Osteomyelitis with methicillin-resistant Staphylococcus aureus

We describe 10 patients with hospital-acquired osteomyelitis due to methicillin-resistant Staphylococcus aureus. The patients were posttraumatic and eight had a foreign body in situ at the site of infection. Vancomycin therapy in association with radical debridement was followed by clinical and radiological cure in eight patients at 2-3.5 years follow-up, in two of whom a foreign body was left in situ. Only minor adverse effects of vancomycin therapy (one rash, two thrombophlebitis) were seen.     

Transmission and control of methicillin-resistant Staphylococcus aureus in a skilled nursing facility

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly frequent in both acute care facilities (ACFs) and skilled nursing facilities (SNFs). Admissions to SNFs from ACFs with endemic MRSA are one likely source of infection in SNFs. The occurrence of MRSA in SNFs and the relative roles of ACFs and SNFs in MRSA transmission have not been well characterized. We conducted an epidemiologic investigation in an SNF reporting a high incidence of MRSA cases and found that the prevalence of MRSA exceeded that reported in acute care settings. Fifteen (9.1%) of the 164 residents were colonized or infected with MRSA. Risk factors for MRSA identified through a prevalence case-control study were nasogastric intubation (odds ratio = 5.5; 95% confidence interval = 1.2, 26.4), antibiotic therapy (OR = 3.9; CI = 1.2, 13.0), and hospitalization in an acute care facility within the previous six months (OR = 2.9; CI = 0.9, 9.7). During a three-month period, 6 of 100 new admissions were MRSA-positive; all positive patients were from ACFs. Five new cases also emerged from previously MRSA-negative residents. SNF residents are often discharged to ACFs. Transmission of MRSA within the SNF and the transfer of patients to ACFs increases the reservoir of potentially infective patients and the potential for MRSA infections in ACFs. Modest control measures, including targeted surveillance culturing and cohorting of colonized residents, may minimize MRSA transmission in the SNF and decrease the reservoir of MRSA in the community.     

耐甲氧西林金黄色葡萄球菌引起的医院内获得性抗生素相关性腹泻

抗生素相关性腹泻(AAD)是由于患者长期使用广谱抗生素,造成肠道正常菌群的改变,同时伴随病原微生物的繁殖以及毒素的产生,最终引起肠道细胞病变。会引起AAD的致病菌包括:艰难梭状芽孢杆菌、产气梭状芽孢杆菌、产酸克雷伯菌、金黄色葡萄球菌等,病毒如诺如病毒、轮状病毒和腺病毒等。但由金黄色葡萄球菌(Staphylococcus aureus,简称金葡菌)引起的抗生素相关性腹泻一直备受质疑。本文将回顾最近20年有关金葡菌引起AAD的报道和研究,内容包括临床病例、病原微生物的鉴定、组织病理学证据以及动物实验证据,以探讨这一致病菌是否会造成医院内抗生素相关性腹泻。     

Molecular epidemiology of methicillin-resistant Staphylococcus aureus

Subtyping methicillin- resistant Staphylococcus aureus (MRSA) isolates and tracking nosocomial infections have evolved from phenotypic to genotypic approaches; most laboratories now depend on pulsed-field gel electrophoresis (PFGE). We discuss the limitations of current image-based genotyping methods, including PFGE, and the advantages (including ease of entering data into a database) of using DNA sequence analysis to control MRSA infections in health-care facilities.     

Human-to-dog transmission of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) was cultured from the nose of a healthy dog whose owner was colonized with MRSA while she worked in a Dutch nursing home. Pulsed-field gel electrophoresis and typing of the staphylococcal chromosome cassette mec (SCCmec) region showed that both MRSA strains were identical.     

耐甲氧西林金黄色葡萄球菌的耐药性分析

目的 了解耐甲氧西林金黄色葡萄球菌临床感染现状及其耐药性,为临床合理使用抗菌药物提供科学依据.方法 采用phonix-100对314株金黄色葡萄球菌进行鉴定和药敏试验,数据统计使用WHONET5.5软件及SPSS17.0软件进行.结果 共分离出314株金黄色葡萄球菌,其中耐甲氧西林金黄色葡萄球菌(MRSA) 164株,占52.2％,甲氧西林敏感金黄色葡萄球菌(MSSA) 150株,占47.8％;标本来源以痰液为主,占58.3％,其次是伤口分泌物占29.3％;MRSA和MSSA对万古霉素、替考拉宁、利奈唑胺无耐药,MRSA对阿米卡星、庆大霉素、妥布霉素、利福平、环丙沙星、磺胺甲噁唑/甲氧苄啶、克林霉素、红霉素、四环素耐药率分别为86.6％、89.6％、93.3％、43.3％、87.8％、6.7％、84.1％、84.1％、85.3％;MSSA对青霉素、阿米卡星、庆大霉素、妥布霉素、利福平、环丙沙星、磺胺甲噁唑/甲氧苄啶、克林霉素、红霉素、四环素耐药率分别为92.0％、0.7％、32.7％、32.7％、2.7％、10.0％、34.7％、36.0％、59.3％、22.0％;MRSA对大环内酯类、氨基糖苷类、氟喹诺酮类、四环素类、克林霉素耐药率明显高于MSSA.结论 MRSA分离率较高,耐药性严重,应引起重视,临床应根据药敏试验结果合理选择抗菌药物.     

Genetic characterization of methicillin-resistant Staphylococcus aureus

The genome structure of Staphylococcus aureus is analyzed. The genome is composed of two domains. The first domain, descendent from an ancestral bacterial species, contains house-keeping genes that showed highest homology to those of Bacillus species. The second domain contained the genes responsible for virulence and drug-resistance in human infection that seems to have been acquired from other bacterial species via lateral gene transfer. The latter domain constitutes the genetic information that makes S. aureus a notorious hospital pathogen.     

