本文選題：耐甲氧西林金黃色葡萄球菌 + 危險因素　； 參考：《蘇州大學(xué)》2016年博士論文

【摘要】：第一部分醫(yī)院內(nèi)MRSA感染危險因素研究目的探討醫(yī)院內(nèi)耐甲氧西林金黃色葡萄球菌(MRSA)感染的危險因素,為提出有效減少醫(yī)院MRSA感染的措施提供依據(jù)。方法對寧波市某三級甲等綜合性醫(yī)院2013年、2014年的MRSA、MSSA感染進(jìn)行監(jiān)測。以監(jiān)測收集到的所有院內(nèi)MRSA患者為病例組,以院內(nèi)MSSA患者為對照組進(jìn)行危險因素研究。查閱病案收集病例和對照既往暴露資料,考慮的暴露因素包括年齡、基礎(chǔ)疾病(心腦血管疾病、糖尿病、腫瘤、結(jié)構(gòu)性肺病、肝腎功能不全)、住院時間、侵入性操作(種類、個數(shù))、使用抗生素(暴露時間、暴露個數(shù))等。運(yùn)用卡方檢驗(yàn)、非條件logistic回歸模型進(jìn)行危險因素分析。結(jié)果1、樣本量:本研究共入組MRSA組的患者118例,MSSA組116例。2、菌株分布特點(diǎn):MRSA菌株以神經(jīng)內(nèi)科、腦外科分離株最多,兩科共占32.21%;MSSA菌株以骨科分離到最多,占25.86%。標(biāo)本類型中,MRSA主要為痰液分離株,而MSSA主要為創(chuàng)面分泌物分離株。3、本研究顯示,MRSA組的住院時間顯著長于MSSA組。4、危險因素分析:單因素分析發(fā)現(xiàn)年齡、中樞神經(jīng)系統(tǒng)疾病、基礎(chǔ)疾病數(shù)量、侵入性操作(動靜脈置管、氣管插管、留置胃管、留置導(dǎo)尿管、術(shù)后引流)的暴露及侵入性操作數(shù)量、細(xì)菌分離前住院時間、抗生素暴露時間、抗生素暴露個數(shù)在MRSA組和MSSA組間存在差異(P0.05)。多因素分析發(fā)現(xiàn)僅侵入性操作個數(shù)、抗感染藥物暴露≥2種、抗感染藥物暴露時間≥7天這3個因素是MRSA感染的危險因素(P0.05)。結(jié)論侵入性操作個數(shù)、抗感染藥物暴露≥2種、抗感染藥物暴露時間≥7天是MRSA相對于MSSA的獨(dú)立危險因素,因此避免非必要性的侵入性操作、合理應(yīng)用抗感染藥物是預(yù)防MRSA的重要手段。第二部分金黃色葡萄球菌血液分離株毒力與耐藥編碼基因研究目的分析院內(nèi)MRSA及MSSA血液分離菌株臨床及菌株分子生物學(xué)特征,了解MRSA的毒力和耐藥機(jī)制。方法對某三級甲等醫(yī)院2011年1月~2012年12月自血液分離的19株MRSA和13株MSSA的臨床特征進(jìn)行分析,采用瓊脂稀釋法對32株金葡菌進(jìn)行抗菌藥物敏感性檢測;采用聚合酶鏈?zhǔn)椒磻?yīng)(PCR)在32株菌株中檢測55種毒力基因(黏附毒素sas X、fnb A、clf A、clf B、ica A、cna、efb、isd A、isd B、isd C;細(xì)胞毒素hla、hlb、hld、hlg、hlg-2、pvl、luk E、luk M、psm-mec;侵襲性酶ssp、sak、nuc、hys A、lip;超抗原sea、seb、sec、sed、see、seg、seh、sei、sej、sek、sel、sem、sen、seo、sep、seq、eta、tst;外毒素set1、set2、set3、set4、set5、set6、set7、set8、set9、set10、set11;莢膜抗原cap5、cap8)和7種耐藥基因(mec A、aac(6’)/aph(2”)、aph(3’)-Ⅲ、erm A、erm B、erm C、tet M)。隨機(jī)選取上述PCR陽性產(chǎn)物進(jìn)行測序,測序結(jié)果用Chromas軟件直接做BLAST Search比對;金黃色葡萄球菌毒力與耐藥基因檢測結(jié)果作樣本聚類分析(UPGMA法)。結(jié)果1、臨床特征:感染MRSA的患者平均年齡為(78.5±7.6)歲,高于MSSA患者(67.6±15.3)歲(P0.05)。兩組細(xì)菌檢出時間分別為入院后(9.84±4.11)天和(6.93±3.26)天(P0.05),MRSA組檢出時間晚于MSSA組。2、藥敏試驗(yàn):32株金葡菌均對萬古霉素敏感。MRSA的耐藥率由高到低為:苯唑西林(100.0%)、青霉素(100.0%)、氨芐西林(100.0%)、頭孢唑林(100.0%)環(huán)丙沙星(94.7%)紅霉素(84.2%)克林霉素(73.7%)四環(huán)素(52.6%)、慶大霉素(52.6%)利福平(26.3%)磺胺甲VA唑/甲氧芐啶(21.1%)萬古霉素(0.0%)。3、毒力基因檢出情況:本組金黃色葡萄球菌中黏附毒素、細(xì)胞毒素、侵襲性酶、超抗原、外毒素、莢膜抗原六大類毒力基因均有檢出,其中毒力基因cna、luk E、psm-mec、ssp、nuc、lip、seg、sem、sen、set6、set11在MRSA組和MSSA組的檢出率存在差異(P0.05)。55種毒力基因中有12種未檢出,分別為hlg、luk M、sak、eta、seb、sec、sed、sej、sel、set2、set4、set5。MRSA組的菌株攜帶的毒力基因個數(shù)多于MSSA組的菌株(P0.05)。4、耐藥基因檢出情況:mec A、aac(6’)/aph(2”)、aph(3’)-Ⅲ、tet M這4個耐藥基因的表達(dá)在MRSA組與MSSA組間存在統(tǒng)計學(xué)差異(P0.05)。erm A、erm B在兩組中均未檢出。5、樣本聚類分析中可見兩組菌株中均存在克隆現(xiàn)象,提示院內(nèi)感染。結(jié)論MRSA菌與MSSA菌黏附素基因檢出率高提示菌株的定植特性。MRSA組毒力基因的檢出個數(shù)高于MSSA組,提示MRSA具有更強(qiáng)的宿主組織損傷特性。在臨床處置中要特別注意院內(nèi)感染的控制手段以降低感染風(fēng)險。
[Abstract]:The first part of the hospital MRSA infection risk factors study to explore the risk factors of methicillin resistant Staphylococcus aureus (MRSA) infection in hospital, in order to provide effective measures to reduce the hospital MRSA infection measures to provide the basis. Methods for a three grade a comprehensive hospital in Ningbo in 2013, 2014, MRSA, MSSA infection monitoring. All the hospitalized MRSA patients were the case group and the MSSA patients in the hospital were used as the control group for the risk factors. The exposure factors including age, basic disease (cardio cerebrovascular disease, diabetes, tumor, structural lung disease, liver and kidney insufficiency), hospitalization time, invasive operation were considered. (type, number), use of antibiotics (exposure time, exposure number) and so on. Using chi square test and unconditional logistic regression model, the risk factors were analyzed. Results 1, sample size: 118 cases in group MRSA, 116 cases in group MSSA, 116 cases of.2, the distribution characteristics of strain: MRSA in the neurology, the Department of cerebral surgery, the most, the two families accounted for 32.21%; MSSA isolates were most isolated in the Department of orthopedics, accounting for the type of 25.86%. specimens, MRSA was