中国七城市儿童耐甲氧西林金黄色葡萄球菌感染分离株分子学特征的研究

目的 探讨我国7个城市儿童耐甲氧西林的金黄色葡萄球菌(MRSA)感染分离株的分子特征.方法 收集2005至2009年全国7个城市(北京、上海、深圳、广州、温州、沈阳、重庆)9所三级儿童医院分离的134株MRSA.采用PCR和测序对MRSA进行多位点序列分型(MLST)和spa分型,采用多重PCR进行SCCmec分型,同时检测pvl基因.结果 MRSA大多数来源于肺炎和皮肤软组织感染分离株,占82.1％;共检测到16个MLST型,最主要的ST型是ST59 (44.8％),其次是ST239(16.4％);SCCmec分型共有Ⅱ、Ⅲ、Ⅳ和Ⅴ型4型,其中Ⅳ型是最常见的SCCmec型(50.0％),其次是Ⅴ型(23.9％)和Ⅲ型(23.9％),Ⅳ型中最常见的亚型是Ⅳa(77.6％);检测到26种spa分型,最重要的spa型是t437 (47.8％);菌株的pvl携带率与菌株SCCmec分型有关,SCCmecⅣ和Ⅴ型菌株的pvl携带率大于Ⅱ和Ⅲ型(58.6％ vs.14.3％,P＜0.05),且差异有统计学意义.不同疾病来源和不同地区来源的菌株,其流行克隆不同.结论 2005至2009年我国儿童MRSA感染分离株的流行克隆为ST59-MRSA-Ⅳa(t437)和ST239-MRSA-Ⅲ(t037),可能分别属于社区获得性MRSA与医院获得性MRSA.因此,开展对于MRSA临床流行病学监测和分子生物学的研究十分必要,能够为制定本地区防治措施提供循证依据,从而有效降低MRSA在社区和医院内的发病.     

耐甲氧西林金黄色葡萄球菌研究进展

耐甲氧西林金黄色葡萄球菌(MRSA)是儿科院内和社区感染中常见的致病菌,引起感染的比例不断上升。自1961年发现第1株MRSA以来,MRSA在世界各地流行并引起爆发流行,耐药程度不断加重。尤其1996年万古霉素不敏感金葡菌(VISA)及2002年耐万古霉素金黄色葡萄球菌(VRSA)的出现,显示MRSA对人类的威胁愈趋严重,已成为当今感染医学一个难题。本文介绍MRSA的流行情况、流行因素、耐药机制、检测方法及防治措施。     

耐甲氧西林金黄色葡萄球菌的研究进展

耐甲氧西林金黄色葡萄球菌（ｍｅｔｈｉｃｌｉｉｌｉｎｒｅｓｉｓｔａｎｔｓｔａｐｈｙｌｏｃｏｃｃｕｓａｕｒｕｅｓ,ＭＲＳＡ）是医院内感染和社区感染中常见的致病原,致病力强而治疗效果甚差,自１９６１年发现第一株ＭＲＳＡ以来,其在世界各地临床分离金葡茵中比例不断增加,耐药程度不断加重,目前已成为世界范围内的一个难题,本文介绍了ＭＲＳＡ的流行情况,流行的相关因素,耐药机制,检测方法以及耐药菌的预防措施和临床     

耐甲氧西林金黄色葡萄球菌的研究进展

耐甲氧西林金黄色葡萄球菌 (methicillin resistantstaphylococcus aurues,MR-SA)是医院内感染和社区感染中常见的致病原 ,致病力强而治疗效果甚差。自 1 96 1年发现第一株 MRSA以来 ,其在世界各地临床分离金葡菌中的比例不断增加 ,耐药程度不断加重 ,目前已成为世界范围内的一个难题。本文介绍了 MRSA的流行情况、流行的相关因素、耐药机制、检测方法以及耐药菌的预防措施和临床治疗方案。     

小儿社区获得性耐甲氧西林金黄色葡萄球菌感染临床分析

目的：研究小儿社区获得性耐甲氧西林金黄色葡萄球菌(MRSA)感染的临床特征和耐药情况,以指导临床治疗。方法：以同期分离的医院获得性感染的MRSA菌株作对照,分析该院2002年1月至2005年3月从临床各类标本中分离的社区获得性MRSA菌株的临床特征和耐药情况。结果：25株MRSA占同期分离的全部金黄色葡萄球菌512株的4.7%,其中社区获得性感染的MRSA20例,医院获得性感染的MRSA5例。两组发病年龄无统计学差异。MRSA占金黄色葡萄球菌检出率在连续2年多的时间内呈逐年增多趋势,2003年3.1%、2004年5.4%、2005年第一季度7.2%。两组对多种抗生素敏感实验结果及多重耐药比较均无统计学差异。两组中所有菌株对万古霉素均敏感,未发现万古霉素中介和耐药菌株。医院感染组合并基础疾病比例明显高于社区获得性感染组(P<0.05)。3例社区获得感染组的肺炎患者,痰培养获得MRSA,其中1例给予非敏感抗生素治愈。结论：小儿社区获得性MRSA感染呈上升趋势,其临床和耐药特征与医院感染者未见明显差别。     

