ABSTRACT
To study the main enteropathogens causing diarrhea in the region of Ribeirão Preto regarding serogroups and serotypes, the feces of 1836 children under 10 years old, from both sexes, attack of acute gastroenteritis, were analysed during a period of 4 years in Adolfo Lutz Institute - Ribeirão Preto, SP. The pathogens identified by standard methods were the following: Escherichia coli, Salmonella spp., Shigella spp., Campylobacter spp., Yersinia spp., and Cryptosporidium spp. Positive samples were 22.8% (419) with 1.7% association of pathogens. Larger isolates were mainly from children 0 to 11 months old. Enteropathogenic E. coli (EPEC) was most frequent (8.7%) with predominance of serogroup O119 (40.2%), followed by Shigella (6.2%), 63.6% of which S. sonnei.
Subject(s)
Diarrhea/microbiology , Enterobacteriaceae/isolation & purification , Acute Disease , Age Distribution , Brazil/epidemiology , Campylobacter/isolation & purification , Child , Child, Preschool , Diarrhea/epidemiology , Feces/microbiology , Female , Humans , Infant , Infant, Newborn , MaleABSTRACT
Genetic variation of 33 enteroinvasive Escherichia coli (EIEC), 12 non-EIEC and 39 Shigella strains (representing the 4 species of this genus) was analyzed using the random amplified polymorphic DNA (RAPD) technique. Reproducible polymorphisms were generated and the combined data allowed us to construct a dendrogram using Jaccard's distance. Two main groups were obtained: one for Shigella and the other for EIEC and non-EIEC strains. The first group contained four clusters, one for each Shigella species. The second group contained one cluster for EIEC and another for non-EIEC strains. The main clusters encompassed many small clusters corresponding to different serotypes. It was possible to characterize each one of the 84 strains under study as well as the boundaries among Shigella species and between this genus and EIEC strains.
Subject(s)
Escherichia coli/genetics , Polymorphism, Genetic/genetics , Shigella/genetics , Bacterial Typing Techniques , DNA Fingerprinting , DNA, Bacterial/genetics , Electrophoresis, Agar Gel , Escherichia coli/classification , Genetic Variation , Humans , Random Amplified Polymorphic DNA Technique , Shigella/classificationABSTRACT
Genotypic and phenotypic virulence markers of the different categories of diarrheagenic Escherichia coli were investigated in 76 strains of the enteropathogenic E. coli (EPEC) serogroup O125. The most frequent serotype found was O125ac:H21. None of the serotypes behaved as EPEC, i.e. carried the eaeA, bfpA, and EAF DNA sequences simultaneously and presented localized adherence to HeLa cells. All strains of O125ac:H6 were atypical EPEC since they carried eaeA only, and presented an indefinite pattern of adherence. All strains of O125ab:H9, O125ac:H9, O125?:H16, and O125ab:H21 and 79% of the O125ac:H21 strains were enteroaggregative E. coli, since they carried a specific DNA sequence and presented the typical aggregative adherence pattern.
