Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-29 (of 29 Records) |
Query Trace: Kaitlin M[original query] |
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Surveillance for coccidioidomycosis, histoplasmosis, and blastomycosis - United States, 2019
Smith Dallas J , Williams Samantha L , Benedict Kaitlin M , Jackson Brendan R , Toda Mitsuru . MMWR Surveill Summ 2022 71 (7) 1-14 Problem/Condition: Coccidioidomycosis, histoplasmosis, and blastomycosis are underdiagnosed fungal diseases that often mimic bacterial or viral pneumonia and can cause disseminated disease and death. These diseases are caused by inhalation of fungal spores that have distinct geographic niches in the environment (e.g., soil or dust), and distribution is highly susceptible to climate changes such as expanding arid regions for coccidioidomycosis, the northward expansion of histoplasmosis, and areas like New York reporting cases of blastomycosis previously thought to be nonendemic. The national incidence of coccidioidomycosis, histoplasmosis, and blastomycosis is poorly characterized. Reporting Period: 2019. Description of System: The National Notifiable Diseases Surveillance System (NNDSS) tracks cases of coccidioidomycosis, a nationally notifiable condition reported to CDC by 26 states and the District of Columbia. Neither histoplasmosis nor blastomycosis is a nationally notifiable condition; however, histoplasmosis is voluntarily reported in 13 states and blastomycosis in five states. Health departments classify cases based on the definitions established by the Council of State and Territorial Epidemiologists. Results: In 2019, a total of 20,061 confirmed coccidioidomycosis, 1,124 confirmed and probable histoplasmosis, and 240 confirmed and probable blastomycosis cases were reported to CDC. Arizona and California reported 97% of coccidioidomycosis cases, and Minnesota and Wisconsin reported 75% of blastomycosis cases. Illinois reported the greatest percentage (26%) of histoplasmosis cases. All three diseases were more common among males, and the proportion for blastomycosis (70%) was substantially higher than for histoplasmosis (56%) or coccidioidomycosis (52%). Coccidioidomycosis incidence was approximately four times higher for non-Hispanic American Indian or Alaska Native (AI/AN) persons (17.3 per 100,000 population) and almost three times higher for Hispanic or Latino persons (11.2) compared with non-Hispanic White (White) persons (4.1). Histoplasmosis incidence was similar across racial and ethnic categories (range: 0.9-1.3). Blastomycosis incidence was approximately six times as high among AI/AN persons (4.5) and approximately twice as high among non-Hispanic Asian and Native Hawaiian or other Pacific Islander persons (1.6) compared with White persons (0.7). More than one half of histoplasmosis (54%) and blastomycosis (65%) patients were hospitalized, and 5% of histoplasmosis and 9% of blastomycosis patients died. States in which coccidioidomycosis is not known to be endemic had more cases in spring (March, April, and May) than during other seasons, whereas the number of cases peaked slightly in autumn (September, October, and November) for histoplasmosis and in winter (December, January, and February) for blastomycosis. Interpretation: Coccidioidomycosis, histoplasmosis, and blastomycosis are diseases occurring in geographical niches within the United States. These diseases cause substantial illness, with approximately 20,000 coccidioidomycosis cases reported in 2019. Although substantially fewer histoplasmosis and blastomycosis cases were reported, surveillance was much more limited and underdiagnosis was likely, as evidenced by high hospitalization and death rates. This suggests that persons with milder symptoms might not seek medical evaluation and the symptoms self-resolve or the illnesses are misdiagnosed as other, more common respiratory diseases. Public Health Action: Improved surveillance is necessary to better characterize coccidioidomycosis severity and to improve detection of histoplasmosis and blastomycosis. These findings might guide improvements in testing practices that enable timely diagnosis and treatment of fungal diseases. Clinicians and health care professionals should consider coccidioidomycosis, histoplasmosis, and blastomycosis in patients with community-acquired pneumonia or other acute infections of the lower respiratory tract who live in or have traveled to areas where the causative ungi are known to be present in the environment. Culturally appropriate tailored educational messages might help improve diagnosis and treatment. Public health response to these three diseases is hindered because information gathered from states' routine surveillance does not include data on populations at risk and sources of exposure. Broader surveillance that includes expansion to other states and more detail about potential exposures and relevant host factors can describe epidemiologic trends, populations at risk, and disease prevention strategies. |
COVID-19 Surveillance and Investigations in Workplaces - Seattle & King County, Washington, June 15-November 15, 2020.
Bonwitt J , Deya RW , Currie DW , Lipton B , Huntington-Frazier M , Sanford SJ , Pallickaparambil AJ , Hood J , Rao AK , Kelly-Reif K , Luckhaupt SE , Pogosjans S , Lindquist S , Duchin J , Kawakami V . MMWR Morb Mortal Wkly Rep 2021 70 (25) 916-921 Workplace activities involving close contact with coworkers and customers can lead to transmission of SARS-CoV-2, the virus that causes COVID-19 (1,2). Information on the approach to and effectiveness of COVID-19 workplace investigations is limited. In May 2020, Public Health - Seattle & King County (PHSKC), King County, Washington established a COVID-19 workplace surveillance and response system to enhance COVID-19 contact tracing and identify outbreaks in workplaces. During June 15-November 15, 2020, a total of 2,881 workplaces in King County reported at least one case of COVID-19. Among 1,305 (45.3%) investigated workplaces,* 524 (40.3%) met the definition of a workplace outbreak.(†) Among 306 (58.4%) workplaces with complete data,(§) an average of 4.4 employee COVID-19 cases(¶) (median = three; range = 1-65) were identified per outbreak, with an average attack rate among employees of 17.5%. PHSKC and the Washington State Department of Health optimized resources by establishing a classification scheme to prioritize workplace investigations as high, medium, or low priority based on workplace features observed to be associated with increased COVID-19 spread and workforce features associated with severe disease outcomes. High-priority investigations were significantly more likely than medium- and low-priority investigations to have two or more cases among employees (p<0.001), two or more cases not previously linked to the workplace (p<0.001), or two or more exposed workplace contacts not previously identified during case interviews (p = 0.002). Prioritization of workplace investigations allowed for the allocation of limited resources to effectively conduct workplace investigations to limit the potential workplace spread of COVID-19. Workplace investigations can also serve as an opportunity to provide guidance on preventing workplace exposures to SARS-CoV-2, facilitate access to vaccines, and strengthen collaborations between public health and businesses. |
Integrated genomic, epidemiologic investigation of Candida auris skin colonization in a skilled nursing facility.
