Characterization of Diarreaghenic Escherichia coli Strains Isolated from Healthy Donors, including a Triple Hybrid Strain

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.

Prevalence of Antibiotic-Resistant E. coli Strains in a Local Farm and Packing Facilities of Honeydew Melon in Hermosillo, Sonora, Mexico

“…The samples were inoculated on MacConkey (Becton, Dickson and Company Sparks, MD, USA) and Eosin Methylene Blue (Becton, Dickson and Company, Sparks, MD, USA) agar plates, and both were incubated for 18 h at 37 ± 2 °C. Subsequently, biochemical identification was confirmed by tests of indole, mobility, sulfhydric acid production, glucose fermentation, lactose fermentation, gas production, Simmons citrate, methyl red, Voges-Proskauer, lysine decarboxylase, and urea [ 41 ].…”

Draft genome sequence of a triple hybrid Escherichia coli strain isolated from a healthy donor feces

“…E. coli Ec-36.3 belongs to a strain collection previously characterized ( 7 ). It was isolated from a healthy donor feces in Caborca, Sonora, Mexico in October 2022.…”

“…A lactose-positive colony was selected. This strain was characterized with biochemical tests using a Vitek2 system (Biomerièux, France) and molecularly using specific primers for ybbW as previously reported ( Table 1 ) ( 8 , 9 ); in addition, using a PCR approach were identified the genetic determinants of three diarrheagenic pathotypes: bfpA (but not eae , classifying it as atypical EPEC or aEPEC), staI (from ETEC), and daaE (from DAEC) ( 7 ) that codify for main subunit of bundle forming pilus, thermostable toxin, and the structural subunit of the F1845 fimbriae, respectively ( Table 1 ). The strain was stored at −80°C in Luria Bertani (LB) broth supplemented with glycerol 20%.…”

Pandemic ST131Escherichia colipresenting the UPEC/EAEC and ExPEC/EAEC hybrid pathotypes recovered from extraintestinal infections in a clinical setting of the Brazilian Amazon region

“…A recent study in South Africa demonstrated the high prevalence of several different DEC hybrid pathotypes, including strains sharing three virulence markers of three different DEC pathotypes, which were recovered from inanimate surfaces and presented a higher resistance profile compared to the classic pathotypes identified [8]. Another report demonstrated the occurrence of different DEC hybrid strains recovered from healthy individuals in Mexico [9].…”