Survey of methicillin-resistant Staphylococcus aureus strains from two hospitals in El Paso, Texas.

Seventy-one percent of 76 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from two medical centers in El Paso, Texas, represent three similar pulsed-field gel electrophoresis types. Overall, six pulsed-field types were identified represented by multilocus sequence/staphylococcal chromosomal cassette DNA mec (SCCmec) types: ST5-MRSA-II; ST36-MRSA-II; ST8 (untypeable SCCmec); and a newly described clonal cluster 8 strain, ST507-MRSA-IV. This study demonstrates the presence of multiple-antibiotic-resistant epidemic MRSA clones in El Paso.

Community-onset methicillin-resistant Staphylococcus aureus bacteremia in Northern Australia.

Background: Community-onset infections caused by methicillin-resistant Staphylococcus aureus (COMRSA) are being increasingly reported worldwide.

Methods: A retrospective study was performed of 14 patients with 15 episodes of COMRSA bacteremia (COMRSAB) admitted to the Royal Darwin Hospital, Northern Territory, Australia from 1998 to 2001. Isolates from COMRSAB episodes underwent extended susceptibility testing and molecular typing by pulsed field gel electrophoresis and allotyping of the staphylococcal cassette chromosome mec (SCCmec) region by polymerase chain reaction.

Are all community methicillin-resistant Staphylococcus aureus related? A comparison of their mec regions.

Aims: To compare the relationship of community-acquired, methicillin-resistant Staphylococcus aureus (CMRSA) from five Australian States and New Zealand.

Methods: Contour-clamped homogeneous electric field (CHEF) electrophoresis and analysis of the mec complex and ccr gene complex by PCR were used to compare 22 CMRSA isolates from Western Australia (WA), South Australia (SA), Victoria (VIC), New South Wales (NSW) and New Zealand (NZ) and three hospital-acquired epidemic MRSA (EMRSA).

Results: Sixteen community isolates were found to carry Class B mec complex and Type 2 ccr gene complex.

Genetic organization of mecA and mecA-regulatory genes in epidemic methicillin-resistant Staphylococcus aureus from Australia and England.

The mecA gene that encodes methicillin resistance in Staphylococcus aureus may be regulated by the mecR1 and mecI genes, and this region has been referred to as the mec complex. An analysis of these regulatory genes in 35 epidemic methicillin-resistant S. aureus (MRSA) isolated in England and Australia has found that they contain three classes of mec complex.