DNA microarray-based genotyping of methicillin-resistant Staphylococcus aureus strains from Eastern Saxony


Corresponding author and reprint requests: S. Monecke, Institute for Medical Microbiology and Hygiene, Faculty of Medicine Carl Gustav Carus, Technical University of Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
E-mail: monecke@rocketmail.com


A diagnostic microarray was used to characterise a collection of methicillin-resistant Staphylococcus aureus (MRSA) isolates from hospitals in the German region of Eastern Saxony. The most abundant epidemic MRSA (EMRSA) strains were ST5-MRSA  II (Rhine–Hesse EMRSA, EMRSA-3), CC5/ST228-MRSA  I (South German EMRSA), ST22-MRSA  IV (Barnim EMRSA, EMRSA-15) and ST45-MRSA  IV (Berlin EMRSA). Other strains were found only as sporadic isolates or in minor outbreaks. These strains included ST1-MRSA  IV, ST8-MRSA  IV (Hannover EMRSA and others), clonal group 5 strains carrying SCCmec type IV elements (Paediatric clone), ST45-MRSA  V, CC8/ST239-MRSA  III and ST398-MRSA  V. Panton–Valentine leukocidin-positive MRSA isolates were still very rare. The predominant strain was ST80-MRSA  IV, although increasing numbers of different strains have recently been detected (ST8-MRSA  IV, ST30-MRSA  IV and ST59-MRSA  V). For more common MRSA strains, it was possible to detect variants that differed mainly in the carriage of additional resistance determinants and certain virulence-associated genes. Detection of such variants can sometimes allow epidemic strains to be resolved beyond spa types to a hospital-specific level, which is of significant value for epidemiological purposes.