金属蛋白酶对涤纶材料表面金黄色葡萄球菌生物膜形成的影响

目的观察不同浓度下金属蛋白酶(A ur)对金黄色葡萄球菌在涤纶材料表面细菌生物膜形成的影响。方法90片涤纶片按随机数字表法分成3组,每组30片。3组均将涤纶片放入有金黄色葡萄球菌液(105CFU/m l)的无菌瓶中,A组再加入含400ng/m l浓度的A ur,B组再加入含80ng/m l浓度的A ur。3组均置入电热恒温水浴箱(98.6°F)中培育,分别于培育后6h、16h、24h、30h和48h用扫描电子显微镜(SEM),激光共聚焦扫描显微镜(CLSM)观察细菌生物膜的厚度和单位面积内细菌生物膜群落数量。结果对照组涤纶片细菌生物膜的厚度和群落数呈时间依赖性明显增加,A组涤纶片金黄色葡萄球菌生物膜的厚度和群落数在各时间点均明显低于B组和对照组(P<0.05),B组生物膜的厚度和群落数在各时间点亦明显低于对照组(P<0.05)。结论A ur对金黄色葡萄球菌在涤纶片上细菌生物膜的形成有抑制作用,其抑制作用的强度与A ur剂量呈正相关。     

Development of Simultaneous Anastomotic False Aneurysms at Both Ends of an Autologous Vein Graft caused by Methicillin-Resistent Staphylococcus Aureus (MRSA)

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a well recognised problem, especially in vascular surgical patients with synthetic bypass grafts. This is to our knowledge the first report in the literature of the development of anastomotic false aneurysms at both ends of an autologous vein graft, as a result of MRSA infection within the vascular wall.     

金黄色葡萄球菌耐药性及mecA、qacA／B和pvl基因检测

金黄色葡萄球菌是临床上最常见的致病菌之一,可产生多种毒素和酶,包括凝固酶、葡萄球菌溶血素、杀白细胞素、肠毒素和表皮溶解毒素等。耐甲氧西林金黄色葡萄球菌（MRSA）具有多药耐药特征,是导致医院感染的主要革兰阳性菌,已成为临床抗感染治疗的难题。监测金黄色葡萄球菌的耐药现状,了解金黄色葡萄球菌的耐药和致病机制,以及分析感染的危险因素与治疗对策具有重要的临床意义。     

在鼠复杂骨损伤模型中金黄色葡萄球菌和绿脓杆菌间感染的协同作用

目的 研究动物接种和伴随金黄色葡萄球菌(以下简称金葡菌)和绿脓杆菌感染的互相作用。方法 采用二组Sprague-Dawley鼠作动物试验。一组用金葡菌或绿脓杆菌接种,另一组接受可变浓度的两种实验微生物的复合菌接种。在接种后14d处死,将来自伤口的标本用来培养。计算相关的每个接种体的感染率,以及将两项接种进行比较。结果 1D_(50)对金葡菌是2.8×10~4CFU,以及对绿脓杆菌是4.8×10~5CFU。10~3CFU的金葡菌与低浓度(10~2,10~3,或10~4CFU)的绿脓杆菌结合产生的感染率,比单独任何一种相同的浓度感染率高的多。结合10~3CFU的金葡菌和10~3CFU的绿脓杆菌产生75％的感染率,比相关的10~3CFU的任何一种微生物CFU高的多。绿脓杆菌的浓度增高时(C10~5,10~6和10~7CFU),这种倾向则倒转,以及感染率则减少至33％(P=0.04)。低浓度的绿脓杆菌(0～10~5CFU)结合10~6CFU的金葡菌产生83％～100％的感染率。在高浓度的绿脓杆菌(10~6及10~7CFU)减少感染率至33％(P=0.005)。结论 当伤口中存在每种低浓度细菌时,在金葡菌和绿脓杆菌之间的协同作用证明,当绿脓杆菌浓度增加时,感染率预期下降。在这种骨科切口模型中,认为低浓度的绿脓杆菌增加金葡菌感染的能力。同时,以这个率值的金葡菌试验,减少绿脓杆菌的感染率。     

