耐红霉素葡萄球菌诱导克林霉素耐药的检测

目的 了解该院葡萄球菌对红霉素及克林霉素的耐药性,测定葡萄球菌对克林霉素的诱导耐药率。方法 用双纸片扩散法检测葡萄球菌对红霉素和克林霉素的耐药性,用D试验检测红霉素对克林霉素的诱导耐药率。结果 D试验阳性葡萄球菌占所检测葡萄球菌的18．2％;在葡萄球菌、金葡菌、凝固酶阴性葡萄球菌（CNS）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）（葡萄球菌、金葡菌、CNS和MRCNS均为红霉素耐药而克林霉素敏感）中,诱导克林霉素耐药检出率分别为63．6％、100．0％、50．0％和53．3％。结论 临床微生物实验室应加强细菌诱导克林霉素耐药的检测,以指导临床合理使用抗生素。     

临床分离表皮葡萄球菌相关基因与生物膜表型的关系

目的：分析临床分离表皮葡萄球菌 icaA、aap 、atlE、sarA 基因与生物膜表型的关系。方法收集临床分离的表皮葡萄球菌78株,采用 PCR 法扩增 icaA、aap 、atlE、sarA 基因,组织细胞培养板黏附法检测生物膜表型,χ2检验分析上述基因与生物膜表型的关系,Wilcoxon 符号秩检验分别分析 icaA ＋菌及 icaA -菌在胰酶大豆肉汤（TSB）与TSB＋3％氯化钠中生物膜表型光密度（OD）值的差异。结果78株表皮葡萄球菌 icaA、aap 、atlE、sarA 基因阳性率分别为24．4％（19/78）、79．5％（62/78）、73．8％（57/78）、82．1％（64/78）。产生物膜株阳性率为51．3％（40/78）,其中高产生物膜16株,均携带 icaA 基因;弱产生物膜24株。经统计学分析,上述基因与生物膜表型之间有相关性,icaA 基因与高产生物膜表型有相关性。icaA ＋菌及 icaA -菌在 TSB 与TSB＋3％氯化钠中生物膜 OD 值的差异有统计学意义（P ＜0．05）。结论表皮葡萄球菌生物膜表型涉及多种因子参与,而 icaA 基因有助于高产生物膜表型形成。环境因素也可影响表皮葡萄球菌生物膜表型。     

凝固酶阴性葡萄球菌生物膜形成与多重耐药关系的研究

目的探讨临床怀本中凝固酶阴性葡萄球菌（coagulasenegativeStaphylococci,CNS）生物膜形成的状况,及其对细菌耐药的影响和多重耐药的关系,提高临床对CNS感染的重视,并帮助临床根据药敏试验结果选用抗菌药物。方法采用微孔板法制备生物膜,结晶紫染色,酶标仪比色检测42株CNS的生物膜形成情况;对临床标本分离的CNS进行鉴定,并采崩纸片法进行药敏试验;所有数据采用SPSS17．0统计软件进行统计学分析。结果比色法检测CNS的生物膜阳性率为76．19％（32／42）。药敏试验结果显示生物膜阳性的CNS耐药情况较严重,尤其是对青霉素G和红霉素,耐药率分别为96．88％和78．13％,对复办新诺明、克林霉素、四环素、环丙沙星耐药率亦超过50．00％,且呈多重耐药;生物膜阴性的CNS耐药情况较轻,仅对青霉素G和红霉素耐药情况较严重,耐药率分别为60．00％和140．00％;尚未发现对万古霉素耐药的CNS菌株。生物膜阳性CNS菌株对青霉素G、红霉素、克林霉索和复方新诺明的耐药率均显著高于生物膜阴性CNS菌株,差异均有统计学意义（P均〈0．05）。CNS生物膜生成多少与多重耐药的严重情况呈正相关性（r=0．975,P〈0．01）。结论临床标本分离出的CNS绝大部分能产生生物膜,对常见抗菌药物的耐约情况严重,且生物膜形成多少与多重耐药情况呈正相关关系。     

