Prevalence and characterization of Campylobacter jejuni from chicken meat sold in French retail outlets

• 76% of the French chicken meat was contaminated by Campylobacter.
• The C. jejuni population was genetically diverse and the ST-21 complex predominated.
• More than 25% of the isolates were potentially neuropathic with LOS class A or B.
• Isolates were susceptible to erythromycin, but more than 30% were ciprofloxacin-resistant.
• ST-21 complex isolates had mostly LOS class C and a high proportion was ciprofloxacin-resistant.

Campylobacter was detected in 76% of broiler meat products collected in retail outlets during a monitoring plan carried out in France throughout 2009. Campylobacter jejuni was the most prevalent species (64.7% of products being contaminated). The 175 C. jejuni isolates collected were characterized. MLST typing results confirmed substantial genetic diversity as the 175 C. jejuni isolates generated 76 sequence types (STs). The ST-21, ST-45 and ST-464 complexes predominated accounting for 43% of all isolates.A class-specific PCR to screen the sialylated lipooligosaccharide (LOS) locus classes A, B and C showed that 50.3% of the C. jejuni isolates harbored sialylated LOS.The antimicrobial resistance profiles established using a subset of 97 isolates showed that resistance to tetracycline was the most common (53.6%), followed with ciprofloxacin and nalidixic acid (32.9%, and 32.0% respectively). All the tested isolates were susceptible to erythromycin, chloramphenicol and gentamicin.Clear associations were demonstrated between certain clonal complexes and LOS locus classes and between certain clonal complexes and antimicrobial resistance.This work paints a representative picture of C. jejuni isolated from poultry products circulating in France, providing data on STs, LOS locus classes and antibiotic resistance profiles in isolates recovered from products directly available to the consumer.