The Prevalence and Genetic Diversity of Campylobacter spp. in Domestic ‘Backyard’ Poultry in Canterbury, New Zealand

Abstract

Campylobacteriosis is the most commonly notified illness in New Zealand. Whilst the importance of commercial poultry in campylobacteriosis is well established, little is known about the possible role of chickens kept at home as a direct animal/faecal contact or consumption exposure pathway. The aim of this study was to determine the prevalence and genetic diversity of Campylobacter spp. in domestic backyard chicken flocks in the Canterbury region of New Zealand. Poultry faecal samples were collected from 35 domestic 'backyard' poultry flocks from urban and rural properties around the Canterbury Region of New Zealand. A total of 291 samples were collected and tested for the presence of thermotolerant Campylobacter spp. and positive isolates were analysed using pulsed-field gel electrophoresis (PFGE) using both SmaI and KpnI enzymes. There was a high prevalence of Campylobacter spp. with 86% of flocks testing positive. Campylobacter jejuni alone, Campylobacter coli alone and both C. jejuni and C. coli were detected in 20 (57%), 2 (6%) and 8 (23%) of the flocks respectively. SmaI/KpnI PFGE analysis identified 50 different genotypes across the 35 flocks. Genotype diversity richness was highest on the lifestyle block and farm properties with 43 different genotypes isolated, whilst urban properties displayed the least richness with 12 genotypes isolated. Rural flocks tended to have more different genotypes in a given flock than urban flocks. Comparison of the genotypes with the PulseNet Aotearoa Campylobacter database showed that 28 of the genotypes had previously been isolated from human cases of campylobacteriosis. Many of these were also indistinguishable from Campylobacter spp. previously isolated from retail chicken. Therefore, contact with backyard poultry or their faecal material is a potential additional infection pathway outside of exposure to the established pathways associated with the consumption of Campylobacter-contaminated commercial meat or foods cross-contaminated from contaminated poultry.

Frequency and antimicrobial behaviour of thermophilic Campylobacter species isolated from Ecuadorian backyard chickens

“…The prevalence of the thermotolerant species of Campylobacter found in this study (41.7%) was higher than the prevalence reported in Southern Chile (25.7%) by Fernández and Torres (2000) but lower to that informed in New Zealand, where 86% of flocks tested positive with a Campylobacter isolation rate of 57.7% (Anderson et al 2012). However, in agreement with the results of these authors, our isolation rate of C. jejuni was higher than the rate obtained for C. coli.…”

“…However we could not obtain information from the owners about the use of antibiotics, we believe that as occurs in other places of the developing world, this probably reflects an overuse of these antibiotics in backyard chickens in this region, something that could represent an epidemiological problem with implications for treatment in human beings (WHO 2013, Whitehead andRoberts 2014). This is particularly important in backyard chickens because i) exposure of children to infected backyard poultry may represent another route of transmission for Campylobacter infection (Anderson et al 2012, Whitehead and Roberts 2014, El-Tras et al 2015, on which there are not sufficient epidemiological studies and ii) there is a lack of good biosecurity and good management practices applicable to reduce the risk of infection and antimicrobial resistance levels in backyard chickens (Whitehead andRoberts 2014, El-Tras et al 2015).…”

Campylobacterinfections in children exposed to infected backyard poultry in Egypt

“…However, since only four birds were sampled per flock it is likely that there was misclassification with some infected flocks being defined as 'negative' on sampling results. Other exposure routes may also account for infection of these children namely ingestion of contaminated water, milk, food and exposure via other livestock or other households' backyard poultry [2,18,32,33].…”

“…Humans acquire Campylobacter infections chiefly through handling and/or consumption of contaminated food or drinks; mainly poultry, untreated water and unpasteurized milk [14,16,17]. Direct and indirect contact with infected animals (including poultry) and/or their faeces is also a risk factor for acquisition of infection by Campylobacter species [18]. In developing countries, Campylobacter infections occur most frequently in children as older children and adults acquire a level of protective immunity following exposure [9,19,20].…”

Genotyping of Campylobacter coli strains isolated in Brazil suggests possible contamination amongst environmental, human, animal and food sources

“…For example, in a study reported by Abay et al (2014) in Turkey, 152 C. jejuni samples isolated from humans and chickens were analysed by PFGE; 81 of the isolates exhibited unique band patterns. Likewise, in a study by Anderson et al (2012), 168 C. jejuni and C. coli strains isolated from faeces of chickens exhibiting 34 different properties were analysed by PFGE, and a high diversity was found amongst the strains. Sma I/Kpn I PFGE analysis identified 50 different genotypes amongst the 168 isolated strains (Anderson et al, 2011).…”