Methicillin resistance of airborne coagulase-negative staphylococci in homes of persons having contact with a hospital environment.

BACKGROUND: The persons having contact with a hospital environment (hospital personnel workers and discharged patients) are highly exposed to colonization with multidrug-resistant bacteria. The aim of this study was to evaluate the airborne Staphylococcus genus features in homes in which inhabitants have had contact with the hospital environment. METHODS: Airborne bacteria were collected using a 6-stage Anderson impactor. The Staphylococcus species composition and resistance to methicillin, and other antimicrobial agents among 3 coagulase-negative staphylococci (CNS) species (S cohnii spp cohnii, S epidermidis, S hominis), were determined. Antibiotic resistance of isolates was tested using the agar screen method with methicillin, the polymerase chain reaction technique to detect the mecA gene, and the disk diffusion method. RESULTS: A higher prevalence of methicillin-resistant (MR) strains among the species isolated (40% of S epidermidis, 40% of S hominis, and 60% of S cohnii spp cohnii) was found in homes of persons who had contact with a hospital environment compared with the reference homes (only 12% of S hominis). The mecA gene was revealed in all MR S epidermidis strains and in some MR S hominis (50%) and S cohnii spp cohnii (33%) strains. All isolated MR CNS strains were susceptible to vancomycin, rifampicin, and linezolid. CONCLUSION: High numbers of airborne multidrug-resistant MR CNS in the homes of persons having contact with a hospital environment indicates that such inhabitants pose a risk of intrafamilial spreading of MR strains via air.

[Legal aspects of the supervision of nosocomial infection]. / Aspekty prawne nadzoru nad zakazeniami szpitalnymi.

Hospital infections are a serious epidemiological problem since hospital departments have been established. Through many years the problem of hospital infections was unsatisfactorily recognized and not until 1970 appeared in Poland publications concerning hospital infections and suggesting systems of control as well as inspection. In the same time acts and instructions were issued defining principles and procedures in case of nosocomial infections. The aim of this paper was to show changes in legislation concerning the incidence, registration and action against hospital infections.

[Microbiological and molecular analysis of mycobacterium tuberculosis complex strains isolated from patients with pulmonary tuberculosis]. / Mikrobiologiczna i molekularna analiza szczepów Mycobacterium tuberculosis complex izolowanych od chorych na gruzlice ukladu oddechowego.

The aim of the study was to perform microbiological and molecular analysis of Mycobacterium tuberculosis complex strains isolated from patients with pulmonary tuberculosis originating from two different regions of Silesia voivodship in 2000 year. One of 135 strains subjected to the study lacked IS6110 insertion sequence. Its belonging to Mycobacterium tuberculosis complex was confirmed by positive test for specific gyrB gene sequence. Strain resistance analysis revealed that in previously diagnosed patients resistance to streptomycin (16,2%) was more frequent than other. In contrast to never treated patients group where the prevalence of resistance to isoniazid was the most frequent (4,5%). In both group of patients resistance to rifampin or ethambutol was not detected. The multidrug resistance strains (4,6%) were detected only in the previously diagnosed group. Combined analysis of microbiological, epidemiological and molecular data are essential for creation of functional registry of patients infected with resistant Mycobacteria, giving the possibility of surveillance of drug resistant tuberculosis in populations.

GyrA mutations in ciprofloxacin-resistant clinical isolates of Pseudomonas aeruginosa in a Silesian Hospital in Poland.

Among 73 clinical isolates of Pseudomonas aeruginosa 48 strains were ciprofloxacine (CIP) susceptible and 25 CIP resistant (Minimal inhibitory concentration--MIC>32 microg/ml - 14 strains) or of intermediate susceptibility to CIP (MIC > or = 1,5 - 32 microg/ml - 11 isolates). Mutations in the quinolone-resistance-determining region (QRDR) of gyrA gene were searched in groups of CIP resistant and of intermediate susceptibility to CIP isolates. Two methods: restriction fragment length polymorphism (RFLP) analysis and DNA sequencing analysis allowed to detect three different mutations. The nucleotide substitutions observed led to the following amino acid replacements: Thr-83 --> Ile, Asp-87 --> Asn, Asp-87 --> Gly. One mutated strain among the group of mutants analyzed showed double mutation (Thr-83 --> Ile, Asp-87 --> Gly) and additional silent mutation (Val-103 --> Val); whilst the rest of the isolates showed different single missense mutations. The most frequently detected mutation in the gyrA gene (16 out of 25 mutants) was the Thr-83 --> Ile substitution.

PCR-RFLP analysis of a point mutation in codons 315 and 463 of the katG gene of Mycobacterium tuberculosis isolated from patients in Silesia, Poland.

Resistance to antituberculous agents is an important cause of ineffectiveness of antimicrobial therapy. The resistance of M. tuberculosis to antituberculous agents is a result of mutations in genes participating in those agent's action. The antituberculous drug--isoniazid can be activated by Mycobacterium tuberculosis either through a hydroperoxidase I/II or a superoxide-dependent oxyferrous pathway. The present study analyzed the frequency of the mutations occurring in codons 315 and 463 in katG gene of Mycobacterium tuberculosis strains, isolated from patients with pulmonary tuberculosis from Silesia, Poland. In this study 23 isoniazid-resistant Mycobacterium tuberculosis strains were analyzed. For RFLP analysis, a 620 bp amplified fragment of katG gene was digested with restriction endonuclease MspI. Among 24 isoniazid-resistant strains, isolated from patients between 2000-2001, point mutations were found in 30% of analyzed isoniazid-resistant strains in codons 315 or 463 (7 strains). In contrast, no mutations in codons 315 and/or 463 katG gene were found in 16 strains (70%). Obtained results suggests that point mutations S315T (AGC-->ACC) and R463L in katG gene are infrequent in the analyzed population.

[Fluoroquinolone susceptibility of Pseudomonas aeruginosa strains isolated from clinical materials]. / Wrazliwosc na fluorochinolony szczepów Pseudomonas aeruginosa izolowanych z materialu klinicznego.

The goal of our research was an analysis of sensitivity of Pseudomonas aeruginosa to fluoroquinolones (SPX, PEF, UB, LOM, CIP, ENX, OFX, NOR). The sensitivity was tested by disk diffusion method, according to NCCLS standards. 120 strains isolated from hospitalized (76 strains) and outpatient clinic (44 strains) persons were tested. The highest sensitivity of strains was observed to norfloxacin (36.8% and 86.4% of strains, respectively) and ciprofloxacin (30.3% and 81.8%). None of tested microorganisms was sensitive to flumequine. Resistant strains, isolated from sick persons in outpatient clinics were fewer (13.6%) as compared to hospitalized persons (51.3%).