葡萄球菌属的分离及耐药性研究

目的　对 1 974株临床分离的葡萄球菌的耐药性进行研究 ,以观察葡萄球菌属的耐药现状。方法　药敏试验采用纸片扩散法 (K -B法 )。结果　临床分离到的葡萄球菌中 ,MRSA的分离率为 2 0 .8% (66/ 31 7) ,MRCNS的分离率为 66 .9% (1 1 0 9/ 1 657) ,MRSA主要来源于生殖道分泌物、痰、伤口分泌物 ,分别占 2 7.3 % ,2 2 .7% ,1 8.2 % ;血液标本中MRSA和MRCNS分别占总分离数的 0 .2 5 %和 4 .9% ,而MRSA只占 0 .2 5 %。MRSA和MRCNS对红霉素、庆大霉素、氯霉素、克林霉素、环丙沙星、复方磺胺甲恶唑、四环素的耐药率分别为 86 .2 %、47.6 %、50 .8%、61 .3 %、54 .5 %、83 .3 %、66 .1 %和 84.9%、37.5 %、45 .9%、53 .7%、58.2 %、84.9%、67.6 % ;MSCNS中环丙沙星、复方磺胺甲恶唑、四环素、氯霉素的耐药率分别为 33 .0 %、64 .1 %、58.5 %、2 7.8%均高于MSSA的 1 4 .6 %、42 .8%、41 .5 %、1 7.7% ,但对于MSS环丙沙星、庆大霉素、氯霉素、克林霉素有较高的敏感性。结论　重视对葡萄球菌的耐药性监测 ,合理使用抗生素、特别是合理使用糖肽类抗生素是非常必要的。     

三种实验性IgA肾病模型的比较

目的探讨建立一种理想的IgA肾病（IgAN）动物模型方法。方法分别采用葡聚糖G200、大肠杆菌外膜蛋白和金葡菌的细胞膜20肽抗原决定簇诱导小鼠IgA肾病模型。用分子生物学和病理学方法对3组IgAN模型小鼠进行鉴定和比较。结果（1）葡聚糖组尿蛋白增高，伴有血尿；免疫荧光显示部分肾小球大量IgA沉积；光镜下肾小球系膜细胞增多，肝和脾可见弥漫性的粉染物质沉积；电镜下肾小球系膜区少量低电子密度的致密沉积物，肝和脾可见淀粉丝样物质沉积。（2）大肠杆菌外膜蛋白组尿蛋白增高，伴有血尿；免疫荧光显示肾小球有少量IgA沉积；光镜下肾小球系膜细胞轻度增多，间质炎细胞浸润明显；电镜下肾小球系膜区无电子致密沉积物。（3）金葡菌细胞膜20肽抗原决定簇组尿蛋白增高，伴有血尿；免疫荧光显示多数肾小球均可见大量IgA沉积；光镜下肾小球系膜细胞增多，伴系膜基质轻度增生；电镜下肾小球系膜区和基底膜的内皮细胞下可见高电子密度的致密沉积物。结论金葡菌细胞膜20肽抗原决定簇组诱导的IgAN模型从临床表现和病理学变化与人IgAN极其相似，是3种IgAN模型中最理想的IgAN模型。     

凝固酶阴性葡萄球菌检测在慢性前列腺炎中的意义

目的　研究慢性前列腺炎与凝固酶阴性葡萄球菌 (CNS)的关系 ,探讨前列腺液中CNS检测的临床意义。　方法　对 4 2 8例慢性前列腺炎患者采用Meares Stamey四段取样法作前列腺液细菌培养和药敏试验。患者年龄 18～ 4 6岁 ,平均 31岁。病程 3～ 32个月 ,平均 6个月。慢性前列腺炎症状指数 (NIH CPSI)平均 2 3.2分。　结果　 4 2 8例均行细菌培养 ,其中 2 4 8例 (5 7.94 % )分离出细菌。革兰阳性菌 195例 (78.6 3% ) ,其中葡萄球菌 16 0例 (6 4 .5 2 % ,16 0 / 2 4 8) ,CNS 89例 (35 .89% ,89/ 2 4 8) ;CNS中以表皮葡萄球菌为主者 81例 (32 .6 6 % ) ,其次为腐生葡萄球菌 3例和溶血性葡萄球菌 2例 ;NIH CPSI积分与细菌培养结果无明显相关。CNS对常用抗菌药物 (β 内酰胺类、喹诺酮类、氨基糖苷类 )耐药率较高 (5 1.9%～ 10 0 % )。　结论　CNS为慢性前列腺炎的主要致病菌 ,应引起高度重视 ;适时监测前列腺液病原菌及药敏试验对临床诊断和治疗慢性前列腺炎具有重要意义。     

