嗜麦芽窄食单胞菌生物被膜的鉴定和抗生素的体外抗菌活性研究

发布时间：2018-03-23 15:47

本文选题：嗜麦芽窄食单胞菌　切入点：生物被膜　出处：《天津医科大学》2008年硕士论文

【摘要】： 目的:了解天津地区嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia,SMA)感染与耐药现状,探讨银染法对鉴定SMA生物被膜形成的应用价值;观察并了解治疗嗜麦芽窄食单胞菌感染的8种常用抗菌药物对其生物被膜单独和联合作用后的效果,为临床上更合理的治疗SMA感染提供理论依据。方法:通过改良平板法在硅胶膜片——水解酪蛋白肉汤(Mueller-Hintonbroth,MHB)系统中构建SMA生物被膜的体外模型,并以银染法和扫描电镜进行鉴定。分析临床分离的51株SMA对12种常用抗菌药物的耐药情况,通过微量接种针装置建立SMA生物被膜的体外模型,测定左氧氟沙星、环丙沙星、头孢哌酮/舒巴坦、头孢他啶、哌拉西林、红霉素、磺胺甲嗯唑、庆大霉素对产生物被膜SMA的细菌生物被膜抑制浓度(Biofilm Inhibitory Concentration,BIC),并与相应抗生素的最低抑菌浓度(Minimum Inhibitory Concentration,MIC)进行比较。应用联合药敏实验测定红霉素与左氧氟沙星、头孢哌酮/舒巴坦、哌拉西林对5株SMA成熟生物被膜的联合作用,同时行扫描电镜观察抗菌药物作用后细菌生物被膜的形态学变化。结果:银染法和扫描电镜下观察到嗜麦芽窄食单胞菌能在硅胶膜片上形成成熟的生物被膜;51株SMA对12种常用抗菌药物的耐药率分别是:左氧氟沙星12.70%、氧氟沙星25.70%、环丙沙星37.50%、头孢哌酮/舒巴坦43.90%、哌拉西林44.60%、头孢吡肟45.10%、头孢哌酮49.00%、头孢他啶60.30%、庆大霉素81.80%、头孢曲松87.90%、阿米卡星90.60%、头孢噻肟95%;其中,对两种抗菌药物耐药的有4株,对两种以上抗菌药物耐药的临床菌共47株,占总数的92.16%(47/51)。42株SMA利用微量接种针成功建立成熟生物被膜的体外模型,形成BBF后8种抗菌药物的BIC_(50)分别为:左氧氟沙星4μg/ml、环丙沙星8μg/ml、头孢他啶128μg/ml、头孢哌酮/舒巴坦128μg/ml、哌拉西林256μg/ml、红霉素128μg/ml、磺胺甲嗯唑304μg/ml、庆大霉素256μg/ml。联合药敏实验和扫描电镜下显示,左氧氟沙星单独或联合红霉素均能破坏成熟生物被膜的结构。结论:本地区分离的SMA具有耐药谱广、耐药率高特点:左氧氟沙星、磺胺甲VA唑和头孢哌酮/舒巴坦对SMA有较强的抗菌活性。银染法操作简单,可用于SMA生物被膜的初步鉴定。与浮游态细菌相比,形成生物被膜后SMA对抗生素的耐药程度增加;联合左氧氟沙星、红霉素可破坏SMA-BBF完整结构,细菌数量减少,有助于增强杀菌效果。
[Abstract]:Objective: to understand the Tianjin region of Stenotrophomonas maltophilia (Stenotrophomonas maltophilia, SMA) infection and drug resistance status, investigate the application value of silver staining method for the identification of SMA biofilm formation; to observe and understand the treatment of Stenotrophomonas maltophilia infection in 8 kinds of antibacterial drugs on the biofilm alone and in combination with after effect, provide a theoretical basis for clinical rational treatment of SMA infection.
Methods: by modified plating method on silica gel membrane - casein hydrolysate Allbumen broth (Mueller-Hintonbroth, MHB) in vitro model of SMA biofilm system, and the silver staining method and scanning electron microscopy were identified. Analysis of 51 clinical isolates of SMA to 12 kinds of antimicrobial drug resistance drug, an in vitro model SMA the biofilm by micro inoculation needle device for determination of levofloxacin, ciprofloxacin, Cefoperazone / sulbactam, ceftazidime, piperacillin, erythromycin, sulfamethoxazole, gentamicin on biological production by bacteria biofilm SMA film (Biofilm Inhibitory Concentration, inhibitory concentration BIC), and the minimum inhibitory concentration and the corresponding antibiotics (Minimum Inhibitory Concentration, MIC) were compared. The determination of erythromycin and levofloxacin combined drug sensitivity test, Cefoperazone / Shubatan, piperacillin against 5 strains of SMA biofilms At the same time, the morphological changes of the bacterial biofilm were observed by scanning electron microscopy.
Results: silver staining and scanning electron microscope to observe the Stenotrophomonas maltophilia can mature biofilm formation in silica gel membrane; 51 strains of SMA are 12 kinds of commonly used antimicrobial drugs resistance rate: 12.70% with levofloxacin, 25.70% ofloxacin, ciprofloxacin 37.50%, ceftazidime Cefoperazone / sulbactam 43.90%. Piperacillin 44.60%, cefepime cefoperazone 45.10%, 49%, 60.30% and 81.80% of ceftazidime, gentamicin, ceftriaxone 87.90%, Amikacin 90.60%, cefotaxime 95%; among them, two kinds of antimicrobial resistance of 4 strains of more than two kinds of anti bacteria drug resistance of clinical bacteria were 47 strains, accounting for the total number of 92.16% (47/51).42 strain SMA using micro inoculation needle successfully established in vitro model of mature biofilm formation after BBF, 8 kinds of antibiotics were BIC_ (50): 4 g/ml of levofloxacin, ciprofloxacin and ceftazidime in 8 g/ml, 128 g/ml, Cefoperazone / sulbactam 128 G/ml, piperacillin 256 mu g/ml, erythromycin 128 mu g/ml, sulfamethoxazole 304 g/ml, gentamicin 256 mu g/ml. combined with drug sensitivity test and scanning electron microscope showed that levofloxacin alone or combined with erythromycin could destroy the structure of mature biofilm.
Conclusion: local separation of SMA has a broad resistance spectrum, high resistance rate: levofloxacin, trimethoprim VA triazole and Cefoperazone / sulbactam had strong antibacterial activity to SMA. Silver staining method has the advantages of simple operation, can be used for the identification of SMA biofilm. Compared with planktonic bacteria, forming biofilm after the film degree of resistance to antibiotics increased SMA; combined with levofloxacin, erythromycin can destroy the SMA-BBF structure, the number of bacteria decreased, helps to enhance the sterilization effect.

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R378

【相似文献】