Distribution of Campylobacter jejuni multilocus sequence types isolated from chickens in Poland

Abstract

Poultry is recognized as the most important source of food-related transmission of Campylobacter jejuni to humans and campylobacteriosis is the most commonly reported zoonotic bacterial disease in the European Union. It has been documented that C. jejuni is genetically diverse and analyses of bacterial isolates usually show a large strain variety. Therefore, molecular typing of strains represents an important tool to study the genetic diversity of isolates and to trace individual strains that cause human infections. The aim of the study was characterization of genetic population structure and antimicrobial resistance (AMR) of C. jejuni isolated from Polish chickens. C. jejuni from chicken ceca and the corresponding carcasses (72 and 61 strains, respectively), originating from 128 flocks in Poland during February 2011 and May 2013, were used in the study. The isolates were tested for their population structure and genetic diversity using a multilocus sequence typing (MLST) scheme with connection to their antimicrobial resistance. The molecular analysis of 133 C. jejuni generated 39 different sequence types (ST); 3 of them were defined for the first time. Additionally, 16 STs were represented by single isolates. The most common STs observed were 6411 (16.5% isolates) and 257 (15.0% strains). The first mentioned ST was resistant to 3 different classes of antibiotics, i.e., quinolones, tetracyclines, and aminoglycosides. Overall, 125 (94.4%) of C. jejuni isolates demonstrated antimicrobial resistance and the most frequent AMR profile observed was ciprofloxacin, nalidixic acid, tetracycline (47.4% strains). Likewise, the clonal complexes CC 257 and CC 353 were defined as the predominant molecular groups covering altogether 37 C. jejuni strains. No associations between CCs and the origin of the samples as well as the place of isolation were found. This study highlights that the C. jejuni population from chickens in Poland was diverse and showed a weak clonal structure.

MLST-based genetic relatedness of Campylobacter jejuni isolated from chickens and humans in Poland

“…Our previous study demonstrated that C. jejuni strains with ST6411 and ST257 were predominant among chickens in Poland, representing a total of 31.5% isolates tested [15]. These sequence types were also often identified in chicken sources in the present investigation although they were not as common as before (a total of 58 out of 451 isolates; 12.7%).…”

“…MLST was carried out as described by Colles and Maiden [7] and Dingle et al [8]. Amplifications of the seven housekeeping genes that are included in the analysis scheme (aspA, glnA, gluA, glyA, pgm, tkt, uncA) were separately performed in a final volume of 25 μl PCR reaction as described previously [15]. The primers used for the amplification and sequencing of the genes and the PCR protocols were available at the Campylobacter MLST website (http:// pubmlst.org/campylobacter).…”

“…The primers used for the amplification and sequencing of the genes and the PCR protocols were available at the Campylobacter MLST website (http:// pubmlst.org/campylobacter). The obtained sequences were imported, checked for quality and analyzed to obtain the allele identifiers and sequence types (STs) together with clonal complex (CC) information using the BioNumerics v. 7.6 software (Applied Maths, Sint-Martens-Latem, Belgium) as described previously [15]. New alleles and STs were submitted to the PubMLST database.…”

“…6.0.1 (Palisade Co., Ithaca, N.Y.). An index greater than 0.90 is considered desirable if the typing results are to be interpreted with confidence [15]. Minimum spanning tree (MST) was generated using BioNumerics based on the MLST allele number and the predefined template for categorical data.…”

Quantitative microbiological slaughter process analysis in a large-scale Swiss poultry abattoir

“…ST 21 and ST 48 were the most prevalent ST in this study. These sequence types were frequently found in broiler meat or caeca swab samples by other authors (Di Giannatale et al, 2016;Wieczorek, Denis, Lachtara, & Osek, 2016;G. Zhang, Zhang, Hu, Jiao, & Huang, 2015), while ST 45 predominated in sample from Finnish broilers and human patients for years (Llarena, Huneau, Hakkinen, & Hänninen, 2015).…”