Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
Records 1-30 (of 44 Records) |
Query Trace: Guerrero L[original query] |
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COVID-19 prevention practices and vaccine acceptability among Hispanic and non-Hispanic households in an agricultural community-Washington, 2020
Ortiz N , Hoffman A , Schnall AH , Clara A , Lilo EA , Lofgren H , Guerrero L , Miller JS , Houck P , Weed N , Monterroso E . Disaster Med Public Health Prep 2024 18 e261 OBJECTIVE: To investigate COVID-19 disparities between Hispanic/Latino persons (H/L) and non-H/L persons in an agricultural community by examining behavioral and demographic differences. METHODS: In September 2020, we conducted Community Assessments for Public Health Emergency Response in Wenatchee and East Wenatchee, Washington, to evaluate differences between H/L and non-H/L populations in COVID-19 risk beliefs, prevention practices, household needs, and vaccine acceptability. We produced weighted sample frequencies. RESULTS: More households from predominately H/L census blocks (H/L-CBHs) versus households from predominately non-H/L census blocks (non-H/L-CBHs) worked in essential services (79% versus 57%), could not telework (70% versus 46%), and reported more COVID-19 cases (19% versus 4%). More H/L-CBHs versus non-H/L-CBHs practiced prevention strategies: avoiding gatherings (81% versus 61%), avoiding visiting friends/family (73% versus 36%), and less restaurant dining (indoor 24% versus 39%). More H/L-CBHs versus non-H/L-CBHs needed housing (16% versus 4%) and food assistance (19% versus 6%). COVID-19 vaccine acceptance in H/L-CBHs and non-H/L-CBHs was 42% versus 46%, respectively. CONCLUSIONS: Despite practicing prevention measures with greater frequency, H/L-CBHs had more COVID-19 cases. H/L-CBHs worked in conditions with a higher likelihood of exposure. H/L-CBHs had increased housing and food assistance needs due to the pandemic. COVID-19 vaccine acceptability was similarly low (<50%) between groups. |
Antibiotic use in medical-surgical intensive care units and general wards in Latin American hospitals
Fabre V , Cosgrove SE , Lessa FC , Patel TS , Aleman WR , Aquiles B , Arauz AB , Barberis MF , Bangher MDC , Bernachea MP , Bernan ML , Blanco I , Cachafeiro A , Castañeda X , Castillo S , Colque AM , Contreras R , Cornistein W , Correa SM , Correal Tovar PC , Costilla Campero G , Esquivel C , Ezcurra C , Falleroni LA , Fernandez J , Ferrari S , Frassone N , Garcia Cruz C , Garzón MI , Gomez Quintero CH , Gonzalez JA , Guaymas L , Guerrero-Toapanta F , Lambert S , Laplume D , Lazarte PR , Lemir CG , Lopez A , Lopez IL , Martinez G , Maurizi DM , Melgar M , Mesplet F , Morales Pertuz C , Moreno C , Moya LG , Nuccetelli Y , Núñez G , Paez H , Palacio B , Pellice F , Pereyra ML , Pirra LS , Raffo CL , Reino Choto F , Vence Reyes L , Ricoy G , Rodriguez Gonzalez P , Rodriguez V , Romero F , Romero JJ , Sadino G , Sandoval N , Silva MG , Smud A , Soria V , Stanek V , Torralvo MJ , Urueña AM , Videla H , Valle M , Vera Amate Perez S , Vergara-Samur H , Villamandos S , Villarreal O , Viteri A , Warley E , Quiros RE . Open Forum Infect Dis 2024 11 (11) ofae620 BACKGROUND: The objective of this study was to identify antibiotic stewardship (AS) opportunities in Latin American medical-surgical intensive care units (MS-ICUs) and general wards (Gral-wards). METHODS: We conducted serial cross-sectional point prevalence surveys in MS-ICUs and Gral-wards in 41 Latin American hospitals between March 2022 and February 2023. Patients >18 years of age in the units of interest were evaluated for antimicrobial use (AU) monthly (MS-ICUs) or quarterly (Gral-wards). Antimicrobial data were collected using a standardized form by the local AS teams and submitted to the coordinating team for analysis. RESULTS: We evaluated AU in 5780 MS-ICU and 7726 Gral-ward patients. The hospitals' median bed size (interquartile range) was 179 (125-330), and 52% were nonprofit. The aggregate AU prevalence was 53.5% in MS-ICUs and 25.5% in Gral-wards. Most (88%) antimicrobials were prescribed to treat infections, 7% for surgical prophylaxis and 5% for medical prophylaxis. Health care-associated infections led to 63% of MS-ICU and 38% of Gral-ward AU. Carbapenems, piperacillin-tazobactam, intravenous (IV) vancomycin, and ampicillin-sulbactam represented 50% of all AU to treat infections. A minority of IV vancomycin targeted therapy was associated with documented methicillin-resistant Staphylococcus aureus infection or therapeutic drug monitoring. In both units, 17% of antibiotics prescribed as targeted therapy represented de-escalation, while 24% and 15% in MS-ICUs and Gral-wards, respectively, represented an escalation of therapy. In Gral-wards, 32% of antibiotics were used without a microbiologic culture ordered. Half of surgical prophylaxis antibiotics were prescribed after the first 24 hours. CONCLUSIONS: Based on this cohort, areas to improve AU in Latin American hospitals include antibiotic selection, de-escalation, duration of therapy, and dosing strategies. |
Contextual barriers to infection prevention and control program implementation in hospitals in Latin America: a mixed methods evaluation
Fabre V , Secaira C , Herzig C , Bancroft E , Bernachea MP , Galarza LA , Aquiles B , Arauz AB , Bangher MDC , Bernan ML , Burokas S , Canton A , Cazali IL , Colque A , Comas M , Contreras RV , Cornistein W , Cordoba MG , Correa SM , Campero GC , Chamorro Ayala MI , Chavez N , De Ascencao G , García CC , Esquivel C , Ezcurra C , Fabbro L , Falleroni L , Fernandez J , Ferrari S , Freire V , Garzón MI , Gonzales JA , Guaymas L , Guerrero-Toapanta F , Laplume D , Lambert S , Lemir CG , Lazarte PR , Lopez IL , Maldonado H , Martínez G , Maurizi DM , Mesplet F , Moreno Izquierdo C , Moya GL , Nájera M , Nuccetelli Y , Olmedo A , Palacio B , Pellice F , Raffo CL , Ramos C , Reino F , Rodriguez V , Romero F , Romero JJ , Sadino G , Sandoval N , Suarez M , Suayter MV , Ureña MA , Valle M , Vence Reyes L , Perez SVA , Videla H , Villamandos S , Villarreal O , Viteri MA , Warley E , Quiros RE . Antimicrob Resist Infect Control 2024 13 (1) 132 BACKGROUND: Infection prevention and control (IPC) programs are essential to prevent and control the spread of