耐甲氧西林金黄色葡萄球菌对万古霉素敏感性的监测

目的为了引起广大医务人员高度重视耐甲氧西林金黄色葡萄球菌(MRSA)对万古霉素敏感性的监测,掌握其耐药特性,依据药敏结果合理使用抗菌药物,延缓其耐药性的产生. 方法采用美国Microscan微生物鉴定仪、革兰阳性菌鉴定药敏复合板(PC11),对1998～2000年分离的MRSA对万古霉素敏感性的监测. 结果 1998～2000年分离的MRSA菌株中,有4株对万古霉素敏感性降低,其中1株对万古霉素的MIC=8μg/ml;3株对万古霉素的MIC>16μg/ml. 结论在我院监测中出现1株万古霉素中介敏感金黄色葡萄球菌(VISA);3株万古霉素耐药金黄色葡萄球菌(VRSA),药敏结果显示多重耐药.     

儿童金黄色葡萄球菌血流感染临床特征及耐药分析

【目的】研究儿童金黄色葡萄球菌的血流感染临床特点、易患因素、转归及耐药性,为合理控制及治疗儿童金黄色葡萄球菌血流感染提供依据。【方法】以2016年1月至2018年6月间血培养金黄色葡萄球菌阳性182例,对患儿的科室分布、感染类型、基础疾病、临床特征、抗生素耐药、治疗转归及影响预后的因素等进行分析。【结果】血培养金黄色葡萄球菌阳性182例中,①按科室分：来自新生儿科63例（34.62%）、骨科22例（12.09%）、PICU20例（10.99%）、血液肿瘤科15例（8.24%）、风湿免疫科15例（8.24%）、呼吸科13例（7.14%）;②按感染来源：社区感染109例（59.89%）、医院获得性感染73例（40.11%）;③有基础疾病者103例（56.59%）;④首发症状中最常见的为发热148例（81.76％）;⑤耐甲氧西林金黄色葡萄球菌（MRSA）141例（77.47%）;⑥金黄色葡萄球菌对青霉素耐药率100%,对氨苄青霉素、红霉素、阿莫西林/克拉维酸、苯唑青霉素、氨苄青霉素/舒巴坦、头孢曲松、克林霉素严重耐药,未发现对万古霉素、利奈唑胺、达托霉素耐药菌株;⑦转归：治愈及好转161例（88.46%）,未愈及死亡21例（11.54%）;⑧预后的不良因素为严重脓毒血症（χ2=68.633,P=0.000）及机械通气（χ2=67.467,P=0.000）。【结论】【结论】有基础疾病者、新生儿是金黄色葡萄球菌血流感染的易患因素,而严重脓毒血症及机械通气者预后差,MRSA在金黄色葡萄球菌血流感染占很高比例,其中院内感染较社区获得感染比例更高,在重症金黄色葡萄球菌血流感染经验性治疗效果不佳时,应及时调整治疗兼顾MRSA感染。     

Effects of extracts from Italian medicinal plants on planktonic growth, biofilm formation and adherence of methicillin-resistant Staphylococcus aureus

AIM OF STUDY: One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infection (SSTI). Staphylococcus aureus, a common cause of SSTI, has generated increasing concern due to drug resistance. Many plants possess antimicrobial agents and provide effective remedies for SSTI. Our aim was to investigate plants from different ethnobotanical usage groups for inhibition of growth and biofilms in methicillin-resistant Staphylococcus aureus (MRSA). MATERIALS AND METHODS: Three groups were assessed: plant remedies for SSTI, plant remedies not involving the skin, and plants with no ethnomedical application. We screened 168 extracts, representing 104 botanical species, for activity against MRSA (ATCC 33593). We employed broth dilution methods to determine the MIC after 18 h growth using an optical density (OD 600 nm) reading. Anti-biofilm effects were assessed by growing biofilms for 40 h, then fixing and staining with crystal violet. After washing, 10% Tween 80 was added and OD 570 nm readings were taken. RESULTS: Extracts from 10 plants exhibited an IC50相似文献   

