發(fā)布時間：2018-09-07 06:41

【摘要】：研究背景肺炎克雷伯菌是革蘭陰性兼性厭氧桿菌,是臨床細(xì)菌分離培養(yǎng)最為常見的條件致病菌之一。但是由于廣譜青霉素類、第三代頭孢菌素、單環(huán)類、β-內(nèi)酰胺酶抑制劑的復(fù)合制劑及喹諾酮類等廣譜抗生素在臨床治療肺炎克雷伯菌感染患者中的大量使用,肺炎克雷伯菌能夠產(chǎn)生超廣譜內(nèi)酰胺酶(ESBLs)和頭孢菌素酶(AmpC酶)等從而對廣譜類抗生素表現(xiàn)出多重耐藥性。碳青霉烯類是β-內(nèi)酰胺類,是臨床治療ESBLs及AmpC酶等腸桿菌科細(xì)菌感染患者的一類廣譜抗生素。然而,伴隨著碳青霉烯類抗生素在臨床大量的使用,對碳青霉烯類抗生素耐藥的腸桿菌科以及不動桿菌屬也在逐漸上升,給臨床治療帶來了嚴(yán)峻挑戰(zhàn)。其中,耐碳青霉烯類抗生素的主要機(jī)制就是細(xì)菌產(chǎn)生碳青霉烯酶。碳青霉烯酶是指能夠水解青霉素類、頭孢菌素類、碳青霉烯類以及β-內(nèi)酰胺酶抑制劑、氨基糖苷類、喹諾酮類等多種抗菌藥物的一大類β-內(nèi)酰胺酶,能大大降低藥物的作用效果甚至消失。碳青霉烯酶大都由質(zhì)粒介導(dǎo),具有廣泛的傳播性。本研究對廣州軍區(qū)廣州總醫(yī)院收集的53株耐碳青霉烯類肺炎克雷伯菌(CRKP)進(jìn)行了菌種鑒定以及藥敏試驗(yàn),并對其耐藥譜以及耐藥表型進(jìn)行了研究,檢測碳青霉烯酶基因以及進(jìn)行了脈沖場凝膠電泳(PFGE)和多位點(diǎn)序列分型(MLST),并且制定了調(diào)查表進(jìn)行臨床病例資料收集以及整理。為我院臨床抗生素的合理使用及采取防治措施提供信息參考。研究方法收集2015年7月到2016年7月自51名患者分離出53株CRKP;VITEK-2全自動微生物儀器以及MALDI-TOF MS對CRKP進(jìn)行鑒定及藥敏試驗(yàn),并同時使用K-B法以及E-test法進(jìn)行確認(rèn);采用改良Hodge試驗(yàn)(MHT)和EDTA試驗(yàn)進(jìn)行碳青霉烯酶表型實(shí)驗(yàn);PCR檢測常見碳青霉烯酶基因KPC、VIM、IMP、NDM-1、OXA-48基因,并進(jìn)行測序以及亞型的確定;PFGE和PLST兩種技術(shù)進(jìn)行同源性研究。研究結(jié)果53株菌株均為碳青霉烯類耐藥;MHT 52株陽性,EDTA均為陰性;52株CRKP攜帶KPC-2,僅有1株細(xì)菌攜帶IMP-4,未發(fā)現(xiàn)VIM、NDM-1、OXA-48基因;經(jīng)PFGE分為Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型4種不同類型;PFGE的Ⅰ型、Ⅱ型和Ⅲ型耐碳青霉烯類肺炎克雷伯菌株屬于ST11;16號為Ⅳ型屬于ST16;本次研究VITEK MS鑒定出來的CRKP包括粘液型在內(nèi)菌株鑒定分值Vitek≥90%,結(jié)果高度可信且與MLST分型的結(jié)果高度相符。結(jié)論本次研究,53株耐碳青霉烯類肺炎克雷伯菌主要耐藥機(jī)制是攜帶KPC-2,存在克隆感染,表明醫(yī)院得加強(qiáng)感染控制;PFGE的Ⅰ型、Ⅱ型為主要流行菌株并且在ICU以及MICU兩大科室克隆傳播,且53株CRKP存在著高度的親緣關(guān)系;ST11作為本院耐碳青霉烯類肺炎克雷伯菌的主要菌株。
[Abstract]:Background Klebsiella pneumoniae is a Gram-negative facultative anaerobic bacterium and one of the most common opportunistic pathogens in clinical bacteria isolation and culture. However, broad-spectrum antibiotics such as broad-spectrum penicillin, third-generation cephalosporins, monocyclic compounds, 尾 -lactamases inhibitors and quinolones are widely used in clinical treatment of Klebsiella pneumoniae infection. Klebsiella pneumoniae can produce extended-spectrum lactamases (ESBLs) and cephalosporinase (AmpC), thus showing multidrug resistance to broad-spectrum antibiotics. Carbapenems are 尾-lactams, which are a kind of broad-spectrum antibiotics for clinical treatment of enterobacteriaceae infections such as ESBLs and AmpC enzymes. However, with the widespread use of carbapenem antibiotics in clinical practice, enterobacteriaceae and Acinetobacter, which are resistant to carbapenem antibiotics, have gradually increased, which has brought severe challenges to clinical treatment. The main mechanism of carbapenem resistance is that bacteria produce carbapenem. Carbapenem is a class of 尾 -lactamases capable of hydrolyzing penicillin, cephalosporins, carbapenes and 尾 -lactamases inhibitors, aminoglycosides, quinolones, etc. Can greatly reduce the effect of drugs or even disappear. Carbapenem is widely transmitted by plasmid. In this study, 53 strains of Klebsiella carbapenicilli (CRKP) collected from Guangzhou General Hospital of Guangzhou military region were identified and tested for drug sensitivity, and the drug resistance spectrum and phenotype were studied. Detection of carbapenase gene, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST),) were carried out, and a questionnaire was developed for clinical case data collection and collation. To provide information reference for rational use of antibiotics and preventive measures in our hospital. Methods from July 2015 to July 2016, 53 strains of CRKP;VITEK-2 were isolated from 51 patients, and MALDI-TOF MS was used to identify CRKP and drug sensitivity test. K-B method and E-test method were used to confirm CRKP. The modified Hodge test (MHT) and EDTA test were used to detect the KPC,VIM,IMP,NDM-1,OXA-48 gene of common carbapenase gene. The homology was studied by sequencing and subtype determination. The results showed that all 53 strains of carbapenem resistant MHT52 were positive for EDTA. Only one strain of CRKP carrying KPC-2, had no VIM,NDM-1,OXA-48 gene, and was classified into four types by PFGE: type 鈪，

本文編號：2227495