ANTIMICROBIAL RESISTANCE, VIRULENCE-ASSOCIATED GENES, AND FLAGELLIN TYPING OF THERMOPHILIC CAMPYLOBACTER SPECIES ISOLATED FROM DIARRHEIC HUMANS, RAW MILK, AND BROILER NICHES
Animal-to-human transmission is frequently linked to commensal bacteria in the gastrointestinal tract, as Campylobacter species. We provide a better insight into the existence of cytolethal distending toxin (cdt) and flagellinA (flaA) genes in different antimicrobial resistance patterns (pandrug-resistance (PDR), extensive drug-resistance (XDR) and multidrug-resistance (MDR)] in Campylobacter species recovered from chickens, milk, and human sources in Egypt. Campylobacter species isolation rate was 89.44%, being 79.50% and 20.50% for C. jejuni and C. coli, respectively. Animal samples (chickens and raw milk) showed a higher prevalence of C. coli (21.17%); whereas C. jejuni was highly documented in human samples (83.33%). Testing of antimicrobial susceptibilities revealed that none of the examined campylobacters was pansusceptible, while PDR (1.86%), XDR (65.53%), and MDR (32.61%) campylobacters were reported. Molecular analysis revealed that 50%, and13.16% of the isolated campylobacters were positive for the cdt and flaA genes, respectively. Interestingly, all flaA-positive isolates were cdt-positive C. jejuni. Restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) assay revealed a genetic diversity among flaA harboring isolates presented as three different RFLP patterns of varying sizes ranged from 112 to 647 bp, where flaA-RFLP pattern-I is overrepresented in C. jejuni isolates from various origins (human, milk, and chicken sources). Evidence from this study showed the possibility of treatment failure in campylobacteriosis due to the existence of resistant isolates to all antimicrobial drugs (PDR) and the marked genetic variability of flaA-RFLP pattern that is useful in the epidemiological issues.
Key words: Campylobacter species; Antimicrobial resistance; Virulence genes; Flagellin typing.