Phenotypic and genotypic characteristics of methicillin-resistant Staphylococcus aureus isolated in Western Pomerania
Bilska, I.
Annales Academiae Medicae Stetinensis 46: 77-86
2000
ISSN/ISBN: 1427-440X PMID: 11712319 Document Number: 513118
One hundred forty-nine Staphylococcus aureus strains were collected between 1994 and 1996 from ambulatory and hospitalized patients in Western Pomerania (north-western part of Poland). The bacteria were isolated from wounds, bronchial tree, bronchoalveolar lavage (BAL), sputum, throat swabs, nose swabs, eye swabs, blood, peritoneal fluid and urine. Resistance to methicillin was checked by disc diffusion test and confirmed using screening according to NCCLS standards. Growth strains was established with crystal violet staining. Furthermore, sensitivity to 17 other antibiotics was tested. Macrorestriction patterns of DNA was studied using the restriction enzyme Sma I and pulsed field gel electrophoresis system (BioRad). Almost all MRSA were identified as multidrug-resistant and all were sensitive to mupirocin, vancomycin and teicoplanin. Basing on Sma I PFGE patterns, 17 different genotypes were identified. The majority of MRSA belonged to Sma I type A (60 isolates) in which 9 closely related subtypes (A1 divided by A9) were identified. The most common was subtype A1 (37 strains), followed by A2 (12 strains), A3 (3), A4 (3), and A5 divided by A9 (each representing a single strain). The strains were ubiquitous and showed large variation as to phenotype. Eleven other MRSA with an identical Sma I PFGE patterns were classified as type B. These strains were predominantly present in material collected at the Department of Urology, Second State Clinical Hospital in Szczecin, First State Clinical Hospital and from outpatients. A typical feature of these strains was an identical resistogram. The remaining types and subtypes (C1, C2, D, E, F, G, and H) were represented by single MRSA strains (Tab. 1). The results indicate that MRSA strains of Staphylococcus aureus present in the region of Western Pomerania belong in general to two genotypes distinguished by Sma I PFGE as type A and B.