment strategies. By elucidating how N. gonorrhoeae responds to host-derived carbon sources such as L-lactate and glucose, this study offers insights into the metabolic adaptations crucial for bacterial survival and virulence during infection. Understanding these adaptations provides a foundation for developing novel therapeutic approaches targeting bacterial metabolism, iron homeostasis, and virulence gene expression. Moreover, the findings reported herein regarding biofilm formation and L-lactate transport and metabolism contribute to our understanding of N. gonorrhoeae pathogenesis, offering potential avenues for preventing and treating gonorrhea infections. |
Systematic review of empiric studies on lockdowns, workplace closures, and other non-pharmaceutical interventions in non-healthcare workplaces during the initial year of the COVID-19 pandemic: benefits and selected unintended consequences
Ahmed F , Shafer L , Malla P , Hopkins R , Moreland S , Zviedrite N , Uzicanin A . BMC Public Health 2024 24 (1) 884 BACKGROUND: We conducted a systematic review aimed to evaluate the effects of non-pharmaceutical interventions within non-healthcare workplaces and community-level workplace closures and lockdowns on COVID-19 morbidity and mortality, selected mental disorders, and employment outcomes in workers or the general population. METHODS: The inclusion criteria included randomized controlled trials and non-randomized studies of interventions. The exclusion criteria included modeling studies. Electronic searches were conducted using MEDLINE, Embase, and other databases from January 1, 2020, through May 11, 2021. Risk of bias was assessed using the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) tool. Meta-analysis and sign tests were performed. RESULTS: A total of 60 observational studies met the inclusion criteria. There were 40 studies on COVID-19 outcomes, 15 on anxiety and depression symptoms, and five on unemployment and labor force participation. There was a paucity of studies on physical distancing, physical barriers, and symptom and temperature screening within workplaces. The sign test indicated that lockdown reduced COVID-19 incidence or case growth rate (23 studies, p < 0.001), reproduction number (11 studies, p < 0.001), and COVID-19 mortality or death growth rate (seven studies, p < 0.05) in the general population. Lockdown did not have any effect on anxiety symptoms (pooled standardized mean difference = -0.02, 95% CI: -0.06, 0.02). Lockdown had a small effect on increasing depression symptoms (pooled standardized mean difference = 0.16, 95% CI: 0.10, 0.21), but publication bias could account for the observed effect. Lockdown increased unemployment (pooled mean difference = 4.48 percentage points, 95% CI: 1.79, 7.17) and decreased labor force participation (pooled mean difference = -2.46 percentage points, 95% CI: -3.16, -1.77). The risk of bias for most of the studies on COVID-19 or employment outcomes was moderate or serious. The risk of bias for the studies on anxiety or depression symptoms was serious or critical. CONCLUSIONS: Empiric studies indicated that lockdown reduced the impact of COVID-19, but that it had notable unwanted effects. There is a pronounced paucity of studies on the effect of interventions within still-open workplaces. It is important for countries that implement lockdown in future pandemics to consider strategies to mitigate these unintended consequences. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration # CRD42020182660. |
Hormonal steroids induce multidrug resistance and stress response genes in Neisseria gonorrhoeae by binding to MtrR
Hooks GM , Ayala JC , Holley CL , Dhulipala V , Beggs GA , Perfect JR , Schumacher MA , Shafer WM , Brennan RG . Nat Commun 2024 15 (1) 1153 Transcriptional regulator MtrR inhibits the expression of the multidrug efflux pump operon mtrCDE in the pathogenic bacterium Neisseria gonorrhoeae. Here, we show that MtrR binds the hormonal steroids progesterone, β-estradiol, and testosterone, which are present at urogenital infection sites, as well as ethinyl estrogen, a component of some hormonal contraceptives. Steroid binding leads to the decreased affinity of MtrR for cognate DNA, increased mtrCDE expression, and enhanced antimicrobial resistance. Furthermore, we solve crystal structures of MtrR bound to each steroid, thus revealing their binding mechanisms and the conformational changes that induce MtrR. |
Notes from the Field: The National Wastewater Surveillance System's Centers of Excellence contributions to public health action during the respiratory virus season - four U.S. Jurisdictions, 2022-23
Valencia D , Yu AT , Wheeler A , Hopkins L , Pray I , Horter L , Vugia DJ , Matzinger S , Stadler L , Kloczko N , Welton M , Bertsch-Merbach S , Domakonda K , Antkiewicz D , Turner H , Crain C , Mulenga A , Shafer M , Owiti J , Schneider R , Janssen KH , Wolfe MK , McClellan SL , Boehm AB , Roguet A , White B , Schussman MK , Rane MS , Hemming J , Collins C , Abram A , Burnor E , Westergaard R , Ricaldi JN , Person J , Fehrenbach N . MMWR Morb Mortal Wkly Rep 2023 72 (48) 1309-1312 Wastewater surveillance (WWS), the systematic detection of infectious agents in wastewater, provided a valuable tool for monitoring SARS-CoV-2 circulation during the COVID-19 pandemic; surveillance has expanded from 20 to 53 jurisdictions across the United States, with increasing capacity to test for more respiratory pathogens (1,2). This report highlights the use of wastewater data by the four National Wastewater Surveillance System’s (NWSS) Centers of Excellence (California; Colorado; Houston, Texas; and Wisconsin) to guide public health action during the 2022–23 respiratory disease season. This activity was reviewed by CDC, deemed not research, and was conducted consistent with applicable federal law and CDC policy.* |
Recommendations on data sharing in HIV drug resistance research
Inzaule SC , Siedner MJ , Little SJ , Avila-Rios S , Ayitewala A , Bosch RJ , Calvez V , Ceccherini-Silberstein F , Charpentier C , Descamps D , Eshleman SH , Fokam J , Frenkel LM , Gupta RK , Ioannidis JPA , Kaleebu P , Kantor R , Kassaye SG , Kosakovsky Pond SL , Kouamou V , Kouyos RD , Kuritzkes DR , Lessells R , Marcelin AG , Mbuagbaw L , Minalga B , Ndembi N , Neher RA , Paredes R , Pillay D , Raizes EG , Rhee SY , Richman DD , Ruxrungtham K , Sabeti PC , Schapiro JM , Sirivichayakul S , Steegen K , Sugiura W , van Zyl GU , Vandamme AM , Wensing AMJ , Wertheim JO , Gunthard HF , Jordan MR , Shafer RW . PLoS Med 2023 20 (9) e1004293 Author summary • Human immunodeficiency virus (HIV) drug resistance has implications for antiretroviral treatment strategies and for containing the HIV pandemic because the development of HIV drug resistance leads to the requirement for antiretroviral drugs that may be less effective, less well-tolerated, and more expensive than those used in first-line regimens. • HIV drug resistance studies are designed to determine which HIV mutations are selected by antiretroviral drugs and, in turn, how these mutations affect antiretroviral drug susceptibility and response to future antiretroviral treatment regimens. • Such studies collectively form a vital knowledge base essential for monitoring global HIV drug resistance trends, interpreting HIV genotypic tests, and updating HIV treatment guidelines. • Although HIV drug resistance data are collected in many studies, such data are often not publicly shared, prompting the need to recommend best practices to encourage and standardize HIV drug resistance data sharing. • In contrast to other viruses, sharing HIV sequences from phylogenetic studies of transmission dynamics requires additional precautions as HIV transmission is criminalized in many countries and regions. • Our recommendations are designed to ensure that the data that contribute to HIV drug resistance knowledge will be available without undue hardship to those publishing HIV drug resistance studies and without risk to people living with HIV. |
