ABSTRACT
Carbapenem-resistant Enterobacterales (CRE) is a critical public health problem in South America, where the prevalence of NDM metallo-betalactamases has increased substantially in recent years. In this study, we used whole genome sequencing to characterize a multidrug-resistant (MDR) Klebsiella pneumoniae (UCO-361 strain) clinical isolate from a teaching hospital in Chile. Using long-read (Nanopore) and short-read (Illumina) sequence data, we identified a novel un-typeable megaplasmid (314,976 kb, pNDM-1_UCO-361) carrying the blaNDM-1 carbapenem resistance gene within a Tn3000 transposon. Strikingly, conjugal transfer of pNDM-1_UCO-361 plasmid only occurs at low temperatures with a high frequency of 4.3 × 10-6 transconjugants/receptors at 27 °C. UCO-361 belonged to the ST1588 clone, previously identified in Latin America, and harbored aminoglycoside, extended-spectrum ß-lactamases (ESBLs), carbapenem, and quinolone-resistance determinants. These findings suggest that blaNDM-1-bearing megaplasmids can be adapted to carriage by some K. pneumoniae lineages, whereas its conjugation at low temperatures could contribute to rapid dissemination at the human-environmental interface.
ABSTRACT
In December 2019, a case of atypical pneumonia was reported in Wuhan, China. It was named COVID-19 and caused by SARS-CoV-2. In a few months, scientific groups around the world developed vaccines to reduce the disease's severity. The objective was to evaluate the humoral and cellular immune response post immunization with three different vaccination schedules administered in Chile until January 2022. Sixty volunteers were recruited with a three-dose schedule, who had no history of infection nor close contact with a positive patient. IgG against the spike antigenic domain was detected, and the neutralization capacity against two groups of variants, Original/Alpha and Beta/Gamma, was also measured. Finally, the cellular response with interferon release was measured through IGRA. Results showed that there were significant differences in the neutralizing antibodies for the original and alpha variant when comparing three Comirnaty doses with Coronavac and Vaxzevria. A high number of reactive subjects against the different SARS-CoV-2 variants, alpha, gamma, and delta, were observed, with no significant differences between any of the three schemes, confirming the existence of a cellular immune response against SARS-CoV-2. In conclusion, the three vaccine schemes generated a cellular immune response in these volunteers.
ABSTRACT
BACKGROUND: The SARS-CoV-2 outbreak originated in the Hubei province in China spread rapidly throughout the world during the first months of 2020. On March 3, the first case was reported in Chile; at 17 days the first case of COVID-19 healthcare worker (HCW) was notified in our institution. AIM: To describe the demographic characteristics and the incidence of SARS-CoV-2 infection in the HCW of a university hospital in Chile. MATERIAL AND METHOD: Retrospective study of SARS-CoV-2 infection on HCW in a university hospital between March 1 and May 31, 2020. RESULTS: There were 273 positive cases. In the period under study, we had an incidence of 5.8%. When we separated the cases into clinical and non-clinical personnel, it was observed that their incidences were practically identical (5.8 vs. 5.7% p = 0.9430). 88% of the officials were oligosymptomatic or asymptomatic at the beginning of the clinical presentation and only 12% had a fever before the medical consultation. CONCLUSION: The incidence reported in the study was around 5 times that reported in Wuhan. If we apply the current definition of cases, we would lose 4 out of 5 cases. 88% of HPW did not present criteria to be considered suspicious, so it would be advisable in HCW to eliminate fever as a criterion to improve the research and trace their contacts on time.
Subject(s)
COVID-19 , SARS-CoV-2 , Chile/epidemiology , Health Personnel , Hospitals, University , Humans , Retrospective StudiesABSTRACT
INTRODUCCIÓN: El brote de SARS-CoV-2 originado en la provincia de Hubei en la República Popular China, se fue extendiendo aceleradamente en el mundo durante los primeros meses del año 2020. El 3 de marzo se notificó el primer caso en Chile; a los 17 días se notificó el primer caso de un Personal de Salud (PS) COVID-19 en nuestra institución. OBJETIVO: Describir las características demográficas y la incidencia de infección por SARS-CoV-2 en el PS de un hospital universitario de alta complejidad. MATERIAL Y MÉTODO: Estudio retrospectivo de los casos de infección por SARS-CoV-2 del PS entre el 1 de marzo y 31 de mayo de 2020. RESULTADOS: Hubo 273 casos positivos, con una incidencia de 5,8% en el período en estudio. Al dividir los casos en personal clínico y no clínico se observó que sus incidencias fueron prácticamente idénticas (5,8 vs 5,7% p = 0,9430). El 88% de los funcionarios fue oligo-sintomático o asintomático al inicio del cuadro clínico y sólo 12% tuvo fiebre antes de la consulta médica. CONCLUSIÓN: La incidencia reportada en el estudio fue alrededor de cinco veces la reportada en Wuhan. Al aplicar la definición de casos vigente, se perderían cuatro de cada cinco casos. Destaca que 88% del PS no presentaba criterios para ser considerado sospechoso, por lo que sería recomendable en el PS eliminar la fiebre como criterio para mejorar la pesquisa y trazar sus contactos de forma oportuna.
BACKGROUND: The SARS-CoV-2 outbreak originated in the Hubei province in China spread rapidly throughout the world during the first months of 2020. On March 3, the first case was reported in Chile; at 17 days the first case of COVID-19 healthcare worker (HCW) was notified in our institution. AIM: To describe the demographic characteristics and the incidence of SARS-CoV-2 infection in the HCW of a university hospital in Chile. MATERIAL AND METHOD: Retrospective study of SARS-CoV-2 infection on HCW in a university hospital between March 1 and May 31, 2020. RESULTS: There were 273 positive cases. In the period under study, we had an incidence of 5.8%. When we separated the cases into clinical and non-clinical personnel, it was observed that their incidences were practically identical (5.8 vs. 5.7% p = 0.9430). 88% of the officials were oligosymptomatic or asymptomatic at the beginning of the clinical presentation and only 12% had a fever before the medical consultation. CONCLUSION: The incidence reported in the study was around 5 times that reported in Wuhan. If we apply the current definition of cases, we would lose 4 out of 5 cases. 88% of HPW did not present criteria to be considered suspicious, so it would be advisable in HCW to eliminate fever as a criterion to improve the research and trace their contacts on time.
