Genetic Basis and Clonal Population Structure of Antibiotic Resistance in Campylobacter jejuni Isolated From Broiler Carcasses in Belgium

Abstract

Human campylobacteriosis is the leading food-borne zoonosis in industrialized countries. This study characterized the clonal population structure, antimicrobial resistance profiles and occurrence of antimicrobial resistance determinants of a set of Campylobacter jejuni strains isolated from broiler carcasses in Belgium. Minimum inhibitory concentrations (MICs) against five commonly-used antibiotics (ciprofloxacin, nalidixic acid, tetracycline, gentamicin, and erythromycin) were determined for 204 C. jejuni isolates. More than half of the isolates were resistant to ciprofloxacin or nalidixic acid. In contrast, a lower percentage of screened isolates were resistant to gentamicin or erythromycin. C. jejuni isolates resistant to ciprofloxacin and/or nalidixic acid were screened for the substitution T86I in the quinolone resistance determining region (QRDR) of the gyrA gene, while C. jejuni isolates resistant to tetracycline were screened for the presence of the tet(O) gene. These resistance determinants were observed in most but not all resistant isolates. Regarding resistance to erythromycin, different mutations occurred in diverse genetic loci, including mutations in the 23S rRNA gene, the rplD and rplV ribosomal genes, and the intergenic region between cmeR and cmeABC. Interestingly, and contrary to previous reports, the A2075G transition mutation in the 23S rRNA gene was only found in one strain displaying a high level of resistance to erythromycin. Ultimately, molecular typing by multilocus sequence typing revealed that two sequence types (ST-824 and ST-2274) were associated to quinolones resistance by the presence of mutations in the gene gyrA (p = 0.01). In addition, ST-2274 was linked to the CIP-NAL-TET-AMR multidrug resistant phenotype. In contrast, clonal complex CC-45 was linked to increased susceptibility to the tested antibiotics. The results obtained in this study provide better understanding of the phenotypic and the molecular basis of antibiotic resistance in C. jejuni, unraveling some the mechanisms which confer antimicrobial resistance and particular clones associated to the carriage and spread of resistance genes.

Antimicrobial resistance patterns and molecular resistance markers of Campylobacter jejuni isolates from human diarrheal cases

“…Phenotypic screening of antimicrobial resistance frequencies among the clinical C. jejuni isolates tested in this study revealed high resistance rates to nalidixic acid (55.8%), ciprofloxacin (56.3%), and tetracycline (49.7%). In Belgium, similarly high resistance rates to these antimicrobials in broiler carcasses were reported in different recent epidemiological studies [35,52]. Therefore, the continued overuse of antibiotics in the case of poultry, which is the main reservoir of Campylobacter spp., is proposed to be responsible, at least in part, to the alarming elevated rate of AMR in Belgium.…”

“…Multi-locus sequence typing (MLST) is widely applied for studying the epidemiology of campylobacteriosis. MLST can also be used to track the dissemination of antimicrobial-resistant C. jejuni strains [34,35]. Different recent studies supported the clonal expansion of antimicrobial-resistant C. jejuni strains by revealing an association between different sequence types (STs) and antimicrobial resistance [35][36][37][38][39][40].…”

Increasing prevalence of a fluoroquinolone resistance mutation amongst Campylobacter jejuni isolates from four human infectious intestinal disease studies in the United Kingdom

“…The only difference reaching statistical significance was an increase in prevalence of an A103V mutation in rplV (encoding L22), rising from 7.6% in IID1 to 19.6% in ENIGMA (p = 0.034). A103V mutations in L22 have been reported previously in erythromycin-resistant Campylobacter isolates, though the mutation can also occur in susceptible isolates [38,39]. Mutations in the 23S rRNA gene (position 2074 or 2075) have also been implicated in resistance to erythromycin [38].…”

Multilocus Sequence Types and Antimicrobial Resistance of Campylobacter jejuni and C. coli Isolates of Human Patients From Beijing, China, 2017–2018

“…Campylobacter can colonize poultry, swine, and ruminants (Gallay et al, 2007;Elhadidy et al, 2018); therefore, people are easily infected when handling and consuming raw and semiraw contaminated foods, as well as contaminated water (Klein-Jöbstl et al, 2016;Kovanen et al, 2016). Most Campylobacter infections are mild, self-limiting, and resolve within a few days.…”