Characterization of Uropathogenic Escherichia coli Reveals Hybrid Isolates of Uropathogenic and Diarrheagenic (UPEC/DEC) E. coli .

(1) Background: Pathogenic Escherichia coli are divided into two groups: diarrheagenic (DEC) and extraintestinal pathogenic (ExPEC) E. coli . ExPEC causing urinary tract infections (UTIs) are termed uropathogenic E. coli (UPEC) and are the most common cause of UTIs worldwide. (2) Methods: Here, we characterized 112 UPEC in terms of phylogroup, serotype, the presence of virulence factor-encoding genes, and antimicrobial resistance. (3) Results: The majority of the isolates were assigned into the phylogroup B2 (41.07%), and the serogroups O6 (12.5%) and O25 (8.9%) were the most frequent. Five hybrid UPEC (4.5%), with markers from two DEC pathotypes, i.e., atypical enteropathogenic (aEPEC) and enteroaggregative (EAEC) E. coli , were identified, and designated UPEC/aEPEC (one isolate) and UPEC/EAEC (four isolates), respectively. Three UPEC/EAEC harbored genes from the pap operon, and the UPEC/aEPEC carried ibeA . The highest resistance rates were observed for ampicillin (46.4%) and trimethoprim/sulfamethoxazole (34.8%), while 99.1% of the isolates were susceptible to nitrofurantoin and/or fosfomycin. Moreover, 9.8% of the isolates were identified as Extended Spectrum β-Lactamase producers, including one hybrid UPEC/EAEC. (4) Conclusion: Our data reinforce that hybrid UPEC/DEC are circulating in the city of Botucatu, Brazil, as uropathogens. However, how and whether these combinations of genes influence their pathogenicity is a question that remains to be elucidated.