Wastewater surveillance data as a complement to emergency department visit data for tracking incidence of influenza a and respiratory syncytial virus - Wisconsin, August 2022-March 2023
DeJonge PM , Adams C , Pray I , Schussman MK , Fahney RB , Shafer M , Antkiewicz DS , Roguet A . MMWR Morb Mortal Wkly Rep 2023 72 (37) 1005-1009 Wastewater surveillance has been used to assist public health authorities in tracking local transmission of SARS-CoV-2. The usefulness of wastewater surveillance to track community spread of other respiratory pathogens, including influenza virus and respiratory syncytial virus (RSV), is less clear. During the 2022-23 respiratory diseases season, concentrations of influenza A virus and RSV in wastewater samples in three major Wisconsin cities were compared with emergency department (ED) visits associated with these pathogens. In all three cities, higher concentrations of influenza A virus and RSV in wastewater were associated with higher numbers of associated ED visits (Kendall's tau range = 0.50-0.63 for influenza-associated illness and 0.30-0.49 for RSV-associated illness). Detections of both influenza A virus and RSV in wastewater often preceded a rise in associated ED visits for each pathogen, and virus material remained detectable in wastewater for up to 3 months after pathogen-specific ED visits declined. These results demonstrate that wastewater surveillance has the potential to complement conventional methods of influenza and RSV surveillance, detecting viral signals earlier and for a longer duration than do clinical data. Continued use of wastewater surveillance as a supplement to established surveillance systems such as ED visits might improve local understanding and response to seasonal respiratory virus outbreaks. |
Mechanistic basis for decreased antimicrobial susceptibility in a clinical isolate of Neisseria gonorrhoeae possessing a mosaic-like mtr efflux pump locus (preprint)
Rouquette-Loughlin CE , Reimche JL , Balthazar JT , Dhulipala V , Gernert KM , Kersh EN , Pham CD , Pettus K , Abrams AJ , Trees DL , St Cyr S , Shafer WM . bioRxiv 2018 448712 Recent reports suggest that mosaic-like sequences within the mtr (multiple transferable resistance) efflux pump locus of Neisseria gonorrhoeae likely originating from commensal Neisseria sp. by transformation can increase the ability of gonococci to resist structurally diverse antimicrobials. Thus, acquisition of numerous nucleotide changes within the mtrR gene encoding the transcriptional repressor (MtrR) of the mtrCDE efflux pump-encoding operon or overlapping promoter region for both along with those that cause amino acid changes in the MtrD transporter protein were recently reported to decrease gonococcal susceptibility to numerous antimicrobials, including azithromycin (Azi) (Wadsworth et al. 2018. MBio. doi.org/10.1128/mBio.01419-18). We performed detailed genetic and molecular studies to define the mechanistic basis for why such strains can exhibit decreased susceptibility to MtrCDE antimicrobial substrates including Azi. We report that a strong cis-acting transcriptional impact of a single nucleotide change within the -35 hexamer of the mtrCDE promoter as well gain-of-function amino acid changes at the C-terminal region of MtrD can mechanistically account for the decreased antimicrobial susceptibility of gonococci with a mosaic-like mtr locus.IMPORTANCE Historically, after introduction of an antibiotic for treatment of gonorrhea, strains of N. gonorrhoeae emerge that display clinical resistance due to spontaneous mutation or acquisition of resistance genes. Genetic exchange between members of the Neisseria genus occurring by transformation can cause significant changes in gonococci that impact the structure of an antibiotic target or expression of genes involved in resistance. The results presented herein provide a framework for understanding how mosaic-like DNA sequences from commensal Neisseria that recombine within the gonococcal mtr efflux pump locus function to decrease bacterial susceptibility to antimicrobials including antibiotics used in therapy of gonorrhea. |
Tracing the origin of SARS-CoV-2 Omicron-like Spike sequences detected in wastewater (preprint)
Shafer MM , Bobholz MJ , Vuyk WC , Gregory D , Roguet A , Haddock Soto LA , Rushford C , Janssen KH , Ries HJ , Pilch HE , Mullen PA , Fahney RB , Wei W , Lambert M , Wenzel J , Halfmann P , Kawaoka Y , Wilson NA , Friedrich TC , Pray IW , Westergaard R , O'Connor DH , Johnson MC . medRxiv 2022 31 Background: The origin of divergent SARS-CoV-2 spike sequences found in wastewater, but not in clinical surveillance, remains unclear. These "cryptic" wastewater sequences have harbored many of the same mutations that later emerged in Omicron lineages. We first detected a cryptic lineage in municipal wastewater in Wisconsin in January 2022. Named the "Wisconsin Lineage", we sought to determine this virus's geographic origin and characterize its persistence and evolution over time. Method(s): We systematically sampled maintenance holes to trace the Wisconsin Lineage's origin. We sequenced spike RBD domains, and where possible, whole viral genomes, to characterize the evolution of this lineage over the 13 consecutive months that it was detectable. Finding(s): The persistence of the Wisconsin Lineage signal allowed us to trace it from a central wastewater plant to a single facility, with a high concentration of viral RNA. The viral sequences contained a combination of fixed nucleotide substitutions characteristic of Pango lineage B.1.234, which circulated in Wisconsin at low levels from October 2020 to February 2021, while mutations in the spike gene resembled those subsequently found in Omicron variants. Interpretation(s): We propose that prolonged detection of the Wisconsin Lineage in wastewater represents persistent shedding of SARS-CoV-2 from an infected individual, with ongoing within-host viral evolution leading to an ancestral B.1.234 virus accumulating "Omicron-like" mutations. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC 4.0 International license. |
Public trust is earned: Historical discrimination, carceral violence, and the COVID-19 pandemic
