Antimicrobial Resistance Profiles, Virulence Genes, and Genetic Diversity of Thermophilic Campylobacter Species Isolated From a Layer Poultry Farm in Korea

Abstract

Thermophilic Campylobacter species are among the major etiologies of bacterial enteritis globally. This study aimed at assessing the antimicrobial resistance (AMR) profiles, virulence genes, and genetic diversity of thermophilic Campylobacter species isolated from a layer poultry farm in South Korea. One hundred fifty-three chicken feces were collected from two layer poultry farms in Gangneung, South Korea. The Campylobacter species were isolated by cultural techniques, while PCR and sequencing were used for species confirmation. Antimicrobial susceptibility testing for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)] was carried out by broth microdilution. Three AMR and nine virulence genes were screened by PCR. Genotyping was performed by flaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Of the 153 samples, Campylobacter spp. were detected in 55 (35.9%), with Campylobacter jejuni and Campylobacter coli being 49 (89.1%) and six (10.9%), respectively. High-level resistance was observed for CIP (100%), NAL (100%), and TET (C. jejuni, 93.9%; C. coli: 83.3%). No resistance was observed for SIT. The missense mutation (C257T) in gyrA gene was confirmed by sequencing, while the tet(O) gene was similar to known sequences in GenBank. The rate of multidrug-resistant (MDR) strains was 8.2%, and they all belonged to C. jejuni. All Campylobacter isolates possessed five virulence genes (cdtB, cstII, flaA, cadF, and dnaJ), but none possessed ggt, while the rates for other genes (csrA, ciaB, and pldA) ranged between 33.3 and 95.9%. The flaA-RFLP yielded 26 flaA types (C. jejuni: 21 and C. coli: five), while the MLST showed 10 sequence types (STs) for C. jejuni and three STs for C. coli, with CC-607 (STs 3611) and CC-460 (ST-460) being predominant. Among the 10 STs of C. jejuni, three were newly assigned. The findings of this study highlight the increased resistance to quinolones and TET, the virulence potential, and the diverse genotypes among Campylobacter strains isolated from the layer poultry farm.

Wildlife Waterfowl as a Source of Pathogenic Campylobacter Strains

“…Regarding invasion abilities, the authors' previous studies have revealed the common prevalence of ciaB (83.3%) and pldA (70%) genes among wildlife waterfowl, regardless of the source. The high prevalence of these genes was previously noted in wild bird isolates [37], layer poultry isolates [41], chicken meat isolates [42], and in human and cattle isolates [43]. The overall prevalence rates of two other tested virulence genes associated with invasion (virB11 and iam) were 26.7% and 6.7%, respectively.…”

Genomic Relatedness, Antibiotic Resistance and Virulence Traits of Campylobacter jejuni HS19 Isolates From Cattle in China Indicate Pathogenic Potential

“…Increasing rates of Campylobacter strains resistant to the drugs of choice and alternative therapies, making AMR Campylobacter a public health concern ( Mourkas et al, 2019 ; Gahamanyi et al, 2021 ), and MDR is still very common in Campylobacter strains isolated from farmed animals in many European countries ( Pascoe et al, 2017 ). In this study, MDR was common in C. jejuni HS19 isolates from cattle, indicating a potential hazard.…”

Pan-Genome Analysis of Campylobacter: Insights on the Genomic Diversity and Virulence Profile

“…The genetic diversity of the pathogenic factors of Campylobacter is an important cause of differing pathogenicity ( 17 ). Much research has been invested to identify species-unique genes of Campylobacter and genes of different pathogenicity ( 18 , 19 ). With the application of whole-genome sequencing technologies, diverse Campylobacter species have been sequenced in recent years ( 20 , 21 ).…”