multidrug-resistant organisms in healthcare facilities (HCFs). The current implementation of these programs in Latin America remains largely unknown. METHODS: We conducted a mixed-methods evaluation of IPC program implementation in HCFs from Guatemala, Panama, Ecuador, and Argentina, March-July 2022. We used the World Health Organization (WHO) IPC Assessment Framework (IPCAF) survey, a previously validated structured questionnaire with an associated scoring system that evaluates the eight core components of IPC (IPC program; IPC guidelines; IPC education and training; healthcare-associated infection [HAI] surveillance; multimodal strategies; monitoring and audit of IPC practices and feedback; workload, staffing, and bed occupancy; and the built environment and materials and equipment for IPC). Each section generates a score 0-100. According to the final score, the HCF IPC program implementation is categorized into four levels: inadequate (0-200), basic (201-400), intermediate (401-600), or advanced (601-800). Additionally, we conducted semi-structured interviews among IPC personnel and microbiologists using the Systems Engineering Initiative for Patient Safety model to evaluate barriers and facilitators for IPC program implementation. We performed directed content analysis of interview transcripts to identify themes that focused on barriers and facilitators of IPC program implementation which are summarized descriptively. RESULTS: Thirty-seven HCFs (15 for-profit and 22 non-profit) completed the IPCAF survey. The overall median score was 614 (IQR 569, 693) which corresponded to an "advanced" level of IPC implementation (32% [7/22] non-profit vs. 93% [14/15] for-profit HCFs in this category). The lowest scores were in workload, staffing and bed occupancy followed by IPC training and multimodal strategies. Forty individuals from 16 HCFs were interviewed. They perceived inadequate staffing and technical resources, limited leadership support, and cultural determinants as major barriers to effective IPC guideline implementation, while external accreditation and technical support from public health authorities were perceived as facilitators. CONCLUSIONS: Efforts to strengthen IPC activities in Latin American HCFs should focus on improving support from hospital leadership and public health authorities to ensure better resource allocation, promoting safety culture, and improving training in quality improvement. |
Strategies to strengthen COVID-19 vaccine uptake and improve vaccine equity in U.S. Territories and Freely Associated States during the first six months of vaccine rollout
Tippins A , Acevedo JC , Palomeque FS , Coy KC , Chadd P , Stowell D , Ademokun O , Apaisam C , Basilius M , Brostrom R , Collazo IOG , Encarnacion J , Gerena IC , Hancock T , Hunte-Ceasar T , Judicpa P , Leon-Guerrero M , Martinez M , Masunu Y , Pangelinan H , Parian E , Pedro D . Vaccine 2024 The eight U.S. territories and freely associated states (TFAS) have historically faced unique social and structural barriers in the implementation of vaccination programs due to geographic remoteness, a high prevalence of socioeconomic disparities, increasing prevalence of natural disasters, limited vaccine providers and clinics, difficulties with procurement and shipping, and difficulty tracking highly mobile populations. In the months leading up to emergency authorizations for the use of COVID-19 vaccines, the TFAS developed tailored vaccination strategies to ensure that key at-risk populations received timely vaccination, and successfully implemented these strategies during the first six months of the vaccine rollout. Subject matter experts supporting the Centers for Disease Control and Prevention's COVID-19 Response recognized the unique historical, geographic, social, and cultural dynamics for residents in the TFAS and worked with partners to prevent, detect, and respond to the pandemic in these jurisdictions. As a result of innovative partnerships and vaccine distribution strategies, vaccine equity was improved in the TFAS during the COVID-19 vaccine rollout. |
Knowledge, attitudes and perceptions of Latin American healthcare workers relating to antibiotic stewardship and antibiotic use: a cross-sectional multi-country study
Fabre V , Cosgrove SE , Lessa FC , Patel TS , Reyes-Morales G , Aleman WR , Alvarez AA , Aquiles B , Arauz AB , Arguello F , Barberis MF , Barcan L , Bernachea MP , Bernan ML , Buitrago C , Del Carmen Bangher M , Castañeda X , Colque AM , Canton A , Contreras R , Correa S , Campero GC , Espinola L , Esquivel C , Ezcurra C , Falleroni LA , Fernandez J , Ferrari S , Frassone N , Cruz CG , Garzón MI , Quintero CHG , Gonzalez JA , Guaymas L , Guerrero-Toapanta F , Lambert S , Laplume D , Lazarte PR , Lemir CG , Lopez A , Lopez IL , Maldonado H , Martinez G , Maurizi DM , Melgar M , Mesplet F , Pertuz CM , Moreno C , Moya GL , Nuccetelli Y , Núñez G , Osuna C , Palacio B , Pellice F , Raffo C , Choto FR , Ricoy G , Rodriguez V , Romero F , Romero JJ , Russo ME , Sadino G , Sandoval N , Silva MG , Urueña AM , Reyes LV , Videla H , Valle M , Perez SVA , Vergara-Samur H , Villamandos S , Villarreal O , Viteri A , Warley E , Quiros RE . Antimicrob Resist Infect Control 2024 13 (1) 47 BACKGROUND: The burden of antimicrobial resistance (AMR) in Latin America is high. Little is known about healthcare workers' (HCWs) knowledge, attitudes, and perceptions of antimicrobial stewardship (AS), AMR, and antibiotic use (AU) in the region. METHODS: HCWs from 42 hospitals from 5 Latin American countries were invited to take an electronic, voluntary, anonymous survey regarding knowledge, attitudes, and perceptions of AS, AMR, and AU between March-April 2023. FINDINGS: Overall, 996 HCWs completed the survey (52% physicians, 32% nurses, 11% pharmacists, 3% microbiologists, and 2% "other"). More than 90% of respondents indicated optimizing AU was a priority at their healthcare facility (HCF), 69% stated the importance of AS was communicated at their HCF, and 23% were unfamiliar with the term "antibiotic stewardship". Most (> 95%) respondents acknowledged that appropriate AU can reduce AMR; however, few thought AU (< 30%) or AMR (< 50%) were a problem in their HCF. Lack of access to antibiogram and to locally endorsed guidelines was reported by 51% and 34% of HCWs, respectively. Among prescribers, 53% did not consider non-physicians' opinions to make antibiotic-related decisions, 22% reported not receiving education on how to select antibiotics based on culture results and 60% stated patients and families influence their antibiotic decisions. CONCLUSIONS: Although HCWs perceived improving AU as a priority, they did not perceive AU or AMR as a problem in their HCF. AS opportunities include improved access to guidelines, access to AMR/AU data, teamwork, and education on AS for HCWs and patients and families. |
