Typing of coagulase-negative staphylococci isolated from immunocompromised patients

A total of 3121 coagulase-negative staphylococcal strains sourced from clinical samples were characterized during a 4-year period. Biotype, antibiotic resistance pattern, phage pattern and slime production was determined. Plasmid profile analysis was performed on related isolates. Thirty percent of strains originated from the Bone Marrow Transplantation Unit, The National Institute of Haematology, Blood Transfusion and Immunology (NIHBTI), Budapest. Staphylococcus epidermidis occurred most frequently (48.8% in total, 58.2% source from NIHBTI). Total bacteriophage typability was 75.9%, and 603 phage patterns were observed. NIHBTI isolates differed in the incidence of multiply resistance, slime positivity and average frequency of phage patterns from the total suggesting spread of a selected hospital population. Statistical analysis of data obtained by typing showed no predominance of any endemic clone: the strains colonizing the immunocompromised patients and isolated from staff and inanimated environment differed from each other in biotype, phage pattern, antibiotic susceptibility, slime production and/or plasmid profile.