Detection of slime and methicillin resistance genes in Staphylococci isolated from nasal samples of patients with orthopaedic implants
Nizami Duran, Yunus Dogramaci, Cemil Demir, Burcin Ozer, Aydiner Kalaci
Med Sci Monit 2010; 16(8): BR278-284
Available online: 2010-08-01
Background: The purposes of the present study were (1) to determine the prevalence of mecA and femA genes, (2) to investigate the presence of icaA and icaD genes responsible for slime synthesis, and (3) to search in vitro slime synthesis by staphylococcal strains isolated from the nares of patients with orthopaedic implants using the Congo red agar (CRA) plate test.
Material/Methods: Staphylococci strains were defined by multiplex polymerase chain reaction (PCR) technique to determine intercellular adhesion genes icaA and icaD. Slime production capability was searched by the CRA plate test, phenotypically. Also, the presence of mecA and femA genes was determined by PCR in all strains.
Results: The presence of icaA and icaD was detected in 101 isolates of 134 (75.4%) strains. This ratio was 74.8% (89 of 119) among the Staphylococcus epidermidis and 80% (12 of 15) among the Staphylococcus aureus isolates. A total of 63.4% of all the strains were found to be icaA and icaD positive as well as slime-forming on the CRA plate test. The percentage of icaA- and icaD-negative strains was 36.6%, and all of them were negative on the CRA plate test. Although femA presence was detected in all 15 (11.2%) S. aureus isolates, a total of 5 (3.7%) isolates carried the mecA gene.
Conclusions: The frequency of icaA and icaD genes was determined to be of high prevalence among staphylococcal isolates. The staphylococcal strains that were found in the nasal flora of patients with orthopaedic implants may be important potential sources of infection for these patients.
Keywords: Polymerase Chain Reaction, Nasal Cavity - microbiology, Methicillin Resistance - genetics, Genes, Bacterial - genetics, Ethidium - metabolism, Electrophoresis, Agar Gel, Congo Red - metabolism, Prostheses and Implants, Staphylococcal Infections - microbiology, Staphylococcus - metabolism