Phylogenetic relationship of <i>Campylobacter jejuni</i> from various sources of broiler production processes.

<p>Distribution of sequence types in each production chain (i.e., A, B, C, D and E) and production unit (breeder farm, broiler farm and slaughterhouse) was represented by different shading pattern and geometric shape, respectively. Asterisk (*) defined as unassigned clonal complexes.</p

Number of samples collected throughout chicken production process of 5 production chains.

<p>Number of samples collected throughout chicken production process of 5 production chains.</p

Distribution and Genetic Profiles of <i>Campylobacter</i> in Commercial Broiler Production from Breeder to Slaughter in Thailand

<div><p>Poultry and poultry products are commonly considered as the major vehicle of <i>Campylobacter</i> infection in humans worldwide. To reduce the number of human cases, the epidemiology of <i>Campylobacter</i> in poultry must be better understood. Therefore, the objective of the present study was to determine the distribution and genetic relatedness of <i>Campylobacter</i> in the Thai chicken production industry. During June to October 2012, entire broiler production processes (i.e., breeder flock, hatchery, broiler farm and slaughterhouse) of five broiler production chains were investigated chronologically. Representative isolates of <i>C</i>. <i>jejuni</i> from each production stage were characterized by <i>flaA</i> SVR sequencing and multilocus sequence typing (MLST). Amongst 311 selected isolates, 29 <i>flaA</i> SVR alleles and 17 sequence types (STs) were identified. The common clonal complexes (CCs) found in this study were CC-45, CC-353, CC-354 and CC-574. <i>C</i>. <i>jejuni</i> isolated from breeders were distantly related to those isolated from broilers and chicken carcasses, while <i>C</i>. <i>jejuni</i> isolates from the slaughterhouse environment and meat products were similar to those isolated from broiler flocks. Genotypic identification of <i>C</i>. <i>jejuni</i> in slaughterhouses indicated that broilers were the main source of <i>Campylobacter</i> contamination of chicken meat during processing. To effectively reduce <i>Campylobacter</i> in poultry meat products, control and prevention strategies should be aimed at both farm and slaughterhouse levels.</p></div

<i>Campylobacter</i> genotypes detected in each chicken meat production units.

<p><i>Campylobacter</i> genotypes detected in each chicken meat production units.</p

Distribution of <i>Campylobacter</i> in 5 chicken meat production chains in Thailand.

<p>Distribution of <i>Campylobacter</i> in 5 chicken meat production chains in Thailand.</p

Within-flock prevalence and predominant genotypes of <i>Campylobacter</i> during the rearing period.

<p>Within-flock prevalence and predominant genotypes of <i>Campylobacter</i> during the rearing period.</p

Types and number of samples collected throughout the chicken meat production chain.

<p>Area of boot swab sampling at downtime period included anteroom of the target house, inside the target house and area around the house. Area of boot swab sampling during the rearing period included path-leading to the house, anteroom of the target house, inside the target house, area around the house and inside the adjacent house. Flocks D and E were visited at 7^th, 14^th, 21^st, 28^th, 35^th day of the rearing period, while other flocks were visited at 7^th, 14^th, 17^th, 21^st, 24^th, 28^th, 31^st, 35^th, 38^th day of the rearing period.</p