Heterogeneous susceptibility to rotavirus infection and gastroenteritis in two birth cohort studies: parameter estimation and epidemiological implications (preprint)
Lewnard JA , Lopman BA , Parashar UD , Bennett A , Bar-Zeev N , Cunliffe NA , Samuel P , Guerrero ML , Ruiz-Palacios G , Kang G , Pitzer VE . bioRxiv 2018 242172 Variation in susceptibility is a known contributor to bias in studies estimating immune protection acquired from vaccination or natural infection. However, difficulty measuring this heterogeneity hinders assessment of its influence on estimates. Cohort studies, randomized trials, and post-licensure studies have reported reduced natural and vaccine-derived protection against rotavirus gastroenteritis in low- and middle-income countries (LMICs). We sought to understand differences in susceptibility among children enrolled in two birth-cohort studies of rotavirus in LMICs, and to explore the implications for estimation of immune protection. We re-analyzed data from studies conducted in Mexico City, Mexico and Vellore, India. Cumulatively, 573 unvaccinated children experienced 1418 rotavirus infections and 371 episodes of rotavirus gastroenteritis (RVGE) over 17,636 child-months. We developed a model characterizing susceptibility to rotavirus infection and RVGE among children, accounting for aspects of the natural history of rotavirus and differences in transmission rates between settings, and tested whether modelgenerated susceptibility measurements were associated with demographic and anthropometric factors. We identified greater variation in susceptibility to rotavirus infection and RVGE in Vellore than in Mexico City. In both cohorts, susceptibility to rotavirus infection and RVGE were associated with male sex, lower birth weight, lower maternal education, and having fewer siblings; within Vellore, susceptibility was also associated with lower socioeconomic status. Children who were more susceptible to rotavirus also experienced higher rates of diarrhea due to other causes. Simulations suggest that discrepant estimates of naturally-acquired immunity against RVGE can be attributed, in part, to between-setting differences in transmission intensity and susceptibility of children. We found that more children in Vellore than in Mexico City belong to a high-risk group for rotavirus infection and RVGE, and demonstrate that bias owing to differences in rotavirus transmission intensity and population susceptibility may hinder comparison of estimated immune protection against RVGE.Author summary Differences in susceptibility can help explain why some individuals, and not others, acquire infection and exhibit symptoms when exposed to infectious disease agents. However, it is difficult to distinguish between differences in susceptibility versus exposure in epidemiological studies. We developed a modeling approach to distinguish transmission intensity and susceptibility in data from cohort studies of rotavirus infection among children in Mexico City, Mexico, and Vellore, India, and evaluated how these factors may have contributed to differences in estimates of naturally-acquired immune protection between the studies. We found that more children were at “high risk” of acquiring rotavirus infection, and of experiencing gastroenteritis when infected, in Vellore versus Mexico City. The probability of belonging to this high-risk stratum was associated with recognized risk factors such as lower socioeconomic status, lower birth weight, and risk of diarrhea due to other causes. We also found the risk for rotavirus infections to cause symptoms declined with age, and was independent of acquired immunity. Together, these findings can account for estimates of lower protective efficacy of acquired immunity against rotavirus gastroenteritis in high-incidence settings, which mirrors estimates of reduced effectiveness of live oral rotavirus vaccines in low- and middle-income countries. |
Occupational monkeypox virus transmission to healthcare worker, California, USA, 2022
Alarcón J , Kim M , Balanji N , Davis A , Mata F , Karan A , Finn LE , Guerrero A , Walters M , Terashita D , Balter SE . Emerg Infect Dis 2023 29 (2) 435-437 Risk for transmission of monkeypox virus (MPXV) (clade IIb) to healthcare workers (HCWs) is low. Although many cases have been reported among HCW, only a few have been occupationally acquired. We report a case of non-needle stick MPXV transmission to an HCW in the United States. |
Body Lice among People Experiencing Homelessness and Access to Hygiene Services during the COVID-19 Pandemic-Preventing Trench Fever in Denver, Colorado, 2020.
Marshall KE , Martinez HE , Woodall T , Guerrero A , Mechtenberg J , Herlihy R , House J . Am J Trop Med Hyg 2022 107 (2) 427-32 Eight people with human body louse-borne Bartonella quintana infections were detected among people experiencing homelessness (PEH) in Denver during January-September 2020, prompting a public health investigation and community outreach. Public health officials conducted in-person interviews with PEH to more fully quantify body lice prevalence, transmission risk factors, access to PEH resources, and how the COVID-19 pandemic has affected resource access. Recent body lice exposure was reported by 35% of 153 interview participants. In total, 75% of participants reported reduced access to PEH services, including essential hygiene activities to prevent body lice, during Colorado's COVID-19 stay-at-home orders. Future pandemic planning should consider hygiene resource allocation for PEH populations to prevent emerging and reemerging infections such as B. quintana. |
Remdesivir targets a structurally analogous region of the Ebola virus and SARS-CoV-2 polymerases.
