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目的了解1株多药耐药肺炎克雷伯菌的遗传学背景。方法采用聚合酶链反应(PCR)的方法分析1株多药耐药肺炎克雷伯菌可能存在的65种耐药相关基因:包括β-内酰胺类、氨基糖苷类、喹诺酮类耐药相关基因及可移动的遗传元件(整合子、转座子、接合性质粒)遗传标记、抗菌制剂外排泵基因。结果该株多药耐药肺炎克雷伯菌耐β-内酰胺类药物基因检出blaTEM,耐氨基糖苷类药物基因检出aph(3′)-Ⅰ,耐喹诺酮类药物基因检出gyrA,Ⅰ类整合子遗传标记检出intⅠ1,转座子遗传标记检出tnp513,接合性质粒遗传标记检出trbC;抗菌制剂外排泵基因检出qacE△1-sul1,gyrA基因是新亚型(GenBank登录号:JN232083),83位密码子突变方式为TCG→TTC,导致氨基酸从丝氨酸(S)→苯丙氨酸(F);87位密码子突变方式为GAC→GCC,导致氨基酸从天冬氨酸(D)→丙氨酸(A)。结论携带多药耐药基因和抗菌制剂外排泵基因是这株肺炎克雷伯菌呈多药耐药的主要原因,携带多种可移动遗传元件使细菌的耐药性在同种细菌菌株之间,甚至不同种细菌菌株之间得以快速传播。
Objective To understand the genetic background of a multidrug-resistant Klebsiella pneumoniae. Methods The polymerase chain reaction (PCR) method was used to analyze 65 multidrug-resistant Klebsiella pneumoniae may exist in 65 kinds of resistance-related genes: β-lactams, aminoglycosides, quinolone resistance-related genes And genetic markers of mobile genetic elements (integrons, transposons, conjugative plasmids), anti-bacterial efflux pump genes. Results The strain of multidrug - resistant Klebsiella pneumoniae was resistant to blaTEM, the gene of aph (3 ’) - resistant to aminoglycoside was detected, and the gene of quinolone was detected as gyrA, Ⅰ IntI1 was detected in the integron marker, tnp513 in the transposon marker, and trbC in the junctional plasmid. The qacE △ 1-sul1 gene was detected in the efflux pump gene of the antimicrobial agent, and the gyrA gene was a new subtype (GenBank accession (SEQ ID NO: JN232083). The mutation at codon 83 is TCG → TTC, resulting in the amino acid change from serine (S) → phenylalanine (F); the mutation at codon 87 is GAC → GCC, resulting in the conversion of amino acids from aspartic acid (D) → alanine (A). Conclusion The gene of multidrug resistance gene and efflux pump of antimicrobial agents are the main cause of multidrug resistance in this strain of Klebsiella pneumoniae. Between, even different kinds of bacterial strains can be spread rapidly.