Tropical Medicine Commons^™

Phenotypic Diversity Of Type Iii Secretion System Activity In Enteropathogenic Escherichia Coli Clinical Isolates, Carmen A Contreras, Tracy H Hazen, Carmen Guadarrama, Ramón Cervantes-Rivera, Theresa J Ochoa, Pablo Vinuesa, David A Rasko, Jose L Puente

Faculty, Staff and Student Publications

Introduction. Enteropathogenic Escherichia coli (EPEC) strains pose a significant threat as a leading cause of severe childhood diarrhoea in developing nations. EPEC pathogenicity relies on the type III secretion system (T3SS) encoded by the locus of enterocyte effacement (LEE), facilitating the secretion and translocation of bacterial effector proteins.

Gap Statement. While the regulatory roles of PerC (plasmid-encoded regulator) and GrlA (global regulator of LEE-activator) in ler expression and LEE gene activation are well-documented in the EPEC prototype strain E2348/69, understanding the variability in LEE gene expression control mechanisms among clinical EPEC isolates remains an area requiring further investigation.

Aim. This …

Class 1 And 2 Integrons In Escherichia Coli Strains Isolated From Diarrhea And Bacteremia In Children Less Than 2 Years Of Age From Peru, Maribel Riveros, Maria J Pons, David Durand, Theresa J Ochoa, Joaquim Ruiz

Faculty, Staff and Student Publications

Class 1 and Class 2 integrons are mobilizable elements able to carry a variety of antibiotic resistance determinants. In the present study, Class 1 and 2 integrons present in 355 pathogenic Escherichia coli (285 diarrheagenic, of these 129 were enteropathogenic, 90 enteroaggregative, 66 enterotoxigenic, and 70 bacteremic) isolated from healthy and ill children under age 5 from periurban areas of Lima, Peru, were characterized. The presence of integrase 1 and 2 was established by polymerase chain reaction (PCR), and variable regions were grouped by PCR-restriction fragment length polymorphism and subsequent sequencing. Antimicrobial resistance was established by disk diffusion. Ninety-seven isolates …