Lo MK , Albariño CG , Perry JK , Chang S , Tchesnokov EP , Guerrero L , Chakrabarti A , Shrivastava-Ranjan P , Chatterjee P , McMullan LK , Martin R , Jordan R , Götte M , Montgomery JM , Nichol ST , Flint M , Porter D , Spiropoulou CF . Proc Natl Acad Sci U S A 2020 117 (43) 26946-26954 Remdesivir is a broad-spectrum antiviral nucleotide prodrug that has been clinically evaluated in Ebola virus patients and recently received emergency use authorization (EUA) for treatment of COVID-19. With approvals from the Federal Select Agent Program and the Centers for Disease Control and Prevention's Institutional Biosecurity Board, we characterized the resistance profile of remdesivir by serially passaging Ebola virus under remdesivir selection; we generated lineages with low-level reduced susceptibility to remdesivir after 35 passages. We found that a single amino acid substitution, F548S, in the Ebola virus polymerase conferred low-level reduced susceptibility to remdesivir. The F548 residue is highly conserved in filoviruses but should be subject to specific surveillance among novel filoviruses, in newly emerging variants in ongoing outbreaks, and also in Ebola virus patients undergoing remdesivir therapy. Homology modeling suggests that the Ebola virus polymerase F548 residue lies in the F-motif of the polymerase active site, a region that was previously identified as susceptible to resistance mutations in coronaviruses. Our data suggest that molecular surveillance of this region of the polymerase in remdesivir-treated COVID-19 patients is also warranted. |
Zika virus infection and Guillain-Barre syndrome in northeastern Mexico: A case-control study
Gongora-Rivera F , Grijalva I , Infante-Valenzuela A , Camara-Lemarroy C , Garza-Gonzalez E , Paredes-Cruz M , Grajales-Muniz C , Guerrero-Cantera J , Vargas-Ramos I , Soares J , Abrams JY , Styczynski AR , Camacho-Ortiz A , Villarino ME , Belay ED , Schonberger LB , Sejvar JJ . PLoS One 2020 15 (3) e0230132 BACKGROUND: Beginning August 2017, we conducted a prospective case-control investigation in Monterrey, Mexico to assess the association between Zika virus (ZIKV) and Guillain-Barre syndrome (GBS). METHODS: For each of 50 GBS case-patients, we enrolled 2-3 afebrile controls (141 controls in total) matched by sex, age group, and presentation to same hospital within 7 days. RESULTS: PCR results for ZIKV in blood and/or urine were available on all subjects; serum ZIKV IgM antibody for 52% of case-patients and 80% of controls. Subjects were asked about antecedent illness in the two months prior to neurological onset (for case-patients) or interview (for controls). Laboratory evidence of ZIKV infection alone (PCR+ or IgM+) was not significantly different between case-patients and controls (OR: 1.26, 95% CI: 0.45-3.54) but antecedent symptomatic ZIKV infection [a typical ZIKV symptom (rash, joint pain, or conjunctivitis) plus laboratory evidence of ZIKV infection] was higher among case-patients (OR: 12.45, 95% CI: 1.45-106.64). GBS case-patients with laboratory evidence of ZIKV infection were significantly more likely to have had typical ZIKV symptoms than controls with laboratory evidence of ZIKV infection (OR: 17.5, 95% CI: 3.2-96.6). This association remained significant even when only GBS case-patients who were afebrile for 5 days before onset were included in the analysis, (OR 9.57 (95% CI: 1.07 to 85.35). CONCLUSIONS: During ZIKV epidemics, this study indicates that increases in GBS will occur primarily among those with antecedent symptomatic ZIKV. |
Isolation and phylogenomic analysis of Buffalopox virus from Human and Buffaloes in India.
Yadav PD , Mauldin MR , Nyayanit DA , Albarino CG , Sarkale P , Shete A , Guerrero LW , Nakazawa Y , Nichol ST , Mourya DT . Virus Res 2019 277 197836 Three genome sequences of Buffalopox virus (BPVX) were retrieved from a human and two buffaloes scab samples. Phylogenomic analysis of the BPXV indicates that it shares a most recent common ancestor with Lister and closely related vaccine strains when compared to potential wild-type VACV strains (like Horsepox virus). |
Rousette Bat Dendritic Cells Overcome Marburg Virus-Mediated Antiviral Responses by Upregulation of Interferon-Related Genes While Downregulating Proinflammatory Disease Mediators.
Prescott J , Guito JC , Spengler JR , Arnold CE , Schuh AJ , Amman BR , Sealy TK , Guerrero LW , Palacios GF , Sanchez-Lockhart M , Albarino CG , Towner JS . mSphere 2019 4 (6) Dysregulated and maladaptive immune responses are at the forefront of human diseases caused by infection with zoonotic viral hemorrhagic fever viruses. Elucidating mechanisms of how the natural animal reservoirs of these viruses coexist with these agents without overt disease, while permitting sufficient replication to allow for transmission and maintenance in a population, is important for understanding the viral ecology and spillover to humans. The Egyptian rousette bat (ERB) has been identified as a reservoir for Marburg virus (MARV), a filovirus and the etiological agent of the highly lethal Marburg virus disease. Little is known regarding how these bats immunologically respond to MARV infection. In humans, macrophages and dendritic cells (DCs) are primary targets of infection, and their dysregulation is thought to play a central role in filovirus diseases, by disturbing their normal functions as innate sensors and adaptive immune response facilitators while serving as amplification and dissemination agents for the virus. The infection status and responses to MARV in bat myeloid-lineage cells are uncharacterized and likely represent an important modulator of the bat's immune response to MARV infection. Here, we generate DCs from the bone marrow of rousette bats. Infection with a bat isolate of MARV resulted in a low level of transcription in these cells and significantly downregulated DC maturation and adaptive immune-stimulatory pathways while simultaneously upregulating interferon-related pathogen-sensing pathways. This study provides a first insight into how the bat immune response is directed toward preventing aberrant inflammatory responses while mounting an antiviral response to defend against MARV infection.IMPORTANCE Marburg viruses (MARVs) cause severe human disease resulting from aberrant immune responses. Dendritic cells (DCs) are primary targets of infection and are dysregulated by MARV. Dysregulation of DCs facilitates MARV replication and virus dissemination and influences downstream immune responses that result in immunopathology. Egyptian rousette bats (ERBs) are natural reservoirs of MARV, and infection results in virus replication and shedding, with asymptomatic control of the virus within weeks. The mechanisms that bats employ to appropriately respond to infection while avoiding disease are unknown. Because DC infection and modulation are important early events in human disease, we measured the transcriptional responses of ERB DCs to MARV. The significance of this work is in identifying cell type-specific coevolved responses between ERBs and MARV, which gives insight into how bat reservoirs are able to harbor MARV and permit viral replication, allowing transmission and maintenance in the population while simultaneously preventing immunopathogenesis. |
Heterogeneous susceptibility to rotavirus infection and gastroenteritis in two birth cohort studies: Parameter estimation and epidemiological implications
Lewnard JA , Lopman BA , Parashar UD , Bennett A , Bar-Zeev N , Cunliffe NA , Samuel P , Guerrero ML , Ruiz-Palacios G , Kang G , Pitzer VE . PLoS Comput Biol 2019 15 (7) e1007014 Cohort studies, randomized trials, and post-licensure studies have reported reduced natural and vaccine-derived protection against rotavirus gastroenteritis (RVGE) in low- and middle-income countries. While susceptibility of children to rotavirus is known to vary within and between settings, implications for estimation of immune protection are not well understood. We sought to re-estimate naturally-acquired protection against rotavirus infection and RVGE, and to understand how differences in susceptibility among children impacted estimates. We re-analyzed data from studies conducted in Mexico City, Mexico and Vellore, India. Cumulatively, 573 rotavirus-unvaccinated children experienced 1418 rotavirus infections and 371 episodes of RVGE over 17,636 child-months. We developed a model that characterized susceptibility to rotavirus infection and RVGE among children, accounting for aspects of the natural history of rotavirus and differences in transmission rates between settings. We tested whether model-generated susceptibility measurements were associated with demographic and anthropometric factors, and with the severity of RVGE symptoms. We identified greater variation in susceptibility to rotavirus infection and RVGE in Vellore than in Mexico City. In both cohorts, susceptibility to rotavirus infection and RVGE were associated with male sex, lower birth weight, lower maternal education, and having fewer siblings; within Vellore, susceptibility was also associated with lower socioeconomic status. Children who were more susceptible to rotavirus also experienced higher rates of rotavirus-negative diarrhea, and higher risk of moderate-to-severe symptoms when experiencing RVGE. Simulations suggested that discrepant estimates of naturally-acquired immunity against RVGE can be attributed, in part, to between-setting differences in susceptibility of children, but result primarily from the interaction of transmission rates with age-dependent risk for infections to cause RVGE. We found that more children in Vellore than in Mexico City belong to a high-risk group for rotavirus infection and RVGE, and demonstrate that unmeasured individual- and age-dependent susceptibility may influence estimates of naturally-acquired immune protection against RVGE. |
Characterisation of infectious Ebola virus from the ongoing outbreak to guide response activities in the Democratic Republic of the Congo: a phylogenetic and in vitro analysis.
