Methicillin-resistant Staphylococcus aureus in Europe, 1999-2002

We explored the variation in proportions of methicillin-resistant Staphylococcus aureus (MRSA) between and within countries participating in the European Antimicrobial Resistance Surveillance System and temporal trends in its occurrence. This system collects routine antimicrobial susceptibility tests for S. aureus. We examined data collected from January 1999 through December 2002 (50,759 isolates from 495 hospitals in 26 countries). MRSA prevalence varied almost 100-fold, from <1% in northern Europe to >40% in southern and western Europe. MRSA proportions significantly increased in Belgium, Germany, Ireland, the Netherlands, and the United Kingdom, and decreased in Slovenia. Within countries, MRSA proportions varied between hospitals with highest variance in countries with a prevalence of 5% to 20%. The observed trends should stimulate initiatives to control MRSA at national, regional, and hospital levels. The large differences between hospitals indicate that efforts may be most effective at regional and hospital levels.     

Methicillin-resistant Staphylococcus aureus, Hawaii, 2000-2002

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has generated considerable concern among medical and public health professionals. We used a statewide, population-based antimicrobial resistance surveillance system to examine epidemiologic trends for MRSA from outpatients and inpatients in Hawaii. Pediatric and adult patient populations were compared to assess characteristics of MRSA isolates specific for each group. From 2000 to 2002, 8,206 (26%) of 31,482 total S. aureus isolates were MRSA. During this period, the proportion of MRSA isolates increased in both outpatient and inpatient clinical settings (p<0.01). When stratified by age, annual trends showed a significant increase in the proportion of MRSA in adult patients (from 24% to 30%, p<0.01) but not in pediatric patients (from 25% to 27%, p>0.05). Although MRSA isolates from adults demonstrated high resistance to most non-beta-lactams, most MRSA isolates from pediatric outpatients remained susceptible to most non-beta-lactams.     

Methicillin-resistant Staphylococcus aureus, Samoa, 2007-2008

Little is known about the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in most Pacific Island nations. Relatively high rates of MRSA have been reported in Polynesian people living outside the Pacific Islands. To determine the prevalence and characteristics of MRSA, we assessed wound swabs from 399 persons with skin and soft tissue infection living in Samoa. MRSA was isolated from 9% of study participants; 34 of the 196 S. aureus isolates were MRSA. Five MRSA genotypes were identified; the 3 most common were USA300, the Queensland clone, and a sequence type 1 MRSA strain that shares <85% homology with the sequence type 1 MRSA strain common in the region (WA MRSA-1). The Southwest Pacific MRSA clone was identified but accounted for only 12% of MRSA isolates. The high prevalence of MRSA in Samoa provides impetus for initiatives to improve antimicrobial drug resistance surveillance, infection control, and antimicrobial drug use in Pacific Island nations.     

Methicillin-resistant Staphylococcus aureus, Geneva, Switzerland, 1993-2005

Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) strains different from those of an endemic healthcare-associated clone was conducted over 13 years in Geneva, Switzerland. We demonstrated strain diversity, including clones rarely found in Europe. Local epidemiology of community-associated MRSA is diverse and is evolving by importation and transmission of new strains.     

Methicillin-resistant Staphylococcus aureus, Western Australia

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a notable cause of hospital-acquired infections. A statewide screening and control policy was implemented in Western Australia (WA) after an outbreak of epidemic MRSA in a Perth hospital in 1982. We report on statutory notifications from 1998 to 2002 and review the 20-year period from 1983 to 2002. The rate of reporting of community-associated Western Australia MRSA (WAMRSA) escalated from 1998 to 2002 but may have peaked in 2001. Several outbreaks were halted, but they resulted in an increase in reports as a result of screening. A notable increase in ciprofloxacin resistance during the study period was observed as a result of more United Kingdom epidemic MRSA (EMRSA) -15 and -16. WA has seen a persistently low incidence of multidrug-resistant MRSA because of the screening and decolonization program. Non-multidrug-resistant, community-associated WAMRSA strains have not established in WA hospitals.     

Methicillin-resistant Staphylococcus aureus in Taiwan

We found a virulent closely related clone (Panton-Valentine leukocidin-positive, SCCmec V:ST59) of methicillin-resistant Staphylococcus aureus in inpatients and outpatients in Taiwan. The isolates were found mostly in wounds but were also detected in blood, ear, respiratory, and other specimens; all were susceptible to ciprofloxacin, gentamicin, and trimethoprim-sulfamethoxazole.     