Proctor DM , Dangana T , Sexton DJ , Fukuda C , Yelin RD , Stanley M , Bell PB , Baskaran S , Deming C , Chen Q , Conlan S , Park M , Welsh RM , Vallabhaneni S , Chiller T , Forsberg K , Black SR , Pacilli M , Kong HH , Lin MY , Schoeny ME , Litvintseva AP , Segre JA , Hayden MK . Nat Med 2021 27 (8) 1401-1409 ![]() Candida auris is a fungal pathogen of high concern due to its ability to cause healthcare-associated infections and outbreaks, its resistance to antimicrobials and disinfectants and its persistence on human skin and in the inanimate environment. To inform surveillance and future mitigation strategies, we defined the extent of skin colonization and explored the microbiome associated with C. auris colonization. We collected swab specimens and clinical data at three times points between January and April 2019 from 57 residents (up to ten body sites each) of a ventilator-capable skilled nursing facility with endemic C. auris and routine chlorhexidine gluconate (CHG) bathing. Integrating microbial-genomic and epidemiologic data revealed occult C. auris colonization of multiple body sites not targeted commonly for screening. High concentrations of CHG were associated with suppression of C. auris growth but not with deleterious perturbation of commensal microbes. Modeling human mycobiome dynamics provided insight into underlying alterations to the skin fungal community as a possible modifiable risk factor for acquisition and persistence of C. auris. Failure to detect the extensive, disparate niches of C. auris colonization may reduce the effectiveness of infection-prevention measures that target colonized residents, highlighting the importance of universal strategies to reduce C. auris transmission. |
Incidence of Multisystem Inflammatory Syndrome in Children Among US Persons Infected With SARS-CoV-2.
Payne AB , Gilani Z , Godfred-Cato S , Belay ED , Feldstein LR , Patel MM , Randolph AG , Newhams M , Thomas D , Magleby R , Hsu K , Burns M , Dufort E , Maxted A , Pietrowski M , Longenberger A , Bidol S , Henderson J , Sosa L , Edmundson A , Tobin-D'Angelo M , Edison L , Heidemann S , Singh AR , Giuliano JSJr , Kleinman LC , Tarquinio KM , Walsh RF , Fitzgerald JC , Clouser KN , Gertz SJ , Carroll RW , Carroll CL , Hoots BE , Reed C , Dahlgren FS , Oster ME , Pierce TJ , Curns AT , Langley GE , Campbell AP , Balachandran N , Murray TS , Burkholder C , Brancard T , Lifshitz J , Leach D , Charpie I , Tice C , Coffin SE , Perella D , Jones K , Marohn KL , Yager PH , Fernandes ND , Flori HR , Koncicki ML , Walker KS , Di Pentima MC , Li S , Horwitz SM , Gaur S , Coffey DC , Harwayne-Gidansky I , Hymes SR , Thomas NJ , Ackerman KG , Cholette JM . JAMA Netw Open 2021 4 (6) e2116420 IMPORTANCE: Multisystem inflammatory syndrome in children (MIS-C) is associated with recent or current SARS-CoV-2 infection. Information on MIS-C incidence is limited. OBJECTIVE: To estimate population-based MIS-C incidence per 1 000 000 person-months and to estimate MIS-C incidence per 1 000 000 SARS-CoV-2 infections in persons younger than 21 years. DESIGN, SETTING, AND PARTICIPANTS: This cohort study used enhanced surveillance data to identify persons with MIS-C during April to June 2020, in 7 jurisdictions reporting to both the Centers for Disease Control and Prevention national surveillance and to Overcoming COVID-19, a multicenter MIS-C study. Denominators for population-based estimates were derived from census estimates; denominators for incidence per 1 000 000 SARS-CoV-2 infections were estimated by applying published age- and month-specific multipliers accounting for underdetection of reported COVID-19 case counts. Jurisdictions included Connecticut, Georgia, Massachusetts, Michigan, New Jersey, New York (excluding New York City), and Pennsylvania. Data analyses were conducted from August to December 2020. EXPOSURES: Race/ethnicity, sex, and age group (ie, ≤5, 6-10, 11-15, and 16-20 years). MAIN OUTCOMES AND MEASURES: Overall and stratum-specific adjusted estimated MIS-C incidence per 1 000 000 person-months and per 1 000 000 SARS-CoV-2 infections. RESULTS: In the 7 jurisdictions examined, 248 persons with MIS-C were reported (median [interquartile range] age, 8 [4-13] years; 133 [53.6%] male; 96 persons [38.7%] were Hispanic or Latino; 75 persons [30.2%] were Black). The incidence of MIS-C per 1 000 000 person-months was 5.1 (95% CI, 4.5-5.8) persons. Compared with White persons, incidence per 1 000 000 person-months was higher among Black persons (adjusted incidence rate ratio [aIRR], 9.26 [95% CI, 6.15-13.93]), Hispanic or Latino persons (aIRR, 8.92 [95% CI, 6.00-13.26]), and Asian or Pacific Islander (aIRR, 2.94 [95% CI, 1.49-5.82]) persons. MIS-C incidence per 1 000 000 SARS-CoV-2 infections was 316 (95% CI, 278-357) persons and was higher among Black (aIRR, 5.62 [95% CI, 3.68-8.60]), Hispanic or Latino (aIRR, 4.26 [95% CI, 2.85-6.38]), and Asian or Pacific Islander persons (aIRR, 2.88 [95% CI, 1.42-5.83]) compared with White persons. For both analyses, incidence was highest among children aged 5 years or younger (4.9 [95% CI, 3.7-6.6] children per 1 000 000 person-months) and children aged 6 to 10 years (6.3 [95% CI, 4.8-8.3] children per 1 000 000 person-months). CONCLUSIONS AND RELEVANCE: In this cohort study, MIS-C was a rare complication associated with SARS-CoV-2 infection. Estimates for population-based incidence and incidence among persons with infection were higher among Black, Hispanic or Latino, and Asian or Pacific Islander persons. Further study is needed to understand variability by race/ethnicity and age group. |
Modeling of Future COVID-19 Cases, Hospitalizations, and Deaths, by Vaccination Rates and Nonpharmaceutical Intervention Scenarios - United States, April-September 2021.
Borchering RK , Viboud C , Howerton E , Smith CP , Truelove S , Runge MC , Reich NG , Contamin L , Levander J , Salerno J , van Panhuis W , Kinsey M , Tallaksen K , Obrecht RF , Asher L , Costello C , Kelbaugh M , Wilson S , Shin L , Gallagher ME , Mullany LC , Rainwater-Lovett K , Lemaitre JC , Dent J , Grantz KH , Kaminsky J , Lauer SA , Lee EC , Meredith HR , Perez-Saez J , Keegan LT , Karlen D , Chinazzi M , Davis JT , Mu K , Xiong X , Pastore YPiontti A , Vespignani A , Srivastava A , Porebski P , Venkatramanan S , Adiga A , Lewis B , Klahn B , Outten J , Schlitt J , Corbett P , Telionis PA , Wang L , Peddireddy AS , Hurt B , Chen J , Vullikanti A , Marathe M , Healy JM , Slayton RB , Biggerstaff M , Johansson MA , Shea K , Lessler J . MMWR Morb Mortal Wkly Rep 2021 70 (19) 719-724 After a period of rapidly declining U.S. COVID-19 incidence during January-March 2021, increases occurred in several jurisdictions (1,2) despite the rapid rollout of a large-scale vaccination program. This increase coincided with the spread of more transmissible variants of SARS-CoV-2, the virus that causes COVID-19, including B.1.1.7 (1,3) and relaxation of COVID-19 prevention strategies such as those for businesses, large-scale gatherings, and educational activities. To provide long-term projections of potential trends in COVID-19 cases, hospitalizations, and deaths, COVID-19 Scenario Modeling Hub teams used a multiple-model approach comprising six models to assess the potential course of COVID-19 in the United States across four scenarios with different vaccination coverage rates and effectiveness estimates and strength and implementation of nonpharmaceutical interventions (NPIs) (public health policies, such as physical distancing and masking) over a 6-month period (April-September 2021) using data available through March 27, 2021 (4). Among the four scenarios, an accelerated decline in NPI adherence (which encapsulates NPI mandates and population behavior) was shown to undermine vaccination-related gains over the subsequent 2-3 months and, in combination with increased transmissibility of new variants, could lead to surges in cases, hospitalizations, and deaths. A sharp decline in cases was projected by July 2021, with a faster decline in the high-vaccination scenarios. High vaccination rates and compliance with public health prevention measures are essential to control the COVID-19 pandemic and to prevent surges in hospitalizations and deaths in the coming months. |
Performance of Repeat BinaxNOW SARS-CoV-2 Antigen Testing in a Community Setting, Wisconsin, November-December 2020.
