[The hazards of hospitals and selected public buildings of Legionella pneumophila]. / Zagrozenia szpitali oraz wybranych obiektów uzytecznosci publicznej bakteriami Legionella pneumophila.

UNLABELLED: The registered infection and outbreaks of epidemic tend to monitor potential reservoirs of Legionella infection. According to the Act of 29 March 2007 on the requirements for the quality of water intended for human consumption are required to test for the presence and number of Legionella in the water system of hospitals. In case of detection of L. pneumophila serogroup 1 (SG 1) or increased above normal number other serogroups of bacteria it is necessary to eradicate these bacteria from the water system. The aim of this study was to assess the degree of contamination of the water supply system of selected public buildings and analyze the effectiveness of disinfection methods for the elimination of L. pneumophila in hot water systems. MATERIAL AND METHODS: The materials for this study were hot and cold water samples which were collected from the water supply system of 23 different objects. Enumeration of Legionella bacteria in water samples was determined by membrane filtration (FM) and/or by surface inoculation methods according to the standards: PN-ISO 11731: 2002: "The quality of the water. Detection and enumeration of Legionella" and PN-EN ISO 11731-2: 2008: "Water quality--Detection and enumeration of Legionella--Part 2: Methodology of membrane filtration for water with a small number of bacteria". RESULTS: L. pneumophila was present in 164 samples of hot water, which accounted for 76.99%. In all tested water samples L. pneumophila SG 2-14 strains were detected. The most virulent strain--L. pneumophila SG 1 was not detected. In examined 23 objects in 12 of L. pneumophila exceed acceptable levels > 100 CFU/100 ml. CONCLUSIONS: The presence of L. pneumophila SG 2-14 demonstrated in all examined objects, indicating the risk of infection, and the need for permanent monitoring of the water system supply. The thermal disinfection is the most common, inexpensive, and effective method of control of L. pneumophila used in examined objects, but does not eliminate bacterial biofilm. Disinfection using the filters stopped of L. pneumophila, and was the method of complementary thermal disinfection. Chlorine dioxide is a very effective biocide for large numbers of L. pneumophila in water systems.

Antibiotic sensitivity of environmental Legionella pneumophila strains isolated in Poland.

INTRODUCTION AND OBJECTIVE: Legionella bacteria are commonly found in natural aquatic environments such as rivers, lakes, ponds and hot springs. Legionella infection occurs through the inhalation of water-air aerosol generated, for example, by showers or hot tubs. The most common species responsible for infection is Legionella pneumophila, which can cause Pontiac fever, and Legionnaires' disease, as well as a rare extrapulmonary form. The aim of the study's is to assess the susceptibility of Legionella pneumophila bacteria isolated from water systems of public buildings in Poland to antibiotics and chemotherapeutic agents used in the treatment of Legionellosis pneumonia. MATERIAL AND METHODS: A total of 100 L. pneumophila strains isolated from public buildings, such as hospitals and water recreation facilities, were used for the study. The drug sensitivity of the following antibiotics was determined: erythromycin, azithromycin, ciprofloxacin, levofloxacin, rifampicin, trimethoprim-sulfamethoxazole and tetracycline. Mean MIC50 and MIC90 values were read using accepted standards. RESULTS: The highest mean MIC value was obtained for tetracycline 6,130+/-0,353 µg/ml (with a range from 1,500 µg/ml to 16,000 µg/ml. In contrast, the lowest MIC was recorded with rifampicin: 0.020+/-0.037 µg/ml (with a range from 0.016 µg/ml to 0.380 µg/ml). CONCLUSIONS: The lowest biocidal concentration was found for levofloxacin, the highest for tetracycline. The highest MIC50 and MIC90 values were found for tetracycline and the lowest for rifampicin. The highest biocidal values were found for azithromycin and the lowest for tetracycline.

Assessment of antibiotic susceptibility of Legionella pneumophila isolated from water systems in Poland.

INTRODUCTION AND OBJECTIVE: Several studies have reported therapy failures in patients with legionnaires'disease; however, antimicrobial resistance of clinical and environmental isolates of Legionella spp. has not yet been documented. Routine susceptibility testing of Legionella spp. is not recommended because of difficulties in determining standard minimal inhibitory concentration values. The purpose of this study was to analyze the antimicrobial susceptibility of Legionella pneumophila. strains isolated from a water supply system. MATERIALS AND METHOD: Twenty-eight isolates of L. pneumophila (16 - L. pneumophila SG 1, 12 - L. pneumophila SG 2-14) obtained from water systems in public buildings in Poland were tested. Susceptibility testing was performed using the E-test method. The tested antibiotic were azithromycin, ciprofloxacin, and rifampicin. The medium used for the susceptibility testing was BCYE-, a special medium for Legionella cultivation. RESULTS: Among the tested strains, L. pneumophila was the only one resistant to azithromycin. It was a strain of L. pneumophila SG 2-14 isolated from the water system in a sanitorium. All isolates were found to be sensitive to ciprofloxacin and rifampicin. However, the azithromycin-resistant strain exhibited higher ciprofloxacin and rifampicin MIC (1.5 µg/ml, and 0.19 µg/ml, respectively). The MIC50 for azithromycin, ciprofloxacin, and rifampicin were 0,032, 0,125, and 0,003 µg/ml, respectively. The MIC90 for azithromycin, ciprofloxacin, and rifampicin were 0,032, 0,125, and 0,003 µg/ml, respectively. CONCLUSIONS: Azithromycin resistance was found in one strain of L. pneumophila SG 2-14, but the resistance mechanism is unknown and needs further study. It is possible that therapeutic failures in Legionnaires' disease may be associated with bacterial resistance which should be taken into account. The antibiotic sensitivity testing described in this study could be helpful in detecting the resistance of clinical L. pneumophila isolates. Ciprofloxacin and rifampicin have good in vitro activity against environmental L. pneumophila SG 1 and SG 2-14 in Poland.

Prevalence of Legionella pneumophila in water distribution systems in hospitals and public buildings of the Lublin region of eastern Poland.

OBJECTIVE: The aim of this study was to determine the prevalence of L. pneumophila in water supply systems, hospitals and public buildings in the Lublin region of eastern Poland. MATERIAL AND METHODS: The study was carried out in 26 different objects in the Lublin region. The number of Legionella bacteria in water samples was determined by the membrane filtration method and/or by surface inoculation in accordance with the standards. RESULTS: The study showed the presence of L. pneumophila in 166 hot water samples (74.77%). In 34.33% (n=57) of water samples the count of tested bacteria exceeded the acceptable level of >100 CFU/100 ml. Of the samples where an acceptable level of bacteria was exceeded, 49 samples had an average level of L. pneumophila (100-1,000 CFU/100 ml), and the level in 8 samples was high (>1,000 CFU/100 ml). CONCLUSIONS: The water samples collected form the hot water supply system of hospitals and public buildings showed exceeded counts of L. pneumophila, indicating the risk of infection. The constant monitoring of water distribution systems is an important element of the control of infections caused by these organisms.