慢性阻塞性肺疾病细菌生物膜检测及耐药性分析

目的 研究慢性阻塞性肺疾病( COPD)患者细菌生物膜检测及耐药机制.方法 100例慢性阻塞性肺疾病(COPD)住院患者痰液标本采用刚果红培养法,检测细菌生物膜形成,K-B琼脂扩散法进行抗菌药敏试验.结果 检测到G+细菌中14株产生生物膜(阳性率58.3％),其中金黄色葡萄球菌9株,表皮葡萄球菌5株;G-细菌中10株产生生物膜(阳性率17.3％),其中普通变形杆菌6株,铜绿假单孢菌4株;产生生物膜的葡萄球菌呈多重耐药,对复方新诺明耐药明显较重,且高于无生物膜葡萄球菌(x2=4.03,P＜0.05);有生物膜的铜绿假单孢菌/普通变形杆菌对哌拉西林和阿米卡星的耐药率明显比无生物膜的高(x2=6.43,P＜0.05).结论 细菌生物膜形成的实验室检查对COPD患者临床抗生素的使用有极大帮助.     

2012年中国CHINET无菌体液中分离的细菌构成和耐药性监测

目的：了解国内不同地区15所医院2012年从临床分离自脑脊液及其他无菌体液（胸水、腹水、胆汁等）的细菌构成及其对抗菌药物的耐药性。方法对国内主要地区（13所综合性医院、2所儿童医院）临床分离菌株采用纸片扩散法或自动化仪器法按统一方案进行细菌药敏试验,按CLSI 2012版标准判断结果。结果3945株非重复的细菌中,革兰阴性菌2214株,占56．1％,革兰阳性菌1731株,占43．9％。无菌体液中最常见的细菌依次为大肠埃希菌,肺炎克雷伯菌,凝固酶阴性葡萄球菌（CNS）,屎肠球菌,粪肠球菌。无菌体液标本中甲氧西林耐药金黄色葡萄球菌（金葡菌）和CNS（MRSA和MRCNS）的检出率分别为61．3％和77．2％。未发现对万古霉素、利奈唑胺耐药的葡萄球菌。无菌体液中发现1株对万古霉素耐药的粪肠球菌和1株对利奈唑胺耐药的粪肠球菌,还发现6株对万古霉素耐药的屎肠球菌。无菌体液标本中产ESBL大肠埃希菌和肺炎克雷伯菌的检出率分别为48．1％和24．4％。无菌体液标本中泛耐药鲍曼不动杆菌、肺炎克雷伯菌和铜绿假单胞菌的检出率分别为24．5％、5．5％和1．4％。结论应防范泛耐药肠杆菌科细菌和鲍曼不动杆菌对临床造成严重威胁。     

2012年广东省潮州市中心医院细菌耐药性监测

目的了解广东省潮州市中心医院2012年临床分离菌株对常用抗菌药物的耐药性。方法采用WHONET5．6软件对2012年临床分离株进行药敏分析。结果2012年该院住院患者标本中分离出细菌2127株,其中革兰阳性菌686株,占32．3％,革兰阴性菌1441株,占67．7％。大肠埃希菌、金葡菌、克雷伯菌属、流感嗜血杆菌、铜绿假单胞菌、肺炎链球菌、不动杆菌属、卡他莫拉菌、肠球菌属和凝固酶阴性葡萄球菌（CNS）,分别占15．3％、13．2％、11．0％、10．0％、9．0％、7．0％、5．8％、4．1％、3．4％和2．7％。药敏试验结果显示,大肠埃希菌和克雷伯菌属产ESBLs阳性率分别为50．3％（164／326）和31．6％（74／234）,未发现耐碳青霉烯类抗生素的肠杆菌科细菌。不动杆菌属对碳青霉烯类抗生素耐药率为48．8％（60／123）。铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别18．8％（36／192）和10．9％（21／192）。金葡菌和CNS中甲氧西林耐药株（MR—SA和MRCNS）分别占64．0％（180／281）和72．4％（42／58）。青霉素耐药肺炎链球菌（PRSP）检出率为5．4％（8／148）。流感嗜血杆菌和卡他莫拉菌产口内酰胺酶阳性率分别为9．9％（21／212）和99．7％（85／87）。结论定期进行细菌耐药性监测有助于了解医院细菌耐药性的变迁,为临床经验用药提供依据,对加强抗菌药物合理应用的监督和管理起到积极的作用。     

