Prevalence, antibiograms, antibiotic resistance genes, and virulence genes of Arcobacter butzleri isolated from healthy pigs in mid-northeastern Thailand

Abstract

Pigs can have Arcobacter butzleri. However, information on A. butzleri in Thai pigs remains scarce. This work aimed to survey A. butzleri in healthy pigs and assess their antimicrobial susceptibility, potential transferrable antimicrobial resistance (AMR) genes, and virulence-associated genes (VAGs). Cross-sectional fecal samples of 203 pigs from 18 farms were cultured and molecularly identified. A. butzleri prevalence in all pigs was (31/203; 15.3%): nursery (0/8; 0%), finisher (27/144; 18.8%), and sow (4/51; 7.8%). The total farm A. butzleri prevalence was 50%: nursery (0/2: 0%), finisher (8/14: 57.1%), and sow (2/9: 22.2%) farms. From the 10 antibiotic disks evaluated, the isolates were mostly sensitive to imipenem (96.8%), tetracycline (83.9%), streptomycin (67.7%), and amoxycillin/clavulanic acid (54.8%); however, they were mostly resistant to cefotaxime (98.6%), sulbactam/cefoperazone (71%), ampicillin (67.7%), enrofloxacin (48.4%), and fosfomycin (42.9%) and were neither sensitive nor resistant to erythromycin. Most multidrug resistance patterns in this study were in four to six classes. Three isolates resisted all 10 antibiotics. However, only the TetO gene was detected in one isolate, whereas ESBLs (SHV, CTX-M, and TEM), PMQRs (qnrA, qnrS, qnrB, oqxAB, and aac(6’)-Ib-cr), ermB, and mefA genes were not found in any isolates. The rankings of VAGs presented in the isolates were ciaB (100%), mviN (97%), pldA (93%), tlyA (90%), cj1349 (90%), cadF (83%), hecB (10%), hecA (7%), and irgA (0%), and most isolates carried six VAGs (77%). A. butzleri is present in healthy pigs, and this database is the first to show A. butzleri VAG and AMR genes in Thai pigs