Phylogenetic Characterization and Multilocus Sequence Typing of Extended-Spectrum Beta Lactamase-Producing from Food-Producing Animals, Beef, and Humans in Southwest Nigeria.

Multidrug-resistant extended-spectrum beta lactamase (ESBL)-producing strains are emerging globally in both humans and animals. Antimicrobial susceptibility testing and ESBL screening were performed on pure cultures of 216 isolates from human and animal fecal samples as well as beef. Polymerase chain reaction was performed for the detection of resistance genes. Representative isolates of ESBL-producing were randomly selected for multilocus sequence typing and pulsed field gel electrophoresis (PFGE). Sixty of the isolates were identified as ESBL producers, and seven resistance genes were amplified in them: (61.7%), (51.7%), (43.3%), (38.3%), (33.3%), (21.7%), and (11.7%); they were classified into four phylogroups: A (25%), B1 (45%), B2 (20%), and D (10%). Thirty of these isolates were clustered into 10 sequence types with ST131 being mostly prevalent. Six PFGE types were discovered, each of which was shared by isolates from different subjects and had the same phylogroups and resistance gene profiles. There was a dissemination of PFGE types across various groups among humans, animals, and beef. This underlines the fact that the spread of ESBL could be from humans to animals, from animals to humans, as well as across animal species.