| Congresso Brasileiro de Microbiologia 2023 | Resumo: 49-2 | ||||
Resumo:Uropathogenic Escherichia coli (UPEC) comprises the main pathogen associated with cases of urinary tract infections (UTI). UPEC has several virulence factors that allow this pathogen to colonize the urinary tract (fimbrial and afimbrial adhesins), evade the immune system (protactins), uptake iron from the host (siderophores) and damage the host epithelial cells (toxins). On the other hand, isolates associated with gastrointestinal infections are collectively termed diarrheagenic E. coli (DEC) and can be grouped into six distinct pathotypes based on their set of virulence factors. Studies focused on the characterization of UPEC have revealed that some isolates may harbor in their genome genes encoding virulence factors associated with gastrointestinal infections, evidencing the genomic plasticity of these isolates, which allows the emergence of hybrid genomes of UPEC with DEC markers (Hybrid UPEC/DEC). On account of this instigating scenario, this study investigated the prevalence of hybrid UPEC/DEC isolates as the causative agent of UTIs in the city of Botucatu/SP, as well as provided important molecular features associated with their virulence. A collection of 600 UTI E. coli isolates was tested, by polymerase chain reaction (PCR), for the presence of DEC diagnostic marker genes (escN, aatA, stx1 and stx2). Isolates in which at least one diagnostic marker was detected, were classified as hybrid isolates and subsequently tested, by PCR, for the presence of additional DEC (eae, bfpB, aggA, aafA, agg3A, agg4A, agg5A, aggC, aafC, agg3/4/C and afpB), as well as UPEC (fimH, sfa/focDE, afaBC, papA, papC, yfcV, cnf1, vat, sat, hlyA, usp, picU, chuA, fyuA, iutA, iroN, kpsMTII) virulence factor-encoding genes. We observed that 13 (2.16%) of the 600 UPEC isolates were classified as hybrid UPEC/DEC isolates as follow: 3 UPEC/aEPEC (atypical enteropathogenic E. coli), harboring the escN and eae genes; and 10 UPEC/EAEC (enteroaggregative E. coli), all carrying the aatA and at least one of the five aggregative adherence fimbriae (AAF/I – V). Regarding the prevalence of the distinct AAFs, we observed that AAF/III was detected in 40% (4/10) of the UPEC/EAEC hybrid isolates, followed by AAF/I (30%, 3/10). Less frequently, AAF/II, IV and V were detected in only one isolate each (10%, 1/10). All but one UPEC/EAEC hybrid isolate harbored the aggR gene. Taken in consideration the genes encoding virulence factors form UPEC, we observed that 90% (9/10) of the hybrid UPEC/EAEC isolates harbored the fimH, picU and iutA, 80% (8/10) the kpsMTII and 70% (7/10) the papA and papC genes. In conclusion, we showed that hybrid UPEC/DEC, mainly UPEC/EAEC, isolates are being responsible for symptomatic UTIs in the city of Botucatu, Brazil; and the diversity of virulence-factor-encoding genes detected reinforces the high genomic plasticity of these hybrid isolates. Palavras-chave: Escherichia coli, Hybrid pathogenic E. coli, Urinary tract infection, Virulence Agência de fomento:Fundação de Amparo à Pesquisa do Estado de São Paulo | |||||