Anderson A , Lewis DF , Shafer P , Anderson J , LaVeist TA . Health Serv Res 2023 58 Suppl 2 218-228 OBJECTIVE: To assess whether knowledge of Tuskegee, the U.S. Immigration and Customs Enforcement (ICE) agency's detainment of children, and satisfaction with the George Floyd death investigation were associated with trust in actors involved in the development and distribution of coronavirus vaccines. DATA SOURCES AND STUDY SETTING: National survey with a convenience sample of Black (n = 1019) and Hispanic (n = 994) adults between July 1 and 26, 2021. STUDY DESIGN: Observational study using stratified adjusted logistic regression models to measure the association between ratings of the trustworthiness of actors involved in the development and distribution of coronavirus vaccines. PRINCIPAL FINDINGS: Among Black respondents, lower satisfaction with the George Floyd death investigation was associated with lower trustworthiness ratings of pharmaceutical companies (ME: -0.09; CI: -0.15, 0.02), the FDA (ME: -0.07; CI: -0.14, -0.00), the Trump Administration (ME: -0.09; CI: -0.16, -0.02), the Biden Administration (ME: -0.07, CI: -0.10, 0.04), and elected officials (ME: -0.10, CI: -0.18, -0.03). Among Hispanic respondents, lower satisfaction was associated with lower trustworthiness ratings of the Trump Administration (ME: -0.14, CI: -0.22, -0.06) and elected officials (ME: -0.11; CI: -0.19, -0.02). Greater knowledge of ICE's detainment of children and families among Hispanic respondents was associated with lower trustworthiness ratings of state elected officials (ME: -0.09, CI: -0.16, 0.01). Greater knowledge of the US Public Health Service Study of Syphilis in Tuskegee was associated with higher trustworthiness ratings of their usual source of care (ME: 0.09; CI: 0.28, 0.15) among Black respondents (ME: 0.09; CI: 0.01, 0.16). CONCLUSIONS: Among Black respondents, lower satisfaction with the George Floyd death investigation was associated with lowered levels of trust in pharmaceutical companies, some government officials, and administrators; it was not associated with the erosion of trust in direct sources of health care delivery, information, or regulation. Among Hispanic respondents, greater knowledge of the ICE detainments was associated with lower trustworthiness ratings of elected state officials. Paradoxically, higher knowledge of the Study of Syphilis in Tuskegee was associated with higher trustworthiness ratings in usual sources of care. |
Relationship between telework experience and presenteeism during COVID-19 pandemic, United States, March-November 2020
Shafer L , Ahmed F , Kim S , Wernli KJ , Jackson ML , Nowalk MP , Bear T , Zimmerman RK , Martin ET , Monto AS , Gaglani M , Reis M , Chung JR , Flannery B , Uzicanin A . Emerg Infect Dis 2023 29 (2) 278-285 Persons with COVID-19-like illnesses are advised to stay home to reduce the spread of SARS-CoV-2. We assessed relationships between telework experience and COVID-19 illness with work attendance when ill. Adults experiencing fever, cough, or loss of taste or smell who sought healthcare or COVID-19 testing in the United States during March-November 2020 were enrolled. Adults with telework experience before illness were more likely to work at all (onsite or remotely) during illness (87.8%) than those with no telework experience (49.9%) (adjusted odds ratio 5.48, 95% CI 3.40-8.83). COVID-19 case-patients were less likely to work onsite (22.1%) than were persons with other acute respiratory illnesses (37.3%) (adjusted odds ratio 0.36, 95% CI 0.24-0.53). Among COVID-19 case-patients with telework experience, only 6.5% worked onsite during illness. Telework experience before illness gave mildly ill workers the option to work and improved compliance with public health recommendations to stay home during illness. |
Predicted effects of the introduction of long-acting injectable cabotegravir pre-exposure prophylaxis in sub-Saharan Africa: a modelling study
Smith J , Bansi-Matharu L , Cambiano V , Dimitrov D , Bershteyn A , van de Vijver D , Kripke K , Revill P , Boily MC , Meyer-Rath G , Taramusi I , Lundgren JD , van Oosterhout JJ , Kuritzkes D , Schaefer R , Siedner MJ , Schapiro J , Delany-Moretlwe S , Landovitz RJ , Flexner C , Jordan M , Venter F , Radebe M , Ripin D , Jenkins S , Resar D , Amole C , Shahmanesh M , Gupta RK , Raizes E , Johnson C , Inzaule S , Shafer R , Warren M , Stansfield S , Paredes R , Phillips AN . Lancet HIV 2023 10 (4) e254-e265 BACKGROUND: Long-acting injectable cabotegravir pre-exposure prophylaxis (PrEP) is recommended by WHO as an additional option for HIV prevention in sub-Saharan Africa, but there is concern that its introduction could lead to an increase in integrase-inhibitor resistance undermining treatment programmes that rely on dolutegravir. We aimed to project the health benefits and risks of cabotegravir-PrEP introduction in settings in sub-Saharan Africa. METHODS: With HIV Synthesis, an individual-based HIV model, we simulated 1000 setting-scenarios reflecting both variability and uncertainty about HIV epidemics in sub-Saharan Africa and compared outcomes for each with and without cabotegravir-PrEP introduction. PrEP use is assumed to be risk-informed and to be used only in 3-month periods (the time step for the model) when having condomless sex. We consider three groups at risk of integrase-inhibitor resistance emergence: people who start cabotegravir-PrEP after (unknowingly) being infected with HIV, those who seroconvert while on PrEP, and those with HIV who have residual cabotegravir drugs concentrations during the early tail period after recently stopping PrEP. We projected the outcomes of policies of cabotegravir-PrEP introduction and of no introduction in 2022 across 50 years. In 50% of setting-scenarios we considered that more sensitive nucleic-acid-based HIV diagnostic testing (NAT), rather than regular antibody-based HIV rapid testing, might be used to reduce resistance risk. For cost-effectiveness analysis we assumed in our base case a cost of cabotegravir-PrEP drug to be similar to oral PrEP, resulting in a total annual cost of USD$144 per year ($114 per year and $264 per year considered in sensitivity analyses), a cost-effectiveness threshold of $500 per disability-adjusted life years averted, and a discount rate of 3% per year. FINDINGS: Reflecting our assumptions on the appeal of cabotegravir-PrEP, its introduction is predicted to lead to a substantial increase in PrEP use with approximately 2·6% of the adult population (and 46% of those with a current indication for PrEP) receiving PrEP compared with 1·5% (28%) without cabotegravir-PrEP introduction across 20 years. As a result, HIV incidence is expected to be lower by 29% (90% range across setting-scenarios 6-52%) across the same period compared with no introduction of cabotegravir-PrEP. In people initiating antiretroviral therapy, the proportion with integrase-inhibitor resistance after 20 years is projected to be 1·7% (0-6·4%) without cabotegravir-PrEP introduction but 13·1% (4·1-30·9%) with. Cabotegravir-PrEP introduction is predicted to lower the proportion of all people on antiretroviral therapy with viral loads less than 1000 copies per mL by 0·9% (-2·5% to 0·3%) at 20 years. For an adult population of 10 million an overall decrease in number of AIDS deaths of about 4540 per year (-13 000 to -300) across 50 years is predicted, with little discernible benefit with NAT when compared with standard antibody-based rapid testing. AIDS deaths are predicted to be averted with cabotegravir-PrEP introduction in 99% of setting-scenarios. Across the 50-year time horizon, overall HIV programme costs are predicted to be similar regardless of whether cabotegravir-PrEP is introduced (total mean discounted annual HIV programme costs per year across 50 years is $151·3 million vs $150·7 million), assuming the use of standard antibody testing. With antibody-based rapid HIV testing, the introduction of cabotegravir-PrEP is predicted to be cost-effective under an assumed threshold of $500 per disability-adjusted life year averted in 82% of setting-scenarios at the cost of $144 per year, in 52% at $264, and in 87% at $114. INTERPRETATION: Despite leading to increases in integrase-inhibitor drug resistance, cabotegravir-PrEP introduction is likely to reduce AIDS deaths in addition to HIV incidence. Long-acting cabotegravir-PrEP is predicted to be cost-effective if delivered at similar cost to oral PrEP with antibody-based rapid HIV testing. FUNDING: Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases of the National Institutes of Health. |
A Partially Multiplexed HIV Drug Resistance (HIVDR) Assay for Monitoring HIVDR Mutations of the Protease, Reverse-Transcriptase (PRRT), and Integrase (INT).
