Comparative analysis of antimicrobial resistance and genetic diversity of Campylobacter from broilers slaughtered in Poland.

In the current study, the relationship of Campylobacter jejuni and Campylobacter coli strains isolated at slaughter was investigated using comparative analysis of antimicrobial resistance (AMR), virulence gene (VG) and PFGE profiling. A total of 254 Campylobacter isolates from poultry caeca and corresponding carcasses, including 139 C. jejuni and 115 C. coli strains were tested. The most prevalent resistance profiles observed in C. jejuni were ciprofloxacin, nalidixic acid and tetracycline (46 out of 139, 33.1% isolates) as well as ciprofloxacin, nalidixic acid, tetracycline and streptomycin among C. coli strains (34 out of 115, 29.6%). Multi-resistance was found more frequently among C. coli than C. jejuni (P<0.05). The presence of 11 virulence genes exhibited 19 different VG profiles in Campylobacter isolates tested. All Campylobacter strains were classified into 154 different PFGE types. Among them, 56 profiles (28 C. jejuni and 28 C. coli) were common for at least two isolates including 9 clusters covering from 4 to 9 strains. Campylobacter composite types generated by a combination of 154 PFGE types, 10 AMR profiles and 19 VG patterns divided 178 distinct types with 95% similarity. The majority of the composite profiles (76 for C. jejuni and 58 for C. coli; 75.3% in total) included only one bacterial isolate. Furthermore, 11 pairs of C. jejuni and 12 pairs of C. coli from caeca and the corresponding carcasses isolated from the same places possessed the identical PFGE, AMR and VG patterns. This study demonstrated that C. jejuni and C. coli isolated from poultry in Poland showed to have a high genetic diversity and a weak clonal population structure. However, the composite analysis revealed a strong evidence for cross-contamination of chicken carcasses during the slaughter process. Additionally, our results confirm that Campylobacter may easily contaminate poultry carcasses at slaughter process and spread around country. More than half of Campylobacter strains tested (50.4%) were resistant to at least two classes of antimicrobials, i.e. quinolones and tetracyclines, which may cause a public health risk.

Molecular characterization and antibiotic resistance profiling of Campylobacter isolated from cattle in Polish slaughterhouses.

A total of 812 samples from bovine hides and the corresponding carcasses collected at the slaughterhouse level in the eastern part of Poland were examined for the presence of Campylobacter jejuni and Campylobacter coli. Recovered isolates were confirmed using species-specific PCR, characterized by the presence of 11 putative virulence genes and antimicrobial susceptibility was determined using a microbroth dilution method. Furthermore, the genotypic relatedness of the isolates was determined by PFGE profiling and virulence pattern cluster analysis. The prevalence of Campylobacter was 25.6% and 2.7% in bovine hide and carcass samples, respectively. The presence of virulence markers varied between C. jejuni and C. coli species however, the majority of strains possessed the cadF, flhA, flaA genes, irrespective of the bacterial species and origin. The lower number of the strains was positive for the invasive associated markers -virB11 and wlaN. Antibiotic profiling showed that campylobacters were most frequently resistant to quinolones and fluoroquinolones (nalidixic acid and ciprofloxacin, 38.3% of each, respectively) followed by streptomycin (24.3%) and tetracycline (20.9%). Resistance to erythromycin and gentamicin was demonstrated in 4.3% and 2.6% of strains, respectively. Comparisons of the PFGE and virulence marker profiles of the isolates reflected the high genetic diversity of Campylobacter tested. Moreover, a poor correlation between the PFGE type, pathogenic gene marker and antimicrobial resistance patterns was observed.