Hyperbaric hyperoxia suppresses growth of Staphylococcus aureus, including methicillin-resistant strains

Purpose. We investigated the effects of increased oxygen tension on the in vitro growth of Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA), and Escherichia coli (E. coli). Methods. The effects of oxygen tension [normobaric normoxia (21% O₂ at 1 atm), normobaric hyperoxia (100% O₂ at 1 atm), hyperbaric normoxia (21% O₂ at 2 atm), and hyperbaric hyperoxia (100% O₂ at 2 atm) on the in vitro growth of MRSA, MSSA, and E. coli were investigated by population analysis. Results. Compared with normobaric normoxia, a 90-min exposure to hyperbaric hyperoxia significantly inhibited growth of both MRSA (by 25.0 ± 3.0%, mean ± SEM; P < 0.01) and MSSA (by 24.0 ± 3.3%; P < 0.01). Normobaric hyperoxia and hyperbaric normoxia were without effect. In contrast, the growth of E. coli was not affected by any of the above treatments. Conclusion. Our results indicate that the bacterium S. aureus, including resistant strains, is susceptible to oxygen stress. The observation that relatively brief (90-min) treatment with hyperbaric hyperoxia is sufficient to produce significant growth inhibition suggests that hyperbaric hyperoxia may be useful in the treatment of serious staphylococcal infections. Received: March 6, 2000 / Accepted: August 7, 2000     

金黄色葡萄球菌和表皮葡萄球菌体外对人精子运动功能的影响

目的 :研究金黄色葡萄球菌 (SA)和表皮葡萄球菌 (SE)体外对人精子的运动功能有无直接影响。　方法 :将泌尿生殖系感染病人中分离培养的SA和SE制成活菌悬液 ,体外与 10例健康成年男性手淫获得并经上游优化处理的精子孵育。按细菌 /精子比 5 0∶1分别孵育 0、2、4h后 ,采用计算机辅助的精子分析系统检测人精子活率、运动参数 (前向性运动百分率、直线速度、曲线速度、平均路径速度 )和精子形态及凝集情况。　结果 :SA与精子体外孵育 2、4h后 ,精子活率和运动参数明显降低 (P <0 .0 5 )。SE体外对精子的活率和运动功能则无明显影响。　结论 :SA与精子的比例为 5 0∶1,体外孵育 2h后 ,能显著降低精子活率和抑制精子运动功能。SE对精子运动功能无直接影响。     

男性泌尿生殖道感染患者分离的金黄色葡萄球菌耐药性及耐消毒剂基因流行特性研究

目的:研究男性泌尿生殖道感染患者尿道分泌物中分离的金黄色葡萄球菌对常用抗菌药物和消毒剂的耐药情况及消毒剂耐药基因携带情况。方法:收集男性泌尿生殖道感染患者尿道分泌物标本中分离的金黄色葡萄球菌152株,琼脂稀释法检测临床常用抗菌药物以及消毒剂氯已定对其最低抑菌浓度(MIC),同时采用头孢西丁纸片扩散法和mecA基因扩增法确定其中的耐甲氧西林金黄色葡萄球菌(MRSA);多重PCR对MRSA菌株进行SCCmec耐药基因盒(SCCmec)分型,PCR扩增耐消毒剂基因qac;脉冲场凝胶电泳(PFGE)分析qacA/B基因阳性MRSA菌株间的同源性。结果:152株金黄色葡萄球菌中,MRSA占59.9%(91/152);SCCmec分型结果显示以SCCmecⅤ型为主,占63.7%(58/91),Ⅰ型8株(8.8%),Ⅱ型2株(2.2%),Ⅲ型19株(20.9%),Ⅳ型4株(4.4%)。临床分离的金黄色葡萄球菌对青霉素、红霉素、环丙沙星、左氧氟沙星非敏感率较高,依次是:95.4%、72.4%、42.8%、44.7%,对呋喃妥因、替考拉宁、利奈唑胺以及万古霉素具有较高的敏感性。琼脂稀释法测得氯已定对152株菌的MIC值范围为0.25~16μg/ml;对MRSA菌株的MIC50=2.0μg/ml,MIC90=4.0μg/ml,对MSSA菌株的MIC50和MIC90均为1.0μg/ml;152株金黄色葡萄球菌中,有72株(47.4%)携带qacA/B基因,6株(3.9%)携带smr(qacC+qacD)基因,9株(5.9%)携带qacEΔ1基因,2株(1.3%)携带qacH基因,未检出qacG、qacJ基因。PFGE结果显示qacA/B基因阳性MRSA菌株呈多克隆分布。结论:临床分离的金黄色葡萄球菌对常用抗菌药物表现出不同程度耐药,部分菌株对消毒剂氯已定耐受力较强,耐消毒剂基因以qacA/B为主,临床医生应该合理使用抗菌药物和体外消毒剂。     

