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

Air humidifiers using cold water and cooling towers of air-conditioning systems provide the best settings for the growth of bacteria. Hence, we investigated 90 water samples for humidifiers and 15 water samples from cooling towers of hospitals, authorities, schools, and factories. The colony forming units/ml at 20 degrees C and 36 degrees C, the biological activity of added biocidal substances, and the occurrence of legionella were determined. About 90 percent of the samples showed no activity of the biocidal substance added, suggesting the uselessness of such substances. Furthermore, they exercised neither an influence on the CFU of the water samples nor on the occurrence of legionella. Legionella were isolated in 7 per cent of the humidifiers investigated, in 3 per cent of air conditioned buildings, respectively. 13 per cent of the cooling towers contained legionella. The risk of infection by air conditioning systems, humidifiers, cooling towers, and other emitters of infections agents should be controlled by the public health service.
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PMID:[Legionella and other bacteria in air humidifiers and cooling systems of air conditioning units--a survey]. 128 57

The colonization, survival and control of Legionella pneumophila in a hospital hot-water system was examined. The organism was consistently isolated from calorifier drain-water samples at temperatures of 50 degrees C or below, despite previous chlorination of the system. When the temperature of one of two linked calorifiers was raised to 60 degrees C, by closing off the cold-water feed, the legionella count decreased from c. 10(4) c.f.u./l to an undetectable level. However, 10 min after turning on the cold-water feed which produced a fall in calorifier temperature, the count in the calorifier drain water returned to its original level. Investigations revealed that the cold-water supply was continually feeding the calorifiers with L. pneumophila. Simple modifications in the design of the system were made so that the cold-water feed no longer exceeds 20 degrees C; these measures have considerably reduced the number of L. pneumophila reaching the calorifiers.
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PMID:A field study of the survival of Legionella pneumophila in a hospital hot-water system. 218 41

Legionella inevitably are imported from natural reservoirs into drinking-water supplies. Bacterial growth predominantly occurs at water temperatures between 40 degrees C und 50 degrees C (104 degrees F and 122 degrees F). Heat conduction to insufficiently insulated cold water tubes implies the possibility of increased contamination also there. Problems with contamination arise in parts of the water supplies with stagnant warm water. Therefore, reservoirs should be descaled regularly. In general, for prophylaxis are recommended raising the temperature of warm water to 60 degrees C (140 degrees F), regular microbiological control of water quality and regular technical maintenance of waterworks where warm water stagnates for some time. Patients bearing a higher risk of Legionella-infections require intensified precautionary measures. The diagnosis of legionellosis should be based on the direct evidence of immunofluorescence-stained microorganisms. Finding increased antibody titers alone is not always correlated with the response to Legionella-specific therapy.
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PMID:[Aspects of hospital hygiene in Legionella infections]. 232 22

In a new hospital building, cold and warm water systems were examined for microbiological parameters before opening. All of the 35 sampling sites showed elevated colony counts, i.e. greater than 100 cfu/ml. 11 of these contained Legionella species at various times. While Escherichia coli, coliform bacteria and Pseudomonas aeruginosa could not be found, Legionella longbeachae serogroup 1 + 2 was identified in 13 samples. Only one sample contained Legionella pneumophila serogroup 3. Legionella species were detected using a commercial gene probe assay and culture techniques. The gene probe method proved to be superior to the culture techniques insofar as significantly positive results were obtained more frequently, and evidence for the presence of Legionella of different species and serogroups could be obtained with a single procedure. The gene probe method appears to be a suitable screening method for the detection of Legionella species.
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PMID:[The detection of legionellae in a water pipe system using gene probe technics and culture methods]. 239 93

Many common aquatic bacteria like Legionella pneumophila are able to colonize man-made water systems. Poorly maintained systems or those that are seldom used provide ideal sites for growth and often also provide the means for aerosolizing the organism. Compounds leached from construction materials and the by-products of other organisms can be used as food by the Legionellaceae and can thus aid their growth. Keeping water systems clean and well serviced, keeping hot water at or above, and cold water below, recommended temperatures and additionally in cooling towers maintaining the required levels of biocide, will reduce or prevent the growth of legionellas. To be certain that the control measures are successful microbiological and chemical monitoring should be done. The results of this and the maintenance work undertaken should be kept in a log so that failures in treatment can be quickly seen and remedial action taken before any risk of infection arises. Adhering to these simple guidelines will go a long way to removing the risk of infection and will also provide systems that are more efficient and thus cheaper to run.
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PMID:Reducing the risk of Legionnaires' disease. 240 Jan 79

We studied the lipopolysaccharide (LPS) of Legionella pneumophila and six other Legionella species to determine whether strain differences were apparent. The LPS was purified by a cold ethanol extraction procedure, and total carbohydrates represented 10 to 20% of LPS weight. 2-keto-3-deoxyoctonate represented 1 to 13% of the total carbohydrate present in the LPS. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all strains except L. dumoffi showed smooth-type LPS with multiple high-molecular-weight complexes. Proteinase K-treated, whole-cell lysates showed profiles similar to those of purified LPS. Each serogroup of L. pneumophila and each Legionella species had a distinct sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile. L. pneumophila lipid A is antigenically related to the lipid A of Enterobacteriaceae. In immunoblot assays with the LPS of L. pneumophila serogroups 1 to 6 as antigens, serogroup-specific immune monkey sera recognized homologous purified LPS, but not the LPS of the five heterologous serogroups. These studies indicate that LPS composition may be a determinant of serogroup specificity as defined by the immunofluorescence-based serogrouping schema for L. pneumophila and other Legionella species.
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PMID:Serogroup specificity of Legionella pneumophila is related to lipopolysaccharide characteristics. 241 53