mainly sputum isolation, and MSSA was mainly the.3 of the wound secretions. This study showed that the time of hospitalization in the MRSA group was significantly longer than that of the MSSA group.4, and the risk factors were analyzed: the single factor analysis found the age, central nervous system disease, the number of basic diseases, invasive operations. (IV) (arteriovenous catheterization, tracheal intubation, indwelling gastric tube, indwelling catheter, postoperative drainage) exposure and invasive operation number, the time of hospitalization before bacterial isolation, antibiotic exposure time, and the number of antibiotic exposure between the MRSA group and the MSSA group (P0.05). The 3 factors of the exposure time of the infected drugs over 7 days are the risk factors of MRSA infection (P0.05). Conclusion the number of invasive operations, the exposure of anti infective drugs more than 2, and the exposure time of anti infective drugs over 7 days are independent risk factors of MRSA relative to MSSA, so the non essential invasive operation is avoided, and the rational application of anti infective drugs is the prevention of MRSA. Important means. The second part of the toxicity and resistance encoding gene of Staphylococcus aureus blood isolates were used to analyze the clinical and molecular biological characteristics of MRSA and MSSA isolated strains in hospital and to understand the virulence and resistance mechanism of MRSA. Methods 19 strains of MRSA and 13 isolated from the blood of a Class Three Grade A hospital in December January 2011 were isolated from blood. 32 strains of Staphylococcus aureus were detected by agar dilution method, and 55 kinds of virulence genes were detected by polymerase chain reaction (PCR) in 32 strains (SAS X, FNB A, CLF A, CLF B, ICA A). Sm-mec, invasive enzyme SSP, sak, NUC, HYS A, lip; superantigen sea, SEB, SEC, sed. The PCR positive products were sequenced by the machine, and the sequencing results were directly compared with the BLAST Search comparison with the Chromas software. The results of the toxicity and resistance genes of Staphylococcus aureus were analyzed by cluster analysis (UPGMA method). Results 1, the clinical characteristics: the average age of the patients infected with MRSA was (78.5 + 7.6) years old, higher than that of the MSSA patients (67.6 + 15.3) years (P0.05) two. The time of detection of bacteria was (9.84 + 4.11) days and (6.93 + 3.26) days (P0.05). The detection time of group MRSA was later than.2 in group MSSA, and drug sensitivity test: the resistance rate of 32 strains of Staphylococcus aureus to vancomycin sensitive.MRSA was from high to low: benzoxacillin (100%), penicillin (100%), ampicillin (100%), and cefazolin (100%) ciprofloxacin (94.7%) Erythromycin (84.2%) clindamycin (73.7%) tetracycline (52.6%), gentamicin (52.6%) rifampin (26.3%) sulfamethoxazole / trimethoprim (21.1%) vancomycin (0%).3, virulence gene detection: this group of Staphylococcus aureus in this group of adhesion toxin, cytotoxin, invasive enzyme, superantigen, exotoxin, capsule antigen six major toxic genes have been examined. The virulence genes of cna, Luk E, psm-mec, SSP, NUC, lip, SEG, SEM, Sen, set6 were different. 4, the detection of resistance genes: MEC A, AAC (6 ') /aph (2 "), APH (3') - III, Tet M, the expression of 4 resistance genes between the MRSA group and the MSSA group was statistically different (P0.05).Erm A. The high detection rate of the attachment gene suggests that the number of virulence genes in the.MRSA group is higher than that of the MSSA group, suggesting that MRSA has a stronger host tissue damage characteristic. In clinical treatment, special attention should be paid to the control of nosocomial infection to reduce the risk of infection.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：R446.5
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本文編號：2081472