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We report extensively drug-resistant (XDR) Shigella sonnei infection in an immunocompromised patient in Texas, USA. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry failed to identify XDR Shigella, but whole-genome sequencing accurately characterized the strain. First-line antimicrobials are not effective against emerging XDR Shigella. Fosfomycin, carbapenems, and tigecycline are potential alternatives.
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Antiinfecciosos , Disentería Bacilar , Shigella , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Antiinfecciosos/farmacología , Disentería Bacilar/diagnóstico , Disentería Bacilar/tratamiento farmacológico , Disentería Bacilar/epidemiología , Pruebas de Sensibilidad Microbiana , Shigella sonnei/genética , Estados Unidos/epidemiologíaRESUMEN
SARS-CoV-2 pandemic continues with emergence of new variants of concerns. These variants are fueling the third and fourth waves of pandemic across many nations. Here we describe the new emerging variants of SARS-CoV-2 and why they have enhanced infectivity and possess the ability to evade immunity.
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The coronavirus disease COVID-19 has spread throughout the world and has been declared as a pandemic by the World Health Organization on March 11th, 2020. The COVID-19 is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). One possible mode of virus transmission is through surfaces in the healthcare settings. This paper reviews currently used disinfection strategies to control SARS-CoV-2 at the healthcare facilities. Chemical disinfectants include hypochlorite, peroxymonosulfate, alcohols, quaternary ammonium compounds, and hydrogen peroxide. Advanced strategies include no-touch techniques such as engineered antimicrobial surfaces and automated room disinfection systems using hydrogen peroxide vapor or ultraviolet light.
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The novel coronavirus disease (COVID-19) has rapidly spread across the world and was subsequently declared as a pandemic in 2020. To overcome this public health challenge, comprehensive understanding of the disease transmission is urgently needed. Recent evidences suggest that the most common route of transmission for SARS-CoV-2 is likely via droplet, aerosol, or direct contact in a person-to-person encounter, although the possibility of transmission via fomites from surfaces cannot be ruled out entirely. Environmental contamination in COVID-19 patient rooms is widely observed due to viral shedding from both asymptomatic and symptomatic patients, and SARS-CoV-2 can survive on hospital surfaces for extended periods. Sequence of contact events can spread the virus from one surface to the other in a hospital setting. Here, we review the studies related to viral shedding by COVID-19 patients that can contaminate surfaces and survival of SARS-CoV-2 on different types of surfaces commonly found in healthcare settings, as well as evaluating the importance of surface to person transmission characteristics. Based on recent evidences from the literature, decontamination of hospital surfaces should constitute an important part of the infection control and prevention of COVID-19.
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The differential regulation of COX17, COX19 and COX23 mRNAs by the nonsense-mediated mRNA decay (NMD) pathway was investigated. The NMD pathway regulates mRNAs that aberrantly terminate translation. This includes mRNAs harboring premature translation termination codons and natural mRNAs. Most natural mRNAs regulated by NMD encode fully functional proteins involved in various cellular processes. However, the cause and targeting of most of these mRNAs by the pathway is not understood. Analysis of a set of mRNAs involved in copper homeostasis showed that a subset of these mRNAs function in mitochondrial copper homeostasis. Here, we examined the regulation of COX17, COX19 and COX23 mRNAs by NMD. These mRNAs encode homologous mitochondrial proteins involved in metallation of cytochrome c oxidase. We found that COX17, COX19 and COX23 mRNAs are differentially regulated by NMD depending on environmental copper levels. A long 3'-UTR contributes to the direct regulation of COX19 mRNA by the pathway. Alternatively, COX23 mRNA contains a long 3'-UTR, but is indirectly regulated by the pathway under two conditions tested here. Analysis of the functionality of the NMD targeting features in COX23 mRNA showed that the COX23 3'-UTR is sufficient to trigger NMD. The regulation of mRNAs involved in mitochondrial copper metabolism by NMD is physiologically significant because excess copper enhances growth of NMD mutants on a non-fermentable carbon source. These findings suggest that regulation of mRNAs encoding homologous proteins by NMD can be differential depending on environmental copper levels. Furthermore, these findings suggest copper ion homeostatic mechanisms in the mitochondria occur at the mRNA level via the NMD pathway.
