克罗诺杆菌的生物膜检测和药敏性分析

Biofilm Detection and Antibiotic Sensitivity Analysis of Cronobacter

目的:了解38株主要来源于我国婴幼儿食品克罗诺杆菌分离株的生物膜形成能力和药敏性。方法:首先用fusA序列分析,对43株克罗诺杆菌进行准确鉴定;采用半定量黏附实验(结晶紫染色法)测定分离株的生物膜形成能力,并选用八大类11种抗生素测定其抗生素敏感性。结果:鉴定出34株阪崎克罗诺杆菌、7株丙二酸盐克罗诺杆菌和2株都柏林克罗诺杆菌。这些克罗诺杆菌分离株均有一定生物膜成膜能力,其中丙二酸盐克罗诺杆菌的成膜能力较强;菌株普遍对四环素和万古霉素耐药性较高,共有14个耐药谱;四环素的耐药性与生物膜形成能力有显著相关性。结论:实验结果表明克罗诺杆菌的成膜性和耐药性都较强,对相关食品企业的消杀措施和临床治疗提出了挑战。

Cronobacter isolates including 5 standard strains and 38 isolates from infant foods were studied for biofil-formating capability and antibiotic sensitivity. The fusA sequence analysis was used to identify the species of these isolates. Then the isolates were tested for biofilm-forming capability by crystal violet staining. And 11 antibiotics belonging to 8 categories were selected to test their antibiotic sensitivity. Totally 34 C. sakazakii, seven C. malonaticus and two C. dublinensis strains were identified. All these isolates were able to form biofilm. C. malonaticus showed stronger biofilm-forming capability. The resistance to tetracycline and vancomycin was higher. Totally 14 antibiotic resistance homologies were identified. The resistance to tetracycline correlated with biofilm-forming capability. All the Cronobacter isolates investigated showed biofilm-forming capability and antibiotic resistance to some extent, which pose a challenge the disinfection and sterilization methods used in food industries and clinical therapy.