Nasal meticillin-resistant Staphylococcus aureus carriage among intensive care unit hospitalised adult patients in a Taiwanese medical centre: one time-point prevalence, molecular characteristics and risk factors for carriage.

From 25 June to 11 July 2008, a total of 177 adult patients hospitalised in an intensive care unit (ICU) (94 in medical ICUs and 83 in surgical ICUs) at a tertiary care hospital were screened for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA) by polymerase chain reaction. The overall prevalence of S. aureus and MRSA nasal carriage among the patients was 42% and 32%, respectively. MRSA carriage rate of the patients hospitalised in medical ICUs was significantly higher than that of those hospitalised in surgical ICUs (47% vs 16%, P<0.001). Multivariate logistic regression analysis revealed that pneumonia, chronic obstructive pulmonary disease, current MRSA infection, and medical ICU admission were independent predictors for nasal carriage of MRSA. Of the 38 MRSA isolates available for molecular analysis, a total of six pulsed-field gel electrophoresis (PFGE) patterns with two major patterns (F, 42%; A, 37%) were identified. Most MRSA isolates belonged to one of two major clones characterised as sequence type 5/PFGE F/staphylococcal cassette chromosome mec (SCCmec) II/Panton-Valentine leucocidin (PVL) genes negative (34%) and ST239/PFGE A/SCCmec III/PVL negative (26%), both clones being associated with healthcare-associated (HA) clones in Taiwan. Six isolates (16%) were characterised as ST59/SCCmec IV or V(T) and were associated with community strains in Taiwan. In conclusion, 32% of ICU hospitalised adult patients in a Taiwanese tertiary care teaching hospital between June and July 2008 were colonised with MRSA in their nares. Though most isolates were HA-MRSA, community strains accounted for a proportion of the isolates.

Chen CB ，Chang HC ，Huang YC 《-》

Molecular analysis and susceptibility patterns of meticillin-resistant Staphylococcus aureus (MRSA) strains circulating in the community in the Ligurian area, a northern region of Italy: emergence of USA300 and EMRSA-15 clones.

Marchese A ，Gualco L ，Maioli E ，Debbia E ... -  《-》

Nasal carriage of methicillin-resistant Staphylococcus aureus among preclinical medical students: epidemiologic and molecular characteristics of methicillin-resistant S. aureus clones.

Between May 2008 and October 2009, a total of 2103 interns were randomly tested for nasal colonization of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA). The prevalence of S. aureus among staphylococci specimens was 23.1%, and among the total S. aureus the MRSA prevalence was 9.4%. MRSA isolates were further subtyped using genetic element staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE) band pattern, and multilocus sequence typing. SCCmec type IVa was the most prevalent strain, at 45.4 %. Eleven PFGE patterns were identified in MRSA strains, with 1 predominant (pulsotype A, 45.5%). Eight strains which belonged to clonal complex 78 carried type IVa SCCmec and produced type 3 coagulase. Panton-Valentine leukocidin (PVL) genes (lukS and F-PV) were identified in 10 (45.4%) MRSA strains; these predominately carried ϕSa2958type and ϕSa108PVL-like type PVL phages. After inducing prophages, 8 strains infected other S. aureus isolates and could generate novel PVL-positive strains of S. aureus. The present study demonstrates that interns can carry certain MRSA strains asymptomatically and contribute to the spread of MRSA between the community and hospital.

Ma XX ，Sun DD ，Wang S ，Wang ML ，Li M ，Shang H ，Wang EH ，Luo EJ ... -  《-》

Risk factors and molecular analysis of panton-valentine leukocidin-positive methicillin-resistant Staphylococcus aureus colonization in healthy children.

Lo WT ，Lin WJ ，Tseng MH ，Wang SR ，Chu ML ，Wang CC ... -  《PEDIATRIC INFECTIOUS DISEASE JOURNAL》

Nasal carriage of Staphylococcus aureus, including community-associated methicillin-resistant strains, in Queensland adults.

Munckhof WJ ，Nimmo GR ，Schooneveldt JM ，Schlebusch S ，Stephens AJ ，Williams G ，Huygens F ，Giffard P ... -  《-》