McMullan LK , Flint M , Chakrabarti A , Guerrero L , Lo MK , Porter D , Nichol ST , Spiropoulou CF , Albarino C . Lancet Infect Dis 2019 19 (9) 1023-1032 BACKGROUND: The ongoing Ebola virus outbreak in the Ituri and North Kivu Provinces of the Democratic Republic of the Congo, which began in July, 2018, is the second largest ever recorded. Despite civil unrest, outbreak control measures and the administration of experimental therapies and a vaccine have been initiated. The aim of this study was to test the efficacy of candidate therapies and diagnostic tests with the outbreak strain Ituri Ebola virus. Lacking a virus isolate from this outbreak, a recombinant Ituri Ebola virus was compared with a similarly engineered Makona virus from the 2013-16 outbreak. METHODS: Using Ebola virus sequences provided by organisations in DR Congo and a reverse genetics system, we generated an authentic Ebola virus from the ongoing outbreak in Ituri and North Kivu provinces. To relate this virus to other Ebola viruses in DR Congo, we did a phylogenetic analysis of representative complete Ebola virus genome sequences from previous outbreaks. We evaluated experimental therapies being tested in clinical trials in DR Congo, including remdesivir and ZMapp monoclonal antibodies, for their ability to inhibit the growth of infectious Ituri Ebola virus in cell culture. We also tested diagnostic assays for detection of the Ituri Ebola virus sequence. FINDINGS: The phylogenetic analysis of whole-genome sequences from each Ebola virus outbreak suggests there are at least two Ebola virus strains in DR Congo, which have independently crossed into the human population. The Ituri Ebola strain initially grew slower than the Makona strain, yet reached similar mean yields of 3 x 10(7) 50% tissue culture infectious dose by 72 h infection in Huh-7 cells. Ituri Ebola virus was similar to Makona in its susceptibility to inhibition by remdesivir and to neutralisation by monoclonal antibodies from ZMapp and other monoclonal antibodies. Remdesivir inhibited Ituri Ebola virus at a 50% effective concentration (EC50) of 12nM (with a selectivity index of 303) and Makona Ebola virus at 13nM (with a selectivity index of 279). The Zmapp monoclonal antibodies 2G4 and 4G7 neutralised Ituri Ebola virus with a mean EC50 of 0.24 mug/mL and 0.48 mug/mL, and Makona Ebola virus with a mean EC50 of 0.45 mug/mL and 0.2 mug/mL. The Xpert Ebola and US Centers for Disease Control and Prevention real-time RT-qPCR diagnostic assays detected Ituri and Makona Ebola virus sequences with similar sensitivities and efficiencies, despite primer site binding mismatches in the Ituri Ebola virus. INTERPRETATION: Our findings provide a rationale for the continued testing of investigational therapies, confirm the effectiveness of the diagnostic assays used in the region, and establish a paradigm for the use of reverse genetics to inform response activities in an outbreak. FUNDING: US Centers for Disease Control and Prevention. |
Antibody-mediated virus neutralization is not a universal mechanism of Marburg, Ebola or Sosuga virus clearance in Egyptian rousette bats
Schuh AJ , Amman BR , Sealy TK , Kainulainen MH , Chakrabarti AK , Guerrero LW , Nichol ST , Albarino CG , Towner JS . J Infect Dis 2018 219 (11) 1716-1721 Although bats are increasingly being recognized as natural reservoir hosts of emerging zoonotic viruses, little is known about how they control and clear virus infection in the absence of clinical disease. Here, we test >50 convalescent sera from Egyptian rousette bats (ERBs) experimentally primed or prime-boosted with Marburg virus, Ebola virus or Sosuga virus for the presence of virus-specific neutralizing antibodies using infectious reporter viruses. After serum neutralization testing, we conclude that antibody-mediated virus neutralization does not contribute significantly to the control and clearance of Marburg virus, Ebola virus or Sosuga virus infection in ERBs. |
Complete Genome Sequences of Monongahela Hantavirus from Pennsylvania, USA.
Albarino CG , Guerrero LW , Chakrabarti AK , Rollin PE , Nichol ST . Microbiol Resour Announc 2018 7 (11) Monongahela hantavirus was first identified in deer mice and was later found responsible for hantavirus pulmonary syndrome cases in Pennsylvania and West Virginia in the United States. Here, we report the complete sequences of Monongahela virus S, M, and L genomic segments obtained from a fatal clinical case reported in 1997. Copyright © 2018 Microbiology Resource Announcements. All rights reserved. |
The S Genome Segment Is Sufficient to Maintain Pathogenicity in Intra-Clade Lassa Virus Reassortants in a Guinea Pig Model.
Welch SR , Scholte FEM , Albarino CG , Kainulainen MH , Coleman-McCray JD , Guerrero LW , Chakrabarti AK , Klena JD , Nichol ST , Spengler JR , Spiropoulou CF . Front Cell Infect Microbiol 2018 8 240 Genome reassortment in Lassa virus (LASV) has been reported in nature, but phenotypic consequences of this phenomenon are not well described. Here we characterize, both in vitro and in vivo, reassortment between 2 LASV strains: the prototypic 1976 Josiah strain and a more recently isolated 2015 Liberian strain. In vitro analysis showed that although cis- and trans-acting elements of viral RNA synthesis were compatible between strains, reassortants demonstrated different levels of viral replication. These differences were also apparent in vivo, as reassortants varied in pathogenicity in the guinea pig model of LASV infection. The reassortant variant containing the Josiah S segment retained the virulence of the parental Josiah strain, but the reassortant variant containing the S segment of the Liberian isolate was highly attenuated compared to both parental strains. Contrary to observations in reassortants between LASV and other arenavirus species, which suggest that L segment-encoded factors are responsible for virulence, these studies highlight a role for S segment-encoded virulence factors in disease, and also suggest that inefficient interactions between proteins of heterologous strains may limit the prevalence of reassortant LASV variants in nature. |
Transcriptional analysis of viral mRNAs reveals common transcription patterns in cells infected by five different filoviruses.
