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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The apparent failure of hyperchlorination and continuous dosing with chlorine to eliminate legionellae from a dental teaching hospital water supply prompted a prospective study to evaluate charcoal filters as a means of decontamination. Legionella pneumophila serogroup 10 and L. bozemanii serogroup 2 were isolated from dental units yielding 10(1)-10(3) colony forming units (cfu) ml-1 with total bacterial counts in the range 10(2)-greater than 10(4) cfu ml-1. After chair-side installation of charcoal filters bacterial contamination of the dental unit water was prevented and legionellae were initially not detected, but after 7 days the total count returned to pre-filtration levels of greater than 10(4) cfu ml-1; L. pneumophila serogroup 10 was eliminated but L. bozemanii serogroup 2 persisted. These results suggest that neither chlorination nor charcoal filtration deal adequately with the potential hazard of Legionella spp. in dental water.
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PMID:The efficacy of chlorination and filtration in the control and eradication of Legionella from dental chair water systems. 197 12

Guidelines for the prevention of nosocomial pneumonia specify that only sterile fluids should be used for aerosol therapy; however, this recommendation may not be uniformly followed. Thirteen patients with nosocomial pneumonia due to Legionella pneumophila serogroup 3 (Lp3) were identified at a community hospital in the period from 1984 through 1988; 12 patients (92%) had chronic obstructive pulmonary disease; and 9 patients (69%) died. An epidemiologic investigation suggested that the use of nebulizers to deliver medication was associated with acquiring legionnaires' disease. The hospital potable water system was contaminated with Lp3, and a survey indicated that tap water was commonly used to wash medication nebulizers. Lp3 in respirable-size droplets was isolated from aerosols generated by a nebulizer containing Lp3 at one-tenth the concentration found in the hospital potable water. These findings support the recommendation that only sterile fluids be used for filling or cleaning respiratory care equipment and suggest that this guideline is not universally followed.
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PMID:Nosocomial Legionnaires' disease and use of medication nebulizers. 199 43

Cytotoxic activity assays of Gram-negative, heterotrophic bacteria are often laborious and time consuming. The objective of this study was to develop in situ procedures for testing potential cytotoxic activities of heterotrophic bacteria isolated from drinking water systems. Water samples were passed through 0.45 microns membrane filters which were then placed upon appropriate media incubated. After incubation, each membrane filter was transferred to the surface of Y-1 mouse adrenal cells overlaid with 1% agar. The filters were removed after exposure for 15 min. The Y-1 cells were then incubated at 37 degrees C in 2.5% CO2 for an additional 24 h. The release of putative cytotoxic and cytotonic products from the bacterial colonies was recognized by zones of cellular lysis and injury of Y-1 cells that appeared immediately beneath the membrane. Cytotoxic strains of Aeromonas, Vibrio, Escherichia, and Legionella spp. were readily recognized by this method. About 1% of the bacteria isolated from drinking water also released cytotoxic products. This frequency was dependent upon the primary medium used and the density of bacteria present. The majority of cytotoxic strains isolated from drinking water also expressed protease activity (95%) and haemolytic activity (70%). This in situ membrane filter procedure is a facile method for simultaneously testing many different bacterial colonies.
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PMID:A membrane filter procedure for assaying cytotoxic activity in heterotrophic bacteria isolated from drinking water. 201 13

Legionella pneumophila serotype 6 was isolated from the peritoneal fluid of a 59-year-old immunosuppressed patient who developed peritonitis shortly after kidney transplantation. Clinical and radiological examination did not show pulmonary abnormalities until shortly before his death when multiple organ failure developed with adult respiratory distress syndrome (ARDS). Post mortem examination showed L. pneumophila in the peritoneum and in a small pulmonary infiltrate, confirmed by positive cultures. A primary peritoneal inoculation via an indwelling Tenckoff catheter seems to have been the most likely route of infection. Positive L. pneumophila type 6 cultures were obtained from the shower and hot water tap in the room of the patient. L. pneumophila must be considered as a potential cause of peritonitis in which routine microbiological cultures remain negative.
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PMID:Legionella pneumophila peritonitis in a kidney transplant patient. 202 25

Forty eyewash units were sampled for protozoa, bacteria, and fungi. Total heterotrophic bacterial counts on nutrient agar and R2A agar (Difco Laboratories, Detroit, Mich.) ranged from 0 to 10(5) CFU/ml, with Pseudomonas spp. being the most frequently isolated. Total counts of 10(4) and 10(8) cells per ml were obtained with the acridine orange staining procedure. All samples were examined for Legionella spp. by direct fluorescent-antibody staining and by culturing on buffered charcoal-yeast extract agar containing alpha-ketoglutarate and glycine and supplemented with cycloheximide, vancomycin, and polymyxin B. DNA-DNA hybridization was used to confirm identification of the Legionella isolates. Legionellae were detected in 35 of 40 (87.5%) samples by direct fluorescent-antibody staining, with 3 samples yielding both Legionella spp. and amoebae. Amoebae identified as Hartmannella, Vahlkampfia, Acanthamoeba, and Cochliopodium spp. were detected in 19 of 40 (47:5%) samples. Sabouraud dextrose agar was used to obtain a crude estimate of viable fungal populations, pH, hardness, and ammonia, alkalinity, chlorine, copper, and iron contents were recorded for all water samples collected from eyewash stations; 33% of the samples had greater than or equal to 10 mg of CO2 per liter. It is concluded that eyewash stations not regularly flushed and/or cleaned and used to flush traumatized eye tissue may be a source of infection and can contaminate laboratory environments via aerosol transmission.
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PMID:Isolation of amoebae and Pseudomonas and Legionella spp. from eyewash stations. 203 3