葡萄球菌的分离鉴定及药敏分析

目的：了解不同种类葡萄球菌在本院临床标本中的感染情况及耐药性，为临床治疗和控制此类感染提供参考。方法：采用VITEK-AMS GPI卡进行鉴定，纸片扩散法(NCCLS)及GPS卡进行药敏实验、β内酰胺酶测定和MRS检测，并结合临床资料进行分析。结果：总共3753株感染菌中822株为葡萄球菌(21．90％)，其中金黄色葡萄球菌(SA)322株(39．17％)，凝固酶阴性葡萄球菌(CNS)500株(60．83％)。SA中293株(90．99％)产生β内酰胺酶，苯唑西林耐药者(MRSA)183株(56．83％)；CNS中450株(90．00％)产生β内酰胺酶，苯唑西林耐药的凝固酶阴性葡萄球菌(MRCNS)350株(70．00％)。结论：葡萄球菌特别是凝固酶阴性葡萄球菌是临床感染的主要致病菌之一；万古霉素是有效治疗苯唑西林耐药的葡萄球菌(MRS)的唯一可选药物；合理使用抗生素对治疗和控制感染至关重要。     

Clinical index to predict bacteraemia caused by staphylococci

Abstract. Objectives. To define risk factors associated with bacteraemia caused by Staphylococcus aureus or coagulase-negative staphylococci; and to use them to define patients in need of empiric anti-staphylococcal antibiotic treatment. Design, Derivation set: observational, prospective study; validation set: retrospective analysis of a prospectively collected database. Setting. Derivation set: Beilinson Medical Centre, Petah Tiqva, Israel—a 900-bed university hospital. Validation set: St Thomas's Hospital, London, UK—an 800-bed teaching hospital. Subjects. All episodes of bacteraemia detected at Beilinson Medical Centre between March 1988 and September 1990 (derivation set, n = 1410), and at St Thomas's Hospital during 1987–1990 (validation set, n = 1040). Interventions. None. Main outcome measures. Percentage of staphylococcal bacteraemia in groups of patients defined by the models. Results. The following factors were associated with Staphylococcus aureus bacteraemia: focus of infection (whether high or low risk), haemodialysis, intravenous drug abuse and infection acquired in the orthopaedic ward. A logistic model was used to divide the derivation set into three groups with percentages of Staphylococcus aureus bacteraemia of 1.8%, 13.2% and 33.7% (P < 0.0001); and the validation group 2.5%, 18.2% and 53.2% (P < 0.0001). Factors associated with coagulase-negative staphylococcal bacteraemia were: central or peripheral intravenous catheter as the focus of infection, a preterm neonate, the presence of a central intravenous catheter, low temperature, and a low white blood cell count. A second model including those factors was used to divide the derivation set into three groups with percentages of coagulase-negative staphylococcal bacteraemia of 1.9%, 22.8%, and 43% (P < 0.0001). In the validation set, the percentages were 2.9%, 22.4% and 31.0% (P < 0.001). Conclusions. The present study defines groups at high risk for staphylococcal bloodstream infection, in which empiric treatment should include an anti-staphylococcal drug.     

医院内携带的葡萄球菌对8种抗生素的敏感度

测定216株葡萄球菌(126株金葡菌,90株凝固酶阴性葡萄球菌)对8种临床常用抗生素药敏。结果为:医院内携带的金葡菌对青霉素G、红霉素、林可霉素耐药率分别为76.42%、61.36%、27.26%,对头孢噻啶、利福霉素敏感性较好。医院内表葡菌对青霉素G、红霉素、林可霉素耐药率分别达65.29%、58.82%、50%。故治疗医院内金葡菌、表葡菌感染时要选用有效药物。医院内携带的金葡菌产酶率81.40%,CNS产酶率71.11%,绝大多数产酶株对青霉素G耐药,头孢噻啶对产酶株有良好的抗菌活性。     