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Proteínas de Transporte de Catión/genética , Regulación Fúngica de la Expresión Génica , Chaperonas Moleculares/genética , Degradación de ARNm Mediada por Codón sin Sentido , ARN Mensajero/genética , Proteínas de Saccharomyces cerevisiae/genética , Regiones no Traducidas 3' , Proteínas de Transporte de Catión/metabolismo , Cobre/metabolismo , Cobre/farmacología , Proteínas Transportadoras de Cobre , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Chaperonas Moleculares/metabolismo , Degradación de ARNm Mediada por Codón sin Sentido/efectos de los fármacos , ARN Mensajero/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismoAsunto(s)
COVID-19 , SARS-CoV-2 , Secuencia de Bases , COVID-19/diagnóstico , Genoma Viral , Humanos , ARN Viral/genética , SARS-CoV-2/genéticaRESUMEN
The SARS-CoV-2 virus steadily evolves, and numerous antigenically distinct variants have emerged over the past three years. Tracking the evolution of the virus would help us understand the process that generates the diverse variants and predict the future evolutionary trajectory of SARS-CoV-2. Here, we report the evolutionary trajectory of a unique Omicron lineage identified during an outbreak investigation that occurred in a residence unit in the healthcare system. The new lineage had four distinct non-synonymous and two distinct synonymous mutations apart from its parental lineage. Since this lineage of virus was exclusively found during the outbreak, we were able to track the detailed evolutionary history of the entire lineage along the transmission path. Furthermore, we estimated the evolutionary rate of the SARS-CoV-2 Omicron variant from the analysis of the evolution of the lineage. This new Omicron sub-lineage acquired 3 mutations in a 12-day period, and the evolutionary rate was estimated as 3.05 × 10-3 subs/site/year. This study provides more insight into an ever-evolving virus.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiología , Brotes de Enfermedades , Hospitales , MutaciónRESUMEN
We investigated a skin abscess caused by Trueperella bernardiae in a patient with comorbidities. Initial empirical therapy with Clindamycin did not yield a response, and follow-up culture revealed the presence of T. bernardiae through MALDI-TOF and NGS. Since no CLSI or FDA breakpoints have been published for this strain, resistant gene screening of the genetic sequence showed the presence of the erm(X) gene (with 95 % identity). This gene confers resistance to erythromycin, clindamycin, lincomycin, pristinamycin, quinupristin, and virginiamycin. Subsequent therapy with oral amoxicillin/clavulanate led to complete healing.
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We report a large outbreak of severe acute respiratory syndrome coronavirus 2 in a residential living facility. Measurements of carbon dioxide levels, aerosol particle clearance, and airflow were used to identify and remediate areas with suboptimal ventilation. A simple intervention involving continuous operation of bathroom fans was effective in significantly improving ventilation in resident rooms.
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BACKGROUND: Wastewater surveillance for SARS-CoV-2 has been used widely in the United States for indication of community incidence during the COVID-19 pandemic, but less is known about the feasibility of its use on a building level in nursing homes to provide early warning and prevent transmission. METHODS: A pilot study was conducted at 8 Department of Veterans Affairs nursing homes across the United States to examine operational feasibility. Wastewater from the participating facilities was sampled daily during the week for 6 months (January 11, 2021-July 2, 2021) and analyzed for SARS-CoV-2 genetic material. Wastewater results were compared to new SARS-CoV-2 infections in nursing home residents and employees to determine if wastewater surveillance could provide early warning of a COVID-19-positive occupant. RESULTS: All 8 nursing homes had wastewater samples positive for SARS-CoV-2 and COVID-19-positive occupants. The sensitivity of wastewater surveillance for early warning of COVID-19-positive residents was 60% (3/5) and for COVID-19-positive employees was 46% (13/28). CONCLUSIONS: Wastewater surveillance may provide additional information for reinforcing infection control practices and lead to preventing transmission in a setting with high-risk residents. The low sensitivity for early warning in this real-world pilot highlights limitations and insights for applicability in buildings.
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COVID-19 , Casas de Salud , SARS-CoV-2 , Aguas Residuales , Humanos , COVID-19/prevención & control , COVID-19/epidemiología , COVID-19/diagnóstico , COVID-19/transmisión , Proyectos Piloto , Aguas Residuales/virología , SARS-CoV-2/aislamiento & purificación , Estados Unidos/epidemiologíaRESUMEN
Background: Community-associated Clostridioides difficile infection is a major public health hazard to adults and older children. Infants frequently excrete toxigenic C difficile asymptomatically in their stool, but their importance as a community reservoir of C difficile is uncertain. Methods: Families of healthy infants were recruited at the baby's 4-month well child visit and were followed longitudinally until the baby was approximately 9 months old. Babies and mothers submitted stool or rectal swabs every 2 weeks that were cultivated for C difficile; fathers' participation was encouraged but not required. Clostridioides difficile isolates were strain-typed by fluorescent polymerase chain reaction ribotyping and by core genome multilocus sequence typing, and the number of families in whom the same strain was cultivated from >1 family member ("strain sharing") was assessed. Results: Thirty families were enrolled, including 33 infants (3 sets of twins) and 30 mothers; 19 fathers also participated. Clostridioides difficile was identified in 28 of these 30 families over the course of the study, and strain sharing was identified in 17 of these 28. In 3 families, 2 separate strains were shared. The infant was involved in 17 of 20 instances of strain sharing, and in 13 of these, the baby was identified first, with or without a concomitantly excreting adult. Excretion of shared strains usually was persistent. Conclusions: Clostridioides difficile strain sharing was frequent in healthy families caring for an infant, increasing the likelihood that asymptomatically excreting babies and their families represent a reservoir of the organism in the community.
