Antimicrobial resistance in Campylobacter spp. focussing on C. jejuni and C. coli - A narrative review

Campylobacter species represent one of the leading causes of human foodborne infections, including gastroenteritis and bloody diarrhoea. Overuse of antibiotics in veterinary, agriculture, and humans has led to an increase in multidrug antimicrobial resistance (AMR). Fluoroquinolones and macrolides resistant Campylobacters are WHO and CDC priority pathogens, with fluoroquinolone resistance doubling in the past 20 years, complicating treatment.

Published studies relating to AMR and associated molecular mechanisms in both Campylobacter jejuni (C. jejuni) and C. coli from animals, humans and environment (1981-2024), were retrieved from PubMed and Google Scholar using relevant keywords. In addition, genomic analyses of publicly available C. jejuni and C. coli genomes along with multilocus sequence typing results from the PubMLST database were used to analyse these AMR determinants and their phylogenomic relationships. Review articles were excluded from the analyses.

A total of 429 research papers were reviewed to get insights into multidrug resistance in C. jejuni and C. coli. Fluroquinolone resistance has been predominantly associated with international travel. The gyrA subunits were associated with ecological niches and overall, it is suggestive that C. coli might be the donor. A positive synergism was observed between cmeA gene expression and quinolone resistance. Additionally, the results speculated the possibility of horizontal gene transfers in chromosomal resistance clusters between C. coli and C. jejuni.

This review indicated significant concern of multidrug resistance in C. jejuni and C. coli. This requires continent-wide surveillance and research for standard practices to achieve effective antimicrobial stewardship.