71株葡萄球菌克林霉素诱导耐药分析

目的了解我院2004年葡萄球菌临床分离株的克林霉素诱导耐药分布情况以及纸片距离对试验结果的影响。方法收集我院2004年分离到的红霉素耐药、克林霉素敏感和中介的葡萄球菌临床株71株，其中金葡菌16株，凝固酶阴性葡萄球菌（CNS）55株。双纸片法检测克林霉素诱导耐药（D试验），对D试验阳性菌株再次用纸片边缘距离分别为10～15mm，16～20mm，21～25mm，26-28mm4组测定D试验结果，了解纸片距离对D试验结果的影响。结果克林霉素的诱导耐药比例为45．1％，其中金葡菌组68．8％，CNS组38．2％，P〈0。05，差异具有非常显著性，纸片距离大于26mm会对D试验结果造成影响。结论实验室必须加强对葡萄球菌诱导耐药检测。     

金黄色葡萄球菌耐药性分析

目的了解金葡菌对常用抗菌药物的耐药情况，指导临床合理用药。方法对2002-2005年各类感染标本分离出的159株金葡菌使用纸片扩散法进行药敏试验和克林霉素诱导试验，并对结果进行分析。结果129株（81．1％）金葡菌为MRSA，敏感度最高的5种抗菌药物依次为万古霉素（100％）、氯霉素（92．5％）、复方磺胺甲嗯唑（88．7％）、利福平（30．8％）和阿米卡星（26．4％）。D试验阳性率为63．6％。结论临床分离的金葡菌对常用抗菌药物产生多重耐药性，应根据分离株耐药特点选用不同的治疗方案。     

头孢西丁纸片扩散法检测耐甲氧西林葡萄球菌

目的以PCR法检测葡萄球菌的mecA基因(mecA基因法)为标准，评价头孢西丁纸片扩散法、苯唑西林纸片扩散法和苯唑西林盐平板法检测葡萄球菌中耐甲氧西林葡萄球菌的灵敏度和特异性。方法PCR扩增葡萄球菌的特异性mecA基因片段，头孢西丁纸片扩散法、苯唑西林纸片扩散法和苯唑西林盐平板法检测葡萄球菌中耐甲氧西林葡萄球菌，药敏试验方法按标准K—B(Kirby-Bauer)法进行。结果在190株临床分离的葡萄球菌中金黄色葡萄球菌(金葡菌)138株，表皮葡萄球菌30株，溶血葡萄球菌22株，经。PCR法检测mecA基因，金葡菌中耐甲氧西林金葡菌(MRSA)和凝固酶阴性葡萄球菌中耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的发生率分别为81.2％(112／138)、96．1％(50／52)。头孢西丁纸片扩散法检测金葡菌中MRSA和CNS中MRCNS的发生率分别为81.2％(112／138)、94．2％(49／52)，与mecA基因法结果相比较，头孢西丁纸片扩散法检测葡萄球菌中MRS的灵敏度和特异度分别为99．4％(161／162)、100．0％(28／28)，两者符合率为99．5％(189／190)。2种方法所获得的结果经统计学处理，两者差异无显著性。结论头孢西丁纸片扩散法检测耐甲氧西林葡萄球菌具有很高的灵敏度和特异度，适合在临床微生物实验室中进行推广。     

双相显色体液培养瓶临床应用及评价

目的评价双相显色体液培养瓶在细菌感染检测中的应用价值。方法用双相显色体液培养瓶床边接种体液标本，同时用常规法接种血平板和麦康凯平板，并对其阳性检出率、检出时间、检出的细菌种类等指标进行分析比较。结果278份体液标本中，双相显色培养瓶分离出37株细菌，阳性率为13．3％，其中肠杆菌科14株（37．8％），葡萄球菌属7株（18．9％），肠、链球菌属6株（16．2％），真菌5株（13．5％）；而常规培养方法分离出19株细菌，阳性率为6．8％。结论双相显色体液培养瓶检测患者体液标本比常规法好，能做到体液标本及时接种（床边接种），操作简便，菌落易于观察，阳性检出率高，结果准确，是诊断细菌感染的一种较好的方法。     

葡萄球菌对高水平莫匹罗星及奎奴普丁/达福普汀的耐药性

目的 了解临床分离的葡萄球菌对高水平莫匹罗星和奎奴普丁/达福普汀两种药物的耐药.方法 2009～2011年临床分离的669株葡萄球菌用K-B法检测其对两种药物的耐药性.结果 669株葡萄球菌共检出22株高水平莫匹罗星耐药株(MuH),总耐药率为3.29%,其中金黄色葡萄球菌(SA)3株,耐药率1.89%,凝固酶阴性葡萄球菌(CNS)19株,耐药率为3.73%;奎奴普丁/达福普汀耐药株52株,耐药率为7.77%,其中SA 7株,耐药率为4.40%,CNS45株,耐药率为7.77%.对两种药物的耐药率SA比CNS都稍低.结论 莫匹罗星和奎奴普丁/达福普汀对葡萄球菌具有强抗菌活性,都是治疗葡萄球菌感染的良好选择,且对SA的效果更优于CNS.     

