Isolation of Legionella species from drinking water

Hsu, Shih-Yung; Martín, R; Wentworth, Berttina B.

doi:10.1128/aem.48.4.830-832.1984

Cited by 62 publications

(20 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Under the conditions experienced in this study, where the counts of Legionella spp. were, on average, higher than those found in other similar studies (Hsu et al 1984;Tobin et al 1986;Stout et al 1992;Kusnetsov et al 1994), direct inoculum detected signi®cantly higher concentrations compared with the techniques involving decontamination, which brought about an average reduction of 67±68% in detectable Legionellae. As a consequence, in environmental surveillance programmes where heat decontamination is used due to its greater sensitivity and speci®city, it should be recognized that this method underestimates the number of Legionella spp.…”

Section: Discussioncontrasting

confidence: 50%

Comparison of selective procedures for isolation and enumeration ofLegionellaspecies from hot water systems

Leoni

Legnani

2001

Journal of Applied Microbiology

112

View full text Add to dashboard Cite

E. LEONI AND P.P. LEGNANI. 2001. Various sample pre‐treatment techniques and different growth media for the isolation of Legionellae from hot water supplies in public buildings were compared. A total of 102 hot water samples from taps and showers was examined. The highest recovery frequency was obtained with the heat pre‐treatment method and using the selective medium GVPC. However, the results differed according to the concentration of legionellas. In the case of low plate counts (≤5000 cfu l−1), the heat pre‐treatment technique gave a significantly higher percentage of positive samples compared with other techniques (P < 0·05). With increasing concentration, the differences between the procedures decreased until they became statistically not significant for concentrations above 50 000 cfu l−1. The direct inoculum method allowed a significantly higher detection of concentrations (P < 0·001) compared with heat and acid decontamination methods, which brought about a 67–68% reduction in detectable Legionellae. Heat decontamination techniques show greater sensitivity and specificity. However, they underestimate the number of legionellas. In environmental surveillance programmes, this underestimate must be taken into consideration when assessing the health risk.

show abstract

Section: Discussioncontrasting

confidence: 50%

Comparison of selective procedures for isolation and enumeration ofLegionellaspecies from hot water systems

Leoni

Legnani

2001

Journal of Applied Microbiology

112

View full text Add to dashboard Cite

show abstract

“…Cases of Legionnaires' disease and Pontiac fever have been associated with air conditioning cooling towers [1,2], portable water systems [3][4][5][6], plumbing and water systems in hotels, hospitals [7][8][9][10], and homes [11]. Legionellosis acquired from artificial water systems is generally due to Legionella pneumophila serogroup (sg) 1, which appears to be the most common legionella in these environments [12].…”

Section: Introductionmentioning

confidence: 99%

Relationship betweenLegionellaspp. and antibody titres at a therapeutic thermal spa in Portugal

et al. 1995

View full text Add to dashboard Cite

The presence of Legionella spp. in the water of a Portuguese spa was ascertained during the spa season, between May and November. Simultaneously the prevalence of anti-legionella antibodies in people attending the spa was also investigated. The antibody titres of 172 randomly selected patients and 42 therapists were determined, and compared with a control group of 503 blood donors. Legionellae were present in the spa water at low concentrations, generally lower than 10(3) c.f.u./l. A total of 92 strains representing eight different species or serogroups were isolated; the predominant isolates belonged to Legionella pneumophila serogroup 6 and to L. londiniensis. During the study, no clinical cases of Legionnaires' disease were observed, and the antibody titres were generally low in the groups studied. However, the antibody titres of the patients increased slightly during their stay at the spa, approaching the values for the therapists. Mean antibody titres in the groups related with the spa were significantly higher than those in the blood donors against five of the seven legionella antigens tested. The largest number of elevated antibody titres in the exposed groups were to the L. pneumophila sg 5 and sg 6 antigens.

show abstract

“…Epidemiological links between bacteria from these sources and legionellosis have been established (Best et al, 1983). Studies on municipal water supplies have shown that L. pneumophila is relatively uncommon in the waters (Hsu et al, 1984). In hot water, however, Legionella has frequently been recovered especially in hospitals and hotels (Bartlett et al, 1983).…”

Section: Introductionmentioning

confidence: 99%

“…The exact origin of L. pneumophila found in water distribution systems is unknown. It has been suggested that plumbing systems may be seeded by small numbers of Legionellae from public water supplies, but isolation of the bacterium at the outlet of water treatment plants or mains has rarely been successful (Hsu et al, 1984). Others have proposed that contamination of the plumbing fixtures occurred during their installation (Shands et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Contamination of domestic water heaters with Legionella pneumophila: Impact of water temperature on growth and dissemination of the bacterium

Dewailly

Joly

1991

Environ. Toxicol. Water Qual.

View full text Add to dashboard Cite

~ ~~Sediment and tap water from 255 randomly selected domestic water heaters were cultured on buffered charcoal yeast extract agar and two semiselective media to detect the presence of Legionellaceae. Different serogroups of L . pneumophila, the only species of Legionellaceae identified in this study, were found in 84 of the 255 water heaters and this contamination occurred only in electric water heaters ( n = 205). Sediment contamination by L . pneumophila was strongly associated with water temperature. The bacterium was detected in 45% (80/176) of the sediments with temperature lower than 40°C and in only 14% (4129) of the sediments at this or higher temperatures. When the peripheral water temperature was lower than 56"C, 23% (9/39) of the tap water samples were contaminated with Legionella while only one of the 161 samples that were above this temperature contained Legionella.These results do suggest that reducing the water temperature in electric water heaters could play a role in the multiplication of L . pneumophila in the water heaters and in its dissemination in the household.

show abstract

Isolation of Legionella species from drinking water

Cited by 62 publications

References 8 publications

Comparison of selective procedures for isolation and enumeration ofLegionellaspecies from hot water systems

Comparison of selective procedures for isolation and enumeration ofLegionellaspecies from hot water systems

Relationship betweenLegionellaspp. and antibody titres at a therapeutic thermal spa in Portugal

Contamination of domestic water heaters with Legionella pneumophila: Impact of water temperature on growth and dissemination of the bacterium

Contact Info

Product

Resources

About