大肠埃希菌和肺炎克雷伯菌外排泵转录水平与耐药的关系

目的调查细菌耐药性与其主动外排泵系统的作用关系,并探讨大肠埃希菌外排泵调控基因对其外排泵结构基因表达水平的影响,分析其耐药机制。方法收集大肠埃希菌和肺炎克雷伯菌共59株,根据头孢他啶耐药情况分为实验组(耐药)与对照组(敏感),多重聚合酶链反应(PCR)扩增外排泵调控基因acrR并测序,实时定量逆转录(RT)-PCR检测外排泵及调控基因marA的相对转表达水平,三维试验检测AmpC酶。结果实验组大肠埃希菌46.7%(7株)acrAB基因转录水平增高,肺炎克雷伯菌中51.9%(14株)acrAkp基因转录水平增高,敏感组外排泵基因均未见增高。实验组大肠埃希菌中,3株acrR发现突变,9株marA基因转录水平增高。59株菌株中39株(66.1%)AmpC阳性。结论主动外排泵系统是细菌耐药机制之一,常与其他耐药机制共同存在。acrR突变与marA表达增高均可引起大肠埃希菌acrAB表达增加。     

碳青霉烯类抗生素耐药肠杆菌科细菌中KPC酶的研究

目的了解上海部分医院肠杆菌科细菌中KPC酶的产生及耐药情况。研究KPC酶的分子生物学特性和blaKPC的转移和传播。方法在上海4所医院收集亚胺培南或美罗培南（纸片扩散法）中介或耐药的肠杆菌科菌株,PCR检测blaKPC、DNA测序、接合转移试验、质粒电泳、Southern blot。结果在上海4所医院共收集到7株对亚胺培南药敏结果（纸片扩散法）中介或耐药的肠杆菌科细菌;PCR检测显示有2株菌株携带blaKPC-2接合转移试验、质粒电泳、Southern blot试验显示blaKPC-2是由一个50kb大小的质粒携带。结论上海4所医院2006年的KPC酶的检出率还比较低;2株肠杆菌科菌株的blaKPC-2都是由1个50kb的质粒所携带。     

梅毒非特异性类脂质反应素抗体试验操作的改进及应用评价

Objective To estimate the application value of a standard operating procedure (SOP) in the detection of syphilitic anticardiolipin reagin. Methods Clinical laboratories from 9 local hospitals in Shanghai participated the program. Quality control samples with unknown target value were qualitatively and quantitatively examined according to the uniform SOP in these laboratories with the same reagent and facility of horizontal reaction. External quality assessment (EQA) was carried out by using seven serum samples with no, or low (1∶ 128 dilution) to high (1∶1 dilution) concentrations of target before and after the implementation of SOP. The test results were statistically analyzed and the reasons for the detecting error were assessed. Results A total of 388 tests were performed in the 9 clinical laboratories. The total accuracy rate was 93.0%, including 40.2% in the detection of samples with 1 ∶ 8 dilution of target, 49.2% in the detection of samples with 1 ∶ 16 dilution of target, and 3.6% in the detection of samples with 1 ∶ 32 dilution of target. No forward bias was observed in these tests. There was a significant difference in the accuracy rate between the two times of EQA before and after the implementation of SOP (x2 = 4.17, P < 0.05). Conclusions The improved standard procedure for nontreponemal antigen test is beneficial to the decrease of testing error, and may provide a basis for the establishment of SOP and implementation of internal quality assessment.     

梅毒非特异性类脂质反应素抗体试验操作的改进及应用评价

目的探讨标准化操作对梅毒非特异性类脂质反应素抗体试验的使用价值.方法上海市9个医院实验室按照统一的操作程序、使用相同试剂和水平反应装置,在检测系统受控情况下,对未知靶值(盲样)的梅毒血清质控品进行连续检测.在实施新操作方案前后,用一套靶值范围覆盖从阴性到1∶128的7份新鲜血清样品各进行一次室间质量评价.统计反馈结果,分析误差产生的原因.结果 9个实验室共计进行了388次肓样检测,结果分布在1∶8、1∶16和1∶32分别是40.2%、49.2%和3.6%,总合格率为93.0%,没有高于合格标准的正向偏倚结果.两次室间质量评价的合格率经统计学分析,差异有统计学意义(x2=4.17,P<0.05).结论改进的非梅毒螺旋体抗原试验程序有助于减少试验误差,为建立标准化操作和开展室内质控提供了基础.

Abstract：

Objective To estimate the application value of a standard operating procedure (SOP) in the detection of syphilitic anticardiolipin reagin. Methods Clinical laboratories from 9 local hospitals in Shanghai participated the program. Quality control samples with unknown target value were qualitatively and quantitatively examined according to the uniform SOP in these laboratories with the same reagent and facility of horizontal reaction. External quality assessment (EQA) was carried out by using seven serum samples with no, or low (1∶ 128 dilution) to high (1∶1 dilution) concentrations of target before and after the implementation of SOP. The test results were statistically analyzed and the reasons for the detecting error were assessed. Results A total of 388 tests were performed in the 9 clinical laboratories. The total accuracy rate was 93.0%, including 40.2% in the detection of samples with 1 ∶ 8 dilution of target, 49.2% in the detection of samples with 1 ∶ 16 dilution of target, and 3.6% in the detection of samples with 1 ∶ 32 dilution of target. No forward bias was observed in these tests. There was a significant difference in the accuracy rate between the two times of EQA before and after the implementation of SOP (x2 = 4.17, P < 0.05). Conclusions The improved standard procedure for nontreponemal antigen test is beneficial to the decrease of testing error, and may provide a basis for the establishment of SOP and implementation of internal quality assessment.     

