Campylobacter coli and Campylobacter jejuni exchange genes

A North Carolina State University study of Campylobacter isolates from live food animals, poultry carcasses at production and retail meat has found that Campylobacter coli and Campylobacter jejuni are exchanging genetic material, which could result in more antibiotic-resistant and infectious strains. The findings are published in PLoS ONE.

Both C. coli and C. jejuni are commonly found throughout the poultry production process in North Carolina, according to corresponding author Sid Thakur, professor of population health and pathobiology and director of global health programs at North Carolina State University and the College of Veterinary Medicine.

“Since Campylobacter has a fairly ‘plastic’ genome, the strains can exchange genetic material,” Thakur says. “If C. coli starts to take in a lot of C. jejuni’s genetic material and increases its virulence, then it will cause larger numbers of infections that are antibiotic resistant, which could become a big public health issue. Likewise, if C. jejuni takes up antibiotic-resistant genes from C. coli, the same thing happens.”

The team sampled chicken and turkey from retail grocery stores across North Carolina during 2018-2019. They compared Campylobacter isolates from the meat to USDA samples taken from poultry farms and production facilities in North Carolina. C. coli was most prevalent on farms and production facilities, at 54% and 60% for chicken isolates respectively, while C. jejuni was found in 69% of retail chicken meat.

They then tested the isolates from food animals and meat for antimicrobial-resistant (AMR) genes and found that 90% of both C. coli and C. jejuni contained at least one AMR gene while 43% contained resistance genes to three or more antibiotic drug classes. 24% of C. jejuni included resistance genes to fluoroquinolones, the “last line of defence” against Campylobacter.

The team also noted the appearance of a significantly higher number of new Campylobacter strains (21 in 2019 compared to only two in 2018). This indicates extensive changes occurring in the Campylobacter genome that have the potential to increase its virulence and drug resistance profile.

The researchers say, “As Campylobacter continues to be the worldwide leading cause for foodborne illness, further research is needed to track evolutionary patterns and interspecies genomic exchange, which may alter sensitivity and specificity of diagnostic tests and aid Campylobacter survivability and transmission through food processing.”

Article: Hull, D. M., Harrell, E., van Vliet, A., Correa, M., Thakur, S. (2021). Antimicrobial resistance and interspecies gene transfer in Campylobacter coli and Campylobacter jejuni isolated from food animals, poultry processing, and retail meat in North Carolina, 2018-2019. PloS ONE 16(2): e0246571, doi: 10.1371/journal.pone.0246571

[SOURCE: North Carolina State University]