Molecular Epidemiology ofCampylobacter jejuniin a Geographically Isolated Country with a Uniquely Structured Poultry Industry

Abstract

In New Zealand the number of campylobacteriosis notifications increased markedly between 2000 and 2007. Notably, this country's poultry supply is different than that of many developed countries as the fresh and frozen poultry available at retail are exclusively of domestic origin. To examine the possible link between human cases and poultry, a sentinel surveillance site was established to study the molecular epidemiology of Campylobacter jejuni over a 3-year period from 2005 to 2008 using multilocus sequence typing. Studies showed that 60.1 to 81.4% of retail poultry carcasses from the major suppliers were contaminated with C. jejuni. Differences were detected in the probability and level of contamination and the relative frequency of genotypes for individual poultry suppliers and humans. Some carcasses were contaminated with isolates belonging to more than one sequence type (ST), and there was evidence of both ubiquitous and supplier-associated strains, an epidemiological pattern not recognized yet in other countries. The common poultry STs were also common in human clinical cases, providing evidence that poultry is a major contributor to human infection. Both internationally rare genotypes, such as ST-3069 and ST-474, and common genotypes, such as ST-45 and ST-48, were identified in this study. The dominant human sequence type in New Zealand, ST-474, was found almost exclusively in isolates from one poultry supplier, which provided evidence that C. jejuni has a distinctive molecular epidemiology in this country. These results may be due in part to New Zealand's geographical isolation and its uniquely structured poultry industry.

A Longitudinal 6-Year Study of the Molecular Epidemiology of Clinical Campylobacter Isolates in Oxfordshire, United Kingdom

“…In common with similar studies of human infection (31,33,41,43), the Campylobacter genotypes responsible for human disease were highly diverse, with a predominance of genotypes similar to those seen previously. However, investigation of isolates having an ST unassigned to a clonal complex identified 62 isolates of ST-464.…”

“…Genetic attribution studies have identified the principal source of infection as retail meat, especially chicken, in a number of countries, including the United Kingdom. Molecular data have led to interventions in the poultry industry in New Zealand which have proved to be effective in reducing human disease (40); however, New Zealand poultry production is limited to three major suppliers (33) and the extent to which this will be possible in countries with more complex industries remains unclear. In any case, ongoing surveillance of the genotypes causing human disease is essential if the impact of such interventions is to be measured and understood, particularly as the predominant genotypes in human disease show pronounced changes over time and new genotypes are frequently observed, reflecting the size and diversity of the Campylobacter populations that infect chickens.…”

The Evolution ofCampylobacter jejuniandCampylobacter coli

“…This approach has formed the basis of many recent investigations of the cryptic epidemiology of these organisms (Lang et al 2010;Müllner et al 2010;Thakur et al 2010;Hastings et al 2011;Jorgensen et al 2011;Kittl et al 2011;Magnú sson et al 2011;Sheppard et al 2011a,b;Sproston et al 2011;Read et al 2013) and will be the focus of this review. Such studies have included molecular epidemiological and evolutionary analyses and, in the past 15 years or so, the application of high-throughput DNA sequencing technologies of increasing capacity has enhanced the integration of these two areas of investigation to their mutual benefit.…”

Molecular Epidemiology of Campylobacter coli Strains Isolated from Different Sources in New Zealand between 2005 and 2014

“…Most epidemiological studies of campylobacteriosis that applied bacterial identification in New Zealand focused on C. jejuni (10,11). Consumption of chicken meat is considered the main risk factor for C. jejuni infections in New Zealand and in a number of other countries (10,12).…”