Methicillin-Resistant Staphylococcus aureus USA300 Clone in Long-Term Care Facility

We performed a longitudinal analysis of 661 methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained from patients in a long-term care facility. USA300 clone increased from 11.3% of all MRSA isolates in 2002 to 64.0% in 2006 (p<0.0001) and was mostly recovered from skin or skin structures (64.3% vs. 27.0% for non-USA300 MRSA; p<0.0001).     

耐甲氧西林葡萄球菌监测报告

本文报道了我们于1989年8月～1991年3月对耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林表皮葡萄球菌(MRSE)的监测结果。结果表明:从各种临床标本分离出的99株金黄色葡萄球菌中筛选出48株MRSA(48.5％),25株表皮葡萄球菌中筛选出17株MRSE(68.0％)。在MRSA感染患者中,从脓液中检出的机会最多,占39.6％;MRSE感染患者中,从尿和脓液中检出的机会较多,分别占35.3％和29.4％。从甲氧西林敏感的金黄色葡萄球菌(MSSA)和 MRSA对11种抗生素的敏感试验结果来看,MRSA对被试的11种抗生素的耐药率均高于MSSA。另外,本工作中首次检出1株对万古霉素耐药的MRSA株,值得高度重视。     

Novel Lineage of Methicillin-Resistant Staphylococcus aureus, Hong Kong

To determine whether spa type of methicillin-resistant Staphylococcus aureus in pigs belonged to sequence type (ST) 398, we analyzed nasal swabs from pig carcasses at Hong Kong markets in 2008. ST9 belonging to spa type t899 was found for 16/100 samples, which indicates that a distinct lineage has emerged in pigs.     

Methicillin-Resistant and -Susceptible Staphylococcus aureus Infections in Dogs

Methicillin-resistant Staphylococcus aureus (MRSA) has become a pathogen of animals. To compare types of infections, clinical outcomes, and risk factors associated with MRSA in dogs with those associated with methicillin-susceptible Staphylococcus aureus (MSSA) infections, we conducted a case–control study at 3 veterinary referral hospitals in the United States and Canada during 2001–2007. Risk factors analyzed were signalment, medical and surgical history, and infection site. Among 40 dogs with MRSA and 80 with MSSA infections, highest prevalence of both infections was found in skin and ears. Although most (92.3%) dogs with MRSA infections were discharged from the hospital, we found that significant risk factors for MRSA infection were receipt of antimicrobial drugs (odds ratio [OR] 3.84, p = 0.02), β-lactams (OR 3.58, p = 0.04), or fluoroquinolones (OR 5.34, p = 0.01), and intravenous catheterization (OR 3.72, p = 0.02). Prudent use of antimicrobial drugs in veterinary hospitals is advised.     

Imported Methicillin-Resistant Staphylococcus aureus, Sweden

Countries such as Sweden that have a low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) offer the opportunity to discern and study transmission of imported cases of MRSA. We analyzed 444 imported cases of MRSA acquisition reported in Sweden during 2000–2003. Risk for MRSA in returning travelers ranged from 0.1 (95% confidence interval [CI] 0.01–0.4) per 1 million travelers to Nordic countries to 59.4 (95% CI 44.5–79.3) per 1 million travelers to North Africa and the Middle East. Most imported cases (246, 55%) were healthcare acquired, but regions with the highest risk for MRSA in travelers showed a correlation with community acquisition (r = 0.81, p = 0.001). Characteristic differences in MRSA strains acquired were dependent on the region from which they originated and whether they were community or healthcare acquired. Knowledge of differences in transmission of MRSA may improve control measures against imported cases.     

Methicillin-Resistant Staphylococcus aureus ST398 in Swine Farm Personnel, Belgium

We assessed methicillin-resistant Staphylococcus aureus (MRSA) in persons on 49 swine farms in Belgium. Surveys showed that 48 (37.8%) persons carried MRSA ST398 and 1 (0.8%) had concurrent skin infection. Risk factors for carriage were MRSA carriage by pigs, regular contact with pigs and companion animals, and use of protective clothing.     

Human Cases of Methicillin-Resistant Staphylococcus aureus CC398, Finland

Nationwide surveillance identified 10 human isolates of methicillin-resistant Staphylococcus aureus clonal complex (CC) 398. Further typing in comparison with animal isolates identified 4 clusters: 1 related to a horse epidemic and 3 to persons who had no direct contact with animals or each other. These findings may indicate unrecognized community transmission.     

Methicillin-Resistant Staphylococcus aureus Prevalence among Captive Chimpanzees,Texas, USA, 2012

Methicillin-resistant Staphylococcus aureus (MRSA) infection in humans and animals is concerning. In 2012, our evaluation of a captive chimpanzee colony in Texas revealed MRSA prevalence of 69%. Animal care staff should be aware of possible zoonotic MRSA transmission resulting from high prevalence among captive chimpanzees.     

