Article ID: JJID.2015.454
ETEC is the most common cause of diarrhea in children under 5 years from developing world. We used the sequencing of the 16S rRNA gene, the Biolog® system, and the Amplified Ribosomal DNA Restriction Analysis (ARDRA), to identify 69 Enterobacteria isolated from feces of healthy children up to 12 years old, and 54 Enterobacteria isolated from stool samples obtained from children up to 5 years old with diarrhea, from Morelia, Michoacán, Mexico. In the diarrheic group, 18 isolates belong to the Enterotoxigenic pathotype, 17 have the ST gene and one has both LT and ST genes. The identity of most of the strains harboring the ST gene was E. coli, three of the strains were identified as Morganella morganii. The ST toxin gene of one of the strains typed as M. morganii showed a 100% of identity with a ST toxin gene of Escherichia coli. The ARDRA was a very useful tool to differentiate between Escherichia coli and Morganella morganii. The phenotypic and a genetic analysis of diversity conducted on the isolates using respectively the Biolog® system and Random Amplified Polymorphic DNA, showed variations in the physiologic abilities of the studied strains and genetic differences between subgroups.