DeVos J , McCarthy K , Sewe V , Akinyi G , Junghae M , Opollo V , Nouhin J , Shafer R , Zeh C , Ramos A , Alexander H , Chang J . Microbiol Spectr 2022 10 (3) e0177621 As dolutegravir (DTG)-containing HIV regimens are scaled up globally, monitoring for HIV drug resistance (HIVDR) will become increasingly important. We designed a partially multiplexed HIVDR assay using Sanger sequencing technology to monitor HIVDR mutations in the protease, reverse-transcriptase (PRRT), and integrase (INT). A total of 213 clinical and analytical plasma and dried blood spot (DBS) samples were used in the evaluation. The assay detected a wide range of known HIV-1 subtypes and circulating recombinant forms (CRFs) of group M from 139 samples. INT accuracy showed that the average nucleotide (nt) sequence concordance was 99.8% for 75 plasma samples and 99.5% for 11 DBS samples compared with the reference sequences. The PRRT accuracy also demonstrated the average nucleotide sequence concordance was 99.5% for 57 plasma samples and 99.2% for 33 DBS samples. The major PRRT and INT DR mutations of all samples tested were concordant with those of the reference sequences using the Stanford HIV database (db). Amplification sensitivity of samples with viral load (VL) >5000 copies/mL showed plasma exceeded 95% of positivity, and DBS exceeded 90% for PRRT and INT. Samples with VL (1000 to 5000 copies/mL) showed plasma exceeded 90%, and DBS reached 88% positivity for PRRT and INT. Assay precision and reproducibility showed >99% nucleotide sequence concordance in each set of replicates for PRRT and INT. In conclusion, this HIVDR assay met WHO HIVDR assay performance criteria for surveillance, worked for plasma and DBS, used minimal sample volume, was sensitive, and was a potentially cost-effective tool to monitor HIVDR mutations in PRRT and INT. IMPORTANCE This HIVDR genotyping assay works for both plasma and DBS samples, requires low sample input, and is sensitive. This assay has the potential to be a user-friendly and cost-effective HIVDR assay because of its partially multiplexed design. Application of this genotyping assay will help HIVDR monitoring in HIV high-burdened countries using a DGT-based HIV drug regimen recommended by the U.S. President's Emergency Plan for AIDS Relief and the WHO. |
Current status and future directions for a neurotoxicity hazard assessment framework that integrates in silico approaches
Crofton KM , Bassan A , Behl M , Chushak YG , Fritsche E , Gearhart JM , Marty MS , Mumtaz M , Pavan M , Ruiz P , Sachana M , Selvam R , Shafer TJ , Stavitskaya L , Szabo DT , Szabo ST , Tice RR , Wilson D , Woolley D , Myatt GJ . Comput Toxicol 2022 22 Neurotoxicology is the study of adverse effects on the structure or function of the developing or mature adult nervous system following exposure to chemical, biological, or physical agents. The development of more informative alternative methods to assess developmental (DNT) and adult (NT) neurotoxicity induced by xenobiotics is critically needed. The use of such alternative methods including in silico approaches that predict DNT or NT from chemical structure (e.g., statistical-based and expert rule-based systems) is ideally based on a comprehensive understanding of the relevant biological mechanisms. This paper discusses known mechanisms alongside the current state of the art in DNT/NT testing. In silico approaches available today that support the assessment of neurotoxicity based on knowledge of chemical structure are reviewed, and a conceptual framework for the integration of in silico methods with experimental information is presented. Establishing this framework is essential for the development of protocols, namely standardized approaches, to ensure that assessments of NT and DNT based on chemical structures are generated in a transparent, consistent, and defendable manner. 2022 Elsevier B.V. |
Gonococcal Clinical Strains Bearing a Common gdhR Single Nucleotide Polymorphism That Results in Enhanced Expression of the Virulence Gene lctP Frequently Possess a mtrR Promoter Mutation That Decreases Antibiotic Susceptibility.
Ayala JC , Schmerer MW , Kersh EN , Unemo M , Shafer WM . mBio 2022 13 (2) e0027622 GdhR is a transcriptional repressor of the virulence factor gene lctP, which encodes a unique l-lactate permease that has been linked to pathogenesis of Neisseria gonorrhoeae, and loss of gdhR can confer increased fitness of gonococci in a female mouse model of lower genital tract infection. In this work, we identified a single nucleotide polymorphism (SNP) in gdhR, which is often present in both recent and historical gonococcal clinical strains and results in a proline (P)-to-serine (S) change at amino acid position 6 (P6S) of GdhR. This mutation (gdhR6) was found to reduce GdhR transcriptional repression at lctP in gonococcal strains containing the mutant protein compared to wild-type GdhR. By using purified recombinant proteins and in vitro DNA-binding and cross-linking experiments, we found that gdhR6 impairs the DNA-binding activity of GdhR at lctP without an apparent effect on protein oligomerization. By analyzing a panel of U.S. (from 2017 to 2018) and Danish (1928 to 2013) clinical isolates, we observed a statistical association between gdhR6 and the previously described adenine deletion in the promoter of mtrR (mtrR-P A-del), encoding the repressor (MtrR) of the mtrCDE operon that encodes the MtrCDE multidrug efflux pump that can export antibiotics, host antimicrobials, and biocides. The frequent association of gdhR6 with the mtrR promoter mutation in these clinical isolates suggests that it has persisted in this genetic background to enhance lctP expression, thereby promoting virulence. IMPORTANCE We report the frequent appearance of a novel SNP in the gdhR gene (gdhR6) possessed by Neisseria gonorrhoeae. The resulting amino acid change in the GdhR protein resulted in enhanced expression of a virulence gene (lctP) that has been suggested to promote gonococcal survival during infection. The mutant GdhR protein expressed by gdhR6 had a reduced ability to bind to its target DNA sequence upstream of lctP. Interestingly, gdhR6 was found in clinical gonococcal strains isolated in the United States and Denmark at a high frequency and was frequently associated with a mutation in the promoter of the gene encoding a repressor (MtrR) of both the mtrCDE antimicrobial efflux pump operon and gdhR. Given this frequent association and the known impact of these regulatory mutations, we propose that virulence and antibiotic resistance properties are often phenotypically linked in contemporary gonococcal strains. |
Examination of sleep and obesity in children and adolescents in the United States
Chehal PK , Shafer L , Cunningham SA . Am J Health Promot 2021 36 (1) 46-54 PURPOSE: This study contributes to the growing literature on the association between sleep and obesity by examining the associations between hours of sleep, consistency of bedtime, and obesity among children in the US. DESIGN: Analysis of a nationally representative sample of non-institutionalized children from the 2016-17 National Survey of Children's Health. SETTING: US, national. SUBJECTS: Children ages 10-17 years (n = 34,640). MEASURES: Parent reported weeknight average hours of sleep and consistency of bedtime. Body mass index classified as underweight, normal, overweight or obesity using parent-reported child height and weight information, classified using CDC BMI-for-Age Growth Charts. ANALYSIS: Multivariate logistic regression models were used to estimate associations between measures of sleep and body mass index weight category adjusting for individual, household and neighborhood characteristics. RESULTS: An additional hour of sleep was associated with 10.8% lower odds of obesity, net of consistency in bedtime. After controlling for sleep duration, children who usually went to bed at the same time on weeknights had lower odds of obesity (24.8%) relative to children who always went to bed at the same time. CONCLUSION: Sleep duration is predictive of lower odds of obesity in US children and adolescents. Some variability in weeknight bedtime is associated with lower odds of obesity, though there were no additional benefits to extensive variability in bedtime. |
A community-driven resource for genomic epidemiology and antimicrobial resistance prediction of Neisseria gonorrhoeae at Pathogenwatch.