Shah MM , Salvatore PP , Ford L , Kamitani E , Whaley MJ , Kaitlin M , Currie DW , Morgan CN , Segaloff HE , Lecher S , Somers T , Van Dyke ME , Bigouette JP , Delaney A , DaSilva J , O'Hegarty M , Boyle-Estheimer L , Abdirizak F , Karpathy SE , Meece J , Ivanic L , Goffard K , Gieryn D , Sterkel A , Bateman A , Kahrs J , Langolf K , Zochert T , Knight NW , Hsu CH , Kirking HL , Tate JE . Clin Infect Dis 2021 73 S54-S57 Repeating the BinaxNOW antigen test for SARS-CoV-2 by two groups of readers within 30 minutes resulted in high concordance (98.9%) in 2,110 encounters. BinaxNOW test sensitivity was 77.2% (258/334) compared to real-time reverse transcription-polymerase chain reaction. Same day antigen testing did not significantly improve test sensitivity while specificity remained high. |
SARS-CoV-2 transmission in a Georgia school district - United States, December 2020-January 2021.
Gettings JR , Gold JAW , Kimball A , Forsberg K , Scott C , Uehara A , Tong S , Hast M , Swanson MR , Morris E , Oraka E , Almendares O , Thomas ES , Mehari L , McCloud J , Roberts G , Crosby D , Balajee A , Burnett E , Chancey RJ , Cook P , Donadel M , Espinosa C , Evans ME , Fleming-Dutra KE , Forero C , Kukielka EA , Li Y , Marcet PL , Mitruka K , Nakayama JY , Nakazawa Y , O'Hegarty M , Pratt C , Rice ME , Rodriguez Stewart RM , Sabogal R , Sanchez E , Velasco-Villa A , Weng MK , Zhang J , Rivera G , Parrott T , Franklin R , Memark J , Drenzek C , Hall AJ , Kirking HL , Tate JE , Vallabhaneni S . Clin Infect Dis 2021 74 (2) 319-326 ![]() ![]() BACKGROUND: To inform prevention strategies, we assessed the extent of SARS-CoV-2 transmission and settings in which transmission occurred in a Georgia public school district. METHODS: During December 1, 2020-January 22, 2021, SARS-CoV-2-infected index cases and their close contacts in schools were identified by school and public health officials. For in-school contacts, we assessed symptoms and offered SARS-CoV-2 RT-PCR testing; performed epidemiologic investigations and whole-genome sequencing to identify in-school transmission; and calculated secondary attack rate (SAR) by school setting (e.g., sports, elementary school classroom), index case role (i.e., staff, student), and index case symptomatic status. RESULTS: We identified 86 index cases and 1,119 contacts, 688 (63.1%) of whom received testing. Fifty-nine (8.7%) of 679 contacts tested positive; 15 (17.4%) of 86 index cases resulted in ≥2 positive contacts. Among 55 persons testing positive with available symptom data, 31 (56.4%) were asymptomatic. Highest SAR were in indoor, high-contact sports settings (23.8%, 95% confidence interval [CI] 12.7, 33.3), staff meetings/lunches (18.2%, CI 4.5-31.8), and elementary school classrooms (9.5%, CI 6.5-12.5). SAR was higher for staff (13.1%, CI 9.0-17.2) versus student index cases (5.8%, CI 3.6-8.0) and for symptomatic (10.9%, CI 8.1-13.9) versus asymptomatic index cases (3.0%, CI 1.0-5.5). CONCLUSIONS: Indoor sports may pose a risk to the safe operation of in-person learning. Preventing infection in staff members, through measures that include COVID-19 vaccination, is critical to reducing in-school transmission. Because many positive contacts were asymptomatic, contact tracing should be paired with testing, regardless of symptoms. |
Evolution of the complex transcription network controlling biofilm formation in Candida species
Mancera E , Nocedal I , Hammel S , Gulati M , Mitchell KF , Andes DR , Nobile CJ , Butler G , Johnson AD . Elife 2021 10 ![]() ![]() We examine how a complex transcription network composed of seven 'master' regulators and hundreds of target genes evolved over a span of approximately 70 million years. The network controls biofilm formation in several Candida species, a group of fungi that are present in humans both as constituents of the microbiota and as opportunistic pathogens. Using a variety of approaches, we observed two major types of changes that have occurred in the biofilm network since the four extant species we examined last shared a common ancestor. Master regulator 'substitutions' occurred over relatively long evolutionary times, resulting in different species having overlapping, but different sets of master regulators of biofilm formation. Second, massive changes in the connections between the master regulators and their target genes occurred over much shorter timescales. We believe this analysis is the first detailed, empirical description of how a complex transcription network has evolved. |
Candida auris Whole-Genome Sequence Benchmark Dataset for Phylogenomic Pipelines
Welsh RM , Misas E , Forsberg K , Lyman M , Chow NA . J Fungi (Basel) 2021 7 (3) ![]() ![]() Candida auris is a multidrug-resistant pathogen that represents a serious public health threat due to its rapid global emergence, increasing incidence of healthcare-associated outbreaks, and high rates of antifungal resistance. Whole-genome sequencing and genomic surveillance have the potential to bolster C. auris surveillance networks moving forward. Laboratories conducting genomic surveillance need to be able to compare analyses from various national and international surveillance partners to ensure that results are mutually trusted and understood. Therefore, we established an empirical outbreak benchmark dataset consisting of 23 C. auris genomes to help validate comparisons of genomic analyses and facilitate communication among surveillance networks. Our outbreak benchmark dataset represents a polyclonal phylogeny with three subclades. The genomes in this dataset are from well-vetted studies that are supported by multiple lines of evidence, which demonstrate that the whole-genome sequencing data, phylogenetic tree, and epidemiological data are all in agreement. This C. auris benchmark set allows for standardized comparisons of phylogenomic pipelines, ultimately promoting effective C. auris collaborations. |
Whole-Genome Sequencing Reveals the Presence of the blaCTX-M-65 Gene in Extended-Spectrum β-Lactamase-Producing and Multi-Drug-Resistant Clones of Salmonella Serovar Infantis Isolated from Broiler Chicken Environments in the Galapagos Islands
Burnett E , Ishida M , de Janon S , Naushad S , Duceppe MO , Gao R , Jardim A , Chen JC , Tagg KA , Ogunremi D , Vinueza-Burgos C . Antibiotics (Basel) 2021 10 (3) 1-13 ![]() Salmonella Infantis, a common contaminant of poultry products, is known to harbor mobile genetic elements that confer multi-drug resistance (MDR) and have been detected in many continents. Here, we report four MDR S. Infantis strains recovered from poultry house environments in Santa Cruz Island of the Galapagos showing extended-spectrum β-lactamase (ESBL) resistance and reduced fluoroquinolone susceptibility. Whole-genome sequencing (WGS) revealed the presence of the ESBL-conferring blaCTX-M-65 gene in an IncFIB-like plasmid in three S. Infantis isolates. Multi-locus sequence typing (MLST) and single nucleotide variant/polymorphism (SNP) SNVPhyl analysis showed that the S. Infantis isolates belong to sequence type ST32, likely share a common ancestor, and are closely related (1–3 SNP difference) to blaCTX-M-65-containing clinical and veterinary S. Infantis isolates from the United States and Latin America. Furthermore, phylogenetic analysis of SNPs following core-genome alignment (i.e., ParSNP) inferred close relatedness between the S. Infantis isolates from Galapagos and the United States. Prophage typing confirmed the close relationship among the Galapagos S. Infantis and was useful in distinguishing them from the United States isolates. This is the first report of MDR blaCTX-M-65-containing S. Infantis in the Galapagos Islands and highlights the need for increased monitoring and surveillance programs to determine prevalence, sources, and reservoirs of MDR pathogens. |
Media Reports as a Tool for Timely Monitoring of COVID-19-Related Deaths Among First Responders-United States, April 2020.