Albarino CG , Wiggleton Guerrero L , Chakrabarti AK , Nichol ST . PLoS One 2018 13 (8) e0201827 Filoviruses are notorious viral pathogens responsible for high-consequence diseases in humans and non-human primates. Transcription of filovirus mRNA shares several common features with transcription in other non-segmented negative-strand viruses, including differential expression of genes located across the viral genome. Transcriptional patterns of Ebola virus (EBOV) and Marburg virus (MARV) have been previously described using traditional, laborious methods, such as northern blots and in vivo labeling of viral mRNAs. More recently, however, the availability of the next generation sequencing (NGS) technology has offered a more straightforward approach to assess transcriptional patterns. In this report, we analyzed the transcription patterns of four ebolaviruses-EBOV, Sudan (SUDV), Bundibugyo (BDBV), and Reston (RESTV) viruses-in two different cell lines using standard NGS library preparation and sequencing protocols. In agreement with previous reports mainly focused on EBOV and MARV, the remaining filoviruses used in this study also showed a consistent transcription pattern, with only minor variations between the different viruses. We have also analyzed the proportions of the three mRNAs transcribed from the GP gene, which are characteristic of the genus Ebolavirus and encode the glycoprotein (GP), the soluble GP (sGP), and the small soluble GP (ssGP). In addition, we used NGS methodology to analyze the transcription pattern of two previously described recombinant MARV. This analysis allowed us to correct our construction design, and to make an improved version of the original MARV expressing reporter genes. |
Identification and characterization of novel mosquito-borne (Kammavanpettai virus) and tick-borne (Wad Medani) reoviruses isolated in India.
Yadav PD , Shete AM , Nyayanit DA , Albarino CG , Jain S , Guerrero LW , Kumar S , Patil DY , Nichol ST , Mourya DT . J Gen Virol 2018 99 (8) 991-1000 In 1954, a virus named Wad Medani virus (WMV) was isolated from Hyalomma marginatum ticks from Maharashtra State, India. In 1963, another virus was isolated from Sturnia pagodarum birds in Tamil Nadu, India, and named Kammavanpettai virus (KVPTV) based on the site of its isolation. Originally these virus isolates could not be identified with conventional methods. Here we describe next-generation sequencing studies leading to the determination of their complete genome sequences, and identification of both virus isolates as orbiviruses (family Reoviridae). Sequencing data showed that KVPTV has an AT-rich genome, whereas the genome of WMV is GC-rich. The size of the KVPTV genome is 18 234 nucleotides encoding proteins ranging 238-1290 amino acids (aa) in length. Similarly, the size of the WMV genome is 16 941 nucleotides encoding proteins ranging 214-1305 amino acids in length. Phylogenetic analysis of the VP1 gene, along with the capsid genes VP5 and VP7, revealed that KVPTV is likely a novel mosquito-borne virus and WMV is a tick-borne orbivirus. This study focuses on the phylogenetic comparison of these newly identified orbiviruses with mosquito-, tick- and Culicoides-borne orbiviruses isolated in India and other countries. |
Equine encephalosis virus in India, 2008
Yadav PD , Albarino CG , Nyayanit DA , Guerrero L , Jenks MH , Sarkale P , Nichol ST , Mourya DT . Emerg Infect Dis 2018 24 (5) 898-901 A virus isolated from a sick horse from India in 2008 was confirmed by next-generation sequencing analysis to be equine encephalosis virus (EEV). EEV in India is concerning because several species of Culicoides midge, which play a major role in EEV natural maintenance and transmission, are present in this country. |
Development of a reverse genetics system for Sosuga virus allows rapid screening of antiviral compounds.
Welch SR , Chakrabarti AK , Wiggleton Guerrero L , Jenks HM , Lo MK , Nichol ST , Spiropoulou CF , Albarino CG . PLoS Negl Trop Dis 2018 12 (3) e0006326 Sosuga virus (SOSV) is a recently discovered zoonotic paramyxovirus isolated from a single human case in 2012; it has been ecologically and epidemiologically associated with transmission by the Egyptian rousette bat (Rousettus aegyptiacus). Bats have long been recognized as sources of novel zoonotic pathogens, including highly lethal paramyxoviruses like Nipah virus (NiV) and Hendra virus (HeV). The ability of SOSV to cause severe human disease supports the need for studies on SOSV pathogenesis to better understand the potential impact of this virus and to identify effective treatments. Here we describe a reverse genetics system for SOSV comprising a minigenome-based assay and a replication-competent infectious recombinant reporter SOSV that expresses the fluorescent protein ZsGreen1 in infected cells. First, we used the minigenome assay to rapidly screen for compounds inhibiting SOSV replication at biosafety level 2 (BSL-2). The antiviral activity of candidate compounds was then tested against authentic viral replication using the reporter SOSV at BSL-3. We identified several compounds with anti-SOSV activity, several of which also inhibit NiV and HeV. Alongside its utility in screening for potential SOSV therapeutics, the reverse genetics system described here is a powerful tool for analyzing mechanisms of SOSV pathogenesis, which will facilitate our understanding of how to combat the potential public health threats posed by emerging bat-borne paramyxoviruses. |
Personalized medicine and Hispanic health: improving health outcomes and reducing health disparities - a National Heart, Lung, and Blood Institute workshop report
Aviles-Santa ML , Heintzman J , Lindberg NM , Guerrero-Preston R , Ramos K , Abraido-Lanza AL , Bull J , Falcon A , McBurnie MA , Moy E , Papanicolaou G , Pina IL , Popovic J , Suglia SF , Vazquez MA . BMC Proc 2017 11 11 Persons of Hispanic/Latino descent may represent different ancestries, ethnic and cultural groups and countries of birth. In the U.S., the Hispanic/Latino population is projected to constitute 29% of the population by 2060. A personalized approach focusing on individual variability in genetics, environment, lifestyle and socioeconomic determinants of health may advance the understanding of some of the major factors contributing to the health disparities experienced by Hispanics/Latinos and other groups in the U.S., thus leading to new strategies that improve health care outcomes. However, there are major gaps in our current knowledge about how personalized medicine can shape health outcomes among Hispanics/Latinos and address the potential factors that may explain the observed differences within this heterogeneous group, and between this group and other U.S. demographic groups. For that purpose, the National Heart, Lung, and Blood Institute (NHLBI), in collaboration with the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and the Food and Drug Administration (FDA), held a workshop in which experts discussed (1) potential approaches to study medical treatments and health outcomes among Hispanics/Latinos and garner the necessary evidence to fill gaps of efficacy, effectiveness and safety of therapies for heart, lung, blood and sleep (HLBS) disorders and conditions--and their risk factors; (2) research opportunities related to personalized medicine to improve knowledge and develop effective interventions to reduce health disparities among Hispanics/Latinos in the U.S.; and (3) the incorporation of expanded sociocultural and socioeconomic data collection and genetic/genomic/epigenetic information of Hispanic/Latino patients into their clinical assessments, to account for individual variability in ancestry; physiology or disease risk; culture; environment; lifestyle; and socioeconomic determinants of health. The experts also provided recommendations on: sources of Hispanic/Latino health data and strategies to enhance its collection; policy; genetics, genomics and epigenetics research; and integrating Hispanic/Latino health research within clinical settings. |
Genome Sequences of Crimean-Congo Hemorrhagic Fever Virus Strains Isolated in South Africa, Namibia, and Turkey.