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Background: Understanding routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in long-term care facilities is essential for the development of effective control measures. Methods: Between March 1, 2020, and August 31, 2023, we identified coronavirus disease 2019 (COVID-19) cases among residents and employees in a Veterans Affairs community living center that conducted routine screening for asymptomatic COVID-19. Contact tracing was conducted to identify suspected transmission events, and whole genome sequencing was performed to determine the relatedness of SARS-CoV-2 samples. Results: During the 42-month study period, 269 cases of COVID-19 were diagnosed, including 199 employees and 70 residents. A total of 48 (24.1%) employees and 30 (42.9%) residents were asymptomatic. Sequencing analysis provided support for multiple events in which employees transmitted SARS-CoV-2 to co-workers and residents. There was 1 episode of likely transmission of SARS-CoV-2 from one resident to another resident, but no documented transmissions from residents to employees. Conclusions: Transmission of SARS-CoV-2 in the community living center predominantly involved transmission from employees to co-workers and residents. There is a need for improved measures to prevent transmission of SARS-CoV-2 by healthcare personnel.
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Campylobacter coli (C. coli) is a gram negative, non-spore forming, mobile, curved, or spiral-shaped rod organisms and one of the most common gastrointestinal human pathogens. Campylobacter very rarely causes bacteremia. However, there are reports of bloodstream infection of C. coli and most of the Campylobacterbacteremia have been found among immunocompromised patients. In this study, a case of C. coli blood stream infection that was associated with diarrhea in an immunocompetent patient.
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The Cepheid Xpert® Xpress SARS-CoV-2 assay is 1 of the several real-time reverse transcription polymerase chain reaction (RT-PCR) assays that received Emergency Use Authorization from the United States Food and Drug Administration (FDA) for detection of SARS-CoV-2. Here we report 4 SARS-CoV-2 samples that were reported as presumptive positives on the Cepheid platform while reported as positives on alternative RT-PCR platforms. Whole genome sequencing indicated that the samples were Delta variants and had point mutations in the N gene which potentially interfered with SARS-CoV-2 detection. Two types of point mutations were found in these samples in the US CDC 2019-nCoV Real time PCR N2 Probe region: C29203T and C29200T. C29203T is a novel point mutation, and C29200T has not been previously reported in the Delta variants. This underlines the fact that mutations in the real-time RT-PCR assay target region could hinder accurate detection of SARS-CoV-2.
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COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Prueba de COVID-19 , Humanos , Mutación , SARS-CoV-2/genética , Sensibilidad y Especificidad , Estados UnidosRESUMEN
OBJECTIVES: No-touch disinfection systems like xenon- or mercury-based ultraviolet (UV) are now commonly being used for hospital room disinfection. However, serial exposure to UV light can potentially lead to the development of bacterial resistance. We sought to determine whether UV resistance develops due to serial exposure to UV light using 3 epidemiologically important multidrug-resistant microbial strains. METHODS: Methicillin-resistant Staphylococcus aureus (MRSA), carbapenemase-producing Klebsiella pneumoniae (KPC) and metallo-ß-lactamase-producing Klebsiella pneumoniae (MBL) were serially exposed to 25 growth-irradiation cycles of UV produced by a xenon-based UV (Xe-UV) lamp for 5 minutes or a mercury-based UV (Hg-UV) lamp for 10 minutes. After each UV exposure cycle, the surviving colony-forming units (CFUs) were measured and compared with the initial inoculum of each cycle for each strain, respectively. RESULTS: In each cycle, Ë1-10 million of MRSA, KPC, and MBL were used to test the effect of UV irradiation. Postexposure colony counts remained low (3-100 colonies) throughout the 25 serial exposures to both xenon- and mercury-based UV. The log-kill rate after each exposure showed no changes following UV disinfection by Xe-UV. The MRSA log-kill rate increased after repeated exposure to Hg-UV unlike KPC and MBL K. pneumoniae, which did not change. Whole-genome sequencing (WGS) analyses performed on these 3 strains demonstrated no significant genetic changes after multiple UV irradiation cycles. CONCLUSIONS: Exposure of multidrug-resistant bacteria to UV produced from 2 different UV sources did not engender UV resistance after 25 serial exposures, as demonstrated by WGS analysis; thus, UV disinfection is unlikely to generate UV-resistant hospital flora.
