Evaluation of Antibiotic Resistance and adeABC, adeR, adeS Efflux Pump Genes among Foodborne and Clinical Acinetobacter spp. in Türkiye

The adeABC efflux pump has a crucial role in the resistance of Acinetobacter baumannii strains to antimicrobial agents; it is encoded by adeABC, adeR, adeS genes. We evaluated antibiotic resistance, efflux pump genes, clonal relationships, and analyzed a probable correlation that can exist between antibiotic resistance and the aforementioned genes.

We conducted this study on 27 food-originated and 50 human clinical Acinetobacter spp. in Southern Türkiye. MALDI-TOF system and disc diffusion/agar dilution (colistin) methods were used for the identification and antibiotic susceptibility. The efflux pump genes and genetic relatedness of the two groups were investigated by (PCR) and (PFGE) methods.

Foodborne A. dijkshoorniae strain was multidrug- resistant (MDR), and none of them resistant to colistin. Most of the clinical isolates (92%) were Extensive-Drug Resistant (XDR); highest resistant to ceftazidime, piperacillin-tazobactam, and imipenem (47, 94%), and were lowest to colistin (7, 14%), respectively. adeABC, and adeR, adeS genes were (23, 85.2%), (9, 33.3%), (27, 100%) and (10, 37.3%), (18, 66.7%) in foodborne strains respectively. These rates were (43, 86%), (48, 96%), (50, 100%), and (34, 68%), (48, 96.7%) in clinical strains respectively. A positive correlation existed between adeA gene positivity and piperacillin-tazobactam, ceftazidime, gentamycin, imipenem (P=0.048), amikacin (P=0.007) and trimethoprim-sulfamethoxazole (P=0.029) resistance in clinical strains. A positive correlation of trimethoprim-sulfamethoxazole resistance and adeS gene positivity was seen in foodborne strains (P=0.018).

Multiple-efflux pump genes rise in parallel to multidrug-resistance in clinical isolates, while susceptible to diverse antibiotics; food may be a potential provenance for the dissemination of adeABC, adeR and adeS genes.