Objective. To determine the prevalence of
Staphylococcus aureus strains among hospitalized patients at the beginning of their hospitalization and during their treatment and the resistance of strains to antibiotics, and to evaluate epidemiologic characteristics of these strains.
Patients and methods. Sixty-one patients treated at the Department of Cardiac, Thoracic and Vascular Surgery were examined. Identification of
Staphylococcus aureus strains was performed using plasmacoagulase and DNase tests. The resistance of
Staphylococcus aureus to antibiotics, b-lactamase production, phagotypes, and phagogroups were determined. The isolated
Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 mg per disk and oxacillin 1 mg per disk).
Results. A total of 297
Staphylococcus aureus strains were isolated. On the first day of hospitalization, the prevalence rate of
Staphylococcus aureus strains among patients was 67.3%, and it statistically significantly increased to 91.8% on days 7–10 of hospitalization (
P<0.05). During hospitalization, patients were colonized with
Staphylococcus aureus strains resistant to cephalothin (17.6% of patients,
P<0.05), cefazolin (14.6%,
P<0.05), tetracycline (15.0%,
P<0.05), gentamicin (37.7%,
P<0.001), doxycycline (30.7%,
P<0.001), and tobramycin (10.6%,
P>0.05). Three patients (4.9%) were colonized with methicillin-resistant
Staphylococcus aureus strains, belonging to phage group II phage type 3A and phage group III phage types 83A and 77; 22.6– 25.5% of
Staphylococcus aureus strains were nontypable. During hospitalization, the prevalence rate of phage group II
Staphylococcus aureus strains decreased from 39.6% to 5.7% (
P<0.05) and the prevalence rate of phage group III
Staphylococcus aureus strains increased to 29.5% (
P<0.001).
Conclusions. Although our understanding of
Staphylococcus aureus is increasing, well-designed communitybased studies with adequate risk factor analysis are required to elucidate further the epidemiology of
Staphylococcus aureus and methicillin-resistant
Staphylococcus aureus. Surveillance of methicillin-resistant
Staphylococcus aureus provides relevant information on the extent of the methicillin-resistant
Staphylococcus aureus epidemic, identifies priorities for infection control and the need for adjustments in antimicrobial drug policy, and guides intervention programs.
Full article