Potential sources of Legionella spp. in a university hospital were investigated over 3 years in order to gain better understanding of the ecology and transmission of this organism to hospitalized patients. The survey highlighted the contamination of the hot water system with high concentrations of legionellas (up to 10(6) cfu 1(-1]. Legionella pneumophila serogroup 6 was predominant followed by L. pneumophila serogroup 10. Serogroup 1 and other species (L. longbeachae, L. micdadei) were rarely isolated. Serogroup 6 was also the predominant cause of nosocomial legionellosis in 15 sporadic cases in immunocompromised patients from 1981 to 1987. In light of this problem, several control measures were tried consecutively. A disinfection cycle with 6 ppm free chlorine failed to eradicate legionellas because of difficulties with the plumbing system. Raising the temperature in hot water tanks to 80 degrees C was effective locally, but mixer tanks where cold and hot water (60-65 degrees C) are mingled in order to achieve 45 degrees C became the principal reservoirs. Disconnecting the mixer tanks, maintaining a temperature of 60 degrees C in the heating tanks and accelerating the flow rate in the hot water system proved to be the most useful measures.
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PMID:Legionella spp. in a hospital hot water system: effect of control measures. 256 4

A microbiological and epidemiological investigation at the Infectious Diseases Hospital in Turin, Italy, demonstrated Legionella pneumophila serogroup 3 at 10(2) to greater than 4 X 10(3) cfu l-1 from 24 of 32 hot water samples collected from hand-basins in six separate buildings. A sample taken from the public water supply, and a hot water sample (80 degrees C) collected from hot water tanks, did not yield legionellas. Legionella pneumophila serogroup 3 was found in samples taken at the first point of mixed hot and cold water (50 degrees C) at 3 X 10(2) cfu l-1. 12 of 26 samples from the shower-heads yielded 10(3) to 2.5 X 10(5) cfu l-1 and one of 12 water samples from oxygen bubble humidifiers tested yielded 1.6 X 10(4) cfu l-1. No other legionellas species or serogroups of Legionella pneumophila were isolated during the study. No cases of nosocomial pneumonia were detected among 3653 patients' records, nor was there serological evidence of Legionella infection in the 180 patients tested.
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PMID:Endemicity of Legionella pneumophila serogroup 3 in a hospital water supply. 256 58

Mycoplasma pneumoniae is a frequent causal agent of respiratory infections. A recent french survey was carried out on adults in hospital for an acute pneumonia which was acquired outside hospital. This study showed Mycoplasma pneumoniae in third position, behind the pneumococcus and Legionella pneumophila, accounting for 17% of those cases with an established aetiology. Nevertheless its exact importance is difficult to establish on account of the high frequency of very benign forms in which a clinical diagnosis is not achieved. M. pneumoniae pneumonia occurs particularly in young subjects without any seasonal or geographical predominance. The infection is endemic with little epidemic peaks every four to five years. It is weakly contagious and is limited to close contacts. The laboratory diagnosis of M. pneumoniae pneumonia can be made by isolating the germ responsible or by a serological examination. Isolation is rarely performed. It is lengthy and difficult and may be obtained from sputum or better from throat swabs. Several serological examinations have been performed. The presence of cold agglutinins is non specific. A search for anti M. pneumoniae antibodies is much more helpful. It is done by complement fixation in most laboratories. The diagnosis of a M. pneumoniae infection can be confirmed by a significant change in antibody level between the first and second blood specimens 15 days apart (at least a four fold rise in the antibody level) if the first specimen was taken at the beginning of the illness. If a single serum specimen is examined a minimum titre of 1/64 may be taken as a presumptive diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Biological diagnosis of Mycoplasma pneumoniae respiratory infections]. 308 89

Warm and cold water as well as water from wash basin drains and faucet aerators was examined to determine the number of viable and dead bacteria by culture and by staining and to establish the spectrum of species with special consideration of Legionella pneumophila. The relation between the number of Legionella pneumophila, the temperature, and the iron content of the water was determined in three separate warm water systems. High colony counts (up to 8.9 X 10(5) colony-forming units), were detected in both warm and cold water at certain sampling sites. The most prevalent genera were Pseudomonas, Bacillus, Flavobacterium, Acinetobacter, and Moraxella. Legionella pneumophila was found in every building in 35 of 150 warm samples and in 1 of 43 cold water samples. The highest water temperature of a sample containing Legionella pneumophila was 64 degrees C. The correlation between high colony counts and the occurrence of Legionella pneumophila in the samples was not significant. High iron concentrations, however, appear to have a positive effect on the growth of Legionella pneumophila.
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PMID:Bacterial colonization and occurrence of Legionella pneumophila in warm and cold water, in faucet aerators, and in drains of hospitals. 310 60


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