Kelly-Reif K , Rinsky JL , Chiu SK , Burrer S , de Perio MA , Trotter AG , Miura SS , Seo JY , Hong R , Friedman L , Hand J , Richardson G , Sokol T , Sparer-Fine EH , Laing J , Oliveri A , McGreevy K , Borjan M , Harduar-Morano L , Luckhaupt SE . Public Health Rep 2021 136 (3) 315-319 We aimed to describe coronavirus disease 2019 (COVID-19) deaths among first responders early in the COVID-19 pandemic. We used media reports to gather timely information about COVID-19-related deaths among first responders during March 30-April 30, 2020, and evaluated the sensitivity of media scanning compared with traditional surveillance. We abstracted information about demographic characteristics, occupation, underlying conditions, and exposure source. Twelve of 19 US public health jurisdictions with data on reported deaths provided verification, and 7 jurisdictions reported whether additional deaths had occurred; we calculated the sensitivity of media scanning among these 7 jurisdictions. We identified 97 COVID-19-related first-responder deaths during the study period through media and jurisdiction reports. Participating jurisdictions reported 5 deaths not reported by the media. Sixty-six decedents worked in law enforcement, and 31 decedents worked in fire/emergency medical services. Media reports rarely noted underlying conditions. The media scan sensitivity was 88% (95% CI, 73%-96%) in the subset of 7 jurisdictions. Media reports demonstrated high sensitivity in documenting COVID-19-related deaths among first responders; however, information on risk factors was scarce. Routine collection of data on industry and occupation could improve understanding of COVID-19 morbidity and mortality among all workers. |
Genomic Drivers of Multidrug-Resistant Shigella Affecting Vulnerable Patient Populations in the United States and Abroad.
Worley JN , Javkar K , Hoffmann M , Hysell K , Garcia-Williams A , Tagg K , Kanjilal S , Strain E , Pop M , Allard M , Francois Watkins L , Bry L . mBio 2021 12 (1) ![]() ![]() Multidrug-resistant (MDR) Shigella infections have been identified globally among men who have sex with men (MSM). The highly drug-resistant phenotype often confounds initial antimicrobial therapy, placing patients at risk for adverse outcomes, the development of more drug-resistant strains, and additional treatment failures. New macrolide-resistant Shigella strains complicate treatment further as azithromycin is a next-in-line antibiotic for MDR strains, and an antibiotic-strain combination confounded by gaps in validated clinical breakpoints for clinical laboratories to interpret macrolide resistance in Shigella We present the first high-resolution genomic analyses of 2,097 U.S. Shigella isolates, including those from MDR outbreaks. A sentinel shigellosis case in an MSM patient revealed a strain carrying 12 plasmids, of which two carried known resistance genes, the pKSR100-related plasmid pMHMC-004 and spA-related plasmid pMHMC-012. Genomic-epidemiologic analyses of isolates revealed high carriage rates of pMHMC-004 predominantly in U.S. isolates from men and not in other demographic groups. Isolates genetically related to the sentinel case further harbored elevated numbers of unique replicons, showing the receptivity of this Shigella lineage to plasmid acquisition. Findings from integrated genomic-epidemiologic analyses were leveraged to direct targeted clinical actions to improve rapid diagnosis and patient care and for public health efforts to further reduce spread.IMPORTANCE Multidrug-resistant Shigella isolates with resistance to macrolides are an emerging public health threat. We define a plasmid/pathogen complex behind infections seen in the United States and globally in vulnerable patient populations and identify multiple outbreaks in the United States and evidence of intercontinental transmission. Using new tools and sequence information, we experimentally identify the drivers of antibiotic resistance that complicate patient treatment to facilitate improvements to clinical microbiologic testing for their detection. We illustrate the use of these methods to support multiagency efforts to combat multidrug-resistant Shigella using publicly available tools, existing genomic data, and resources in clinical microbiology and public health laboratories to inform credible actions to reduce spread. |
Candida auris Outbreak in a COVID-19 Specialty Care Unit - Florida, July-August 2020.
Prestel C , Anderson E , Forsberg K , Lyman M , de Perio MA , Kuhar D , Edwards K , Rivera M , Shugart A , Walters M , Dotson NQ . MMWR Morb Mortal Wkly Rep 2021 70 (2) 56-57 In July 2020, the Florida Department of Health was alerted to three Candida auris bloodstream infections and one urinary tract infection in four patients with coronavirus disease 2019 (COVID-19) who received care in the same dedicated COVID-19 unit of an acute care hospital (hospital A). C. auris is a multidrug-resistant yeast that can cause invasive infection. Its ability to colonize patients asymptomatically and persist on surfaces has contributed to previous C. auris outbreaks in health care settings (1-7). Since the first C. auris case was identified in Florida in 2017, aggressive measures have been implemented to limit spread, including contact tracing and screening upon detection of a new case. Before the COVID-19 pandemic, hospital A conducted admission screening for C. auris and admitted colonized patients to a separate dedicated ward. |
Carriage and Gene Content Variability of the pESI-Like Plasmid Associated with Salmonella Infantis Recently Established in United States Poultry Production.
