Prevalence, Antimicrobial Susceptibility, Virulence and Genotyping of Campylobacter jejuni with a Special Reference to the Anti-Virulence Potential of Eugenol and Beta-Resorcylic Acid on Some Multi-Drug Resistant Isolates in Egypt

SIMPLE SUMMARY: Campylobacter jejuni is the main reason for human foodborne bacterial enteritis globally. Contaminated chickens and their products are the principal reservoirs of C. jejuni and they are responsible for up to 80% of human campylobacter infection cases. In the current study, we determined the prevalence, antibiogram, the virulence factors encoding genes, and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) profiles of C. jejuni isolated from chicken and human in Egypt, and we also assessed the effects of two phytochemicals (eugenol and beta-resorcylic acid) on the virulence of avian multi-drug resistant (MDR) and multi-virulent C. jejuni isolates. Our results revealed high prevalence of C. jejuni isolates (32.8%), and all isolates were MDR. Chicken and human C. jejuni isolates were clustered together as found in ERIC-PCR fingerprinting clusters II–V, which confirmed the genetic relatedness between both origins. Additionally, beta-resorcylic acid and eugenol reduced the invasion of MDR C. jejuni isolates to chicken intestinal epithelial cells and also minimized the transcription of flaA, virB11, and wlaN genes in the tested isolates. In conclusion, eugenol and beta-resorcylic acid could be used for minimizing the colonization and pathogenicity of C. jejuni; therefore, they could be utilized for controlling C. jejuni in broiler chickens and potentially for managing human campylobacteriosis. ABSTRACT: Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis in humans worldwide. Contaminated chickens and their products are the main sources of human campylobacteriosis. Therefore, this study aimed to detect the genotypic and virulence genes‘ profiles of multi-drug resistant (MDR) C. jejuni isolates and to assess the effects of sub-inhibitory concentrations (SICs) of eugenol and beta-resorcylic acid on the virulence of avian MDR C. jejuni isolates. These isolates were clustered together with the human isolates via enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) fingerprinting. A total of 345 samples were collected from human stool (100) and different chicken (245) samples in Sharkia Governorate, Egypt. Conventional phenotypic methods identified 113 isolates (32.8%) as C. jejuni, and all C. jejuni isolates were MDR and resistant to erythromycin and ampicillin. The genes virB11, wlaN, and flaA were detected in 52%, 36% and 100% strains, respectively. ERIC-PCR yielded 14 profiles and five main clusters. Interestingly, human and chicken C. jejuni isolates were clustered together in ERIC-PCR clusters II-V, which confirmed the genetic relatedness between the isolates from both origins. Beta-resorcylic acid and eugenol inhibited the invasion of C. jejuni isolates to chicken intestinal cells by 41.66–38.19% and 31.94–29.16%, respectively, and minimized the transcription of flaA, virB11, and wlaN genes in the tested isolates by real-time quantitative reverse transcription PCR (qRT-PCR). In essence, eugenol and beta-resorcylic acid are promising natural antimicrobials for minimizing the virulence of MDR C. jejuni in chickens, thereby managing human campylobacteriosis.