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Staphylococcus aureus Resistente a Meticilina , Rayos Ultravioleta , Desinfección , Farmacorresistencia Bacteriana Múltiple/genética , Genómica , Humanos , Klebsiella pneumoniae/genética , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/efectos de la radiaciónRESUMEN
Persistent severe acute respiratory syndrome coronavirus 2 infection is difficult to treat. Here, we report a case of 5-month persistent coronavirus disease 2019 in an immunocompromised patient who was successfully treated with 30 consecutive days of remdesivir. Prolonged remdesivir infusion with concurrent cycle threshold monitoring might provide a potential solution to cure these patients with difficult-to-treat infections.
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Identification of clinical bacterial isolates is an essential first step to provide guidelines for treatment of pathogenic bacterial infection. Infection occurred in a laceration along the medial aspect of left upper arm of a 71-year-old female. Conventional biochemical testing and MALDI-TOF MS identification failed to correctly identify a bacterial isolate. Using whole genome sequencing, the isolate was identified as Lelliottia nimipressuralis. WGS can overcome the limitations of conventional phenotypic and molecular identification methods and successfully identified a rare pathogen. This case is the first report of a human infection of L. nimipressuralis.
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Infecciones por Enterobacteriaceae/diagnóstico , Enterobacteriaceae/aislamiento & purificación , Tipificación Molecular , Secuenciación Completa del Genoma , Infección de Heridas/diagnóstico , Anciano , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/terapia , Femenino , Genoma Bacteriano/genética , Humanos , Pruebas de Sensibilidad Microbiana , Resultado del Tratamiento , Infección de Heridas/microbiología , Infección de Heridas/terapiaRESUMEN
Extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae strain 9120005127 was isolated from a wound infection. We describe the draft genome sequence and antibiotic susceptibility of this strain.
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BACKGROUND: Health care personnel and patients are at risk to acquire severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in health care settings, including in outpatient clinics and ancillary care areas. METHODS: Between May 1, 2020, and January 31, 2021, we identified clusters of 3 or more coronavirus disease 2019 (COVID-19) cases in which nosocomial transmission was suspected in a Veterans Affairs health care system. Asymptomatic employees and patients were tested for SARS-CoV-2 if they were identified as being at risk through contact tracing investigations; for 7 clusters, all personnel and/or patients in a shared work area were tested regardless of exposure history. Whole-genome sequencing was performed to determine the relatedness of SARS-CoV-2 samples from the clusters and from control employees and patients. RESULTS: Of 14 clusters investigated, 7 occurred in community-based outpatient clinics, 1 in the emergency department, 3 in ancillary care areas, and 3 on hospital medical/surgical wards that did not provide care for patients with known COVID-19 infection. Eighty-one of 82 (99%) symptomatic COVID-19 cases and 31 of 35 (89%) asymptomatic cases occurred in health care personnel. Sequencing analysis provided support for several transmission events between coworkers and in 2 cases supported transmission from health care personnel to patients. There were no documented transmissions from patients to personnel. CONCLUSIONS: Clusters of COVID-19 with nosocomial transmission predominantly involved health care personnel and often occurred in outpatient clinics and ancillary care areas. There is a need for improved measures to prevent transmission of SARS-CoV-2 by health care personnel in inpatient and outpatient settings.
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AIM: To study the effect of renalase peptide, RP-220, on cell viability of human corneal epithelial cells after alkali insult. METHODS: A dose-response relationship between cell viability and exposure to NaOH solution were characterized using cultured human corneal epithelial cells. Viability of corneal epithelial cells was determined using commercially available MTT and CyQUANT® assays. RESULTS: At a concentration of 6 mmol/L, insult with NaOH leads to reduced corneal epithelial cell viability by approximately 30%. This reduced viability was prevented by treating the cells after initial insult with the 20-amino acid renalase derived peptide (RP-220). CONCLUSION: RP-220 has a pro-survival role for RP-220 following alkaline insult to corneal epithelial cells.