McMillan EA , Wasilenko JL , Tagg KA , Chen JC , Simmons M , Gupta SK , Tillman GE , Folster J , Jackson CR , Frye JG . Genes (Basel) 2020 11 (12) ![]() ![]() Salmonella Infantis carrying extended spectrum β-lactamase bla(CTX-M-65) on a pESI-like megaplasmid has recently emerged in United States poultry. In order to determine the carriage rate and gene content variability of this plasmid in U.S. Salmonella Infantis, whole genome sequences of Salmonella isolates from humans and animals in the U.S. and internationally containing the pESI-like plasmid were analyzed. The U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) identified 654 product sampling isolates containing pESI-like plasmids through hazard analysis and critical control point (HACCP) verification testing in 2017 and 2018. The Centers for Disease Control and Prevention identified 55 isolates with pESI-like plasmids in 2016-2018 through the National Antimicrobial Resistance Monitoring System. Approximately 49% of pESI-like plasmids from FSIS verification isolates and 71% from CDC NARMS contained bla(CTX-M-65). Pan-plasmid genome analysis was also performed. All plasmids contained traN and more than 95% contained 172 other conserved genes; 61% contained bla(CTX-M-65). In a hierarchical clustering analysis, some plasmids from U.S. animal sources clustered together and some plasmids from South America clustered together, possibly indicating multiple plasmid lineages. However, most plasmids contained similar genes regardless of origin. Carriage of the pESI-like plasmid in U.S. appears to be limited to Salmonella Infantis and carriage rates increased from 2017 to 2018. |
Facility-Wide Testing for SARS-CoV-2 in Nursing Homes - Seven U.S. Jurisdictions, March-June 2020.
Hatfield KM , Reddy SC , Forsberg K , Korhonen L , Garner K , Gulley T , James A , Patil N , Bezold C , Rehman N , Sievers M , Schram B , Miller TK , Howell M , Youngblood C , Ruegner H , Radcliffe R , Nakashima A , Torre M , Donohue K , Meddaugh P , Staskus M , Attell B , Biedron C , Boersma P , Epstein L , Hughes D , Lyman M , Preston LE , Sanchez GV , Tanwar S , Thompson ND , Vallabhaneni S , Vasquez A , Jernigan JA . MMWR Morb Mortal Wkly Rep 2020 69 (32) 1095-1099 Undetected infection with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) contributes to transmission in nursing homes, settings where large outbreaks with high resident mortality have occurred (1,2). Facility-wide testing of residents and health care personnel (HCP) can identify asymptomatic and presymptomatic infections and facilitate infection prevention and control interventions (3-5). Seven state or local health departments conducted initial facility-wide testing of residents and staff members in 288 nursing homes during March 24-June 14, 2020. Two of the seven health departments conducted testing in 195 nursing homes as part of facility-wide testing all nursing homes in their state, which were in low-incidence areas (i.e., the median preceding 14-day cumulative incidence in the surrounding county for each jurisdiction was 19 and 38 cases per 100,000 persons); 125 of the 195 nursing homes had not reported any COVID-19 cases before the testing. Ninety-five of 22,977 (0.4%) persons tested in 29 (23%) of these 125 facilities had positive SARS-CoV-2 test results. The other five health departments targeted facility-wide testing to 93 nursing homes, where 13,443 persons were tested, and 1,619 (12%) had positive SARS-CoV-2 test results. In regression analyses among 88 of these nursing homes with a documented case before facility-wide testing occurred, each additional day between identification of the first case and completion of facility-wide testing was associated with identification of 1.3 additional cases. Among 62 facilities that could differentiate results by resident and HCP status, an estimated 1.3 HCP cases were identified for every three resident cases. Performing facility-wide testing immediately after identification of a case commonly identifies additional unrecognized cases and, therefore, might maximize the benefits of infection prevention and control interventions. In contrast, facility-wide testing in low-incidence areas without a case has a lower proportion of test positivity; strategies are needed to further optimize testing in these settings. |
Comparison of Molecular Subtyping and Antimicrobial Resistance Detection Methods Used in a Large Multi-State Outbreak of Extensively Drug-Resistant Campylobacter jejuni Infections Linked to Pet Store Puppies.
Joseph LA , Francois Watkins LK , Chen J , Tagg KA , Bennett C , Caidi H , Folster JP , Laughlin ME , Koski L , Silver R , Stevenson L , Robertson S , Pruckler J , Nichols M , Pouseele H , Carleton HA , Basler C , Friedman CR , Geissler A , Hise KB , Aubert RD . J Clin Microbiol 2020 58 (10) ![]() Campylobacter jejuni is a leading cause of enteric bacterial illness in the United States. Traditional molecular subtyping methods, such as pulsed-field gel electrophoresis (PFGE) and 7-gene multilocus sequencing typing (MLST), provided limited resolution to adequately identify C. jejuni outbreaks and separate out sporadic isolates during outbreak investigations. Whole genome sequencing (WGS) has emerged as a powerful tool for C. jejuni outbreak detection. In this investigation, 45 human and 11 puppy isolates obtained during a 2016-2018 outbreak linked to pet store puppies were sequenced. Core genome multilocus sequence typing (cgMLST) and high-quality single nucleotide polymorphism (hqSNP) analysis of the sequence data separated the isolates into the same two clades containing minor within clade differences; however, cgMLST analysis does not require selection of an appropriate reference genome making this method preferable to hqSNP analysis for Campylobacter surveillance and cluster detection. The isolates were classified as ST2109-a rarely seen MLST sequence type. PFGE was performed on 38 human and 10 puppy isolates; PFGE patterns did not reliably predict clustering by cgMLST analysis. Genetic detection of antimicrobial resistance determinants predicted that all outbreak-associated isolates would be resistant to six drug classes. Traditional antimicrobial susceptibility testing (AST) confirmed a high correlation between genotypic and phenotypic antimicrobial resistance determinations. WGS analysis linked C. jejuni isolates in humans and pet store puppies even when canine exposure information was unknown, aiding the epidemiological investigation during this outbreak. WGS data were also used to quickly identify the highly drug-resistant profile of these outbreak-associated C. jejuni isolates. |
Understanding the Emergence of Multidrug-Resistant Candida : Using Whole-Genome Sequencing to Describe the Population Structure of Candida haemulonii Species Complex.
Gade L , Munoz JF , Sheth M , Wagner D , Berkow EL , Forsberg K , Jackson BR , Ramos-Castro R , Escandon P , Dolande M , Ben-Ami R , Espinosa-Bode A , Caceres DH , Lockhart SR , Cuomo CA , Litvintseva AP . Front Genet 2020 11 554 ![]() ![]() The recent emergence of a multidrug-resistant yeast, Candida auris, has drawn attention to the closely related species from the Candida haemulonii complex that include C. haemulonii, Candida duobushaemulonii, Candida pseudohaemulonii, and the recently identified Candida vulturna. Here, we used antifungal susceptibility testing and whole-genome sequencing (WGS) to investigate drug resistance and genetic diversity among isolates of C. haemulonii complex from different geographic areas in order to assess population structure and the extent of clonality among strains. Although most isolates of all four species were genetically distinct, we detected evidence of the in-hospital transmission of C. haemulonii and C. duobushaemulonii in one hospital in Panama, indicating that these species are also capable of causing outbreaks in healthcare settings. We also detected evidence of the rising azole resistance among isolates of C. haemulonii and C. duobushaemulonii in Colombia, Panama, and Venezuela linked to substitutions in ERG11 gene as well as amplification of this gene in C. haemulonii in isolates in Colombia suggesting the presence of evolutionary pressure for developing azole resistance in this region. Our results demonstrate that these species need to be monitored as possible causes of outbreaks of invasive infection. |
Candida auris outbreak involving liver transplant recipients in a Surgical Intensive Care Unit.