海洋链霉菌Streptomyces sp. S598中抗菌活性产物的研究

目的 对海洋链霉菌Streptomyces sp. S598固体发酵提取物的抗菌成分进行研究。方法 采用葡聚糖凝胶Sephadex LH-20、反相柱色谱、硅胶柱层析及半制备HPLC等方法分离纯化该菌株的活性次级代谢产物,并通过ESI-MS、NMR等波谱技术结合文献对比鉴定其结构。结果 从10L固体发酵提取物中分离得到5个单体化合物,分别鉴定为缬氨霉素(1)、二活菌素(2)、亚油酸(3)、亚油酸甲酯(4)和油酸(5)。结论 海洋链霉菌Streptomyces sp. S598能代谢产生具有多种生物活性的化合物。化合物1对MRSA 28300和白念珠菌(ATCC10231)的MIC为1μg/mL,化合物2具有较强的广谱抗细菌活性,对肺炎链球菌、流感嗜血菌的MIC为0.125μg/mL,尤其具有显著的抗MRSA的活性,对MRSA     

Ecthyma gangrenosum caused by Staphylococcus aureus in hematological malignancies: Case reports and literature review

Rationale:Ecthyma gangrenosum (EG) is a potentially life-threatening, systemic infection generally caused by Pseudomonas aeruginosa. Data on EG caused by Staphylococcus aureus in patients with hematological malignancies are scarce. The present case report aimed to describe the clinical features of EG caused by S. aureus in patients with hematological malignancies and to provide a comprehensive review of previous studies on the topic.Patient concerns:The first patient was a 61-year-old man with acute myeloid leukemia who presented fever and multiple lesions during chemotherapy. The second patient was a 47-year-old man with myelodysplastic syndrome who developed progressive erythematous necrotic plaques on his extremities and face.Diagnosis:Both cases were diagnosed as EG caused by S. aureus. While the first patient had concurrent methicillin-resistant S. aureus (MRSA) bacteremia, the second patient had positive results only for tissue culture of the skin lesion isolated methicillin-sensitive S. aureus.Interventions:Vancomycin was initiated with critical care to the first patient. Cefazolin was administered to the second patient for 3 weeks, followed by cephalexin for 1 week.Outcomes:The first patient died of a brain hemorrhage and multiple organ failure. The second patient was cured without relapse.Lessons:Of 18 patients in the previous and current studies with EG caused by S. aureus, 6 (33%) had an underlying hematological malignancy, and 10 (56%) had EG caused by MRSA. While 28% of the patients had positive blood cultures, all tissue cultures were positive. All 3 fatalities had concurrent bacteremia (MRSA caused two). EG caused by MRSA with concurrent bacteremia can be fatal, especially in patients with hematological malignancies. Although S. aureus-associated EG in patients with hematological malignancies is relatively uncommon, tissue cultures with an initial gram stain smear are essential for selecting appropriate empirical antimicrobials, including the coverage of S. aureus.     

VITEK-32对葡萄球菌属细菌鉴定及耐药检测观察

目的调查金葡、凝固酶阴性葡萄球菌的耐药现状。方法对390株金黄色葡萄球菌和182株凝固酶阴性葡萄球菌用VITEK-32和GPS-107药敏卡、GPI鉴定卡、API-Spath手工条鉴定细菌并测定其对药物的敏感性。应用胶乳凝集试验检测青霉素结合蛋白2a(PBP2a),同时用NCCLS推荐的纸片扩散法检测耐甲氧西林的葡萄球菌。耐万古霉素的葡萄球菌(VRSA)和异质性耐万古霉素的葡萄球菌(hVISA)。结果耐甲氧西林的金黄色葡萄球菌(MRSA)仪器法、青霉素结合蛋白2a(PBP2a)、纸片扩散法,阳性率分别72%、76%、68%,凝固酶阴性的葡萄球菌耐甲氧西林(CNS)仪器法、纸片扩散法,分别是78%、72%,青霉素结合蛋白2a(PBP2a)全部阴性。未检出VRSA和hVISA。结论万古霉素、复方新诺明和四环素对耐甲氧西林的葡萄球菌有较好的抗菌活性,胶乳凝集试验检测青霉素结合蛋白2a(PBP2a)简便、快速、准确。     

