Background/Purpose: Uropathogenic E. coli (UPEC) is the main cause of urinary tract infection (UTI) and it is known that pregnant women have a higher risk for UTI. UPEC has a variety of virulence and antibiotic resistance factors that facilitate its pathogenic success and it is crucial to know which are the susceptibility patterns, Extended-Spectrum-β-Lactamase (ESBL) production, virulence genes, pathogenicity islands (PAI), phylogenetic groups and serotypes among strains isolated from pregnant and non-pregnant women. Methods: One hundred fifty UPEC strains were isolated from pregnant and non-pregnant women from two different Mexican states (Sonora and Puebla). Strains were analyzed using the Kirby-Bauer method for the determination of antibiotic susceptibility and ESBL. Virulence genes, PAIs and phylogenetic groups were determined using a multiplex PCR. Strains were serotyped by an agglutination assay. Blood agar and CAS agar were used for phenotypic assays. Results: 92.7% of UPEC strains showed multidrug-resistant (MDR), 6.7% extremely-resistant (XDR) and 0.6% pandrug-resistant (PDR). The highest resistance was determined to be for βlactam antibiotics (>72% in both states) and 44.5% of the UPEC strains were ESBL + . The predominant virulence genes found were fimH (100%), iucD (85%) and iha (60%). The strains isolated from pregnant women from Puebla presented a large percentage of genes associated with upper urinary tract infections. PAIs were found in 51% and 68% of the strains from Sonora and Puebla, respectively. All the strains were siderophores producers and 41.5% produced hemolysis. The serotypes found were diverse and belonged to phylogroups A, B2 and C. Conclusion: The UPEC strains from this study are MDR with tendency to XDR or PDR, they can cause upper UTIs and are serotypically and phylogenetically diverse, which supports the need to develop new strategies for UTI treatment in pregnant and nonpregnant Mexican women.

Urinary tract infections (UTIs) belong to the most common pathologies in Mexico and are mainly caused by Uropathogenic Escherichia coli (UPEC). UPEC possesses a wide diversity of virulence factors that allow it to carry out its pathogenesis mechanism in the urinary tract (UT). The development of morphotypes in UT represents an important feature of UPEC because it is associated with complications in diagnosis of UTI. The aim of this study was to determine the presence of bacterial morphotypes, virulence genes, virulence phenotypes, antibiotic resistant, and phylogenetic groups in clinical isolates of UPEC obtained from women in Sonora, Mexico. Forty UPEC isolates were obtained, and urine morphotypes were observed in 65% of the urine samples from where E. coli was isolated. Phylogenetic group B2 was the most prevalent. The most frequent virulence genes were fimH (100%), fliCD (90%), and sfaD/focC (72%). Biofilm formation (100%) and motility (98%) were the most prevalent phenotypes. Clinical isolates showed high resistance to aminoglycosides and β-lactams antibiotics. These data suggest that the search for morphotypes in urine sediment must be incorporated in the urinalysis procedure and also that clinical isolates of UPEC in this study can cause upper, lower, and recurrent UTI.

No abstract

No abstract

Escherichia coli is a well-recognized inhabitant of the animal and human gut. Its presence represents an essential component of the microbiome. There are six pathogenic variants of E. coli associated with diarrheal processes, known as pathotypes. These harbor genetic determinants that allow them to be classified as such. In this work, we report the presence of diarrheagenic pathotypes of E. coli strains isolated from healthy donors. Ninety E. coli strains were analyzed, of which forty-six (51%) harbored virulence markers specifics for diarrheagenic pathotypes, including four hybrids (one of them with genetic determinants of three DEC pathotypes). We also identified phylogenetic groups with a higher prevalence of B2 (45.6%) and A (17.8%). In addition, resistance to sulfonamides (100%), and aminoglycosides (100%) was found in 100% of the strains, with a lower prevalence of resistance to cefotaxime (13.3%), ceftriaxone (12.2%), fosfomycin (10%), and meropenem (0%). All analyzed strains were classified as multidrug resistant. Virulence genes were also investigated, which led us to propose three new virotypes. Among the virulence traits observed, the ability to form biofilms stands out, which was superior to that of the E. coli and Staphylococcus aureus strains used as positive controls.