Zivcec M , Albarino CG , Guerrero LIW , Ksiazek TG , Nichol ST , Swanepoel R , Rollin PE , Spiropoulou CF . Genome Announc 2017 5 (42) We report here the full-length sequences of 16 historical isolates of Crimean-Congo hemorrhagic fever orthonairovirus (CCHFV) obtained in Turkey, Namibia, and South Africa. The strains may be useful for future work to develop molecular diagnostics or viral evolution studies. |
Naturally acquired immunity against rotavirus infection and gastroenteritis in children: Paired reanalyses of birth cohort studies
Lewnard JA , Lopman BA , Parashar UD , Bar-Zeev N , Samuel P , Guerrero ML , Ruiz-Palacios GM , Kang G , Pitzer VE . J Infect Dis 2017 216 (3) 317-326 Background: Observational studies in socioeconomically distinct populations have yielded conflicting conclusions about the strength of naturally acquired immunity against rotavirus gastroenteritis (RVGE), mirroring vaccine underperformance in low-income countries. We revisited birth cohort studies to understand naturally acquired protection against rotavirus infection and RVGE. Methods: We reanalyzed data from 200 Mexican and 373 Indian children followed from birth to 2 and 3 years of age, respectively. We reassessed protection against RVGE, decomposing the incidence rate into the rate of rotavirus infection and the risk of RVGE given infection, and tested for serum antibody correlates of protection using regression models. Results: Risk for primary, secondary, and subsequent infections to cause RVGE decreased per log-month of age by 28% (95% confidence interval [CI], 12%-41%), 69% (95% CI, 30%-86%), and 64% (95% CI, -186% to 95%), respectively, in Mexico City, and by 10% (95% CI, -1% to 19%), 51% (95% CI, 41%-59%) and 67% (95% CI, 57%-75%), respectively, in Vellore. Elevated serum immunoglobulin A and immunoglobulin G titers were associated with partial protection against rotavirus infection. Associations between older age and reduced risk for RVGE or moderate-to-severe RVGE given infection persisted after controlling for antibody levels. Conclusions: Dissimilar estimates of protection against RVGE may be due in part to age-related, antibody-independent risk for rotavirus infections to cause RVGE. |
Identification of broadly neutralizing monoclonal antibodies against Crimean-Congo hemorrhagic fever virus
Zivcec M , Guerrero LIW , Albarino CG , Bergeron E , Nichol ST , Spiropoulou CF . Antiviral Res 2017 146 112-120 Despite the serious public health impact of Crimean-Congo hemorrhagic fever (CCHF), the efficacy of antivirals targeting the causative agent, CCHF virus (CCHFV), remains debatable. Neutralizing monoclonal antibodies (MAbs) targeting the CCHFV glycoprotein Gc have been reported to protect mice against challenge with the prototype CCHFV strain, IbAr10200. However, due to extensive sequence diversity of CCHFV glycoproteins, it is unknown whether these MAbs neutralize other CCHFV strains. We initially used a CCHF virus-like particle (VLP) system to generate 11 VLP moieties, each possessing a glycoprotein from a genetically diverse CCHFV strain isolated in either Africa, Asia, the Middle East, or southeastern Europe. We used these VLPs in biosafety level 2 conditions to efficiently screen MAb cross-neutralization potency. Of the 16 MAbs tested, 3 (8A1, 11E7, and 30F7) demonstrated cross-neutralization activity with most CCHF VLPs, with 8A1 neutralizing all VLPs tested. Although binding studies suggest that none of the MAbs compete for the same epitope, combining 11E7, 30F7, or both 11E7 and 30F7 with 8A1 had no additive effect on increasing neutralization in this system. To confirm our findings from the VLP system, the 3 MAbs capable of strain cross-neutralization were confirmed to effectively neutralize 5 diverse CCHFV strains in vitro. Passaging CCHFV strains in the presence of sub-neutralizing concentrations of MAbs did not generate escape mutants resistant to subsequent neutralization. This study demonstrates the utility of the VLP system for screening neutralizing MAbs against multiple CCHFV strains, and provides the first evidence that a single MAb can effectively neutralize a number of diverse CCHFV strains in vitro, which may lead to development of future CCHF therapeutics. |
Insights into Reston virus spillovers and adaption from virus whole genome sequences.
Albarino CG , Wiggleton Guerrero L , Jenks HM , Chakrabarti AK , Ksiazek TG , Rollin PE , Nichol ST . PLoS One 2017 12 (5) e0178224 Reston virus (family Filoviridae) is unique among the viruses of the Ebolavirus genus in that it is considered non-pathogenic in humans, in contrast to the other members which are highly virulent. The virus has however, been associated with several outbreaks of highly lethal hemorrhagic fever in non-human primates (NHPs), specifically cynomolgus monkeys (Macaca fascicularis) originating in the Philippines. In addition, Reston virus has been isolated from domestic pigs in the Philippines. To better understand virus spillover events and potential adaption to new hosts, the whole genome sequences of representative Reston virus isolates were obtained using a next generation sequencing (NGS) approach and comparative genomic analysis and virus fitness analyses were performed. Nine virus genome sequences were completed for novel and previously described isolates obtained from a variety of hosts including a human case, non-human primates and pigs. Results of phylogenetic analysis of the sequence differences are consistent with multiple independent introductions of RESTV from a still unknown natural reservoir into non-human primates and swine farming operations. No consistent virus genetic markers were found specific for viruses associated with primate or pig infections, but similar to what had been seen with some Ebola viruses detected in the large Western Africa outbreak in 2014-2016, a truncated version of VP30 was identified in a subgroup of Reston viruses obtained from an outbreak in pigs 2008-2009. Finally, the genetic comparison of two closely related viruses, one isolated from a human case and one from an NHP, showed amino acid differences in the viral polymerase and detectable differences were found in competitive growth assays on human and NHP cell lines. |
Lassa and Ebola virus inhibitors identified using minigenome and recombinant virus reporter systems.
