Abstract

The SCCmec element is one of the recommended targets for MRSA characterization and several multiplex-PCR SCCmec typing methods have been developed over the past years. However, there are no data on the consistency of the SCCmec types in clinical isolates as detected by these methods. Using different previously published, commonly used M-PCR methods, this report describes the diversity of SCCmec elements in MRSA isolates in the Pretoria region of South Africa and the discrepancies observed in the assigned SCCmec types. Different SCCmec types were assigned to the same clinical MRSA isolates. The discrepancies included the assignment of composite SCCmec types [(SCCmec II and SCCmecury) 20.7% (40/193)] and [(SCCmec type II+IVc) 22.3% (43/193)] to some of the clinical MRSA isolates. Summarily, the combination of the result of the M-PCR methods showed that the MRSA genotypes circulating in the healthcare facility studied potentially carried SCCmec types I, II, IV (subtypes IVa, IVb and IVd) and V. No SCCmec types III or VIII was detected among the isolates. At least 25.91% of SCCmec type IV was detected in this study, thus corroborating previous findings of the global encroachment of MRSA strains into the hospital settings. The associated epidemiological significance of these observations is discussed and we also call for an African consensus SCCmec typing method in order to allow effective epidemiological data comparison across the countries.

Key words: MRSA genotype, SCCmec elements, multiplex-polymerase chain reaction (PCR), variation.