Carbapenem resistance genes in campylobacter coli and campylobacter jejuni isolated from chickens, and diarrheal children aged less than five years in Kampala City

Abstract

Campylobacter is one of the leading causes of food-borne diseases in humans worldwide. Like other zoonotic bacteria, Campylobacter has the potential to act as reservoirs and vehicles for the transmission of antimicrobial resistance in different settings. Of particular concern is the resistance to critical “last resort” antibiotics “Carbapenems.” In contrast to Enterobacteriaceae such as Klebsiella pneumoniae, Escherichia coli, and Enterobacter, which are major nosocomial pathogens affecting debilitated and immunocompromised patients, Campylobacter has exhibited low resistance to Carbapenems. However, most studies conducted on Carbapenem resistance have been in Enterobacteriaecae of clinical origins while neglecting bacteria associated with food-producing animals and their environment. The aim of this study was therefore to determine the phenotypic susceptibility patterns against Meropenem and Imipenem and decipher occurrence of Carbapenem resistance genes in Campylobacter coli and Campylobacter jejuni isolates from chickens and diarrheal children aged less than five years in Kampala city, Uganda. 292 isolates of cryopreserved Campylobacter (48 from children and 244 from chickens in the childrens’ homes or neighbourhoods) at -40ºC were screened for Campylobacter 16S RNA genes and species re-identification using multiplex PCR, analysis of phenotypic susceptibility patterns was performed using Kirby Bauer disk diffusion methods and subsequent detection of Carbapenem resistance genes using multiplex PCR. 235(80.5%) of the isolates were positive for Campylobacter 16S RNA gene, out of which 31(13.2%) were C. jejuni and 204(86.8%) were C. coli. Phenotypic susceptibility analysis revealed that all the isolates were susceptible to Meropenem and Imipenem. Carbapenem resistance genes (blaVIM, blaNDM-1, blaIMP, and blaOXA-48) were detected in 70(29.8%) of the isolates. The most prevalent gene was blaVIM 43(61.4%), followed by blaNDM-1 8(11.4%), blaIMP 6(8.6%) and blaOXA-48 1(1.4%). A combination of blaVIM and blaIMP was 7(10.0 %), blaVIM and blaNDM-1 4(5.7%), and 1(1.4%) had blaNDM-1, blaVIM and blaIMP. In conclusion, this study demonstrated that even though all the C. jejuni and C. coli isolates were phenotypically susceptible to the selected Carbapenems, blaVIM, blaNDM-1, blaIMP, and blaOXA-48 carbapenem resistance genes were detected. This is the first study to identify carbapenem resistance genes in Campylobacter coli and Campylobacter jejuni globally.