Epidemiology of European Community-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 80 Type IV Strains Isolated in Denmark from 1993 to 2004

Abstract

In Europe, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have been caused predominantly by isolates belonging to the "European CA-MRSA" clone (sequence type 80, staphylococcal cassette chromosome mec type IV). In this study, the epidemiology of European CA-MRSA was investigated on a nationwide scale, covering the period from 1993 to 2004. Denmark has been a low-prevalence country regarding MRSA since the mid-1970s but has experienced an increase in the number of new MRSA cases in recent years. Our results show that European CA-MRSA contributed to this increase. The isolates primarily caused skin and soft tissue infections (SSTIs) in patients outside hospitals, and transmission between household members was the predominant mode of spread. Although some of the isolates were found in hospitalized patients, nosocomial transmission seemed likely in only one instance, pointing to endogenous infections as an important factor. Compared to the CA-MRSA clone most common in the United States (USA300), the European CA-MRSA clone seems less well adapted to persist in hospital environments. Patients with a recent history of travel or family relation to the Mediterranean or Middle East were highly overrepresented. The epidemiological data indicated that the European CA-MRSA isolates were introduced into Denmark on multiple occasions, paralleled by an increasing level of genetic diversity of the isolates found during the study period. European CA-MRSA has previously been described as a rather uniform clone. However, we found pronounced, diverse pulsed-field gel electrophoresis subtypes, staphylococcal protein A gene (spa) types, and susceptibility patterns.

Characterization of Baseline Methicillin-Resistant Staphylococcus aureus Isolates Recovered from Phase IV Clinical Trial for Linezolid

“…Although representative isolates of these clones clustered within different PFGE types, these findings suggest that these isolates may have derived from a common ancestor. Additionally, several reports from Europe have described the dissemination of a new community-acquired MRSA clone associated with ST80 and SCCmec type IV (16). Isolates belonging to this clone display the tetracycline resistance phenotype; however, MRSA isolates with these characteristics from European countries were not observed in this study.…”

“…The clindamycin resistance rate was the highest in Latin America (88.3%), followed by Europe (74.8%) and the United States (22.7%). Overall, among the erythromycin-resistant, clindamycin-susceptible isolates, 16.3% showed inducible clindamycin resistance, and this rate was the highest in Europe (40.3%), followed by the United States (10.2%) and Latin America (3.9%). Gatifloxacin (a fluoroquinolone surrogate) showed limited activity against this collection; and susceptibility rates were 4.2% in Europe, 13.0% in Latin America, and 46.7% in the United States.…”

Genomic insights into the emergence and spread of international clones of healthcare-, community- and livestock-associated meticillin-resistant Staphylococcus aureus : Blurring of the traditional definitions

“…CA-MRSA has been circulating in Europe since the 1990s [41][42][43]. In the beginning, the CC80 lineage predominated the epidemiological group.…”

Methicillin-Resistant Staphylococcus aureus Infections in Uppsala County, Sweden

“…The CC80 has been found to be one of the most common CA-MRSA isolates in Denmark and was recently discovered in HCA-isolates [14]. The CC80 caused invasive infections among young healthy individuals and had an ability to spread among family and household members.…”

“…One characteristic of CC80 isolates that differs from other CA strains is their resistance to fusidic acid. The increase of CA MRSA isolates (DK E97-1) observed recently in Denmark belonged to this clone [14]. In Sweden, CC80 is one of the most common clones [15].…”