DNA microarray profiling of a diverse collection of nosocomial methicillin-resistant staphylococcus aureus isolates assigns the majority to the correct sequence type and staphylococcal cassette chromosome mec (SCCmec) type and results in the subsequent identification and characterization of novel SCCmec-SCCM1 composite islands.

One hundred seventy-five isolates representative of methicillin-resistant Staphylococcus aureus (MRSA) clones that predominated in Irish hospitals between 1971 and 2004 and that previously underwent multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing were characterized by spa typing (175 isolates) and DNA microarray profiling (107 isolates). The isolates belonged to 26 sequence type (ST)-SCCmec types and subtypes and 35 spa types. The array assigned all isolates to the correct MLST clonal complex (CC), and 94% (100/107) were assigned an ST, with 98% (98/100) correlating with MLST.

Livestock-associated methicillin-resistant Staphylococcus aureus in humans, Europe.

To estimate the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans that were sequence type (ST) 398, we surveyed 24 laboratories in 17 countries in Europe in 2007. Livestock-associated MRSA ST398 accounted for only a small proportion of MRSA isolates from humans; most were from the Netherlands, Belgium, Denmark, and Austria.

Characterization of a novel arginine catabolic mobile element (ACME) and staphylococcal chromosomal cassette mec composite island with significant homology to Staphylococcus epidermidis ACME type II in methicillin-resistant Staphylococcus aureus genotype ST22-MRSA-IV.

The arginine catabolic mobile element (ACME) is prevalent among methicillin-resistant Staphylococcus aureus (MRSA) isolates of sequence type 8 (ST8) and staphylococcal chromosomal cassette mec (SCCmec) type IVa (USA300) (ST8-MRSA-IVa isolates), and evidence suggests that ACME enhances the ability of ST8-MRSA-IVa to grow and survive on its host. ACME has been identified in a small number of isolates belonging to other MRSA clones but is widespread among coagulase-negative staphylococci (CoNS). This study reports the first description of ACME in two distinct strains of the pandemic ST22-MRSA-IV clone.

The effect of rapid screening for methicillin-resistant Staphylococcus aureus (MRSA) on the identification and earlier isolation of MRSA-positive patients.

Objectives: (1) To determine whether rapid screening with polymerase chain reaction (PCR) assays leads to the earlier isolation of patients at risk for methicillin-resistant Staphylococcus aureus (MRSA) colonization, (2) to assess compliance with routine MRSA screening protocols, (3) to confirm the diagnostic accuracy of the Xpert MRSA real-time PCR assay (Cepheid) by comparison with culture, and (4) to compare turnaround times for PCR assay results with those for culture results.

Design: Before-and-after study conducted in a 700-bed acute tertiary care referral hospital. Study periods were (1) a 5-week period before PCR testing began, (2) a 10-week period when the PCR assay was used, and (3) a 5-week period after PCR testing was discontinued.

Production of the Bsa lantibiotic by community-acquired Staphylococcus aureus strains.

Lantibiotics are antimicrobial peptides that have been the focus of much attention in recent years with a view to clinical, veterinary, and food applications. Although many lantibiotics are produced by food-grade bacteria or bacteria generally regarded as safe, some lantibiotics are produced by pathogens and, rather than contributing to food safety and/or health, add to the virulence potential of the producing strains. Indeed, genome sequencing has revealed the presence of genes apparently encoding a lantibiotic, designated Bsa (bacteriocin of Staphylococcus aureus), among clinical isolates of S.

Detection of staphylococcal cassette chromosome mec-associated DNA segments in multiresistant methicillin-susceptible Staphylococcus aureus (MSSA) and identification of Staphylococcus epidermidis ccrAB4 in both methicillin-resistant S. aureus and MSSA.

Methicillin-susceptible Staphylococcus aureus (MSSA) can arise from methicillin-resistant S. aureus (MRSA) following partial or complete excision of staphylococcal cassette chromosome mec (SCCmec). This study investigated whether multiresistant MSSA isolates from Irish hospitals, where MRSA has been endemic for decades, harbor SCCmec DNA.

Evaluation of the Xpert methicillin-resistant Staphylococcus aureus (MRSA) assay using the GeneXpert real-time PCR platform for rapid detection of MRSA from screening specimens.

The need for rapid methods to accurately detect methicillin-resistant Staphylococcus aureus (MRSA) is widely acknowledged, and a number of molecular assays are commercially available. This study evaluated the Xpert MRSA assay, which is run on the GeneXpert real-time PCR platform (Cepheid) for use in a clinical laboratory. The following parameters were investigated: (i) the limits of detection (LoDs) for four MRSA strains; (ii) the ability to detect isolates of MRSA from a collection representative of MRSA in Ireland since 1974 (n = 114) and the ability to detect control strains with staphylococcal cassette chromosome mec types IVa (IV.

Nasal carriage of meticillin-resistant Staphylococcus aureus in GPs in the West of Ireland.

This point-prevalence study was conducted to establish rates of meticillin-resistant Staphylococcus aureus (MRSA) nasal carriage in GPs in three counties in the West of Ireland. One hundred and twenty GPs were randomly selected for the study and 78 participated. The prevalence rate of nasal carriage of MRSA in these participants was 7.

Investigation of reduced susceptibility to glycopeptides among methicillin-resistant Staphylococcus aureus isolates from patients in Ireland and evaluation of agar screening methods for detection of heterogeneously glycopeptide-intermediate S. aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) isolates (n = 3,189) from 2,990 patients were investigated by agar screening and by the Etest macromethod for reduced susceptibility to glycopeptide. No vancomycin-resistant S. aureus or glycopeptide-intermediate S.

The emergence and importation of diverse genotypes of methicillin-resistant Staphylococcus aureus (MRSA) harboring the Panton-Valentine leukocidin gene (pvl) reveal that pvl is a poor marker for community-acquired MRSA strains in Ireland.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) carrying pvl is an emerging problem worldwide. CA-MRSA tends to harbor staphylococcal cassette chromosome mec type IV (SCCmec IV), to be non-multiantibiotic resistant, and to have different genotypes from the local hospital-acquired MRSA (HA-MRSA). However, in Ireland, 80% of HA-MRSA isolates have the non-multiantibiotic-resistant genotype ST22-MRSA-IV.

Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.

We analyzed a representative sample of methicillin-resistant Staphylococcus aureus (MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (< or = 3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spa and clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mec genes involved in methicillin resistance (SCCmec).

Seven novel variants of the staphylococcal chromosomal cassette mec in methicillin-resistant Staphylococcus aureus isolates from Ireland.

Methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered in Irish hospitals between 1971 and 2002 were characterized using multilocus sequence typing (MLST) (n = 130) and SCCmec typing (n = 172). Where atypical SCCmec typing results were obtained, PCR amplification of entire SCCmec elements, analysis of amplimer mobility, and nucleotide sequencing were undertaken. MLST revealed that 129/130 isolates had the same genotypes as internationally spread MRSA clones, including ST239, ST247, ST250, ST5, ST22, ST36, and ST8.