大肠埃希菌临床菌株中MicF的转录情况检测及分析

目的 调查大肠埃希菌临床菌株中MicF的转录情况并分析其作用.方法 选取上海交通大学附属第六人民医院2003——2009年间产AmpC酶的部分大肠埃希菌40株,对上述菌株进行药敏试验;实时定量反转录(RT)-PCR技术检测大肠埃希菌膜孔蛋白OmpF的表达情况,并分为OmpF转录水平下调组和上调组,RT-PCR方法 检测MicF的转录水平;用PCR扩增膜孔蛋白(ompF)基因.结果 ompF转录水平下调组耐药率明显高于上调组;ompF转录水平下调组MicF转录水平高于上调组.结论 MicF是大肠埃希菌膜孔蛋白重要的调控机制,可引起细菌耐药性增高.     

可诱导性质粒ampC基因表达的调控

质粒编码AmpC酶绝大多数呈持续高表达，只有少数有诱导性，如DHA-1，DHA-2，DHA-3，CMY-13，ACT-1，CFE-1。诱导现象产生的原因在于含有调控基因，且他们能正常行使功能。研究诱导机制不仅有助于深入了解细菌耐药性产生的原因，还可以为临床用药、控制耐药特性播散和新药开发等提供借鉴。我们将从调控机制及其临床意义方面研究进展做一综述。     

大肠埃希菌和肺炎克雷伯菌质粒β—内酰胺酶的筛选

目的：了解大肠埃菌和肺炎克雷伯菌的质粒介导的β-内酰胺酶的分布，表型及其检测方法，方法：经头孢泊肟初筛，用NCCLS确证试验检测超广谱β-内酰胺酶（ESBL）和用头孢西丁三相试验检测质粒AmpC.结果341株大肠埃希菌和肺炎克雷伯菌中经常规药敏试验筛选出164株（48．1％）头孢泊肟（CPD）的MIC＞1μg/ml，对其中的102株进行检测，结果产ESBL的有64株，头孢西丁三相试验阳性者有6株。结大肠埃钸菌和肺炎克雷伯菌的质粒β-内酰胺酶以ESBL为主（30．2％），质粒AmpCs仅占2．8％。     

血液科病房临床分离菌株的变迁及耐药性分析

目的：分析我院血液科合并感染的住院患者中分离出菌株的菌谱分布和耐药现状，以了解本院血液科感染情况，为经验性抗感染治疗提供依据。方法：收集我院血液科2003年7月至2007年6月住院患者临床分离的菌株，用Kirby-Bauer纸片法检测，根据NCCLS2002标准判断结果，并应用SPSS11．0统计学软件进行统计分析。结果：共收集血液科住院患者分离菌株259株，以革兰阴性菌为主，共188株（72．6％）；其次为革兰阳性球菌71株。其中金黄色葡萄球菌及凝固酶阴性葡萄球菌（CNS）的比例呈逐年上升趋势。甲氧西林耐药金黄色葡萄球菌（MRSA）及甲氧西林敏感凝固酶阴性葡萄球菌（MRCNS）的检出率为56.3％和72．2％，且两者呈多重耐药。未发现耐万古霉素的金葡菌和肠球菌。常见的肠杆菌科主要有大肠埃希菌、肺炎克雷伯菌、阴沟杆菌，对碳青酶烯类敏感度最高。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶（ESBLs）菌株的检出率分别为70.3％和50．0％，2004年至2006年其检出率基本稳定，产ESBLs菌株交叉耐药性高于不产ESBLs株。治疗产ESBLs株感染临床应选用碳青酶烯类、酶抑制剂复合剂及头霉素类抗生素；耐喹诺酮大肠埃希菌检出率较高：非发酵菌属中机会致病菌嗜麦芽窄食单胞菌检出率有上升趋势（P〈0．05），其对碳青酶烯类天然耐药，临床首选复方新诺明。铜绿假单胞菌和鲍曼／溶血不动杆菌对亚胺培南耐药率为8．8％和6．2％，其后敏感率从高到低依次为派拉西林或头孢他啶、酶抑制剂复合制剂、氨基糖苷类。结论：血液系统疾病临床分离菌株多重耐药情况严重，本研究结果对经验性治疗有一定参考价值。     

优菌多颗粒对人体肠道益生菌影响的初步研究

目的探讨服用微生态制剂对人体肠道益生菌的影响。方法通过优菌多颗粒人群试食,对服用前后胃肠道症状、代谢、排便情况和食欲表现及菌群变化等指标进行统计分析,并结合肠道菌群DNA指纹图谱分析,评价优菌多颗粒对人体肠道菌群的调节功能。结果试食人群食欲表现和胃肠道症状在服用优菌多颗粒4~8 d后得到显著改善,12 d后极显著改善;在服用优菌多颗粒20 d后,人体肠道菌群中双歧杆菌和乳酸杆菌与服用前相比有极显著提高,而肠道致病菌产气荚膜梭菌却极显著下降;在服用20 d优菌多颗粒后,人体肠道菌群比服用前更具多样性。结论优菌多颗粒具有调节人体肠道菌群的作用,使人体肠道细菌种群更具多样性。     

用头孢西丁三相试验检测质粒AmpCs

为了解大肠九希菌和肺炎克雷伯菌产质粒介导的１型β－内酰胺酶（ＡｍｐＣ）的情况,利用头孢西丁三相试验的直接法和间接法,对５５株大肠埃希菌和肺炎克雷伯菌进行检测,结果有２株阳性,３株可疑。