First Detection of Critical Carbapenemase Genes (NDM, OXA-48, VIM) in Avian Campylobacter spp. Isolates in Tunisia: A Zoonotic and Public Health Concern

<b>Background/Objectives</b>: The global emergence of carbapenem resistance is a major public health concern. <i>Campylobacter jejuni</i> and <i>Campylobacter coli</i>, key zoonotic agents causing human campylobacteriosis, are mainly isolated from poultry, their primary host. Their increasing resistance in animals and humans highlights the risk of gene transfer. This study investigates the molecular mechanisms of carbapenem resistance in 287 avian <i>Campylobacter</i> spp. isolates from Tunisia within a One Health approach. <b>Methods:</b> Antibiotic susceptibility of 287 carbapenem-resistant isolates, including 147 <i>C. jejuni</i> and 140 <i>C. coli</i>, was determined according to CLSI. All isolates were screened by PCR for genes encoding the most reported carbapenemases, including VIM, IMP, NDM and OXA-48. Eleven multidrug-resistant (MDR)/carbapenem-resistant <i>C. coli</i> isolates were selected to determine their clonal lineage by Multilocus sequence typing (MLST). <b>Results:</b> All isolates were susceptible to imipenem, but resistance to meropenem and ertapenem were observed in 60.71% and 35.71% of <i>C. coli</i> isolates, respectively, versus 13.6% in <i>C. jejuni</i> for each antibiotic. The <i>bla</i>_VIM, <i>bla</i>_NDM and <i>bla</i>_OXA-48 genes were detected in 15, 8, and 19 of the 20 <i>C. jejuni</i> isolates, respectively. However, for <i>C. coli</i>, 53, 12, and 15 isolates harbored <i>bla</i>_VIM, <i>bla</i>_NDM and <i>bla</i>_OXA-48 genes, respectively. The eleven (MDR)/carbapenem-resistant <i>C. coli</i> isolates belonged to a unique ST sequence type ST13450. <b>Conclusions:</b> We report for the first time the emergence of <i>bla</i>_VIM, <i>bla</i>_NDM, and <i>bla</i>_OXA-48 genes in <i>Campylobacter</i> spp. isolates of poultry origin highlighting possible horizontal transfer of these genes to pathogenic Gram-negative bacteria of the poultry's microbiota.