Comparison of Campylobacter jejuni pulsotypes isolated from humans and poultry in Split and Dalmatia County, Croatia

Comparison of pulsed-field gel electrophoresis and a novel amplified intergenic locus polymorphism method for molecular typing of Campylobacter jejuni

Campylobacter is regarded as the leading cause of zoonotic diseases and Campylobacter jejuni (C. jejuni) is one of the predominant pathogenic species. To track C. jejuni infections, various genotyping methods have been used. In this study, amplified intergenic locus polymorphism (AILP) was used to type C. jejuni for the first time. To confirm its feasibility, pulsed-field gel electrophoresis (PFGE) was performed as a control, and the results obtained by the AILP and PFGE methods were compared. Fifty-one isolates were resolved into 34 and 29 different genotypes with Simpson's indices of 0.976 and 0.967 using the AILP and PFGE methods, respectively. The adjusted Rand coefficient of the two approaches was as high as 0.845. In summary, the data showed that the two genotyping methods were similar for discriminating isolates and were both appropriate methods to distinguish whether two isolates were indistinguishable, but the AILP was faster and less costly than PFGE. Therefore, the AILP is a reliable, rapid, and highly discriminative method to genotype C. jejuni collected from poultry meat, which is helpful to effectively monitor C. jejuni.

Genetic diversity of Campylobacter jejuni and Campylobacter coli isolated from poultry meat products sold on the retail market in Southern Brazil

Campylobacter is regarded as the most common bacterial cause of gastroenteritis throughout the world and most cases of human campylobacteriosis can be traced back to the consumption of poultry meat. In Brazil, few studies evaluated the genetic relatedness among Campylobacter isolates. The aim of this research was to evaluate the genetic diversity of Campylobacter spp. isolated from poultry meat products sold on the retail market in Southern Brazil. The presumptive identification of Campylobacter was performed using traditional microbiological analysis, followed by molecular confirmation by PCR. The genetic diversity of isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Campylobacter spp. was isolated from 91.7% (33/36) of the samples, totaling 48 isolates. Campylobacter jejuni was the most prevalent species isolated (90.8%). PFGE data revealed 26 pulsotypes and 18 PFGE patterns composed of only 1 isolate. Campylobacter isolates exhibited high genetic diversity; however, some clones were recurrent in the poultry meat products sold on the retail market. As the south region of Brazil is an important producer and exporter of chicken meat, our results highlight the need to control this pathogen in the food chain in this area of the world to reduce the risks of exposing consumers to campylobacteriosis.

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.