Nosocomial infections are one of the biggest contemporary health and economic problems. Apart from the already known pathogens, several 'new' bacteria, such as Burkholderia cepacia and Stenotrophomonas maltophilia, etc, are now regarded as being responsible for nosocomial infections. This study aimed at evaluating the presence of Burkholderia cepacia and Stenotrophomonas maltophilia strains in diagnostic material and analysing their sensitivity to antibiotics. The study covered 47 strains of Burkholderia cepacia and 27 strains of Stenotrophomonas maltophilia, isolated from diagnostic materials sent to the Department of Medical Microbiology at the University School of Medical Science in Bydgoszcz in 1994-1995. Sensitivity to 15 antibiotics was evaluated by the circle diffusion method on Mueller-Hinton agar according to the procedure elaborated by NCCLS. Most Burkholderia cepacia strains (70.2%) were isolated from urine of patients with urinary tract infection. The basic disease suffered by these patients was usually a tumour of the urinary tract. Four (8.5%) strains of Burkholderia cepacia were isolated from purulent materials. Most strains (28, i.e. 59.6%) came from patients hospitalised on Urology Ward. Nine (19.2%) strains of Burkholderia cepacia came from Intensive Therapy patients. Forty three (91.5%) strains of Burkholderia cepacia were sensitive to co-trimoxazole and imipenem and 40 (85.1%) were sensitive to ceftazidime. Among the tested Burkholderia cepacia strains most of them were resistant to tobramycin and gentamycin (93.6%) and carbenicillin (87.2%). All strains were resistant to tetracycline. Among 27 strains defined as Stenotrophomonas maltophilia, 11 (40.7%) were isolated from wound smears and pus, 7 (25.9%) from secretion found in intubation tubes. Stenotrophomonas maltophilia strains were isolated from sample materials of patients hospitalised in 4 wards: 13 (48.2%) in Intensive Therapy, 5 (18.5%) on Neurology, 5 (18.5%) on Surgical Ward and 4 (14.8%) in Urology Ward. Tested Stenotrophomonas maltophilia strains were mostly sensitive to ticarcillin combined with clavulanic acid (23 strains, i.e. 85.2%), ciprofloxacin (21 strains, i.e. 77.8%), tobramycin (17 strains, i.e. 63.0%) and netilmycin (15 strains, i.e. 55.6%). Literature indicates that antibiotic therapy of Burkholderia cepacia and Stenotrophomonas maltophilia infections is difficult due to resistance of these micro-organisms to most antibiotics. Own results of sensitivity of these bacteria to antibiotics confirm their resistance to many antibiotics.

Keywords: Burkholderia cepacia, Stenotrophomonas maltophilia, resistance to antibiotics, nosocomial infections, Urinary Tract Infections