一株特殊耐药表型肺炎克雷伯菌的耐药机制研究

目的 研究对氨基糖苷类抗生素产生特殊耐药现象（双抑菌圈）的肺炎克雷伯菌的耐药表型和耐药机制.方法 用K-B法、E-test法、三维试验等方法对其耐药表型进行研究.采用聚合酶链反应（PCR）技术对7种氨基糖苷类钝化酶基因、2种核糖体甲基化基因和Ⅰ类整合子进行检测,并对PCR产物测序.结果 细菌的这种特殊耐药表型是稳定的;PCR结果表明：这株菌含有Aac（3）-Ⅱ钝化酶基因、armA核糖体甲基化耐药基因和1000bp左右的Ⅰ类整合子.结论 这株菌对氨基糖苷类抗生素的耐药是多种耐药机制相互作用的结果.但是这尚不能满意地解释这种特殊的耐药现象,其机理有待进一步研究.

Resistant mechanisms of a special antibiotic resistance profile of Klebsiella pneumoniae to aminoglycoside

Objective To investigate the mechanism of a special antibiotic resistance profile of a Klebsiella pneumoniae strain from aminoglycoside resistance to gene patterns. Methods K-B diffusion test, E-test, and three dimensional test were used to investigate the antibiotic resistance profile. AME genes, 16S rRNA methylase genes and integron were confirmed by PCR, respectively. PCR products were then purified and sequenced. Results The special antibiotic resistance profiles were stable.One AME genes [Aac(3)- II ], one 16S rRNA methylase genes (armA), and class 1 integron were identified by PCR. Conclusions The special antibiotic resistance is not induced only by aminoglycoside itself. Aminoglycoside modifying enzymes and plasmid-mediated 16S rRNA methylases may be the major factors which confer aminoglycoside resistance on Klebsiella pneumoniae stains. Until recently, the mechanism causing double inhibition cycles is not clear and needs to be further investigated.