本文關(guān)鍵詞： A族乙型溶血性鏈球菌 emm基因型 生物膜 相關(guān)性　出處：《重慶醫(yī)科大學(xué)》2011年碩士論文　論文類型：學(xué)位論文

【摘要】：研究背景:A族乙型溶血性鏈球菌(group A streptococcus pyogens,GAS)是鏈球菌中致病性較強(qiáng)的一種細(xì)菌,是上呼吸道感染的重要致病原,可以引起急性扁桃體炎、猩紅熱和膿皰瘡,也可引起嚴(yán)重的侵襲性感染如敗血癥、壞死性筋膜炎和鏈球菌中毒休克綜合征。由emm基因編碼M蛋白是GAS的主要致病因子,M蛋白抗原變異是M分型的基礎(chǔ)。到目前為止,根據(jù)M蛋白抗原特異性可將GAS分為100多個型別,不同的型別其致病性不同,部分菌株感染可引起嚴(yán)重并發(fā)癥如風(fēng)濕熱/風(fēng)濕性瓣膜性心臟病(RF/RnD)及急性腎小球腎炎等。 生物膜( b i o f i l m formation, B F )是一種包裹于細(xì)胞外多聚物基質(zhì)中不可逆的黏附于非生物或生物表面的微生物細(xì)胞菌落,是細(xì)菌、真菌在生長過程中為適應(yīng)生存環(huán)境而形成的一種與浮游細(xì)胞相對應(yīng)的生存方式。生物膜被認(rèn)為是各種致病菌的毒力因子,能夠幫助細(xì)菌逃避抗生素或機(jī)體免疫系統(tǒng)的作用,引起許多細(xì)菌性疾病,像心內(nèi)膜炎、骨髓炎、齲齒、中耳炎、醫(yī)療器械相關(guān)感染、眼窩植入物感染、囊性纖維化病人的肺部感染等,造成機(jī)體持續(xù)性感染或免疫性疾病。 目前,對生物膜研究最多的是表皮葡萄球菌、金黃色葡萄球菌和銅綠假單胞菌,變形鏈球菌、格氏鏈球菌等。近些年來,國外已經(jīng)有大量的實驗證實GAS可以形成生物膜,且不同的emm基因型所形成的生物膜存在差異性。但中國目前還沒有相關(guān)文獻(xiàn)報道。 目的:了解重慶地區(qū)A組乙型溶血性鏈球菌生物膜生長情況,了解GAS emm基因分型與生物膜的相關(guān)性。 方法:對我院2000～2009收集的20株A族乙型溶血性鏈球菌培養(yǎng)、進(jìn)行聚合酶鏈反應(yīng)(PCR)擴(kuò)增并測序,對emm基因進(jìn)行分型。培養(yǎng)GAS及變形鏈球菌UA159的生物膜,并測量生物膜的吸光率。 結(jié)果: (一)A組溶血鏈球菌的emm分型: 20株GAS菌株的emm分型分別為emm12.0、emm1.0、emm22.0、emm6.5和emm12.43、emm63.0、emm3.1、emm80.0、emm12.4、emm75.0、emml2.21、emm6.0、emml02.2、emmst181 .5、emm st38 (二)生物膜情況 所有的15個emm基因型與陽性對照組(變形鏈球菌ua159)均可產(chǎn)生生物膜(p0.005).但不同的型別所形成的生物膜存在差異性。其中emmst38和emm12.43生物膜的生成能力要強(qiáng)于陽性對照,Emm12.0和emm75.0生物膜最弱。 結(jié)論: (1)所有的基因型均可形成生物膜; (2)不同的emm基因型的生物膜在不同的時間段生長情況不盡相同,存在差異性; (3)同一基因型的生物膜在不同的時間段的生長情況不同。
[Abstract]:Background: group B hemolytic streptococci group A streptococcus pyogensensus (GASA) is a highly pathogenic bacteria in streptococcus. It is an important pathogen of upper respiratory tract infection and can cause acute tonsillitis, scarlet fever and pustular ulcers. Severe invasive infections such as septicemia, necrotizing fasciitis and streptococcal toxic shock syndrome can also be caused. M protein encoded by emm gene is the main pathogenic factor of GAS. The variation of M protein antigen is the basis of M typing. According to the specificity of M protein antigen, GAS can be divided into more than 100 types. Different types of GAS have different pathogenicity. Some strains infection may cause serious complications such as rheumatic fever / rheumatic valvular heart disease (RFR / RnD) and acute glomerulonephritis. Biofilm (bio f I l m formation (B F)) is a kind of microbial cell colony which is encapsulated in extracellular polymer matrix and adheres to abiotic or biological surface irreversibly. A way of living corresponding to planktonic cells formed during the growth of fungi to adapt to the environment. Biofilms are thought to be virulent factors for various pathogens that can help bacteria escape antibiotics or the body's immune system. It causes many bacterial diseases, such as endocarditis, osteomyelitis, dental caries, otitis media, medical device related infection, orbital implants infection, pulmonary infection of patients with cystic fibrosis, etc., resulting in persistent infection or immune diseases. At present, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus gravis and so on are the most studied biofilms. The biofilms formed by different emm genotypes are different, but there are no related literatures in China. Aim: to investigate the biofilm growth of group A hemolytic streptococcus B in Chongqing and the correlation between GAS emm genotyping and biofilm. Methods: 20 strains of Group A B hemolytic streptococcus collected from our hospital were cultured and amplified by polymerase chain reaction (PCR) and sequenced. The emm gene was genotyped. The biofilm of GAS and Streptococcus mutans UA159 were cultured and the absorptivity of biofilm was measured. Results:. (emm typing of Streptococcus haemolyticus in Group A:. The emm genotypes of 20 strains of GAS were emm12.0emm1.0emm22.0emm6.5 and emm12.43emm63.0 emm80.0emm12.4emm12.4emm75.0Emml2.2emm6.0Emml02.2emmst181 .5EMM st38. (II) Biofilm situation. All 15 emm genotypes and the positive control group (Ua159) could produce biofilm p0.005, but the biofilms formed by different types of biofilms were different. The biofilm production ability of emmst38 and emm12.43 was stronger than that of positive control. Emm 12.0 and emm75.0 biofilm were the weakest. Conclusion:. 1) all genotypes can form biofilm; (2) the biofilm growth of different emm genotypes was different in different time periods. 3) the growth of biofilm of the same genotype was different in different time periods.
【學(xué)位授予單位】：重慶醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：R378.1

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