Sánchez-Busó L , Yeats CA , Taylor B , Goater RJ , Underwood A , Abudahab K , Argimón S , Ma KC , Mortimer TD , Golparian D , Cole MJ , Grad YH , Martin I , Raphael BH , Shafer WM , Town K , Wi T , Harris SR , Unemo M , Aanensen DM . Genome Med 2021 13 (1) 61 BACKGROUND: Antimicrobial-resistant (AMR) Neisseria gonorrhoeae is an urgent threat to public health, as strains resistant to at least one of the two last-line antibiotics used in empiric therapy of gonorrhoea, ceftriaxone and azithromycin, have spread internationally. Whole genome sequencing (WGS) data can be used to identify new AMR clones and transmission networks and inform the development of point-of-care tests for antimicrobial susceptibility, novel antimicrobials and vaccines. Community-driven tools that provide an easy access to and analysis of genomic and epidemiological data is the way forward for public health surveillance. METHODS: Here we present a public health-focussed scheme for genomic epidemiology of N. gonorrhoeae at Pathogenwatch ( https://pathogen.watch/ngonorrhoeae ). An international advisory group of experts in epidemiology, public health, genetics and genomics of N. gonorrhoeae was convened to inform on the utility of current and future analytics in the platform. We implement backwards compatibility with MLST, NG-MAST and NG-STAR typing schemes as well as an exhaustive library of genetic AMR determinants linked to a genotypic prediction of resistance to eight antibiotics. A collection of over 12,000 N. gonorrhoeae genome sequences from public archives has been quality-checked, assembled and made public together with available metadata for contextualization. RESULTS: AMR prediction from genome data revealed specificity values over 99% for azithromycin, ciprofloxacin and ceftriaxone and sensitivity values around 99% for benzylpenicillin and tetracycline. A case study using the Pathogenwatch collection of N. gonorrhoeae public genomes showed the global expansion of an azithromycin-resistant lineage carrying a mosaic mtr over at least the last 10 years, emphasising the power of Pathogenwatch to explore and evaluate genomic epidemiology questions of public health concern. CONCLUSIONS: The N. gonorrhoeae scheme in Pathogenwatch provides customised bioinformatic pipelines guided by expert opinion that can be adapted to public health agencies and departments with little expertise in bioinformatics and lower-resourced settings with internet connection but limited computational infrastructure. The advisory group will assess and identify ongoing public health needs in the field of gonorrhoea, particularly regarding gonococcal AMR, in order to further enhance utility with modified or new analytic methods. |
Developing epilepsy training capacity for primary care providers using the project ECHO telementoring model
McDonald SB , Privitera M , Kakacek J , Owens S , Shafer P , Kobau R . Epilepsy Behav 2021 116 107789 BACKGROUND: Primary care providers (PCPs) provide a large proportion of care for people with epilepsy (PWE) and need regular training for updates. However, PCPs treat patients in so many therapeutic areas that epilepsy often becomes a less important concern. We used an established telementoring program, Project ECHO (Extension for Community Healthcare Outcomes), and combined epilepsy education with general neurology topics to generate more interest among PCPs. METHODS: We offered 20 one-hour webinar sessions over a two-year period, each consisting of a panel of neurology experts, with a combination of case presentations, a 20-minute didactic presentation, and live, interactive question and answer. Attendees logged in from their own computers or phones, and all presentations were archived online for future viewing. Interviews with PCPs indicated a combination of epilepsy and general neurology topics would be better received, so epilepsy topics alternated monthly with general neurology topics (e.g., headache, stroke, and dementia). Session evaluation included participants' comfort in treating patients with neurological disorders and confidence in knowledge of the topic area. RESULTS: After the second session, mean attendance was 27.5 participants (range 15-38), with a total of 164 unique individual participants. Attendees were a mix of mostly regional, some out of state, and a few international learners, including practicing PCPs, trainees, and nurse practitioners. Archived presentations on our website were viewed 212 times; seizure topics were the most viewed. Mean evaluation scores for relevance, value, and increased knowledge were all in the "agree to strongly agree" range. Over 97% of respondents reported greater interest in improving care of patients with epilepsy or neurological disorders, and over 98% reported greater comfort and self-efficacy when treating patients with these conditions. Only eight cases were submitted for review prior to the sessions. CONCLUSIONS: We successfully piloted a telementoring program using Project ECHO methodology, which was effective in educating PCPs about epilepsy treatment. Combining epilepsy and other neurology topics was an effective strategy in garnering interest among PCPs, but additional methods are needed to encourage participants to present their own cases. |
Reply: Evidence of Recent Genomic Evolution in Gonococcal Strains With Decreased Susceptibility to Cephalosporins or Azithromycin in the United States, 2014-2016
Thomas JC , Kersh EN , Gernert KM , Shafer WM , Raphael BH . J Infect Dis 2020 221 (5) 852-853 We would like to extend our gratitude to Drs. Deng and Klausner for their interest in our article, in which we phylogenetically characterized gonococcal isolates collected through national sentinel surveillance and circulating in the United States, between 2014 and 2016 [1]. We identified 2 major subpopulations of strains associated with reduced susceptibility to either azithromycin (multilocus sequence typing [MLST] ST9363) or cephalosporins (MLST ST1901), and we detailed the evolution of several strains that possessed mutations that were not observed in the United States in 2000–2013. | | Antimicrobial resistance (AMR) in the gonococcus represents a major public health threat, chiefly due to its rapidly evolving nature and the increasingly limited number of available treatment options. Although routine surveillance of AMR in circulating strains is essential in monitoring this threat, an equally important practice involves the promotion of antibiotic stewardship in limiting the spread of resistance. It is notable that the Centers for Disease Control and Prevention’s Gonococcal Isolate Surveillance Project, a historic sentinel surveillance program, has tracked AMR trends for over 30 years and, more recently, included whole-genome sequencing (WGS) of a subset of isolates [2]. As a result, the implementation of WGS has generated massive quantities of genomic data that can be used in tandem with data from traditional antimicrobial susceptibility testing to examine AMR trends. In addition, the release of these data to the public repositories has facilitated the ability of other investigators to conduct a myriad of follow-up studies. |
Azithromycin susceptibility of Neisseria gonorrhoeae in the USA in 2017: a genomic analysis of surveillance data.