Intravenously administered pharmaceuticals impact biofilm formation and detachment of Staphylococcus lugdunensis and other staphylococci

Coagulase-negative staphylococci and Staphylococcus aureus are major causes of catheter-related infections because of their ability to form biofilms on indwelling polymeric devices. Staphylococcus lugdunensis is a particularly virulent coagulase-negative species responsible for several types of biofilm-related infections, but factors that influence biofilm formation by this species remain undetermined. Heparin and catecholamine inotropes are common intravenously administered drugs reported to stimulate biofilm formation of some staphylococci. This study assessed the effects of catecholamines and heparin on biofilm formation of a collection of S. lugdunensis isolates and other Staphylococcus species. Dopamine stimulated biofilm formation in two-thirds of S. lugdunensis isolates, whereas dobutamine prevented nearly all S. lugdunensis isolates from adhering to polystyrene. Heparin markedly reduced biofilm formation by 87% of S. lugdunensis isolates. Preformed biofilms of S. lugdunensis and other Staphylococcus species detached from polystyrene after exposure to heparin at concentrations used in catheter locks. Our data suggest that intravenous pharmaceuticals may influence staphylococcal biofilm formation on and detachment from intravascular catheters.     

In vitro effects of antimicrobial agents on planktonic and biofilm forms of Staphylococcus lugdunensis clinical isolates

Staphylococcus lugdunensis is an atypically virulent coagulase-negative staphylococcal species associated with acute and destructive infections that often resemble Staphylococcus aureus infections. Several types of infection caused by S. lugdunensis (e.g., native valve endocarditis, prosthetic joint infection, and intravascular catheter infection) are associated with biofilm formation, which may lead to an inability to eradicate the infection due to the intrinsic nature of biofilms to resist high levels of antibiotics. In this study, planktonic MICs and MBCs and biofilm bactericidal concentrations of 10 antistaphylococcal antimicrobial agents were measured for 15 S. lugdunensis isolates collected from patients with endocarditis, medical device infections, or skin and soft tissue infections. Planktonic isolates were susceptible to all agents studied, but biofilms were resistant to high concentrations of most of the drugs. However, moxifloxacin was able to kill 73% of isolates growing in biofilms at 相似文献   

金黄色葡萄球菌生物膜产生及相关毒力因子研究

目的 金黄色葡萄球菌引起的感染遍及临床各科,人体各部位。对临床分离的金黄色葡萄球菌进行生物膜、生物膜相关因子及毒力因子检测；方法 刚果红培养基法进行生物膜筛选；用电子显微镜观察生物膜的形成；用PCR方法检测生物膜相关基因及毒力因子。结果 100株金黄色葡萄球菌中,63株产生生物膜,产生物膜率达63.0％,均产生与生物膜高度相关的icaA基因、icaD基因；还可产生ebh、sea、seb、pvl、hla、fnbA 等毒力因子；产生物膜的菌中MRSA菌株占51.2%,MSSA占48.8%；结论 产生物膜的金黄色葡萄球菌已经成为医院感染的致病因素之一,常产生各种毒力因子。     

Modification of the Congo red agar method to detect biofilm production by Staphylococcus epidermidis

Staphylococcus epidermidis in immunocompromised patients can cause bacteremia related to the use of catheter due to biofilm production. There are different phenotypic methods to detect biofilm formation. One method is based on culture in brain heart infusion agar (BHIA) containing sucrose and red Congo dye (original Congo red agar). Our group created a new CRA formula and we have confirmed its capacity to detect biofilm production in 210 S. epidermidis strains, including 76 (36.2%) icaAB gene–positive strains. Other parameters were also evaluated. The new CRA formula that gave the best results was BHIA with sucrose (5%), Congo red (0.08%), NaCl (1.5%), glucose (2%), and vancomycin (0.5 mg/mL) (vancomycin-modified CRA—CRAmod). The CRAmod plus vancomycin may be a promising tool and can help to determine the real participation of S. epidermidis in the infectious process.     