Multidrug-Resistant Methicillin-Resistant Staphylococcus aureus Associated with Bacteremia and Monocyte Evasion,Rio de Janeiro,Brazil

We typed 600 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 51 hospitals in the Rio de Janeiro, Brazil, metropolitan area during 2014–2017. We found that multiple new clonal complex (CC) 5 sequence types had replaced previously dominant MRSA lineages in hospitals. Whole-genome analysis of 208 isolates revealed an emerging sublineage of multidrug-resistant MRSA, sequence type 105, staphylococcal cassette chromosome mec II, spa t002, which we designated the Rio de Janeiro (RdJ) clone. Using molecular clock analysis, we hypothesized that this lineage began to expand in the Rio de Janeiro metropolitan area in 2009. Multivariate analysis supported an association between bloodstream infections and the CC5 lineage that includes the RdJ clone. Compared with other closely related isolates, representative isolates of the RdJ clone more effectively evaded immune function related to monocytic cells, as evidenced by decreased phagocytosis rate and increased numbers of viable unphagocytosed (free) bacteria after in vitro exposure to monocytes.     

耐甲氧西林金黄色葡萄球菌感染预后的影响因素

MRSA是院内感染的主要致病菌之一,在过去的20年里,MRSA的发病率以及耐药性日渐增加,治疗方法存在一定的局限性,总体预后较差,加重了院内感染的负担.此文就宿主因素、病原体菌株以及治疗方案等预后影响因素进行综述,以期为医院内MRSA感染的预防控制提供参考.     

甲氧西林耐药金黄色葡萄球菌耐药状况分析

目的探讨甲氧西林耐药金黄色葡萄球菌(Methicillin Resistant Staphylococcus Aureus,MRSA)的药物敏感状况.方法采用Kerby-Bauer纸片扩散法测定临床分离的70株MRSA对18种抗菌药物的耐药性.结果70株MRSA对万古霉素、替考拉宁、利奈唑胺、链阳菌素敏感率达100%,对利福平和磷霉素的敏感率分别92.9%、74.3%,对其他抗菌药物敏感率在0%～41.4%之间.结论MRSA呈多重耐药.其对万古霉素、替考拉宁、利奈唑胺、链阳菌素的敏感率为100%,可作为MRSA感染的首选,其他药物可根据药敏结果选择.     

Methicillin-Resistant Staphylococcus aureus ST398 from Human Patients, Upper Austria

Methicillin-resistant Staphylococcus aureus (MRSA) clonal type ST398 is usually associated with animals. We examined 1,098 confirmed MRSA samples from human patients and found that 21 were MRSA ST398. Most (16) patients were farmers. Increasing prevalence from 1.3% (2006) to 2.5% (2008) shows emergence of MRSA ST398 in humans in Austria.     

Methicillin-Resistant Staphylococcus aureus Carriage and Risk Factors for Skin Infections, Southwestern Alaska, USA

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are common in southwestern Alaska. Outbreak strains have been shown to carry the genes for Panton-Valentine leukocidin (PVL). To determine if carriage of PVL-positive CA-MRSA increased the risk for subsequent soft tissue infection, we conducted a retrospective cohort study by reviewing the medical records of 316 persons for 3.6 years after their participation in a MRSA nasal colonization survey. Demographic, nasal carriage, and antimicrobial drug use data were analyzed for association with skin infection risk. Skin infections were more likely to develop in MRSA carriers than in methicillin-susceptible S. aureus carriers or noncarriers of S. aureus during the first follow-up year, but not in subsequent years. Repeated skin infections were more common among MRSA carriers. In an area where PVL-containing MRSA is prevalent, skin infection risk was increased among MRSA nasal carriers compared with methicillin-susceptible S. aureus carriers and noncarriers, but risk differential diminished over time.     

Transmissibility of Livestock-associated Methicillin-Resistant Staphylococcus aureus

Previous findings have suggested that the nosocomial transmission capacity of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is lower than that of other MRSA genotypes. We therefore performed a 6-month (June 1–November 30, 2011) nationwide study to quantify the single-admission reproduction number, R_A, for LA-MRSA in 62 hospitals in the Netherlands and to compare this transmission capacity to previous estimates. We used spa typing for genotyping. Quantification of R_A was based on a mathematical model incorporating outbreak sizes, detection rates, and length of hospital stay. There were 141 index cases, 40 (28%) of which were LA-MRSA. Contact screening of 2,101 patients and 7,260 health care workers identified 18 outbreaks (2 LA-MRSA) and 47 secondary cases (3 LA-MRSA). R_A values indicated that transmissibility of LA-MRSA is 4.4 times lower than that of other MRSA (not associated with livestock).