兔胫骨金黄色葡萄球菌慢性骨髓炎模型的制备

目的总结利用金黄色葡萄球菌制备新西兰大白兔胫骨慢性骨髓炎动物模型的方法及经验。方法30例健康新西兰大白兔,戊巴比妥钠全麻后利用5mm骨钻在胫骨近段钻孔,制造骨缺损,向骨髓腔内注射5μL鱼肝油酸钠（作为硬化剂）和金黄色葡萄球菌（注射总量为2×106cfu）,骨蜡封闭后不做任何治疗。4周后采用大体观察、放射学、细菌学及组织病理学等方法评价动物模型的制备情况。结果所有大白兔都可以看到早期伤口流脓、局部组织肿胀、病腿跛行,不同程度食欲减退伴有体重减轻。术后早期有3例因菌血症死亡,27例放射学表现为典型的骨髓炎,具体表现为中度到广泛的皮质反应,皮质骨破坏,轻度到广泛新骨形成,在胫骨髓腔的近端多有死骨形成,均培养出金黄色葡萄球菌,病理学显示为慢性活动性炎症、骨溶解、并有新生编织骨,造模成功率为90．O％（27／30）。结论使用本方法可较为稳定可靠地制备出兔胫骨慢性骨髓炎动物模型,值得在骨髓炎的动物研究中推广应用。     

瑞金医院烧伤中心甲氧西林耐药金黄色葡萄球菌同源性分析

目的从分子生物学水平分析甲氧西林耐药金黄色葡萄球菌(MRSA)在上海瑞金医院烧伤中心院内感染的流行状况。方法用 WHONET5统计软件分析2003—2005年瑞金医院烧伤中心 MRSA 的分布状况;用随机扩增多态 DNA(RAPD)技术对本中心住院患者临床标本中分离的17株 MRSA 进行同源性分析。结果分离的17株 MRSA 为同一 RAPD 型(引物为 ERIC2、RAPD7)。结论本中心多年来持续存在和流行的 MRSA 为同一个型别,应成为瑞金医院烧伤中心抗感染治疗和院内感染控制的重点菌株。     