Theodoropoulos NM , Bolstorff B , Bozorgzadeh A , Brandeburg C , Cumming M , Daly JS , Ellison RT3rd , Forsberg K , Gade L , Gibson L , Greenough T , Litvintseva AP , Mack DA , Madoff L , Martins PN , McHale E , Melvin Z , Movahedi B , Stiles T , Vallabhaneni S , Levitz SM . Am J Transplant 2020 20 (12) 3673-3679 ![]() ![]() Candida auris is a difficult to eradicate yeast that has caused outbreaks in healthcare facilities. We report a cluster of five patients in one intensive care unit who were colonized or infected in 2017. The initial two patients were recipients of liver transplants who had cultures that grew C. auris within three days of each other in June 2017 (days 43 and 30 post-transplant). Subsequent screening cultures identified two additional patients with C. auris colonization. Respiratory and urine cultures from a fifth patient yielded C. auris. All isolates were fluconazole-resistant but susceptible to echinocandins. Whole genome sequencing showed the strains were clonal, suggesting in-hospital transmission, and related but distinct from NY/NJ strains, consistent with a separate introduction. However, no source or contact was found. Two of the five patients died. C. auris infection likely contributed to one patient death by infecting a vascular aneurysm at the graft anastomosis. Strict infection control precautions were initiated to control the outbreak. Our experience reveals that while severe disease from C. auris can occur in transplant recipients, outbreaks can be controlled using recommended infection control practices. We have had no further patients infected with C. auris to date. |
Tracing the Evolutionary History and Global Expansion of Candida auris Using Population Genomic Analyses.
Chow NA , Munoz JF , Gade L , Berkow EL , Li X , Welsh RM , Forsberg K , Lockhart SR , Adam R , Alanio A , Alastruey-Izquierdo A , Althawadi S , Arauz AB , Ben-Ami R , Bharat A , Calvo B , Desnos-Ollivier M , Escandon P , Gardam D , Gunturu R , Heath CH , Kurzai O , Martin R , Litvintseva AP , Cuomo CA . mBio 2020 11 (2) ![]() ![]() ![]() Candida auris has emerged globally as a multidrug-resistant yeast that can spread via nosocomial transmission. An initial phylogenetic study of isolates from Japan, India, Pakistan, South Africa, and Venezuela revealed four populations (clades I, II, III, and IV) corresponding to these geographic regions. Since this description, C. auris has been reported in more than 30 additional countries. To trace this global emergence, we compared the genomes of 304 C. auris isolates from 19 countries on six continents. We found that four predominant clades persist across wide geographic locations. We observed phylogeographic mixing in most clades; clade IV, with isolates mainly from South America, demonstrated the strongest phylogeographic substructure. C. auris isolates from two clades with opposite mating types were detected contemporaneously in a single health care facility in Kenya. We estimated a Bayesian molecular clock phylogeny and dated the origin of each clade within the last 360 years; outbreak-causing clusters from clades I, III, and IV originated 36 to 38 years ago. We observed high rates of antifungal resistance in clade I, including four isolates resistant to all three major classes of antifungals. Mutations that contribute to resistance varied between the clades, with Y132F in ERG11 as the most widespread mutation associated with azole resistance and S639P in FKS1 for echinocandin resistance. Copy number variants in ERG11 predominantly appeared in clade III and were associated with fluconazole resistance. These results provide a global context for the phylogeography, population structure, and mechanisms associated with antifungal resistance in C. auris IMPORTANCE In less than a decade, C. auris has emerged in health care settings worldwide; this species is capable of colonizing skin and causing outbreaks of invasive candidiasis. In contrast to other Candida species, C. auris is unique in its ability to spread via nosocomial transmission and its high rates of drug resistance. As part of the public health response, whole-genome sequencing has played a major role in characterizing transmission dynamics and detecting new C. auris introductions. Through a global collaboration, we assessed genome evolution of isolates of C. auris from 19 countries. Here, we described estimated timing of the expansion of each C. auris clade and of fluconazole resistance, characterized discrete phylogeographic population structure of each clade, and compared genome data to sensitivity measurements to describe how antifungal resistance mechanisms vary across the population. These efforts are critical for a sustained, robust public health response that effectively utilizes molecular epidemiology. |
Emergence of a Novel Salmonella enterica Serotype Reading Clonal Group Is Linked to Its Expansion in Commercial Turkey Production, Resulting in Unanticipated Human Illness in North America.
Miller EA , Elnekave E , Flores-Figueroa C , Johnson A , Kearney A , Munoz-Aguayo J , Tagg KA , Tschetter L , Weber BP , Nadon CA , Boxrud D , Singer RS , Folster JP , Johnson TJ . mSphere 2020 5 (2) ![]() ![]() Two separate human outbreaks of Salmonella enterica serotype Reading occurred between 2017 and 2019 in the United States and Canada, and both outbreaks were linked to the consumption of raw turkey products. In this study, a comprehensive genomic investigation was conducted to reconstruct the evolutionary history of S. Reading from turkeys and to determine the genomic context of outbreaks involving this infrequently isolated Salmonella serotype. A total of 988 isolates of U.S. origin were examined using whole-genome-based approaches, including current and historical isolates from humans, meat, and live food animals. Broadly, isolates clustered into three major clades, with one apparently highly adapted turkey clade. Within the turkey clade, isolates clustered into three subclades, including an "emergent" clade that contained only isolates dated 2016 or later, with many of the isolates from these outbreaks. Genomic differences were identified between emergent and other turkey subclades, suggesting that the apparent success of currently circulating subclades is, in part, attributable to plasmid acquisitions conferring antimicrobial resistance, gain of phage-like sequences with cargo virulence factors, and mutations in systems that may be involved in beta-glucuronidase activity and resistance towards colicins. U.S. and Canadian outbreak isolates were found interspersed throughout the emergent subclade and the other circulating subclade. The emergence of a novel S Reading turkey subclade, coinciding temporally with expansion in commercial turkey production and with U.S. and Canadian human outbreaks, indicates that emergent strains with higher potential for niche success were likely vertically transferred and rapidly disseminated from a common source.IMPORTANCE Increasingly, outbreak investigations involving foodborne pathogens are difficult due to the interconnectedness of food animal production and distribution, and homogeneous nature of industry integration, necessitating high-resolution genomic investigations to determine their basis. Fortunately, surveillance and whole-genome sequencing, combined with the public availability of these data, enable comprehensive queries to determine underlying causes of such outbreaks. Utilizing this pipeline, it was determined that a novel clone of Salmonella Reading has emerged that coincided with increased abundance in raw turkey products and two outbreaks of human illness in North America. The rapid dissemination of this highly adapted and conserved clone indicates that it was likely obtained from a common source and rapidly disseminated across turkey production. Key genomic changes may have contributed to its apparent continued success in commercial turkeys and ability to cause illness in humans. |
Molecular characterization and clinical outcomes of Candida auris infection: Single-center experience in Saudi Arabia.
