BackgroundSeveral variants of the SARS-CoV-2 have been documented globally during the current COVID-19 pandemic. The N501Y, 69-70del, K417N, and E484K SARS-CoV-2 mutations have been documented among the most relevant due to their potential pathogenic biological effects. This study aimed to design, validate, and propose a fast real-time RT-qPCR assay to detect SARS-CoV-2 mutations with possible clinical and epidemiological relevance in the Mexican population.MethodsTargeting spike (S) gene mutations of SARS-CoV-2 (N501Y, 69-70del, K417N, and E484K), specific primers, and probes for three specific quantitative reverse transcription PCR (RT-qPCR) assays were designed, and validated using Sanger sequencing. These assays were applied in clinical samples of 1060 COVID-19 patients from Jalisco Mexico.ResultsIn silico analyzes showed high specificity of the three assays. Amplicons of samples were confirmed through sequencing. The screening of samples of COVID-19 patients allowed the identification of the E484K mutation in nine individuals and the identification of P.2 Brazilian variant in Mexico.ConclusionThis work provides low-cost RT-qPCR assays for rapid screening and molecular surveillance of mutations with potential clinical impact. This strategy allowed the detection of E484K mutation and P.2 variant for the first time in samples from the Mexican population.
Background: Diarrhoeal diseases constitute a major public health problem, particularly in the developing world, where the rate of mortality and morbidity is very high. The purpose of this study was to conduct a 2 years and 3 months study in order to determine the prevalence of five enteropathogen diarrheogenic agents in Mexico City.
FIZ15 bacteriophage, from a human clinical isolate of Pseudomonas aeruginosa, causes lysogenic conversion in the P. aeruginosa strain PAO1. The prophage-conferred phenotypes are: (1) increased resistance to phagocytosis by mouse peritoneal macrophages; (2) increased resistance to killing by normal human serum, and (3) increased adhesion to human buccal epithelial cells. These phenotypes are related to the prophage-induced change at the level of its own bacterial receptor, which appears to be the O-antigen.
Avibacterium paragallinarum, the causative agent of infectious coryza, releases extracellular membrane vesicles (MVs), containing immunogenic proteins, proteases, putative RTX proteins, haemagglutinin, and nucleic acids, into the medium. MVs ranging 50-300 nm in diameter were observed by electron microscopy. They contained immunogenic proteins in the range of 20-160 kDa, detected using vaccinated or experimentally infected chicken sera raised against Av. paragallinarum, but not in pooled sera from specific pathogen-free chickens. Proteolytic activity was not detected in MVs through zymograms; however, immune recognition of high molecular mass bands was observed by Western blotting using an antiprotease serum against Actinobacillus pleuropneumoniae serotype 1 purified protease, suggesting its presence. MVs agglutinated glutaraldehyde-fixed chicken red blood cells indicating the presence of haemagglutinating antigens. Nucleic acids were also detected inside MVs. Avibacterium paragallinarum releases MVs containing putative virulence factors, which could be important in the pathogenesis of infectious coryza.
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