植物乳杆菌HNU082抗生素抗性与相关基因的关系

Relationship between Antibiotic Resistance and Related Genes in Lactobacillus plantarum HNU082

以一株分离自海南鱼茶的植物乳杆菌(Lactobacillus plantarum) HNU082为研究对象,经全基因组测序获知该菌株所携带的抗生素抗性基因信息(arlR、emeA、fexA、lmrC、lmrD、macB、mepA、mprF、novA、pbp1a、gyrB、rpoB 9类),并针对11种常用抗生素进行抗性筛选,得到各抗生素对HNU082的最小抑制浓度(Minimum Inhibitory Concentrations,MIC),从而确定其抗性基因与抗生素抗性间的关系。结果表明,并非所有抗性基因都能导致菌株对相应抗生素产生抗性:菌株检出rpoB却未表达利福平抗性;抗性程度与抗性基因所占比例大小无关:与万古霉素和诺氟沙星相关的抗性基因分别占所检测基因总数的6.7%和20.0%,但菌株对二者所表达的抗性均为MIC> 1280μg/mL,而盐酸克林霉素相关基因占所检测基因的20.0%,其MIC(20μg/mL)却与诺氟沙星相差很大;红霉素和罗红霉素的相关抗性基因均为mac B,但菌株对罗红霉素的抗性强于红霉素,即对受同一基因影响的不同药物,菌株所表现的抗性特征也不尽相同。

Taking Lactobacillus plantarum HNU082 isolated from traditional fermented Yucha of Hainan,the antibiotic resistance gene information carried by the strain was interpreted by whole genome sequencing (arlR,emeA,fexA,lmrC,lmrD,macB,mepA,mprF,novA,pbp1a,gyrB,and rpoB). Based on this,resistance screening was carried out for 11 commonly used antibiotics.Thus the minimum inhibitory concentrations (MIC) of the 11 antibiotics against HNU082 were obtained to determine the relationship between the resistance gene and antibiotic resistance under specific experimental conditions.The results showed that not all resistance genes could cause strains to develop resistance to the corresponding antibiotics. For example,rpoB was detected from the strain,but didn’t express rifampicin resistance.The degree of resistance was independent on the proportion of resistance genes.Vancomycin and norfloxacin-related genes respectively accounted for 6.7% and 20.0% of the total detected genes,but the resistance of strains to both genes was MIC > 1280 μg/mL. While clindamycin hydrochloride-related genes accounted for 20.0% of the detected genes,the MIC (20 μg/mL) was quite different from that of norfloxacin. The related resistance genes of erythromycin and roxithromycin were mac B,but the resistance of the strain to roxithromycin was stronger than that of erythromycin.So different drugs affected by the same gene would have different resistance characteristics.