Almaghrabi RS , Albalawi R , Mutabagani M , Atienza E , Aljumaah S , Gade L , Forsberg K , Litvintseva A , Althawadi S . Mycoses 2020 63 (5) 452-460 ![]() ![]() BACKGROUND: Candida auris is a difficult-to-diagnose multidrug-resistant yeast that can cause invasive infections with high mortality. Since emerging in 2009, this pathogen has been associated with numerous outbreaks around the world. Whole genome sequencing (WGS) is instrumental for understanding the emergence and local transmission of this pathogen. OBJECTIVES: To describe the clinical, molecular characteristics of Candida auris infection and clinical outcome in our center. PATIENTS AND METHODS: Patients with positive cultures for Candida auris were identified in a microbiology database. Clinical characteristics and antifungal susceptibility were obtained. Isolates were sent to the US CDC for whole genome sequencing. RESULTS: Seven unique patients with eight different isolates were identified. Seven isolates were sent to the US CDC for whole genome sequencing. None of the patients had blood stream infection. 30-day mortality was higher in infected patients compared with those who were colonized. Seven of the eight isolates were resistant to both fluconazole and five were resistant to amphotericin B. WGS analysis demonstrated that the seven isolates belonged to the South Asian clade but formed two distinct subclades suggesting two independent introductions and ongoing transmission within the facility. CONCLUSIONS: Candida auris is associated with a high mortality rate in infected patients. Strict infection control measures and surveillance for asymptomatic cases are warranted to halt ongoing transmission. |
Outbreak of Salmonella Newport Infections with Decreased Susceptibility to Azithromycin Linked to Beef Obtained in the United States and Soft Cheese Obtained in Mexico - United States, 2018-2019.
Plumb ID , Schwensohn CA , Gieraltowski L , Tecle S , Schneider ZD , Freiman J , Cote A , Noveroske D , Kolsin J , Brandenburg J , Chen JC , Tagg KA , White PB , Shah HJ , Francois Watkins LK , Wise ME , Friedman CR . MMWR Morb Mortal Wkly Rep 2019 68 (33) 713-717 ![]() ![]() In September 2018, CDC identified Salmonella enterica serotype Newport (Newport) infections that were multidrug resistant (MDR), with decreased susceptibility to azithromycin, a recommended oral treatment agent. Until 2017, decreased susceptibility to azithromycin had occurred in fewer than 0.5% of Salmonella isolates from U.S. residents. This report summarizes the investigation of a multistate MDR Salmonella outbreak conducted by CDC, state and local health departments, and the U.S. Department of Agriculture's Food Safety and Inspection Service. During June 2018-March 2019, 255 cases of infection with the outbreak strain were identified in 32 states; 43% of patients (89 of 206 with information on travel) reported recent travel to Mexico. Infections were linked to consumption of soft cheese obtained in Mexico and beef obtained in the United States. Consumers should avoid eating soft cheese that could be made from unpasteurized milk, regardless of the source of the cheese. When preparing beef, a food thermometer should be used to ensure that appropriate cooking temperatures are reached. When antibiotic treatment is needed for a patient, clinicians should choose antibiotics based on susceptibility testing wherever possible. |
On the Origins of a Species: What Might Explain the Rise of Candida auris ?
Jackson BR , Chow N , Forsberg K , Litvintseva AP , Lockhart SR , Welsh R , Vallabhaneni S , Chiller T . J Fungi (Basel) 2019 5 (3) ![]() ![]() Candida auris is an emerging multidrug-resistant yeast first described in 2009 that has since caused healthcare-associated outbreaks of severe human infections around the world. In some hospitals, it has become a leading cause of invasive candidiasis. C. auris is markedly different from most other pathogenic Candida species in its genetics, antifungal resistance, and ability to spread between patients. The reasons why this fungus began spreading widely in the last decade remain a mystery. We examine available data on C. auris and related species, including genomic epidemiology, phenotypic characteristics, and sites of detection, to put forth hypotheses on its possible origins. C. auris has not been detected in the natural environment; related species have been detected in in plants, insects, and aquatic environments, as well as from human body sites. It can tolerate hypersaline environments and higher temperatures than most Candida species. We explore hypotheses about the pre-emergence niche of C. auris, whether in the environmental or human microbiome, and speculate on factors that might have led to its spread, including the possible roles of healthcare, antifungal use, and environmental changes, including human activities that might have expanded its presence in the environment or caused increased human contact. |
Insights into the Unique Nature of the East Asian Clade of the Emerging Pathogenic Yeast, Candida auris .
Welsh RM , Sexton DJ , Forsberg K , Vallabhaneni S , Litvintseva A . J Clin Microbiol 2019 57 (4) ![]() ![]() The emerging yeast Candida auris can be highly drug resistant, cause invasive infections, and large outbreaks. C. auris went from an unknown pathogen a decade ago to being reported in over thirty countries on six continents. C. auris consists of four discrete clades, based on where the first isolates of the clade were reported: South Asian (Clade I), East Asian (Clade II), African (Clade III), and South American (Clade IV). These have unique genetic and biochemical characteristics, which are important to understand and inform the global response to C. auris Clade II has been underrepresented in the literature despite being the first one discovered. In this issue of the Journal of Clinical Microbiology, Y. J. Kwon et al. (J Clin Microbiol 57:e01624-18, 2019, https://doi.org/10.1128/JCM.01624-18) describe the largest collection of clinical isolates from Clade II, which is also the longest running span of clinical cases, 20 years, from any single region to date. Clade II appears to have a propensity for the ear that is uncharacteristic of the other clades, which typically cause invasive infections and large-scale outbreaks. This study provides new information on an understudied lineage of C. auris and has important implications for future surveillance. |
Update on the Epidemiology of coccidioidomycosis in the United States.
McCotter OZ , Benedict K , Engelthaler DM , Komatsu K , Lucas KD , Mohle-Boetani JC , Oltean H , Vugia D , Chiller TM , Sondermeyer Cooksey GL , Nguyen A , Roe CC , Wheeler C , Sunenshine R . Med Mycol 2019 57 S30-s40 ![]() The incidence of reported coccidioidomycosis in the past two decades has increased greatly; monitoring its changing epidemiology is essential for understanding its burden on patients and the healthcare system and for identifying opportunities for prevention and education. We provide an update on recent coccidioidomycosis trends and public health efforts nationally and in Arizona, California, and Washington State. In Arizona, enhanced surveillance shows that coccidioidomycosis continues to be associated with substantial morbidity. California reported its highest yearly number of cases ever in 2016 and has implemented interventions to reduce coccidioidomycosis in the prison population by excluding certain inmates from residing in prisons in high-risk areas. Coccidioidomycosis is emerging in Washington State, where phylogenetic analyses confirm the existence of a unique Coccidioides clade. Additional studies of the molecular epidemiology of Coccidioides will improve understanding its expanding endemic range. Ongoing public health collaborations and future research priorities are focused on characterizing geographic risk, particularly in the context of environmental change; identifying further risk reduction strategies for high-risk groups; and improving reporting of cases to public health agencies. |
PacBio Genome Sequences of Escherichia coli Serotype O157:H7, Diffusely Adherent E. coli , and Salmonella enterica Strains, All Carrying Plasmids with an mcr-1 Resistance Gene.
