携带质粒李斯特菌耐药及重金属抵制特性研究

鉴定单核细胞增生性李斯特菌(Lm)携带质粒特性,分析携带质粒Lm对抗生素、重金属镉及苯扎氯铵的敏感性。结果表明,11株Lm携带内源性质粒;所有Lm菌株对阿莫西林、红霉素和利福平均敏感(22/22),对头孢拉定100%耐药(22/22);其中5株对盐酸万古霉中度耐受,部分菌株对盐酸环丙沙星(17/22)、硫酸新霉素(16/22)及盐酸四环素素(9/22)具有一定耐受性。耐镉分析表明,菌株对重金属镉呈现抵制特性(14/22),且均为携带质粒菌株;而在苯扎氯铵敏感性检测中,仅3株携带质粒Lm菌株对苯扎氯铵具有抵制性。对Lm菌株进行噬菌体杀菌检测,结果均能够被噬菌体识别并裂解。综上所述,Lm分离株耐药性增强,且对苯扎氯铵和镉有抵制特性,而噬菌体能够杀灭抵制菌株,为控制耐药及抵制性菌株污染提供了新途径。

Characterization of Antibiotic, Heavy Metal, and Benzalkonium Chloride Resistance of Plasmid-carrying Listeria monocytogenes

The major aims of this study included the characterization of plasmids carried by Listeria monocytogenes (Lm), and an in-depth analysis of the sensitivity of plasmid-carrying Lm towards antibiotics, the heavy metal cadmium, and benzalkonium chloride. The results of this study showed the presence of endogenous plasmids in 11 Lm strains. All Lm strains displayed average sensitivity to amoxicillin, erythromycin, and rifampicin (22/22), and 100% resistance to cefradine (22/22). Five strains showed intermediate resistance to vancomycin hydrochloride, while some strains were resistant to ciprofloxacin (17/22), neomycinsulphate (16/22), and tetracycline hydrochloride (9/22). The analysis of cadmium resistance showed the presence of plasmids in all strains resistant to the heavy metal cadmium (14/22). In contrast, only three of the plasmid-carrying Lm strains were determined to be resistant to benzalkonium chloride. All Lm strains were identified and lysed via the phage sterilization method. In summary, although the plasmid-carrying Lm isolates displayed increased drug-, benzalkonium chloride-, and cadmium-resistance, they were susceptible to phage action. Therefore, the results of this study indicate a novel method for the control of drug resistance and pollution by resistant-bacteria.