Welch SR , Guerrero LW , Chakrabarti AK , McMullan LK , Flint M , Bluemling GR , Painter GR , Nichol ST , Spiropoulou CF , Albarino CG . Antiviral Res 2016 136 9-18 Lassa virus (LASV) and Ebola virus (EBOV) infections are important global health issues resulting in significant morbidity and mortality. While several promising drug and vaccine trials for EBOV are ongoing, options for LASV infection are currently limited to ribavirin treatment. A major factor impeding the development of antiviral compounds to treat these infections is the need to manipulate the virus under BSL-4 containment, limiting research to a few institutes worldwide. Here we describe the development of a novel LASV minigenome assay based on the ambisense LASV S segment genome, with authentic terminal untranslated regions flanking a ZsGreen (ZsG) fluorescent reporter protein and a Gaussia princeps luciferase (gLuc) reporter gene. This assay, along with a similar previously established EBOV minigenome, was optimized for high-throughput screening (HTS) of potential antiviral compounds under BSL-2 containment. In addition, we rescued a recombinant LASV expressing ZsG, which, in conjunction with a recombinant EBOV reporter virus, was used to confirm any potential antiviral hits in vitro. Combining an initial screen to identify potential antiviral compounds at BSL-2 containment before progressing to HTS with infectious virus will reduce the amount of expensive and technically challenging BSL-4 containment research. Using these assays, we identified 6-azauridine as having anti-LASV activity, and demonstrated its anti-EBOV activity in human cells. We further identified 2'-deoxy-2'-fluorocytidine as having potent anti-LASV activity, with an EC50 value 10 times lower than that of ribavirin. |
Ebola Virus Disease Diagnostics, Sierra Leone: Analysis of Real-time Reverse Transcription-Polymerase Chain Reaction Values for Clinical Blood and Oral Swab Specimens.
Erickson BR , Sealy TK , Flietstra T , Morgan L , Kargbo B , Matt-Lebby VE , Gibbons A , Chakrabarti AK , Graziano J , Presser L , Flint M , Bird BH , Brown S , Klena JD , Blau DM , Brault AC , Belser JA , Salzer JS , Schuh AJ , Lo M , Zivcec M , Priestley RA , Pyle M , Goodman C , Bearden S , Amman BR , Basile A , Bergeron E , Bowen MD , Dodd KA , Freeman MM , McMullan LK , Paddock CD , Russell BJ , Sanchez AJ , Towner JS , Wang D , Zemtsova GE , Stoddard RA , Turnsek M , Guerrero LW , Emery SL , Stovall J , Kainulainen MH , Perniciaro JL , Mijatovic-Rustempasic S , Shakirova G , Winter J , Sexton C , Liu F , Slater K , Anderson R , Andersen L , Chiang CF , Tzeng WP , Crowe SJ , Maenner MJ , Spiropoulou CF , Nichol ST , Stroher U . J Infect Dis 2016 214 S258-S262 During the Ebola virus outbreak of 2013-2016, the Viral Special Pathogens Branch field laboratory in Sierra Leone tested approximately 26 000 specimens between August 2014 and October 2015. Analysis of the B2M endogenous control Ct values showed its utility in monitoring specimen quality, comparing results with different specimen types, and interpretation of results. For live patients, blood is the most sensitive specimen type and oral swabs have little diagnostic utility. However, swabs are highly sensitive for diagnostic testing of corpses. |
Virus fitness differences observed between two naturally occurring isolates of Ebola virus Makona variant using a reverse genetics approach.
Albarino CG , Guerrero LW , Chakrabarti AK , Kainulainen MH , Whitmer SL , Welch SR , Nichol ST . Virology 2016 496 237-243 During the large outbreak of Ebola virus disease that occurred in Western Africa from late 2013 to early 2016, several hundred Ebola virus (EBOV) genomes have been sequenced and the virus genetic drift analyzed. In a previous report, we described an efficient reverse genetics system designed to generate recombinant EBOV based on a Makona variant isolate obtained in 2014. Using this system, we characterized the replication and fitness of 2 isolates of the Makona variant. These virus isolates are nearly identical at the genetic level, but have single amino acid differences in the VP30 and L proteins. The potential effects of these differences were tested using minigenomes and recombinant viruses. The results obtained with this approach are consistent with the role of VP30 and L as components of the EBOV RNA replication machinery. Moreover, the 2 isolates exhibited clear fitness differences in competitive growth assays. |
Assessment of Inhibitors of Pathogenic Crimean-Congo Hemorrhagic Fever Virus Strains Using Virus-Like Particles.
Zivcec M , Metcalfe MG , Albarino CG , Guerrero LW , Pegan SD , Spiropoulou CF , Bergeron E . PLoS Negl Trop Dis 2015 9 (12) e0004259 Crimean-Congo hemorrhagic fever (CCHF) is an often lethal, acute inflammatory illness that affects a large geographic area. The disease is caused by infection with CCHF virus (CCHFV), a nairovirus from the Bunyaviridae family. Basic research on CCHFV has been severely hampered by biosafety requirements and lack of available strains and molecular tools. We report the development of a CCHF transcription- and entry-competent virus-like particle (tecVLP) system that can be used to study cell entry and viral transcription/replication over a broad dynamic range (~4 orders of magnitude). The tecVLPs are morphologically similar to authentic CCHFV. Incubation of immortalized and primary human cells with tecVLPs results in a strong reporter signal that is sensitive to treatment with neutralizing monoclonal antibodies and by small molecule inhibitors of CCHFV. We used glycoproteins and minigenomes from divergent CCHFV strains to generate tecVLPs, and in doing so, we identified a monoclonal antibody that can prevent cell entry of tecVLPs containing glycoproteins from 3 pathogenic CCHFV strains. In addition, our data suggest that different glycoprotein moieties confer different cellular entry efficiencies, and that glycoproteins from the commonly used strain IbAr10200 have up to 100-fold lower ability to enter primary human cells compared to glycoproteins from pathogenic CCHFV strains. |
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