Antimicrobial Resistance Profiles and Molecular Characteristics ofSerovar Agona Isolated from Food-Producing Animals During 2010-2020 in South Korea.

Abstract

Multidrug-resistant (MDR)serovar Agona infections affect public health globally. This investigation aimed to ascertain the antimicrobial resistance profiles and molecular characteristics ofAgona isolates obtained from food-producing animals. A total of 209Agona isolates were recovered from mostly chickens (139 isolates), pigs (56 isolates), cattle (11 isolates), and ducks (3 isolates) between 2010 and 2020 in South Korea. In addition, theseAgona isolates were obtained from 25 slaughterhouses nationwide. Furthermore, this serotype suddenly increased in chickens in 2020.Agona from chickens showed high resistance (69-83%) to ampicillin, streptomycin, tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol. Moreover, chicken/duck isolates (83.1%) showed significantly higher levels of MDR than cattle/pig isolates (1.5%). For molecular analysis by pulsed-field gel electrophoresis, infrared spectroscopy biotyping, and multilocus sequence typing in combination, a total of 23 types were observed. Especially two major types, P1-III-2-13 and P1-IV-2-13, comprised 59.3% of the total isolates spreading in most farms. Moreover,Agona sequence type (ST)13 was predominant (96.7%) among three different STs (ST13, ST11, and ST292) widely detected in chickens (94.3%) in most farms located nationwide. Taken together, MDRAgona in chickens might pose a potential risk to public health through direct contact or the food chain.