Gernert KM , Seby S , Schmerer MW , Thomas JCth , Pham CD , Cyr SS , Schlanger K , Weinstock H , Shafer WM , Raphael BH , Kersh EN . Lancet Microbe 2020 1 (4) e154-e164 BACKGROUND: The number of cases of gonorrhoea in the USA and worldwide caused by Neisseria gonorrhoeae is increasing (555 608 reported US cases in 2017, and 87 million cases worldwide in 2016). Many countries report declining in vitro susceptibility of azithromycin, which is a concern because azithromycin and ceftriaxone are the recommended dual treatment in many countries. We aimed to identify strain types associated with decreased susceptibility to azithromycin. METHODS: We did a genomic analysis of N gonorrhoeae isolates obtained by the US Gonococcal Isolate Surveillance Project. Isolates were whole-genome sequenced based on decreased susceptibility to azithromycin (minimal inhibitory concentration [MIC] ≥2 μg/mL, using agar dilution antibiotic susceptibility testing) and geographical representation. Bioinformatic analyses established genomic diversity, strain population dynamics, and antimicrobial resistance profiles. FINDINGS: 410 isolates were sorted into more than 20 unique phylogenetic clades. One predominant persistent clade (consisting of 97 isolates) included the most isolates with azithromycin MICs of 2 μg/mL or higher (61 of 97 [63%] vs 59 of 311 [19%]; p<0·0001) and carried a mosaic mtr (multiple transferable resistance) locus (68 of 97 [70%] vs two of 313 [1%]; p<0·0001). Of the remaining 313 isolates, 57 (18%) had decreased susceptibility to azithromycin (MIC ≥4 μg/mL), which was attributed to 23S rRNA variants (56 of 57 [98%]) and formed phylogenetically diverse clades, showing various levels of clonal expansion. INTERPRETATION: Reduced azithromycin susceptibility was associated with expanding and persistent clades harbouring two well described resistance mechanisms, mosaic mtr locus and 23S rRNA variants. Understanding the role of recombination, particularly within the mtr locus, on the fitness and expansion of strains with decreased susceptibility has important implications for the public health response to minimise gonorrhoea transmission. FUNDING: US Centers for Disease Control and Prevention (CDC), CDC Combating Antibiotic Resistant Bacteria initiative, Oak Ridge Institute for Science Education, US Department of Energy/CDC/Emory University, National Institutes of Health, and Biomedical Laboratory Research and Development Service of the US Department of Veterans Affairs. |
Moderate-to-High Levels of Pretreatment HIV Drug Resistance in KwaZulu-Natal Province, South Africa.
Chimukangara B , Kharsany ABM , Lessells RJ , Naidoo K , Rhee SY , Manasa J , Graf T , Lewis L , Cawood C , Khanyile D , Diallo K , Ayalew KA , Shafer RW , Hunt G , Pillay D , Abdool SK , de Oliveira T . AIDS Res Hum Retroviruses 2019 35 (2) 129-138 There is evidence of increasing levels of pretreatment HIV drug resistance (PDR) in Southern Africa. We used data from two large population-based HIV surveillance studies to estimate prevalence of PDR in KwaZulu-Natal, the province with the highest HIV prevalence in South Africa. Sanger sequencing was performed on samples obtained from a longitudinal HIV surveillance program (study A, 2013-2014) and the HIV Incidence Provincial Surveillance System (study B, 2014-2015). Sequences were included for adult HIV positive participants (age >/=15 years for study A, age 15-49 years for study B) with no documented prior exposure to antiretroviral therapy (ART). Overall and drug class-specific PDR was estimated using the World Health Organization 2009 surveillance drug resistance mutation (SDRM) list, and phylogenetic analysis was performed to establish evidence of drug resistance transmission linkage. A total of 1,845 sequences were analyzed (611 study A; 1,234 study B). An overall PDR prevalence of 9.2% [95% confidence interval (CI) 7.0-11.7] was observed for study A and 11.0% (95% CI 8.9-13.2) for study B. In study B, the prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) PDR exceeded 10% for sequences collected in 2014 (10.2%, 95% CI 7.5-12.9). The most prevalent SDRMs were K103NS (7.5%), M184VI (2.4%), and V106AM (1.4%). There was no evidence of large transmission chains of drug-resistant virus. High level NNRTI PDR (>10%) suggests a need to modify the standard first-line ART regimen and to focus attention on improving the quality of HIV prevention, treatment, and care. |
Trends in Pretreatment HIV-1 Drug Resistance in Antiretroviral Therapy-naive Adults in South Africa, 2000-2016: A Pooled Sequence Analysis.
Chimukangara B , Lessells RJ , Rhee SY , Giandhari J , Kharsany ABM , Naidoo K , Lewis L , Cawood C , Khanyile D , Ayalew KA , Diallo K , Samuel R , Hunt G , Vandormael A , Stray-Pedersen B , Gordon M , Makadzange T , Kiepiela P , Ramjee G , Ledwaba J , Kalimashe M , Morris L , Parikh UM , Mellors JW , Shafer RW , Katzenstein D , Moodley P , Gupta RK , Pillay D , Abdool Karim SS , de Oliveira T . EClinicalMedicine 2019 9 26-34 Background: South Africa has the largest public antiretroviral therapy (ART) programme in the world. We assessed temporal trends in pretreatment HIV-1 drug resistance (PDR) in ART-naïve adults from South Africa. Methods: We included datasets from studies conducted between 2000 and 2016, with HIV-1 pol sequences from more than ten ART-naïve adults. We analysed sequences for the presence of 101 drug resistance mutations. We pooled sequences by sampling year and performed a sequence-level analysis using a generalized linear mixed model, including the dataset as a random effect. Findings: We identified 38 datasets, and retrieved 6880 HIV-1 pol sequences for analysis. The pooled annual prevalence of PDR remained below 5% until 2009, then increased to a peak of 11·9% (95% confidence interval (CI) 9·2-15·0) in 2015. The pooled annual prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) PDR remained below 5% until 2011, then increased to 10.0% (95% CI 8.4–11.8) by 2014. Between 2000 and 2016, there was a 1.18-fold (95% CI 1.13–1.23) annual increase in NNRTI PDR (p < 0.001), and a 1.10-fold (95% CI 1.05–1.16) annual increase in nucleoside reverse-transcriptase inhibitor PDR (p = 0.001). Interpretation: Increasing PDR in South Africa presents a threat to the efforts to end the HIV/AIDS epidemic. These findings support the recent decision to modify the standard first-line ART regimen, but also highlights the need for broader public health action to prevent the further emergence and transmission of drug-resistant HIV. Source of Funding: This research project was funded by the South African Medical Research Council (MRC) with funds from National Treasury under its Economic Competitiveness and Support Package. Disclaimer: The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of CDC. |
Evidence of Recent Genomic Evolution in Gonococcal Strains with Decreased Susceptibility to Cephalosporins or Azithromycin in the United States, 2014-2016.
Thomas JC , Seby S , Abrams AJ , Cartee J , Lucking S , Vidyaprakash E , Schmerer M , Pham CD , Hong J , Torrone E , St Cyr S , Shafer WM , Bernstein K , Kersh EN , Gernert KM . J Infect Dis 2019 220 (2) 294-305 BACKGROUND: Given the lack of new antimicrobials or a vaccine, understanding the evolutionary dynamics of Neisseria gonorrhoeae is a significant public and global health priority. We investigated the emergence and spread of gonococcal strains with decreased susceptibility to cephalosporins and azithromycin using detailed genomic analyses of gonococcal isolates collected in the United States from 2014 to 2016. METHODS: We sequenced the genomes of 649 isolates collected through the Gonococcal Isolate Surveillance Project (GISP). We examined the genetic relatedness of isolates and assessed associations between clades and various genotypic and phenotypic combinations. RESULTS: We identified a large and clonal lineage of strains (MLST ST9363) associated with elevated azithromycin MICs (AZI em), characterized by a mosaic mtr locus (C-substitution in the mtrR promoter, mosaic mtrR and mtrD). Mutations in 23S rRNA were sporadically distributed among AZI em strains. Another clonal group (MLST ST1901) possessed seven unique PBP2 patterns, and it shared common mutations in other genes associated with cephalosporin resistance. CONCLUSIONS: Whole genome sequencing methods can enhance monitoring of antimicrobial resistant gonococcal strains by identifying gonococcal populations containing mutations of concern. These methods could inform the development of point-of-care diagnostic tests designed to determine the specific antibiotic susceptibility profile of a gonococcal infection within a patient. |
Mechanistic Basis for Decreased Antimicrobial Susceptibility in a Clinical Isolate of Neisseria gonorrhoeae Possessing a Mosaic-Like mtr Efflux Pump Locus.