新生儿社区获得性耐甲氧西林金黄色葡萄球菌皮肤软组织感染临床分离株的分子、耐药性及毒力特征研究

目的探讨新生儿社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）皮肤软组织感染临床分离株的分子、耐药性及毒力特征。方法从NICU中收集皮肤软组织感染的CA-MRSA菌株，总结其临床特点，对所有菌株进行MLST、SCCmec、SPA和agr分型，并行21种超抗原毒素基因、sasX基因和PVL基因检测。所有菌株进行体外药物敏感试验。结果28例CA-MRSA皮肤软组织感染的新生儿，单部位感染10例，多部位感染18例，检出30株CA-MRSA，以脐部蜂窝织炎为主（12/30,40.0%），主要的流行克隆为ST59-IVa-t437-agr-1（73%，22/30）, 超抗原毒力基因的携带率为80%，PVL的阳性率为47%。发现了4株苯唑西林敏感的MRSA（OS-MRSA），红霉素耐药率高。结论新生儿CA-MRSA皮肤软组织感染以脐部蜂窝织炎为主，主要的流行克隆为ST59-IVa-t437-agr-1, 超抗原及PVL基因携带率高，首次发现了OS-MRSA，红霉素耐药率高。     

新生儿社区获得性耐甲氧西林金黄色葡萄球菌皮肤软组织感染临床分离株的分子、耐药性及毒力特征研究

目的探讨新生儿社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）皮肤软组织感染临床分离株的分子、耐药性及毒力特征。方法从NICU中收集皮肤软组织感染的CA-MRSA菌株,总结其临床特点,对所有菌株进行MLST、SCCmec、SPA和agr分型,并行21种超抗原毒素基因、sasX基因和PVL基因检测。所有菌株进行体外药物敏感试验。结果28例CA-MRSA皮肤软组织感染的新生儿,单部位感染10例,多部位感染18例,检出30株CA-MRSA,以脐部蜂窝织炎为主（12/30,40.0%）,主要的流行克隆为ST59-IVa-t437-agr-1（73%,22/30）, 超抗原毒力基因的携带率为80%,PVL的阳性率为47%。发现了4株苯唑西林敏感的MRSA（OS-MRSA）,红霉素耐药率高。结论新生儿CA-MRSA皮肤软组织感染以脐部蜂窝织炎为主,主要的流行克隆为ST59-IVa-t437-agr-1, 超抗原及PVL基因携带率高,首次发现了OS-MRSA,红霉素耐药率高。     

Scarlet fever caused by community-associated methicillin-resistant Staphylococcus aureus

We describe a previously healthy 2.5-year-old boy with staphylococcal scarlet fever associated with acute suppurative otitis media due to community-associated methicillin-resistant Staphylococcus aureus. The patient was successfully treated by spontaneous drainage in combination with trimethoprim-sulfamethoxazole therapy.     

儿童耐甲氧西林金黄色葡萄球菌感染致严重脓毒症12例分析

目的分析儿童耐甲氧西林金黄色葡萄球菌(MRSA)感染导致严重脓毒症的临床特点及细菌耐药性。方法回顾性分析2010年1月至2013年12月收治的12例MRSA感染致严重脓毒症患儿的病史和细菌药敏试验资料。结果 12例患儿中,男5例、女7例,年龄8 d~11岁,中位年龄1岁,9例为1岁婴儿,均急性起病。5例表现为急性骨髓炎和/或化脓性关节炎,5例表现为坏死性肺炎伴脓胸,1例表现为坏死性筋膜炎,1例表现为血流感染;其中8例同时伴有皮肤及软组织感染,7例并发脓毒性休克,1例并发弥漫性血管内凝血。患儿C反应蛋白均显著升高,4例白细胞计数下降。药敏试验显示12株MRSA对万古霉素、利奈唑胺均敏感,对红霉素、克林霉素、复方磺胺甲噁唑有不同程度的耐药。经手术清创、胸腔闭式引流等治疗后,8例存活,4例死亡。结论 MRSA感染导致的严重脓毒症多见于婴儿,发病急、进展迅速,需要积极治疗。     