Lindsey RL , Batra D , Smith P , Patel PN , Tagg KA , Garcia-Toledo L , Loparev VN , Juieng P , Sheth M , Joung YJ , Rowe LA . Microbiol Resour Announc 2018 7 (14) ![]() ![]() We report here Illumina-corrected PacBio whole-genome sequences of an Escherichia coli serotype O157:H7 strain (2017C-4109), an E. coli serotype O[undetermined]:H2 strain (2017C-4173W12), and a Salmonella enterica subsp. enterica serovar Enteritidis strain (2017K-0021), all of which carried the mcr-1 resistance gene on an IncI2 or IncX4 plasmid. We also determined that pMCR-1-CTSe is identical to a previously published plasmid, pMCR-1-CT. |
Multiple introductions and subsequent transmission of multidrug-resistant Candida auris in the USA: a molecular epidemiological survey.
Chow NA , Gade L , Tsay SV , Forsberg K , Greenko JA , Southwick KL , Barrett PM , Kerins JL , Lockhart SR , Chiller TM , Litvintseva AP . Lancet Infect Dis 2018 18 (12) 1377-1384 ![]() ![]() BACKGROUND: Transmission of multidrug-resistant Candida auris infection has been reported in the USA. To better understand its emergence and transmission dynamics and to guide clinical and public health responses, we did a molecular epidemiological investigation of C auris cases in the USA. METHODS: In this molecular epidemiological survey, we used whole-genome sequencing to assess the genetic similarity between isolates collected from patients in ten US states (California, Connecticut, Florida, Illinois, Indiana, Maryland, Massachusetts, New Jersey, New York, and Oklahoma) and those identified in several other countries (Colombia, India, Japan, Pakistan, South Africa, South Korea, and Venezuela). We worked with state health departments, who provided us with isolates for sequencing. These isolates of C auris were collected during the normal course of clinical care (clinical cases) or as part of contact investigations or point prevalence surveys (screening cases). We integrated data from standardised case report forms and contact investigations, including travel history and epidemiological links (ie, patients that had shared a room or ward with a patient with C auris). Genetic diversity of C auris within a patient, a facility, and a state were evaluated by pairwise differences in single-nucleotide polymorphisms (SNPs). FINDINGS: From May 11, 2013, to Aug 31, 2017, isolates that corresponded to 133 cases (73 clinical cases and 60 screening cases) were collected. Of 73 clinical cases, 66 (90%) cases involved isolates related to south Asian isolates, five (7%) cases were related to South American isolates, one (1%) case to African isolates, and one (1%) case to east Asian isolates. Most (60 [82%]) clinical cases were identified in New York and New Jersey; these isolates, although related to south Asian isolates, were genetically distinct. Genomic data corroborated five (7%) clinical cases in which patients probably acquired C auris through health-care exposures abroad. Among clinical and screening cases, the genetic diversity of C auris isolates within a person was similar to that within a facility during an outbreak (median SNP difference three SNPs, range 0-12). INTERPRETATION: Isolates of C auris in the USA were genetically related to those from four global regions, suggesting that C auris was introduced into the USA several times. The five travel-related cases are examples of how introductions can occur. Genetic diversity among isolates from the same patients, health-care facilities, and states indicates that there is local and ongoing transmission. FUNDING: US Centers for Disease Control and Prevention. |
Novel trimethoprim resistance gene dfrA34 identified in Salmonella Heidelberg in the USA.
Tagg KA , Francois Watkins L , Moore MD , Bennett C , Joung YJ , Chen JC , Folster JP . J Antimicrob Chemother 2018 74 (1) 38-41 ![]() ![]() Background: Trimethoprim/sulfamethoxazole is a synthetic antibiotic combination recommended for the treatment of complicated non-typhoidal Salmonella infections in humans. Resistance to trimethoprim/sulfamethoxazole is mediated by the acquisition of mobile genes, requiring both a dfr gene (trimethoprim resistance) and a sul gene (sulfamethoxazole resistance) for a clinical resistance phenotype (MIC >/=4/76 mg/L). In 2017, the CDC investigated a multistate outbreak caused by a Salmonella enterica serotype Heidelberg strain with trimethoprim/sulfamethoxazole resistance, in which sul genes but no known dfr genes were detected. Objectives: To characterize and describe the molecular mechanism of trimethoprim resistance in a Salmonella Heidelberg outbreak isolate. Methods: Illumina sequencing data for one outbreak isolate revealed a 588 bp ORF encoding a putative dfr gene. This gene was cloned into Escherichia coli and resistance to trimethoprim was measured by broth dilution and Etest. Phylogenetic analysis of previously reported dfrA genes was performed using MEGA. Long-read sequencing was conducted to determine the context of the novel dfr gene. Results and conclusions: The novel dfr gene, named dfrA34, conferred trimethoprim resistance (MIC >/=32 mg/L) when cloned into E. coli. Based on predicted amino acid sequences, dfrA34 shares less than 50% identity with other known dfrA genes. The dfrA34 gene is located in a class 1 integron in a multiresistance region of an IncC plasmid, adjacent to a sul gene, thus conferring clinical trimethoprim/sulfamethoxazole resistance. Additionally, dfrA34 is associated with ISCR1, enabling easy transmission between other plasmids and bacterial strains. |
Multilocus sequence typing of Histoplasma capsulatum in formalin-fixed paraffin-embedded tissues from cats living in non-endemic regions reveals a new phylogenetic clade.
Balajee SA , Hurst SF , Chang LS , Miles M , Beeler E , Hale C , Kasuga T , Benedict K , Chiller T , Lindsley MD . Med Mycol 2012 51 (4) 345-51 ![]() Infections caused by Histoplasma capsulatum are found most often in endemic regions of North, Central, and South America. H. capsulatum has been divided into eight geographic clades by multi-locus sequence typing (MLST). Recently, one isolate and five formalin-fixed paraffin-embedded (FFPE) tissue samples were received from six of 15 suspected cases of histoplasmosis in cats residing in areas not known to be endemic for H. capsulatum. Polymerase chain reaction (PCR) amplification and sequence analysis of the rDNA ITS-2 region confirmed the diagnosis of H. capsulatum. Since these cases were not, as noted, from the accepted endemic areas, it was of interest to understand the molecular epidemiology of these isolates. Results of molecular analysis indicated that the H. capsulatum recovered from the cats were most closely related to the North American-1 clade, but clustered separately outside this clade, suggesting that the H. capsulatum infecting the animals may represent a separate clade or phylogenetic species. This study also demonstrated the utility of obtaining valuable molecular subtype data directly from archived FFPE tissue blocks, particularly when a fungus culture was not performed or is otherwise unavailable. |
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