荆州地区耐甲氧西林金黄色葡萄球菌的流行和耐药特征分析

目的 调查荆州地区社区相关性和医院相关性耐甲氧西林金黄色葡萄球菌(CA-MRSA和HA-MRSA)的流行和耐药特征.方法 连续收集2012年1月至2013年12月分离自荆州市中心医院门诊和住院患者送检样本的MRSA 159株.检测16种抗菌药物对所有菌株的最小抑菌浓度,采用多重PCR检测所有菌株的SCCmec分子型别,并分别以脉冲场凝胶电泳(PFGE)和耐药谱聚类分析对ICU的MRSA进行同源性分析.采用WHONET 5.6和SPSS 19.0软件对相关数据进行统计分析.结果 159株MRSA中,HA-MRSA 131株(82.4％),CA-MRSA 28株(17.6％).HA-MRSA和CA-MRSA在患者年龄、病区分布、来源样本类型、住院时间、抗感染治疗时间、感染类型和基础疾病的构成上差异有统计学意义(x2=19.103,31.372,59.756,71.703,54.153,59.756和54.232,P＜0.01).159株MRSA中未检出对万古霉素、利奈唑胺、替加环素和呋喃妥因耐药的菌株,但所有菌株对青霉素、头孢西丁和苯唑两林均耐药.HA-MRSA对莫西沙星、利福平、左氧氟沙星、环丙沙星和庆大霉素的耐药性高于CA-MRSA(x2=30.179,27.352,28.523,28.523和25.987,P＜0.01),但对红霉素和克林霉素的耐药性低于CA-MRSA(x2=13.106和11.743,P＜0.01).159株MRSA中,SCCmecⅡ型12株(7.5％),Ⅲ型113株(71.1％),Ⅳ型26株(16.4％),未能分型8株,CA-MRSA和HA-MRSA分别以Ⅳ(26/28,92.9％)型和Ⅲ型(113/131,86.3％)为主.ICU病区分离的49株HA-MRSA,经PFGE分型可分为6型,以Al(24株,49.0％)、A2亚型(9株,18.4％)和B型(9株,18.4％)为主;耐药谱聚类分析发现3群相关性很高的HA-MRSA,其对应的PFGE型别显示其分属于A1、A2亚型和B型.结论 荆州地区流行的MRSA以HA-MRSA为主,其与CA-MRSA在患者年龄、病区分布、感染类型以及耐药性等方面均显示出差异.HA-MRSA以SCCmecⅢ型为主,且在ICU病区存在HA-MRSA暴发流行.     

金黄色葡萄球菌侵袭烫伤家兔致淋巴细胞蛋白质组的变化

目的 观察金黄色葡萄球菌(SA)侵袭烫伤家兔后淋巴细胞蛋白质组的变化.方法 将24只家兔按随机数字表法分为对照组、烫伤组、sA侵袭2 h组、sA侵袭6 h组,每组6只.对照组家兔37℃模拟烫伤;其余3组家兔均造成背部30%TBSAⅢ度烫伤,SA侵袭2、6 h组分别于伤后18、22 h经耳缘静脉注射2 mL(1.0×108CFU/mL)对数生长期sA悬液.4组家兔致伤后24 h取颈动脉血分离获取淋巴细胞,提取细胞总蛋白,进行双向凝胶电泳和质谱分析.结果 4组家兔淋巴细胞平均蛋向质点数约为1030个;与对照组比较,其余3组筛选出差异蛋白质点19个,1鉴定了其中11个蛋白质点,包括10种蛋白质.表达下调的蛋白质有丝切蛋白、胞溶质蛋白A、泛素、核苷二磷酸激酶、,奋氨酸脱氢酶和膜联蛋白1,而过氧化物氧化还原素表达明显上调.结论 家兔烫伤后或烫伤+SA侵袭后淋巴细胞蛋白质组发生了明显变化,这可能与伤后免疫抑制和脓毒症的发生有关.     

2002-2006年灼伤病房金黄色葡萄球菌耐药情况分析

目的：分析上海瑞金医院灼伤科2002-2006年住院患者金黄色葡萄球菌耐药率的变化和抗菌药物的使用情况,为合理应用抗菌药物提供依据。方法：调查上海瑞金医院2002-2006年灼伤病房细菌的流行病学,抗菌药物的使用量以及金黄色葡萄球菌的耐药变化。结果：①病房分离的主要细菌是金黄色葡萄球菌（29.48%-41.06%）和铜绿假单胞菌（15.59%-23.39%）。②头孢拉定（80.45-286.34DDDs/100住院人天）、头孢哌酮（11.64-238.97 DDDs/100住院人天）等β-内酰胺类抗生素是病房使用最多的抗菌药物,万古霉素（43.19-82.18 DDDs/100住院人天）、阿米卡星（38.99-125.52 DDDs/100住院人天）、环丙沙星（1.96-163.41 DDDs/100住院人天）的使用量也比较大。③金黄色葡萄球菌对几种常用抗菌药物的耐药情况研究显示,青霉素（98.0%-100.0%）、阿米卡星（72.4%-86.1%）、头孢唑啉（68.5%-85.1%）、环丙沙星（51.5%-81.2%）、苯唑西林（72.7%-85.1%）耐药率都比较高,而万古霉素尚未发现耐药菌株。青霉素和阿米卡星的耐药情况较严重,使用量也有相应减少。环丙沙星的耐药情况有所缓解,使用量则相应增加。结论：病房金黄色葡萄球菌的耐药情况比较严重,临床必须严格掌握抗菌药物的使用指证,根据药敏结果选择合适的抗菌药物,通过联合用药、选择不常用的敏感抗菌药物、减少耐药严重的抗菌药物的使用等手段来缓解细菌耐药情况。     