Methicillin-resistant Staphylococcus aureus in children, Taiwan

Highly virulent community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) with Panton-Valentine leukocidin (PVL) is common worldwide. Using antimicrobial drug susceptibility testing, staphylococcal cassette chromosome mec typing, exotoxin profiling, and pulsed-field gel electrophoresis typing, we provide evidence that supports the relationship between nasal strains of PVL-positive MRSA and community-acquired disease.     

质粒介导的MRSA耐药基因定位

目的确定ＭＲＳＡ耐药基因的来源及传播途径，为ＭＲＳＡ流行病学分析提供重要参考。方法对实验菌株做药敏实验、ＭＲＳＡ鉴定、ＭＲＳＡ质粒提取、质粒转化和消除实验，并将提取的多耐药质粒（２３Ｋｂ）进行酶切，应用重组克隆技术，将各酶切片段转化到非耐药受体菌Ｅ．ｃｏｌｉＪＭ１０９中，筛选和确认重组子，经药敏实验分析ＭＲＳＡ耐药基因的位置、大小以及与多重耐药性的关系。结果本实验菌株的耐药谱、质粒外型及酶切图谱极相似，提示有暴发感染的可能性。结论该Ｒ－质粒含有多个３．０Ｋｂ左右的重复耐药基因，包含耐药基因ＤＮＡ片段所诱导的耐药程度，弱于整个Ｒ质粒诱导的细菌耐药性     

Methicillin-resistant Staphylococcus aureus in Canadian aboriginal people.

We describe 279 hospitalized Canadian aboriginals in whom methicillin-resistant Staphylococcus aureus (MRSA) was detected. They were identified in 38 Canadian hospitals from 1995 through 2002. Compared with nonaboriginals, aboriginals were more likely to be younger than 18 years of age (OR, 1.8; P<.0001), to have had an MRSA infection (OR, 3.8; P<.0001), and to have had MRSA isolated from specimens of skin or soft tissue (OR, 4.1; P=.016). The clinical features of MRSA infection in aboriginals are distinct from those in the general patient population with MRSA infection in Canadian hospitals, and the genetic background of MRSA isolates from aboriginals also varies from that of strains from the non-aboriginal population.     

Methicillin-resistant Staphylococcus aureus clones, Western Australia

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) was first reported in Western Australia in the early 1990s from indigenous peoples living in remote areas. Although a statewide policy of screening all hospital patients and staff who have lived outside the state for MRSA has prevented the establishment of multidrug-resistant epidemic MRSA, the policy has not prevented SCCmec type IV and type V MRSA clones from becoming established. Of the 4,099 MRSA isolates analyzed (referred to the Gram-positive Bacteria Typing and Research Unit) from July 2003 to December 2004, 77.5% were community-associated MRSA (CA-MRSA). Using multilocus sequence/staphylococcal chromosome cassette mec typing, 22 CA-MRSA clones were characterized. Of these isolates, 55.5% were resistant to >1 non-beta-lactam antimicrobial drug. Five Panton-Valentine leukocidin (PVL)-positive CA-MRSA clones were identified. The emergence of multidrug-resistant CA-MRSA clones and the detection of PVL toxin genes in clones previously reported as PVL negative is a major public health concern.     

Methicillin-resistant Staphylococcus aureus in horses and horse personnel, 2000-2002

Methicillin-resistant Staphylococcus aureus (MRSA) infection was identified in 2 horses treated at a veterinary hospital in 2000, prompting a study of colonization rates of horses and associated persons. Seventy-nine horses and 27 persons colonized or infected with MRSA were identified from October 2000 to November 2002; most isolations occurred in a 3-month period in 2002. Twenty-seven (34%) of the equine isolates were from the veterinary hospital, while 41 (51%) were from 1 thoroughbred farm in Ontario. Seventeen (63%) of 27 human isolates were from the veterinary hospital, and 8 (30%) were from the thoroughbred farm. Thirteen (16%) horses and 1 (4%) person were clinically infected. Ninety-six percent of equine and 93% of human isolates were subtypes of Canadian epidemic MRSA-5, spa type 7 and possessed SCCmecIV. All tested isolates from clinical infections were negative for the Panton-Valentine leukocidin genes. Equine MRSA infection may be an important emerging zoonotic and veterinary disease.