MRSA PBP2a表达的影响因素及MecA基因的检测价值

【目的】探讨温度、pH、盐浓度对甲氧西林耐药金葡菌 (methicillin resistantstaphylococcusaureus,MRSA)青霉素结合蛋白2a(penicillin bindingprotein ,PBP)表达的影响 ,以及PBP2a编码基因MecA的检测价值。【方法】采用聚合酶链式反应(PCR)检测MRSA特异性MecA基因和美国临床实验室标准委员会 (NCCLS)推荐的琼脂板稀释法 (32℃ ,pH7 2 ,40g/LNaCl苯唑西林MIC≥ 4mg/L)筛选MRSA。检测 2 0株MRSA在不同温度、pH、盐浓度时对苯唑西林、头孢唑林和头孢他啶的体外药物敏感性 ,测定MIC范围 ,MIC50 和MIC90 ;SDS PAGE分析 10株MRSA膜青霉素结合蛋白 (PBP2a)在不同培养条件时表达数量的差异 ,并进行配对差值的t检验。【结果】 180株金葡菌检测出MecA基因阳性MRSA 5 6株 ,按琼脂板稀释法检出 5 2株MRSA ,4株未被检出 (苯唑西林MIC分别为 :2 ,2 ,1,0 5mg/L) ,37℃、pH 5 2和 9g/LNaCl分别与 32℃、pH 7 2和 40 g/LNaCl条件下诱导 10株MRSA ,所表达的PBP2a含量前后比较差值有显著性 (P∶0 .0 2～ 0 .0 5 ,0 .0 1～ 0 .0 0 5 ,0 .0 2～ 0 .0 5 )。【结论】不同温度、pH、盐浓度通过诱导耐药蛋白PBP2a的表达明显影响MRSA对苯唑西林、头孢唑林和头孢他啶耐药水平 ,而其MecA基因却不受培养条件的影响 ,可以快速检测MR     

76株凝固酶阴性葡萄球菌的耐药性分析

目的：研究凝固酶阴性葡萄球菌（ＣＮＳ）的耐药性,指导临床合理用药。方法：对７６株临床标本中分离的ＣＮＳ,使用ＶＩＴＩＫ ＡＭＳ系统进行菌种鉴定,药敏实验采用Ｋ－Ｂ法。结果：７６株ＣＮＳ分为１０个菌种,其中表皮葡萄球菌占６１．８％,其次为溶血葡萄球菌、模仿葡萄球菌和木糖葡萄球菌,分别占９．２％、９．２％和７．９％。耐甲氧西林凝固酶阴性葡萄球菌（ＭＲＣＮＳ）占７６．３％,药敏显示ＣＮＳ对青霉素、红霉素     

Lipoteichoic acid fractions from pathogenic and apathogenic Listeria species and Staphylococcus aureus induce similar amounts of macrophage-derived cytokines

Lipoteichoic acids (LTAs) of pathogenic and apathogenic Listeria species and of Staphylococcus aureus were fractionated and tested for their ability to stimulate production of cytokines (IL-1α, IL-6, TNF-α) in resident peritoneal macrophages (Mϕ) of endotoxin-resistant C3H/HeJ mice using a serum-free medium. For IL-1α and IL-6 there were no detectable differences in the ability of LTA fractions of pathogenic and apathogenic Listeria species and of Staphylococcus aureus. However, LTA-2 fractions of Staphylococcus aureus, which might be less hydrophobic than the LTA-2 fractions of the listeriae-induced lower amounts of TNF-α. Furthermore, the more lipophilic LTA-2 fractions of all LTAs employed were more potent inducers of cytokines than the less lipophilic LTA-1 fractions. The biologic effect of LTAs appears, therefore, to depend mainly on their hydrophobicity.     

不同温度诱导细菌L型的实验观察

目的：观察不同温度诱导细菌形成Ｌ型。方法：抗生素纸片诱导。以苯唑青霉素（每片４０μｇ）、羧苄青霉素（每片５００μｇ）在３７℃、３２℃及２８℃分别诱导金黄色葡萄球菌和福氏痢疾杆菌Ｌ型。结果：三种不同温度诱导细菌形成Ｌ型,其菌落特征、形态及染色性等均无差别。结论：抗生素诱导Ｌ型除３７℃外,３２℃和２８℃均可形成。为探讨Ｌ型可在自然界产生和存在是否与某些传染病流行和传播有关提供依据。