Occurrence and antimicrobial susceptibility of Campylobacter spp. on fresh and refrigerated chicken meat products in Central Italy.

This study investigated the presence and the level of Campylobacter spp. contamination in 41 thigh samples (with skin) and 37 skinless breast samples collected at the end of slaughter (T1) and after 10 day period at refrigeration temperature (4°C) (T2), corresponding to their commercial shelf life. The isolates were phenotypically classified as Campylobacter spp. and successively identified by conventional multiplex PCR. The antimicrobial susceptibility of the isolates from fresh thigh and breast samples was also determined via the microdilution method (MIC) in Eucamp microtitre plates with known scalar concentrations of: gentamicin (GEN), streptomycin (ST), ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), and nalidixic acid (NA). A greater percentage of positivity for Campylobacter spp. (P < 0.001) was observed in thighs and C.jejuni appeared to be the most common species identified at this level (P < 0.001) followed from its association with C.coli. There was a global reduction of Campylobacter spp. in both thigh and breast samples at T2 (P < 0.001) showing that the refrigeration was able to reduce Campylobacter count. The prevalence of resistance to CIP, TET, NA, and ERY was evidenced for C.jejuni and C. coli. The co (TET-NA, CIP-NA) and multiple resistant (CIP-TET-NA, CIP-TET- NA-ERY) isolates came from the thigh products. It should be highlighted the presence of Campylobacter spp. isolates resistant to ST occurred in breast samples, responsible for the ST-CIP co-resistance and ST-CIP-TE multi-resistance profiles, higher in breast than in thigh products (P > 0.001). The presence of Campylobacter isolates resistant to ST can be further investigated since it is used for therapeutic treatment of several bacterial diseases in humans.