Clindamycin treatment of invasive infections caused by community-acquired,methicillin-resistant and methicillin-susceptible Staphylococcus aureus in children

BACKGROUND: Community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) is an established pathogen in several areas of the United States, but experience with clindamycin for the treatment of invasive MRSA infections is limited. We compared the outcome of therapy for MRSA with that of methicillin-susceptible (MSSA) invasive infections in children treated with clindamycin, vancomycin or beta-lactam antibiotics. METHODS: The demographics, hospital course and outcome of children at Texas Children's Hospital between February and November 2000 and between August 2001 and August 2002 with invasive S. aureus infections were reviewed from medical records in this retrospective study. RESULTS: CA-MRSA and community-acquired methicillin-susceptible S. aureus (MSSA) caused invasive infections in 46 and 53 children, respectively. The median ages (range) of the children were: MRSA, 3.5 years (2 months to 18.6 years); MSSA, 4.8 years (3 months to 19.8 years). The sites of infection for MRSA vs. MSSA isolates, respectively, were: bacteremia, 3 vs. 6; osteomyelitis, 14 vs. 14; septic arthritis, 5 vs. 7; pneumonia, 11 vs. 3; lymphadenitis, 7 vs. 14; other, 5 vs. 8. Among MRSA patients 39 (20 received clindamycin only, 18 had vancomycin initially and 8 were treated with a beta-lactam initially) received clindamycin and 6 received vancomycin as primary therapy. Among MSSA patients, clindamycin, nafcillin or other beta-lactam antibiotics were used in 24, 18 and 9, respectively. The median number of febrile days was 3 (0 to 14) and 2 (0 to 6) for MRSA and MSSA patients, respectively (P = 0.07). The median number of days with positive blood cultures was 2 for the MRSA (n = 16) and 1 for the MSSA (n = 18) patients (P = 0.04). CONCLUSION: Clindamycin was effective in treating children with invasive infections caused by susceptible CA-MRSA isolates.     

Community-acquired methicillin-resistant Staphylococcus aureus infections in children

Methicillin-resistant Staphylococcus aureus (MRSA) is now an established community pathogen in many areas of the United States as well as the world. Community-acquired MRSA (CA-MRSA) infections have changed several aspects of staphylococcal infections in children including the epidemiology, clinical manifestations, laboratory approach, antibiotic management, and prevention.     

儿童社区获得性耐甲氧西林金黄色葡萄球菌感染研究

目的 探讨上海地区儿童社区获得性耐甲氧西林金黄色葡萄球菌(CA-MRSA)的流行状况、临床特征、耐药谱和分子学特征.方法 总结2005年1月至2007年1月上海交通大学附属儿童医院收治社区发生MRSA感染的流行病学和临床资料,进行细菌耐药监测及分子学检测;分析本地区儿童CA-MRSA感染现状、发展趋势.结果 在金黄色葡萄球菌感染患儿中MRSA检出率从7.5%增高至9.7%,其中CA-MRSA占MRSA的10.9%,而卫生保健相关性MRSA(HCA-MRSA)为65.2%.MRSA检出率有一定的季节分布.呼吸科和儿童重症监护病房的HCA-MRSA阳性最高(20%),CA-MRSA在外科较多(40%).CA-MRSA皮肤软组织感染比例最高为40%,HCA-MRSA以肺炎和败血症为主(52%和36%).HCA-MRSA危险因素主要是卫生保健机构接触和使用抗生素(64%),而医院获得性MRSA(HA-MRSA)以插管和机械通气为多见(4%).30株MRSA mecA基因均为阳性.其基因型SCCmec Ⅱ型6株,SCCmecⅢ型15株,SCCmecⅣa型1株和SCCmecⅤ型2株,未能分型6株.PVL基因阳性11例,CA-MRSA均携带PVL基因.12株MRSA的spa基因中有3株(25.0%)完全相同.非多药耐药MRSA为17%,多药耐药MRSA对红霉素和克林霉素均达80%.结论 上海地区儿童社区发生的MRSA感染增多,应引起儿科医师重视.儿童HCA-MRSA主要表现为呼吸道疾病和败血症;CA-MRSA除了可引起皮肤软组织感染外,也可引起重症肺炎和败血症.上海地区儿童MRSA菌株以SCCmecⅢ为主,CA.MRSA以SCCmecⅤ和未能分型株稍多.spa基因的多样性提示目前本地儿童MRSA并非流行株,需要作进一步连续耐药监测.     

