ABSTRACT
While monitoring the presence of antibiotic resistance in municipal wastewater bacteria from Mexico City, five Escherichia coli isolates were found to be resistant to carbapenems, antibiotics of "last resort" used mostly in hospitals. Further analysis revealed that these carbapenem-resistant isolates carried the gene encoding a metallo-beta-lactamase, NDM-5. The gene was found to be beared by a large, â¼145 kb conjugative plasmid, which also carries putative genes encoding resistance to sulfonamides, trimethoprim, tetracycline, ciprofloxacin, and chloramphenicol (although no phenotypic chloramphenicol resistance was detected) and quaternary-ammonium compounds. The plasmid also carried gene mobility determinants, such as integron integrase and two transposases. In addition to the direct public health threat posed by the presence of such multi-resistant organisms in wastewater released into the environment and used for crop irrigation; it is particularly concerning that carbapenem-resistant E. coli is rather rare in Mexican hospitals (<1%), but was found in small, 100 mL samples of municipal wastewater. This suggests that these organisms are under-reported by clinical microbiology laboratories, underlining the usefulness of wastewater monitoring, or that there is an unknown source of such carbapenem-resistant organisms that are being dumped into the wastewater. The source of these bacteria must be assessed and controlled to prevent further spread of this multi-resistance plasmid among other environmental and clinical microorganisms.
Subject(s)
Escherichia coli/isolation & purification , Sewage/microbiology , beta-Lactamases , Anti-Bacterial Agents/pharmacology , Escherichia coli/genetics , Escherichia coli Infections , Humans , Mexico , Microbial Sensitivity Tests , beta-Lactamases/geneticsABSTRACT
Helicobacter pylori is a bacteria with high genome plasticity that has been associated with diverse gastric pathologies. The genetic diversity of this bacteria has limited the characterization of virulence factors associated with gastric cancer (GC). To identify potentially helpful disease biomarkers, we compared 38 complete genomes and 108 draft genomes of H. pylori isolated worldwide from patients with diverse gastric pathologies and 53 draft genomes of H. pylori isolated from Mexican patients with GC, intestinal metaplasia, gastritis, peptic ulcer, and dyspepsia. H. pylori strains isolated from GC were 3-11 times more likely to harbor any of seven genes encoded within an integrative and conjugative element (ICE) than H. pylori isolated from subjects with other gastric pathologies. We tested the cytopathic effects on AGS cells of selected H. pylori strains with known cytotoxin-associated gene pathogenicity island (cag-PAI) and ICE status (H. pylori strains 29CaP, 29CaCe, 62A9, 7C, 8822, and 26695) and the histopathological damage of H. pylori 29CaP and 62A9 in a mouse model. H. pylori 29CaP, which harbors a complete ICEHptfs3 but lacks cag-PAI, elicited distinctive morphology changes and higher histopathological scores compared with other H. pylori strains carrying cag-PAI and hybrid ICE with incomplete TFSS. The presence of intact segments of ICE regions might be a risk factor to develop GC that needs to be addressed in future studies.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Stomach Neoplasms , Animals , Antigens, Bacterial , Bacterial Proteins/genetics , Helicobacter pylori/genetics , Humans , Mexico , Mice , Virulence Factors/geneticsABSTRACT
SARS-CoV-2 is a new virus causing an infection and illness referred to as COVID-19. As of July 7th of 2020, this virus has been associated worldwide with over 12 million of infections and more than 550,000 deaths. Transmission rate of SARS-CoV-2 in the population is high, and the origin of this coronavirus appears to be related to some species of the bat. However, scientific information related to the pathogenesis, and immune response to COVID-19 changes rapidly, which is why the aim of this work is to provide recent information related to an exacerbated inflammatory immune response which causes multiorgan failure and patient death. The timely identification of infected individuals will be key to stop the spread of infection and in severe cases to establish optimal strategies to reduce the risk of death in critically ill patients. In this review, we have considered the latest findings collected from the clinical studies, diagnostic tests, and treatment for COVID-19. Information presented here will help to the better understanding of this disease.
El SARS-CoV-2 es un nuevo virus que causa la enfermedad denominada COVID-19. Este virus ha generado hasta el 7 de julio de 2020 12 millones de contagios y más de 550 000 muertes en todo el mundo. Se sabe que la tasa de transmisión es muy alta y su origen está relacionado con una especie del murciélago. Sin embargo, la información científica relacionada con la COVID-19 cambia rápidamente, por lo que este trabajo tiene como objetivo aportar información reciente y relacionada con el desarrollo de la respuesta inflamatoria exacerbada, que con frecuencia causa falla orgánica múltiple y muerte del paciente. La rápida identificación de los individuos infectados es clave para detener la propagación de esta enfermedad y en los casos más graves establecer estrategias que permitan la reducción de la infección y del riesgo de muerte. En esta revisión, hemos considerado los últimos hallazgos recopilados de los estudios clínicos, pruebas diagnósticas y de tratamiento para COVID-19. La información presentada en este trabajo contribuirá al entendimiento de esta enfermedad.
ABSTRACT
Helicobacter pylori-induced gastritis is a risk factor for developing gastric pathologies. Here, we report the complete genome sequence of a multidrug-resistant H. pylori strain isolated from a chronic gastritis patient in Mexico City, Mexico. Nonvirulent VacA and cag-pathogenicity island (PAI) genotypes were found, but the presence of a potential mobilizable plasmid carrying an IS605 element is of outstanding interest.
ABSTRACT
Helicobacter pylori infection is a risk factor for the development of gastric cancer and other gastroduodenal diseases. We report here the complete genome sequence of H. pylori strain 29CaP, isolated from a Mexican patient with gastric cancer. The genomic data analysis revealed a cag-negative H. pylori strain that contains a prophage sequence.