浙江省耐甲氧西林金黄色葡萄球菌分子分型及耐药性分析

目的探讨浙江省分离的耐甲氧西林金黄色葡萄球菌（MRSA）的分子分型及菌株的耐药性。方法连续收集2009年1月至2010年12月浙江省11家三级甲等医院临床分离的MRSA147株。采用琼脂稀释法对13种抗菌药物进行最小抑菌浓度（MIC）测定。通过多位点序列分型（MLST）、SCCmec分型和spa分型进行菌株同源性分析,并比较不同分型菌株的耐药谱。利用辛普森指数计算三种分型方法的分辨率并进行比较。结果147株MRSA菌株共分为14种ST型,其中ST239（75株）、ST5（24株）和ST59（23株）为主要流行克隆;SCCmec分型以Ⅲ型为主（76株）,其次是Ⅳ型（32株）、Ⅱ型（24株）和V型（9株）,6株菌株无法分到已知型;spa基因分型被分为23种,其中以t030、t437、t002和t037菌株数最多,分别为57,17,15和12株。药敏结果显示,MRSA菌株除对利奈唑胺、替考拉宁、万古霉素和去甲万古霉素敏感外,对其他常用抗菌药物的耐药率均很高,尤其是主要流行克隆ST239以及SCCmecⅢ型菌株耐药情况严重。三种分型方法的分辨率分别为0．6885,0．6577和0．8165,其中spa分型方法对菌株的区分能力更强。结论浙江省临床分离的MRSA菌株存在主要流行克隆ST239-SCCmecⅢ-t030-MRSA,耐药形势严峻,应加强院内耐药菌株的监测。     

The effect of Staphylococcus aureus on apoptosis of cultured human osteoblasts

Objective: To investigate the effect of Staphylococcus aureus (S. aureus) on cultured human osteoblast apoptosis and the corresponding mode of action. Methods: Transmission electron microscopy (TEM), assessment of DNA laddering, and flow cytometry assays were used to investigate human osteoblast apoptosis following infection with S. aureus. Results: TEM examination and DNA laddering assessment indicated that S. aureus can induce cultured human osteoblast apoptosis. Flow cytometry assays showed that human osteoblast apoptosis occurs in a dose‐dependent manner following infection with S. aureus. In addition, compared with under co‐culture conditions, inhibition of invasion by S. aureus resulted in a 64.62% reduction in the percentage of early apoptotic cells (P < 0.01); 7.09% ± 1.21% of human osteoblasts under indirect co‐culture with S. aureus at a multiplicity of infection of 250 showed an early apoptotic profile compared with uninfected controls(P < 0.01). Conclusions: S. aureus induces cultured human osteoblast apoptosis in a dose‐dependent manner. Intracellular S. aureus is mainly responsible for cultured human osteoblast apoptosis following infection; secreted soluble factor(s) of S. aureus playing a minor role in this process.     

Penetration of Staphylococcus aureus into sutured wounds

An animal model was developed to study whether Staphylococcus aureus could penetrate a sutured wound. Six days after bacteria were applied to sutured incisions, viable organisms could be recovered from the depths of the wounds in the majority of cases. Specifically, bacteria could be recovered in 23 of 24 wounds when they were applied 1 day after suturing, in 17 of 24 wounds when they were applied 4 days after suturing, and in 13 of 24 when applied 7 days after suturing. When Steri-strips were used to close the wounds, bacteria could not be recovered from any of 24 wounds when bacteria were applied 4 or 7 days after wound closure. When bacteria were applied 5 min after sutures had been placed but without incision, bacteria could be recovered in three of 12 cases and in two of 12 cases when they were applied 7 days after suturing. These results demonstrate that bacteria can penetrate sutured wounds. The sutures themselves probably contributed to this phenomenon.     

