Diarrheagenic and ESBL Potential of Escherichia coli From Publicly Shared Common Touch Surfaces

The present study examined the virulence factors, phylogroups, antimicrobial profiles, and ESBL-associated genes in Escherichia coli isolated from frequently touched surfaces (FTS) in Mymensingh Sadar, Bangladesh. A total of 105 swab samples from seven categories of publicly shared common touch surfaces were collected to assess microbial load, with E. coli identified through molecular assay. The isolates were screened for major diarrheagenic virulence genes and underwent phylogenetic grouping, followed by disk diffusion and double disk synergy tests to evaluate their antimicrobial resistance and ESBL potential. Microbial loads on these surfaces ranged from 6.4 to 8.56 Log₁₀ CFU/cm², with E. coli detected in 12 samples (11.43%). Among these, only two isolates carried diarrheagenic virulence factors (ipaH and daaD), classifying them as enteroinvasive and diffusely adherent E. coli, respectively. The isolates were distributed across all four phylogenetic groups, predominantly group A (n = 5; 41.7%). Notably, 10 out of 12 isolates (83.3%) were multidrug-resistant, exhibiting complete resistance to ampicillin, followed by cefotaxime and trimethoprim/sulfamethoxazole. Additionally, the double disk synergy test confirmed four isolates (33.3%) as ESBL producers. This study highlights the potential risk of human infection with diarrheagenic E. coli from FTS, which may lead to serious illness and limit treatment options.