Control of epidemic methicillin-resistant Staphylococcus aureus

We controlled the spread of epidemic methicillin-resistant Staphylococcus aureus (MRSA) infection in an 884-bed veterans' facility by cohorting known active MRSA carriers and MRSA-infected patients on one nursing unit. Simultaneously, all previously-institutionalized transfers into the veterans' facility were screened with swab cultures for MRSA at the time of admission. All MRSA patients were maintained on contact (gown and glove) or strict isolation and treated aggressively with topical and enteral antibiotics with the assistance of the infectious disease consultant. The monthly incidence of new MRSA patients dropped from a maximum of 16 per month to three or less per month within six months of instituting these infection control measures. There were no further MRSA bacteremias after the establishment of the MRSA cohort in a single unit. Aggressive cohort management of known MRSA patients and screening of previously-institutionalized patients on admission for MRSA controlled epidemic MRSA in this large institution.     

耐甲氧西林金黄色葡萄球菌的目标性监控与分析

目的 了解临床耐甲氧西林金黄色葡萄球菌的分离及耐药性,探索耐甲氧西林金黄色葡萄球菌感染病例的监控措施.方法 对2010年医院临床分离的病原菌进行目标性监测,统计出耐甲氧西林金黄色葡萄球菌的株数以及耐药性,并对临床耐甲氧西林金黄色葡萄球菌感染病例实施监控.结果 全年检测结果发现,共分离出金黄色葡萄球菌334株,耐甲氧西林金黄色葡萄球菌50株,检出率为14.97％;对抗菌药物耐药率较高;全院未发生耐甲氧西林金黄色葡萄球菌的暴发和流行.结论 耐甲氧西林金黄色葡萄球菌分离株数较多,耐药率较高,应该加强临床合理使用抗菌药物的管理,并对耐甲氧西林金黄色葡萄球菌感染病例实施监控,预防和减少多药耐药菌的产生,控制医院感染.     

Changing epidemiology of community-onset methicillin-resistant Staphylococcus aureus bacteremia.

OBJECTIVES: To review cases of community-onset Staphylococcus aureus bacteremia and to evaluate whether the risk factors and epidemiology of methicillin-resistant S. aureus (MRSA) bacteremia have changed from early reports. DESIGN: Retrospective case-comparison study of community-onset MRSA (n = 26) and methicillin-susceptible S. aureus (MSSA) (n = 26) bacteremias at our institution. SETTING: A 600-bed urban academic medical center. PATIENTS: Twenty-six patients with community-onset MRSA bacteremia were compared with 26 patients with community-onset MSSA bacteremia. Molecular analysis was performed on S. aureus isolates from the 26 MRSA cases as well as from 13 cases of community-onset S. aureus bacteremia from 1980 and 9 cases of nosocomial S. aureus bacteremia from 2001. RESULTS: The two groups were similar except that patients with MRSA bacteremia were more likely to have presented from a long-term-care facility (26.9% vs 4%; P = .05) and to have had multiple admissions within the preceding year (46% vs 15%; P = .03). Clamped homogeneous electric fields analysis of MRSA isolates from 1982 revealed predominantly that one clone was the epidemic strain, whereas there were 14 unique strains among current community-onset isolates. Among current nosocomial isolates, 3 patterns were identified, all of which were present in the community-onset cases. CONCLUSIONS: Previously described risk factors for MRSA acquisition may not be helpful in predicting disease due to the polyclonal spread of MRSA in the community. Unlike early outbreaks of MRSA in patients presenting from the community, current acquisition appears to be polyclonal and is usually related to contact with the healthcare system.     

耐甲氧西林金黄色葡萄球菌感染的流行病学及耐药性研究

目的探讨城市中心城区耐甲氧西林金黄色葡萄球菌(MRSA)感染的流行病学及耐药性。方法采用回顾性调查方法,对医院2009年住院患者进行MRSA感染的统计分析。结果在2009年40 846份标本中,检出265株金黄色葡萄球菌,检出率为0.65%;265株金黄色葡萄球菌检出MRSA 229株,检出率为86.42%;MRSA229株中9株是院内MRSA感染,占3.93%;220株为社区MRSA感染,占96.07%;该菌株对临床常用10种抗菌药物的耐药率>60.00%,但对万古霉素的敏感率为100.00%。结论城市中心城区社区MRSA感染现状已相当严重,应当和地段医院或社区医院一起加强MRSA的预防及治疗工作。     

A maternity hospital outbreak of methicillin-resistant Staphylococcus aureus.

A maternity hospital outbreak of methicillin-resistant Staphylococcus aureus with a strain other than EMRSA-1 is described. In contrast to previously documented outbreaks, which have usually centered on special care baby units, this outbreak mainly involved the routine ante-natal and postnatal wards. Thirty-seven mothers, 18 babies and nine staff were affected over a 6-week period. The high turnover of very mobile maternity patients and the open-plan design of the hospital influenced the course of the outbreak and adversely affected implementation of infection control measures. Significant environmental contamination and a very high rate of maternal perineal MRSA colonization were notable epidemiological features.     

Community-associated methicillin-resistant Staphylococcus aureus, Switzerland

Two case-control studies evaluated the prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carriage at hospital admission and characteristics of patients with CA-MRSA. Among 14,253 patients, CA-MRSA prevalence was 0.9/1,000 admissions. Although 5 CA-MRSA isolates contained Panton-Valentine leukocidin, only 1 patient had a previous skin infection. No easily modifiable risk factor for CA-MRSA was identified.