Impact of Oral Antimicrobial Prophylaxis on Surgical Site Infection and Methicillin-Resistant Staphylococcus aureus Infection After Elective Colorectal Surgery. Results of a Prospective Randomized Trial

The impact of oral antimicrobial prophylaxis on the surgical site infection and methicillin-resistant Staphylococcus aureus (MRSA) infection after elective colorectal surgery was evaluated by a prospective randomized single-blind study. The patients were randomly allocated to receive either mechanical bowel cleansing with polyethylene glycol alone (group 1) or mechanical cleansing plus oral antimicrobial prophylaxis with kanamycin and erythromycin for 2 days prior to surgery (group 2). In both groups, cefotiam was intravenously given twice a day for 3 days. A total of 143 patients (71 for group 1 and 72 for group 2) were eligible. The incidence of a surgical site infection was 23.9% in group 1 and 11.1% in group 2 (P = 0.04). The incidence of MRSA infection including at surgical and remote sites was 11.1% in group 1 and 5.6% in group 2 (P = 0.19). A multivariate logistic regression analysis showed that the risk of surgical site infection was influenced by the choice of the chemical bowel preparation (P = 0.03) and blood loss (P < 0.01), while an MRSA infection was predominantly influenced by blood loss (P < 0.01) followed by coexisting underlying diseases (P = 0.07). These results suggest that preoperative antimicrobial prophylaxis would be useful for reducing the incidence of a surgical site infection without increasing the risk of an MRSA infection following elective colorectal surgery. Received: February 6, 2001 / Accepted: July 17, 2001     

Addition of bisphosphonate to antibiotic and anti-inflammatory treatment reduces bone resorption in experimental Staphylococcus aureus-induced arthritis.

Bacterial arthritis is a disease with high morbidity leading to rapidly progressive bone resorption. We have shown earlier that treatment with antibiotics in combination with corticosteroids decreases joint inflammation and mortality but does not significantly affect bone/cartilage destruction of the joints. This study was performed to assess the effect of treatment with bisphosphonate [zoledronic acid (ZA)] in combination with antibiotics and corticosteroids, on the course and outcome of Staphlococcus aureus-induced arthritis. Three days after intravenous inoculation with S. aureus, mice were treated with antibiotics alone, ZA alone, ZA and antibiotics, or ZA combined with antibiotics and corticosteroids, respectively. One group served as controls and received PBS. Clinical assessment of arthritis was performed as well as histological analysis of bone and cartilage destruction in the joints. One femur from each mouse was collected for bone mineral density (BMD) analysis. In addition, serum levels of type I collagen fragments (RatLaps), and osteocalcin, markers for osteoclastic and osteoblastic activity, respectively, were analyzed. Mice treated with ZA and antibiotics or with ZA in combination with antibiotics and corticosteroids lost significantly less in trabecular bone density compared to infected control mice. Furthermore, the addition of corticosteroids to animals treated with ZA and antibiotics, significantly decreased serum levels of RatLaps and osteocalcin, compared to animals treated with ZA and antibiotics or ZA alone. Treatment with bisphosphonates in combination with antimicrobial agents and corticosteroids significantly decreases the activity of osteoclasts in septic arthritis, thereby reducing the risk of skeletal destruction.     

脱镁叶绿酸a对金黄色葡萄球菌、大肠杆菌的抑制作用

以叶绿素为提取物，进行化学修饰得到光敏活性剂-脱镁叶绿酸α，其对微生物生长影响的研究表明：在光照条件下，脱镁叶绿酸α对金黄色葡萄球菌的生长和大肠杆菌原生质体的再生有明显的抑制作用；在暗培养条件下，脱镁叶绿酸α的抑制作用减弱。