The prevalence of aminoglycoside resistance and corresponding resistance genes in clinical isolates of staphylococci from 19 European hospitals

Aminoglycosides still play an important role in antistaphylococcal therapies, although emerging resistance amongst staphylococci is widespread. To further our understanding of the prevalence of aminoglycoside resistance in Europe, we tested 699 and 249 consecutive unrelated clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci (CNS), respectively, from the SENTRY Antimicrobial Surveillance Program, for susceptibility to gentamicin, tobramycin, kanamycin and streptomycin, and examined the relationship between susceptibility to these antimicrobials and susceptibility to methicillin. Three hundred and sixty-three staphylococcal isolates demonstrated resistance to at least one of the aminoglycosides tested; all of these isolates were screened for the presence of aac(6')-Ie + aph(2"), ant(4')-Ia and aph(3')-IIIa, the genes encoding the most clinically relevant aminoglycoside-modifying enzymes. S. aureus isolates derived from hospital-acquired pneumonia tended to be more resistant to aminoglycosides and methicillin than isolates from blood or wound infections. In S. aureus, resistance to aminoglycosides was closely associated with methicillin resistance. Susceptibility of S. aureus to gentamicin has decreased by 9% from previous European studies to a current level of 77%, while susceptibility of CNS, currently at 67%, has increased by 21%. Geographical variation occurred, correlating with methicillin resistance, although intra-country variation was considerable. aac(6')-Ie + aph(2"), ant(4')-Ia and aph(3')-IIIa were found throughout Europe in 68%, 48% and 14% respectively of staphylococci resistant to at least one aminoglycoside. aph(3')-IIIa was considerably more common in methicillin-susceptible S. aureus and CNS isolates; the reverse was true for the other two resistance genes. The prevalence of ant(4')-Ia and aph(3')-IIIa genes in aminoglycoside-resistant staphylococci was significantly greater than that reported in previous European studies.     

Detection of enterotoxin genes seg, seh, sei, and sej and of a novel aroA genotype in Jordanian clinical isolates of Staphylococcus aureus

The presence of staphylococcal enterotoxin (SE) genes (seg, seh, sei, and sej) and the correlation of their prevalence with the genotypes were studied in 100 clinical isolates of Staphylococcus aureus. Polymerase chain reaction (PCR) of SE genes indicated that 39% of the isolates were enterotoxigenic. Thirty-seven percent of the total isolates were seg positive, whereas 24% and 4% were sei and seh positive, respectively. All isolates containing sei were positive for seg, whereas sej gene was not detected. Genotyping by PCR-restriction fragment length polymorphism analysis of the aroA gene revealed that 39% of the isolates were type A and 11% were type B, and 50% displayed a novel (N) genotype. The presence of the enterotoxin genes was independent (P < 0.05) of the genotypes of the tested S. aureus isolates. This study has demonstrated that the seg was the most dominant enterotoxin gene and that the enterotoxigenic Jordanian S. aureus isolates belong to different genotypes, and N genotype was predominant.     

Effect of Varidase (streptokinase) on biofilm formed by Staphylococcus aureus

Staphylococcus aureus forms a fibrin-rich biofilm in the presence of plasma which is highly resistant to attack by the human immune system and to chemotherapy. Varidase, composed mainly of streptokinase, is used for hydrolyzing clots. In this study, we attempted to destroy the biofilm of S. aureus with Varidase and to apply this drug in the treatment of staphylococcal infections. Four clinical isolates were used in the experiments. These organisms formed a several-millimeter-thick biofilm on type IV collagen coated coverslips in trypticase soy broth containing 50% human plasma. The biofilm was composed of bacterial cell which adhered to fibrillar fibers and of sediment derived from plasma. 10,000 U/ml of Varidase, the dose which is used clinically, removed the sediment and reduced the number of live bacteria in biofilms to less than 20% of control. 200 U/ml of Varidase was also effective against biofilms of the organisms. An equal combination of Varidase and ofloxacin had an additive effect on the bacteria. The results of this study demonstrate that Varidase is highly effective in destroying biofilms of S. aureus in vitro and suggest that this drug would be useful for treating staphylococcal infections.