Rouquette-Loughlin CE , Reimche JL , Balthazar JT , Dhulipala V , Gernert KM , Kersh EN , Pham CD , Pettus K , Abrams AJ , Trees DL , St Cyr S , Shafer WM . mBio 2018 9 (6) Recent reports suggest that mosaic-like sequences within the mtr (multiple transferable resistance) efflux pump locus of Neisseria gonorrhoeae, likely originating from commensal Neisseria sp. by transformation, can increase the ability of gonococci to resist structurally diverse antimicrobials. Thus, acquisition of numerous nucleotide changes within the mtrR gene encoding the transcriptional repressor (MtrR) of the mtrCDE efflux pump-encoding operon or overlapping promoter region for both along with those that cause amino acid changes in the MtrD transporter protein were recently reported to decrease gonococcal susceptibility to numerous antimicrobials, including azithromycin (Azi) (C. B. Wadsworth, B. J. Arnold, M. R. A. Satar, and Y. H. Grad, mBio 9:e01419-18, 2018, https://doi.org/10.1128/mBio.01419-18). We performed detailed genetic and molecular studies to define the mechanistic basis for why such strains can exhibit decreased susceptibility to MtrCDE antimicrobial substrates, including Azi. We report that a strong cis-acting transcriptional impact of a single nucleotide change within the -35 hexamer of the mtrCDE promoter as well gain-of-function amino acid changes at the C-terminal region of MtrD can mechanistically account for the decreased antimicrobial susceptibility of gonococci with a mosaic-like mtr locus.IMPORTANCE Historically, after introduction of an antibiotic for treatment of gonorrhea, strains of N. gonorrhoeae emerge that display clinical resistance due to spontaneous mutation or acquisition of resistance genes. Genetic exchange between members of the Neisseria genus occurring by transformation can cause significant changes in gonococci that impact the structure of an antibiotic target or expression of genes involved in resistance. The results presented here provide a framework for understanding how mosaic-like DNA sequences from commensal Neisseria that recombine within the gonococcal mtr efflux pump locus function to decrease bacterial susceptibility to antimicrobials, including antibiotics used in therapy of gonorrhea. |
Antimicrobial Resistance in Neisseria gonorrhoeae: Proceedings of the STAR Sexually Transmitted Infection-Clinical Trial Group Programmatic Meeting.
Cristillo AD , Bristow CC , Torrone E , Dillon JA , Kirkcaldy RD , Dong H , Grad YH , Nicholas RA , Rice PA , Lawrence K , Oldach D , Shafer WM , Zhou P , Wi TE , Morris SR , Klausner JD . Sex Transm Dis 2018 46 (3) e18-e25 The goal of the Sexually Transmitted Infection Clinical Trial Group's (STI-CTG) Antimicrobial Resistance (AMR) in Neisseria gonorrhoeae (NG) meeting was to assemble experts from academia, government, non-profit and industry to discuss the current state of research, gaps and challenges in research and technology as well as priorities and new directions to address the continued emergence of multi-drug resistant NG infections. Topics discussed at the meeting, that will be the focus of this article, include AMR NG global surveillance initiatives, the use of whole genome sequencing (WGS) and bioinformatics to understand mutations associated with AMR, mechanisms of AMR, and novel antibiotics, vaccines and other methods to treat AMR NG. Key points highlighted during the meeting include: (i) US and International surveillance programs to understand AMR in NG. (ii) The US National Strategy for combating antimicrobial resistant bacteria. (iii) Surveillance needs, challenges and novel technologies. (iv) Plasmid- and chromosomally-mediated mechanisms of AMR in NG, (v) Novel therapeutic (e.g., sialic acid analogs, FH/Fc fusion molecule, monoclonal antibodies, topoisomerase inhibitors, fluoroketolides, LpxC inhibitors) and preventative (e.g., peptide mimic) strategies to combat infection. The way forward will require renewed political will, new funding initiatives and collaborations across academic and commercial research and public health programs. |
A longitudinal study of the relationship between receptivity to e-cigarette advertisements and e-cigarette use among baseline non-users of cigarettes and e-cigarettes, United States
Agaku IT , Davis K , Patel D , Shafer P , Cox S , Ridgeway W , King BA . Tob Induc Dis 2017 15 42 Background: We investigated the relationship between receptivity to electronic cigarette (e-cigarette) advertisements at baseline and e-cigarette use at follow-up among adult baseline non-users of cigarettes and e-cigarettes. Methods: A nationally representative online panel was used to survey non-users of cigarettes and e-cigarettes (n = 2191) at baseline and 5-month follow-up. At baseline, respondents were shown an e-cigarette advertisement and asked if they were aware of it (exposure). Among those exposed, receptivity was self-rated for each ad using a validated scale of 1 to 5 for agreement with each of six items: "worth remembering," "grabbed my attention," "powerful," "informative," "meaningful," and "convincing." Logistic regression was used to measure the relationship between receptivity at baseline and e-cigarette use at follow-up. Results: Among baseline non-users of cigarettes and e-cigarettes, 16.6% reported exposure to e-cigarette advertisements at baseline; overall mean receptivity score was 2.77. Among baseline non-users who reported exposure to e-cigarette advertisements, incidence of e-cigarette use at follow-up was 2.7%; among baseline non-users who reported not being exposed to e-cigarette advertisements, incidence of e-cigarette use at follow-up was 1.3%. The attributable risk percentage for e-cigarette initiation from e-cigarette advertisement exposure was 59.3%; the population attributable risk percentage from e-cigarette advertisement exposure was 22.6%. Receptivity at baseline was associated with e-cigarette use at follow-up (aOR = 1.57; 95% CI = 1.04-2.37). Conclusions: Receptivity to e-cigarette advertisements at baseline was associated with greater odds of e-cigarette use at follow-up among baseline non-users of cigarettes and e-cigarettes. Understanding the role of advertising in e-cigarette initiation could help inform public health policy. |
Association between media doses of the tips from Former Smokers Campaign and cessation behaviors and intentions to quit among cigarette smokers, 2012-2015
Davis KC , Patel D , Shafer P , Duke J , Glover-Kudon R , Ridgeway W , Cox S . Health Educ Behav 2017 45 (1) 1090198117709316 BACKGROUND: Since 2012, the Centers for Disease Control and Prevention (CDC) has implemented Tips From Former Smokers ( Tips), the first federally funded tobacco education campaign in the United States. To date, there are no evaluations of its long-term impact. AIMS: To assess the impact of varied doses of the Tips campaign from 2012 through 2015 on cessation-related behaviors and intentions among U.S. smokers. METHOD: We used a national probability-based online survey of cigarette smokers ( n = 22,189) and recent quitters ( n = 776) to examine associations between doses of Tips advertising, measured by gross rating points (GRPs), and intentions to quit smoking in the next 30 days and quit attempts within the past 3 months. A curvilinear (i.e., square root) functional form of GRPs was used to capture patterns of diminishing effects at higher GRP levels. RESULTS: An increase of 1,000 quarterly Tips GRPs at the media market level was associated with increased odds of making a quit attempt in the past 3 months (adjusted odds ratio = 1.23, p < .001) and increased odds of intending to quit in the next 30 days (adjusted odds ratio = 1.17, p = .030). DISCUSSION: Results suggest that CDC-recommended media buys of 800 to 1,000 GRPs per quarter are sufficient to generate statistically significant increases in the likelihood of quit attempts in the past quarter. CONCLUSIONS: The Tips campaign has had a substantial impact on cessation behaviors among U.S. adult smokers over time. These data support the continued use of graphic and/or emotional media campaigns that encourage smokers to quit to further reduce tobacco use in the United States. |
Quit methods used by US adult cigarette smokers, 2014-2016
Caraballo RS , Shafer PR , Patel D , Davis KC , McAfee TA . Prev Chronic Dis 2017 14 E32 To quantify the prevalence of 10 quit methods commonly used by adult cigarette smokers, we used data from a nationally representative longitudinal (2014-2016) online survey of US adult cigarette smokers (n = 15,943). Overall, 74.7% of adult current cigarette smokers used multiple quit methods during their most recent quit attempt. Giving up cigarettes all at once (65.3%) and reducing the number of cigarettes smoked (62.0%) were the most prevalent methods. Substituting some cigarettes with e-cigarettes was used by a greater percentage of smokers than the nicotine patch, nicotine gum, or other cessation aids approved by the US Food and Drug Administration. Further research into the effectiveness of e-cigarettes as a cessation aid is warranted. |
Mutational Correlates of Virological Failure in Individuals Receiving a WHO-Recommended Tenofovir-Containing First-Line Regimen: An International Collaboration.
