【摘要】：目的對嗜麥芽窄食單胞菌感染的臨床分布、抗菌藥物的耐藥狀況及耐藥基因進行研究,為臨床治療提供有力依據;用脈沖場凝膠電泳技術(PFGE)對嗜麥芽窄食單胞菌進行同源性分析,探討該菌的醫(yī)院感染特征。方法收集2010—2012年三年寧夏醫(yī)科大學總醫(yī)院臨床常規(guī)檢出的嗜麥芽窄食單胞菌,采用全自動微生物鑒定儀對細菌進行鑒定,并用K-B瓊脂紙片擴散法進行藥敏試驗;篩選2012年全年114株嗜麥芽窄食單胞菌,采用瓊脂二倍稀釋法測定7種抗菌藥物對細菌的最低抑菌濃度(MIC)值,同批測定諾氟沙星、環(huán)丙沙星、氧氟沙星加入外排泵抑制劑(利血平)后抗菌藥物的MIC值的變化情況;應用聚合酶鏈反應(PCR)檢測嗜麥芽窄食單胞菌中氟喹諾酮類耐藥基因的存在情況;應用實時熒光定量PCR法檢測外排泵sme D和sme F基因m RNA的相對表達水平;測序后進行Blast比對序列;應用脈沖場凝膠電泳進行同源性分析。結果2010—2012年三年共分離得到嗜麥芽窄食單胞菌426株,占非發(fā)酵菌的10.1%(426/4225);114株嗜麥芽窄食單胞菌對諾氟沙星、環(huán)丙沙星和氧氟沙星的耐藥率分別為32.4%、21.9%和13.2%。加入泵抑制劑后共篩選得到19株外排泵陽性株。篩選得到的2株外排泵陽性的耐藥株均有sme D和sme F的高表達。114株嗜麥芽窄食單胞菌中gyr A,par C,sme D,sme E,sme F基因的陽性率均為100%,smqnr基因的陽性率為25.4%。5株菌的gyr A基因有3株菌的第51位氨基酸發(fā)生了由谷氨酸突變?yōu)橘嚢彼?5株菌的par C基因中有4株菌的第37位的氨基酸發(fā)生了由甘氨酸突變?yōu)榫彼�。發(fā)生gyr A或par C基因突變的耐藥與敏感組之間的差異無顯著性(P0.05)。對29株嗜麥芽窄食單胞菌進行PFGE同源性分析,呈現散在分布。結論1.寧夏醫(yī)科大學總醫(yī)院的嗜麥芽窄食單胞菌主要分布在ICU、呼吸科、神經外科以及兒科,以痰、咽拭子、導管和排泄物中檢出率最高。2.在嗜麥芽窄食單胞菌中smqnr基因介導氟喹諾酮的低水平耐藥且與外排泵基因共同介導耐藥。3.通過PFGE技術得出本院嗜麥芽窄食單胞菌并未出現同一克隆株的暴發(fā),呈現散在分布。
[Abstract]:Objective to study the clinical distribution, antibiotic resistance and drug resistance genes of Stenococcus maltophilia infection, so as to provide a powerful basis for clinical treatment. The homology of Stenococcus maltophilia was analyzed by pulse field gel electrophoresis (PFGE), and the characteristics of hospital infection of Stenococcus maltophilia were discussed. Methods from 2010 to 2012, Stenococcus maltophilia was collected from the General Hospital of Ningxia Medical University. The bacteria were identified by automatic microbial identification instrument, and the drug sensitivity test was carried out by K / B Agar disk diffusion method. 114 strains of Stenococcus maltophilia were screened for the whole year of 2012. The minimum inhibitory concentration (MIC) of 7 antibiotics against bacteria was determined by Agar dilution method, and norfloxacin and ciprofloxacin were determined in the same batch. The changes of MIC of antibiotics after ofloxacin was added to efflux pump inhibitor (reserpine). The presence of fluoroquinolones resistance genes in Stenococcus maltophilia was detected by polymerase chain reaction (PCR), and the relative expression of sme D and sme F gene m RNA in efflux pump was detected by real-time fluorescence quantitative PCR. The sequence was compared by Blast after sequencing, and the homology was analyzed by pulse field gel electrophoresis. Results A total of 426 strains of Stenococcus maltophilia were isolated from 2010 to 2012, accounting for 10.1% (426 鈮，

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