Mônica A. M. Vieira

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To analyze whether Escherichia coli strains that cause urinary tract infections (UPEC) share virulence characteristics with the diarrheagenic E. coli (DEC) pathotypes and to recognize their genetic diversity, 225 UPEC strains were examined for the presence of various properties of DEC and UPEC (type of interaction with HeLa cells, serogroups and presence of(More)
Enteroaggregative Escherichia coli (EAEC) strains have been implicated as emerging aetiological agents of diarrhoea worldwide. In the present study, 43 EAEC strains were serotyped and characterized according to random amplification of polymorphic DNA profiles, PFGE, multilocus enzyme electrophoresis (MLEE) and the presence of putative virulence genes (hly,(More)
The enteropathogenic Escherichia coli (EPEC) pathotype is currently divided into two groups, typical EPEC (tEPEC) and atypical EPEC (aEPEC). The property that distinguishes these two groups is the presence of the EPEC adherence factor plasmid, which is only found in tEPEC. aEPEC strains are emerging enteropathogens that have been detected worldwide. Herein,(More)
Atypical enteropathogenic Escherichia coli (EPEC) comprise an important group of paediatric pathogens. Atypical EPEC have reservoirs in farm and domestic animals where they can be either commensal or pathogenic; serogroup O26 is dominant in humans and animals. Central to intestinal colonization by EPEC is the translocation of the type III secretion system(More)
The aim of this work was to verify the presence of seven virulence factors (ST, LT, eae, stx(1), stx(2), INV and EAEC) among Escherichia coli strains isolated from healthy humans, bovines, chickens, sheep, pigs and goats, from two sewage treatment plants and from the Tietê River. We have found a high prevalence of eae, stx(1) and stx(2) in ruminants. The(More)
Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially(More)
In rabbit ligated ileal loops, two atypical enteropathogenic Escherichia coli (aEPEC) strains, 3991-1 and 0421-1, intimately associated with the cell membrane, forming the characteristic EPEC attachment and effacement lesion of the brush border, induced a mucous hypersecretion, whereas typical EPEC (tEPEC) strain E2348/69 did not. Using cultured human(More)
Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhoea in developing countries. While colonizing the gut mucosa, EPEC triggers extensive actin-polymerization activity at the site of intimate bacterial attachment, which is mediated by avid interaction between the outer-membrane adhesin intimin and the type III secretion system(More)
The presence of Shiga toxin-producing Escherichia coli (STEC) in water buffaloes is reported for the first time in South America. The prevalence of STEC ranged from 0 to 64% depending on the farm. STEC isolates exhibiting the genetic profiles stx(1)stx(2)ehxA iha saa and stx(2)ehxA iha saa predominated. Of the 20 distinct serotypes identified, more than 50%(More)
Four of six adhesin-encoding genes (lpfA, paa, iha, and toxB) from Shiga toxin-producing Escherichia coli strains were detected in typical and atypical enteropathogenic E. coli (EPEC) strains of various serotypes. Although the most prevalent gene was lpfA in both groups, paa was the only potential diarrhea-associated gene in atypical EPEC.