Molecular characterization of Campylobacter spp. recovered from beef, chicken, lamb and pork products at retail in Australia.

Rhiannon L Wallace,Angus Mclure,Dieter M Bulach,James J Smith,Natasha Waters,Sally Symes,Themy Saputra,Mary Valcanis,Anastasia Stylianopoulos,Kathryn Glass,Amy V Jennison,Martyn D Kirk,Simon Firestone,Trudy Graham,Iddya Karunasagar

doi:10.1371/journal.pone.0236889

Abstract

Australian rates of campylobacteriosis are among the highest in developed countries, yet only limited work has been done to characterize Campylobacter spp. in Australian retail products. We performed whole genome sequencing (WGS) on 331 C. coli and 285 C. jejuni from retail chicken meat, as well as beef, chicken, lamb and pork offal (organs). Campylobacter isolates were highly diverse, with 113 sequence types (STs) including 38 novel STs, identified from 616 isolates. Genomic analysis suggests very low levels (2.3-15.3%) of resistance to aminoglycoside, beta-lactam, fluoroquinolone, macrolide and tetracycline antibiotics. A majority (>90%) of isolates (52/56) possessing the fluoroquinolone resistance-associated T86I mutation in the gyrA gene belonged to ST860, ST2083 or ST7323. The 44 pork offal isolates were highly diverse, representing 33 STs (11 novel STs) and harboured genes associated with resistance to aminoglycosides, lincosamides and macrolides not generally found in isolates from other sources. Prevalence of multidrug resistant genotypes was very low (<5%), but ten-fold higher in C. coli than C. jejuni. This study highlights that Campylobacter spp. from retail products in Australia are highly genotypically diverse and important differences in antimicrobial resistance exist between Campylobacter species and animal sources.

Highlights

Thermophilic Campylobacter coli and Campylobacter jejuni are the most common causes of foodborne bacterial infections worldwide
Our results indicate Australia’s antimicrobial resistance (AMR) prevalence in Campylobacter spp. from retail products is very low
Consumption of contaminated poultry is well established as a key risk factor for campylobacteriosis, foods derived from other animals can result in Campylobacter infection

Summary

Introduction

Thermophilic Campylobacter coli and Campylobacter jejuni are the most common causes of foodborne bacterial infections worldwide. Campylobacteriosis is the most frequently notified enteric pathogen under surveillance by OzFoodNet, Australia’s government-established foodborne disease surveillance network [1], with 143.5 cases per 100,000 population reported in 2019 [2]. Only a small fraction of people who become ill from food they have consumed seek medical attention [3], the global burden of foodborne disease is substantial. In Australia, foodborne gastroenteritis is responsible for an estimated 4.1 million cases annually [4]. Some cases of Campylobacter infection are associated with serious clinical manifestations such as bacteraemia, reactive arthritis, haemolytic uremic syndrome, meningitis, septicaemia and Guillain-Barresyndrome [5, 6]

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