Management and outcome of children with skin and soft tissue abscesses caused by community-acquired methicillin-resistant Staphylococcus aureus

BACKGROUND: Although the epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has been explored in many investigations, management of this emerging infection has not been well-studied. For non-methicillin-resistant Staphylococcus aureus skin and soft tissue abscesses, incision and drainage is generally adequate therapy without the use of antibiotics, but this has not been established for CA-MRSA. METHODS: Children presenting to Children's Medical Center of Dallas for management of skin and soft tissue abscesses caused by culture-proved CA-MRSA were prospectively followed. We analyzed data from the initial evaluation and from two follow-up visits that focused on the management and outcome of CA-MRSA infection. Retrospective chart review was performed 2 to 6 months after the initial visit. RESULTS: Sixty-nine children were identified with culture-proved CA-MRSA skin and soft tissue abscess. Treatment consisted of drainage in 96% of patients and wound packing in 65%. All children were treated with antibiotics. Five patients (7%) were prescribed an antibiotic to which their CA-MRSA isolate was susceptible before culture results were known. Four patients (6%) required hospital admission on the first follow-up; none of these patients had received an antibiotic effective against CA-MRSA. A significant predictor of hospitalization was having a lesion initially >5 cm (P = 0.004). Initial ineffective antibiotic therapy was not a significant predictor of hospitalization (P = 1.0). Of the 58 patients initially given an ineffective antibiotic and managed as outpatients, an antibiotic active against CA-MRSA was given to 21 (36%) patients after results of cultures were known. No significant differences in response were observed in those who never received an effective antibiotic than in those who did. CONCLUSIONS: Incision and drainage without adjunctive antibiotic therapy was effective management of CA-MRSA skin and soft tissue abscesses with a diameter of <5 cm in immunocompetent children.     

Risk factors and molecular analysis of panton-valentine leukocidin-positive methicillin-resistant Staphylococcus aureus colonization in healthy children

BACKGROUND: Nasal carriage of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is associated with community associated disease. The risk factors for and characteristics of PVL-positive MRSA colonization in the healthy pediatric population are not well understood. METHODS: Anterior nares cultures were obtained from healthy children < or =14 years of age presenting for health maintenance visits or attending 1 of 8 kindergartens during a 3-year period. A case-control study and molecular typing studies were performed. RESULTS: A total of 131 (8.1%) of 1615 children had nares cultures positive for MRSA, and 25 (1.5%) were colonized with PVL-positive MRSA. Nasal colonization of PVL-positive MRSA was significantly higher in 2006 than in 2004 (2.8% versus 0.7%; P = 0.006). By multivariate analysis, antibiotic use during the past 12 months (odds ratio, 29.37; 95% confidence interval, 10.72-80.50; P < 0.001) was the major risk factor associated with PVL-positive MRSA colonization in healthy children. Comparison of hospital MRSA strains with the community colonization strains by antimicrobial susceptibility testing, macrolide-lincosamide-streptogramin resistance gene testing, staphylococcal cassette chromosome mec typing, exotoxin profiling, and pulsed-field gel electrophoresis typing revealed that clonal spread of PVL-positive MRSA distinct from clinical hospital strains contributed to the high PVL-positive MRSA burden in the community. CONCLUSIONS: Nasal PVL-positive MRSA colonization in healthy children with no relationship to the hospital setting has increased significantly in the past 3 years, suggesting that it may be a major factor in the emergence of community-acquired MRSA disease in Taiwan. Previous antibiotic use was associated with PVL-positive MRSA colonization.     

儿童社区获得性耐甲氧西林金黄色葡萄球菌感染研究进展

近年来,社区获得性耐甲氧西林金黄色葡萄球菌(CA-MRSA)已经在无明确危险因素儿童中出现,其发病率在世界各地正在上升.CA-MRSA感染已经使儿童葡萄球菌感染流行病学、实验室方法、抗生素治疗和预防等方面发生了变化.尽管多数CA-MRSA感染是轻度的,最初涉及皮肤和软组织,但也可导致严重的、侵袭性和威胁生命的感染.作为一种遗传学上截然不同的病原,CA-MRSA通常对多种非β-内酰胺类抗生素敏感.在抗生素选择时应考虑当地CA-MRSA的发病率和敏感性,感染严重度和独立危险因素.金黄色葡萄球菌感染时合理的经验性抗生素治疗应考虑甲氧西林耐药的可能性.多数感染表现为皮肤脓肿,局部引流对大部分患儿有效.克林霉素、增效磺胺甲基异嗯唑、万古霉素和利福平对多数儿童CA-MRSA仍有价值.利奈唑胺和其他更新注射用抗生素应保留用于严重感染.