Prevalence of antibiotic resistance profile in relation to phylogenetic background among commensal Escherichia coli derived from various mammals.

The paper describes the prevalence of resistant strains within the genetic structure of E. coli (phylogenetic group A, B1, B2 and D). A total of 200 commensal E. coli strains have been derived from 10 species of healthy animals residing on ZOO Safari Park area, in Swierkocin, Poland. The phylogenetic structure of E. coli has been analysed with the use of a PCR-based method. The strains were tested in terms of their susceptibility to eight classes of antibiotics: aminoglycosides, penicillins, cephalosporins, tetracyclines, nitrofurans, sulphonamides, phinicols, and quinolones. The genetic structure of E. coli revealed a not uniform distribution of strains among the four phylogenetic groups with significantly numerous representation of groups A and B1. Resistant E. coli were found within each of the phylogenetic groups. Strains resistant to one class of antibiotics occurred significantly more frequently in phylogenetic groups B2 and D (potential pathogens), whereas strains resistant to more than one class of antibiotics belonged to phylogenetic groups A and B1 (typical commensals) in a prevailing number of cases.