匹莫齐特对金黄色葡萄球菌的体外和体内抗菌研究

目的 探讨抗精神病类药物匹莫齐特对金黄色葡萄球菌的体外和体内抗菌活性。方法 采用微量肉汤稀释法检测匹莫齐特的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。通过96孔细胞培养板构建生物膜,利用比浊法检测匹莫齐特的抗生物膜活性,进一步通过激光共聚焦显微镜和SYTO9/PI染色观察匹莫齐特对生物膜的作用。采用棋盘稀释法检测匹莫齐特与抗菌药物联合抗菌效果,CCK-8试剂盒检测匹莫齐特的细胞毒性。构建皮肤脓肿模型,检测匹莫齐特的体内抗菌活性及毒性。结果 匹莫齐特对金黄色葡萄球菌具有明显的剂量依赖抑菌活性,其MIC为8～16μg/mL,能显著抑制金黄色葡萄球菌生物膜的形成并分散已形成的生物膜。匹莫齐特与多西环素联合,体外具有协同抗菌效果,其协同抑菌指数为0.5;体内能显著降低小鼠脓肿组织中的细菌载量,使活菌量从(8.25±0.13)对数值CFU/脓肿减少到(3.31±0.81)对数值CFU/脓肿(q=3.74,P<0.05);匹莫齐特的细胞毒性极低,对细胞的半数抑制浓度>64μg/mL。结论 匹莫齐特毒性低且具有明显的体外和体内抗菌活性,有望成为一种精神病患者合并局部金黄色葡萄球菌相...     

金黄色葡萄球菌生物被膜耐药机制研究进展

金黄色葡萄球菌是常见的引起医院感染和社区感染的致病菌之一。近年来, 临床上金黄色葡萄球菌抗感染治疗失败的病例越来越多, 生物被膜的形成被认为是导致抗菌药物治疗失败的主要原因。然而, 金黄色葡萄球菌生物被膜的耐药机制并未完全阐明。证据表明, 金黄色葡萄球菌生物被膜感染难以治愈且容易反复, 感染后反复治疗将大大增加患者的痛苦和经济负担。本文对金黄色葡萄球菌生物被膜耐药机制的研究进展进行综述, 以期为开发新的抗菌药物提供参考依据。     

金黄色葡萄球菌血流感染住院患儿临床特征及危险因素

目的 了解儿童金黄色葡萄球菌(SA)血流感染的临床特点以及菌株的药敏特征,探讨耐甲氧西林金黄色葡萄球菌(MRSA)血流感染和SA血流医院感染(HA)的易感因素。方法 回顾性分析2014年1月—2019年12月某儿童医院血培养检出SA住院患儿的病历资料,根据其药敏试验结果及来源分为MRSA组与甲氧西林敏感金黄色葡萄球菌(MSSA)组、HA组与社区感染(CA)组,应用卡方检验和logistic回归分析MRSA血流感染及HA血流感染的危险因素。结果 共纳入143例病例,男女比例为1.8∶1,<1岁71例(49.6%),病灶性血流感染90例(62.9%)。MARS组50例(35.0%),MSSA组93例(65.0%);HA组73例(51.0%),CA组70例(49.0%)。机械通气[OR=17.320,95%CI(1.576～190.399)]、抗菌药物联合使用[OR=0.580,95%CI(0.359～0.938)]是MRSA血流感染的独立危险因素(均P<0.05)。机械通气[OR=31.466,95%CI(1.434～690.538)]、入院前使用抗菌药物[OR=24.524,...     

Functional and Immunological Studies Revealed a Second Superantigen Toxin in Staphylococcal Enterotoxin C Producing Staphylococcus aureus Strains

Staphylococcus aureus is a human and animal pathogen as well as a commensal bacterium. It can be a causative agent of severe, life-threatening infections with high mortality, e.g., toxic shock syndrome, septic shock, and multi-organ failure. S. aureus strains secrete a number of toxins. Exotoxins/enterotoxins are considered important in the pathogenesis of the above-mentioned conditions. Exotoxins, e.g., superantigen toxins, cause uncontrolled and polyclonal T cell activation and unregulated activation of inflammatory cytokines. Here we show the importance of genomic analysis of infectious strains in order to identify disease-causing exotoxins. Further, we show through functional analysis of superantigenic properties of staphylococcal exotoxins that even very small amounts of a putative superantigenic contaminant can have a significant mitogenic effect. The results show expression and production of two distinct staphylococcal exotoxins, SEC and SEL, in several strains from clinical isolates. Antibodies against both toxins are required to neutralise the superantigenic activity of staphylococcal supernatants and purified staphylococcal toxins.