About one third of adults surveyed in South Australia have shown evidence of past silent infection with Legionella pneumophila serogroup 1. However, the annual notification rate for symptomatic disease is only about 0.5 per 100,000 residents in non-epidemic years. The male to female ratio is 2.5 to one and approximately 50% of the cases are at least 60 years of age. Cases have presented more in summer and in the metropolitan areas. Twenty cases of Legionnaires' disease occurred during the summer of 1985-86. A cooling tower was held to be the principal source with aerosols being dispersed up to three kilometers away during an atmospheric thermal inversion. A subsequent outbreak of 22 L. longbeachae serogroup 1 infections had no marked geographic clustering. The outbreak commenced in spring and cases were distinguished as active gardeners. L. longbeachae was found in garden soil and it is hypothesised that this soil inhabitant can become aerosolised and inhaled during gardening. The potential for primary prevention of Legionnaires' disease is discussed in relation to water-handling equipment and the need for early precautionary treatment of all community-acquired pneumonia as suspect Legionnaires' disease is emphasised.
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PMID:Epidemiological characteristics of Legionella infection in South Australia: implications for disease control. 203 80

Three Legionella-like organisms were isolated from water from the cooling towers of two Australian institutions. The strains grew on buffered charcoal-yeast extract (BCYE) agar but not on BCYE agar in the absence of L-cysteine. Gas-liquid chromatography profiles of the isolates were consistent with those for Legionella spp. They were serologically distinct from other legionellae in a slide agglutination test. DNA hybridization studies showed that the three isolates belong to a new species of Legionella, Legionella fairfieldensis (ATCC 49588).
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PMID:Legionella fairfieldensis sp. nov. isolated from cooling tower waters in Australia. 203 64

A free-living amoeba identified as Hartmannella vermiformis was isolated from a water sample obtained during an investigation of nosocomial legionellosis. Hartmannella vermiformis is known to support the intracellular multiplication of Legionella pneumophila. This strain of H. vermiformis, designated CDC-19, was cloned and established in axenic culture to develop a model for the study of the pathogenicity of legionellae. Isoenzyme patterns of axenically-cultivated strain CDC-19 were compared with two strains of H. vermiformis derived from the type strain, one axenic (ATCC 50236) and the other grown in the presence of bacteria (ATCC 30966). Enzyme patterns suggested that all three strains are assignable to the species H. vermiformis. Axenic H. vermiformis strain CDC-19 has been deposited with the American Type Culture Collection (ATCC 50237) and should prove useful in the study of protozoan-bacterial interaction.
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PMID:Characterization of an axenic strain of Hartmannella vermiformis obtained from an investigation of nosocomial legionellosis. 208 87

The first strain of non-Legionella pneumophila, L-88-1, was isolated from some condensed water in a steam discharge pipe extending from a boiler in China. The organism was characterized by serologic, biochemical, DNA hybridization and electron microscopic studies. It was identified to be L. gormanii.
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PMID:First isolation of Legionella gormanii in China. 211 49

A number of measures were taken to control Legionella pneumophila in a hospital hot water system over a period of 18 months, including (i) raising the temperature of the water leaving the central storage tanks from initially 55-60 degrees C to approximately 73 degrees C, (ii) heat shock treatment of the whole system with water temperatures above 70 degrees C and (iii) increasing the daily return flow from the hospital circulation system from initially 30 m3 to 120 m3. In addition, (iv) three UV irradiation devices were installed on the inlet and outlets of the storage tanks and (v) an attempt was made to decontaminate the water system by means of CO2. Measures (i) and (iii) were demonstrated to be effective for permanent control of Legionellae in the system. Measures (ii) and (v) proved to have only a short term effect of several days and measure (iv) did not show any effect on the presence of Legionellae at all. The extent of Legionella contamination of the water samples correlated negatively with water temperature and depended on the position of the outlets within the hospital. Different pipe materials (copper, plastics) could not be shown to have any influence on the extent of water contamination with Legionella. The findings of the survey indicate that especially the peripheral areas of the hot water system were colonized by Legionellae.
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PMID:[Sanitizing a hospital hot water system contaminated with Legionella pneumophila]. 211 57


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