Molecular characterisation of Staphylococcus aureus isolates belonging to two most prevalent spa types recovered from Romanian hospitals during 20062007
Abstract number: P1436
Oprea M., Dragulescu E.C., Coldea I.L., Codita I., Szmal C., Straut M.
Objectives: In this study, a molecular analysis was undertaken in order to further characterise Staphylococcus aureus clinical isolates belonging to two most prevalent spa types: t030 and t127 that were identified during 20062007, in Romania.
Methods: A total of 91 S. aureus isolates collected from hospital in-patients were examined phenotypically and subtyped using a single-locus sequence typing method, namely spa typing. This method is based upon the polymorphism of S. aureus protein A gene, whose repeats are variable in number and individual sequence. Isolates belonging to spa types t030 and t127 were selected for further molecular characterisation and cluster analysis of the SmaI patterns, generated by pulsed-field gel electrophoresis. Meticillin-resistant S. aureus (MRSA) isolates were confirmed by PCR targeting mecA gene. Staphylococcal chromosomal cassette mec (SCCmec) types were determined by performing a multiplex PCR with specific primers for the key genetic elements. The presence of lukS-lukF genes encoding Panton-Valentine leukocidin (PVL) and other toxin genes was tested by PCR.
Results: spa type t127 comprised 26 S. aureus isolates (28.5% of all examined isolates) and spa type t030 comprised 18 isolates (20%), respectively. All t030 isolates were MRSA with mecA gene carried on a type III SCCmec genetic element. Twenty-one out of 26 t127 isolates were MRSA and harboured a type IV SCCmec structure. Different virulence gene profiles were identified, but all the 44 isolates were PVL and seb genes negative, irrespective of spa type. Clonal relationships were established within each spa type group of isolates.
Conclusion: We have found that the prevalent spa-types of S. aureus isolates recovered from Romanian hospitals in 2006 and 2007 were spa-type t030 associated with SCCmec type III structure and spa-type t127 associated with SCCmec type IV structure. PFGE profiles showed that the isolates which share each of these types belong to the same clone. More detailed studies, including superantigen genes detection, will be performed, in order to further characterise the isolates belonging to these prevalent spa-types.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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