Clonal distribution of meticillin-resistant and susceptible Staphylococcus aureus invasive isolates in Belgium, EARSS/ SeqNet study, 20062007
Abstract number: P1431
Deplano A., Denis O., Hallin M., Rottiers S., De Ryck R., Hendrickx E., Grundmann H., Struelens M.J.
Objectives: To identify and determine spread of predominant clones of S. aureus causing invasive infection in Belgium during the 20062007 period.
Materials and Methods: As a part of the European Antimicrobial Resistance Surveillance System (EARSS)/ SeqNet survey, 23 Belgian hospitals were invited to collect 10 successive, non duplicate S. aureus isolates (5 MRSA and 5 MSSA) from normally sterile body sites during a 6 month period. PCR for detection of 16S/ nuc/ mecA and toxin genes (PVL/ TSST-1) were performed. Molecular typing was performed by spa sequencing using Ridom StaphType 1.4 (Ridom GMbH) and SCCmec type characterisation.
Results: A total of 202 S. aureus isolates including 91 (45%) MRSA and 111 (55%) MSSA were recovered from blood cultures (79%), puncture fluids (20%) and cerebrospinal fluids (1%). Spa typing showed 90 types clustered into 15 spa clonal complexes (CC) using the BURP algorithm. The majority of isolates belonged to spa CC008 (20%), CC740 (18%) and CC002 (15%) corresponding to major epidemic clones ST8, ST45 and ST5 by multi-locus sequence typing, respectively. Most (89%) MRSA isolates were classified in 4 clones, spa CC008-ST8-SCCmec IV (37%), spa CC740-ST45-SCCmec IV (34%), spa CC002-ST5-SCCmecII (10%) and spa CC002-ST5-SCCmecIV (8%). In contrast, MSSA isolates showed a wide diversity and belonged to 15 spa CC, each including 2 to 13 isolates. Among MSSA isolates 20% harboured the 3 major MRSA spa CC and 28% of MSSA isolates were classified into 3 spa types, CC084, CC015 and CC078 not found in MRSA isolates. Toxin gene analysis revealed 2 MRSA isolates carrying PVL genes and belonging to ST59 and ST8. TSST-1 gene was detected in 7 MRSA isolates belonging to CC002-ST5-SCCmec IV.
Conclusions: As found in previous surveys in Belgium, 4 major genotypes predominated among MRSA isolates. In contrast, MSSA isolates showed a wide genotype diversity, with sharing of common genotypes with major MRSA strains. PVL and TSST-1 were recovered in 2% and 8% of MRSA isolates, respectively.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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