Rhee SY , Varghese V , Holmes SP , Van Zyl GU , Steegen K , Boyd MA , Cooper DA , Nsanzimana S , Saravanan S , Charpentier C , de Oliveira T , Etiebet MA , Garcia F , Goedhals D , Gomes P , Gunthard HF , Hamers RL , Hoffmann CJ , Hunt G , Jiamsakul A , Kaleebu P , Kanki P , Kantor R , Kerschberger B , Marconi VC , D'Amour Ndahimana J , Ndembi N , Ngo-Giang-Huong N , Rokx C , Santoro MM , Schapiro JM , Schmidt D , Seu L , Sigaloff KC , Sirivichayakul S , Skhosana L , Sunpath H , Tang M , Yang C , Carmona S , Gupta RK , Shafer RW . EBioMedicine 2017 18 225-235 Tenofovir disoproxil fumarate (TDF) genotypic resistance defined by K65R/N and/or K70E/Q/G occurs in 20% to 60% of individuals with virological failure (VF) on a WHO-recommended TDF-containing first-line regimen. However, the full spectrum of reverse transcriptase (RT) mutations selected in individuals with VF on such a regimen is not known. To identify TDF regimen-associated mutations (TRAMs), we compared the proportion of each RT mutation in 2873 individuals with VF on a WHO-recommended first-line TDF-containing regimen to its proportion in a cohort of 50,803 antiretroviral-naive individuals. To identify TRAMs specifically associated with TDF-selection pressure, we compared the proportion of each TRAM to its proportion in a cohort of 5805 individuals with VF on a first-line thymidine analog-containing regimen. We identified 83 TRAMs including 33 NRTI-associated, 40 NNRTI-associated, and 10 uncommon mutations of uncertain provenance. Of the 33 NRTI-associated TRAMs, 12 - A62V, K65R/N, S68G/N/D, K70E/Q/T, L74I, V75L, and Y115F - were more common among individuals receiving a first-line TDF-containing compared to a first-line thymidine analog-containing regimen. These 12 TDF-selected TRAMs will be important for monitoring TDF-associated transmitted drug-resistance and for determining the extent of reduced TDF susceptibility in individuals with VF on a TDF-containing regimen. |
Whole genome sequencing of a large panel of contemporary Neisseria gonorrhoeae clinical isolates indicates that a wild-type mtrA gene is common: implications for inducible antimicrobial resistance.
Vidyaprakash E , Abrams AJ , Shafer WM , Trees DL . Antimicrob Agents Chemother 2017 61 (4) Previous studies have shown that the expression of the mtrCDE efflux pump operon is inducible at the transcriptional level in gonococci during incubation in sub-lethal concentrations of the nonionic detergent Triton X-100, which along with antibiotics, bile salts, progesterone and antimicrobial peptides, is a substrate of the MtrCDE efflux pump. |
Does digital video advertising increase population-level reach of multimedia campaigns? Evidence from the 2013 Tips from Former Smokers Campaign
Davis KC , Shafer PR , Rodes R , Kim A , Hansen H , Patel D , Coln C , Beistle D . J Med Internet Res 2016 18 (9) e235 BACKGROUND: Federal and state public health agencies in the United States are increasingly using digital advertising and social media to promote messages from broader multimedia campaigns. However, little evidence exists on population-level campaign awareness and relative cost efficiencies of digital advertising in the context of a comprehensive public health education campaign. OBJECTIVE: Our objective was to compare the impact of increased doses of digital video and television advertising from the 2013 Tips From Former Smokers (Tips) campaign on overall campaign awareness at the population level. We also compared the relative cost efficiencies across these media platforms. METHODS: We used data from a large national online survey of approximately 15,000 US smokers conducted in 2013 immediately after the conclusion of the 2013 Tips campaign. These data were used to compare the effects of variation in media dose of digital video and television advertising on population-level awareness of the Tips campaign. We implemented higher doses of digital video among selected media markets and randomly selected other markets to receive similar higher doses of television ads. Multivariate logistic regressions estimated the odds of overall campaign awareness via digital or television format as a function of higher-dose media in each market area. All statistical tests used the .05 threshold for statistical significance and the .10 level for marginal nonsignificance. We used adjusted advertising costs for the additional doses of digital and television advertising to compare the cost efficiencies of digital and television advertising on the basis of costs per percentage point of population awareness generated. RESULTS: Higher-dose digital video advertising was associated with 94% increased odds of awareness of any ad online relative to standard-dose markets (P<.001). Higher-dose digital advertising was associated with a marginally nonsignificant increase (46%) in overall campaign awareness regardless of media format (P=.09). Higher-dose television advertising was associated with 81% increased odds of overall ad awareness regardless of media format (P<.001). Increased doses of television advertising were also associated with significantly higher odds of awareness of any ad on television (P<.001) and online (P=.04). The adjusted cost of each additional percentage point of population-level reach generated by higher doses of advertising was approximately US $440,000 for digital advertising and US $1 million for television advertising. CONCLUSIONS: Television advertising generated relatively higher levels of overall campaign awareness. However, digital video was relatively more cost efficient for generating awareness. These results suggest that digital video may be used as a cost-efficient complement to traditional advertising modes (eg, television), but digital video should not replace television given the relatively smaller audience size of digital video viewers. |
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