Antimicrobial Resistance in Food-Borne Campylobacter spp.

The European Union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2021–2022

“…Resistance to quinolones and fluoroquinolones has been found to be mainly due to the C257T mutation on the gyrA gene (Elhadidy et al., 2020 ; Espinoza et al., 2020 ). Modifications in the expression of the Campylobacter multidrug efflux (Cme) pump CmeABC may result in higher MIC values of various structurally unrelated antimicrobials, including fluoroquinolones, while facilitating the survival of Campylobacter in bile salts and its successful inhabitation of the host intestine (Lekshmi et al., 2023 ). Highly resistant isolates bearing a transferrable ‘super’ efflux pump variant of CmeABC (RE‐CmeABC) were described in China (Yao et al., 2016 ), and their MIC values of ciprofloxacin, along with florfenicol, chloramphenicol, erythromycin and tetracycline, were found to be increased.…”

“…However, it is to be noted that a high proportion of erythromycin‐resistant isolates displayed very high MIC values (MIC > 512 mg/L), particularly in C. coli isolated from food‐producing animals, with the highest level or resistance reported in cattle under 1 year of age (76.6%). Common mechanisms of resistance to macrolides are mutations in one or several copies of the ribosomal gene 23S rRNA, such as A2074G, A2074C and A2075G (Lekshmi et al., 2023 ; Luangtongkum et al., 2009 ). In addition, the transferable erm(B) gene, encoding an rRNA methylase, usually present on multidrug resistance islands (MDRI) or plasmids in Campylobacter , may confer a high level of resistance to macrolides, lincosamides, and/or streptogramin B antibiotics (Wang et al., 2014 ).…”