Detection and recovery of <i>Legionella</i> in water

Barbaree, James M.; Morrill, William E.; Fields, Barry S.; Martin, W. J.; Sanden, Gary N.

doi:10.1002/tox.2540030505

Cited by 14 publications

(8 citation statements)

References 17 publications

(12 reference statements)

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“…Thus, studies that report CFU of legionellae in water samples should describe storage and transport conditions and procedures. If accurate assessments of in situ concentrations of legionellae are needed, samples should be refrigerated as recommended elsewhere (5).…”

Section: Discussionmentioning

confidence: 99%

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Incubation of water samples containing amoebae improves detection of legionellae by the culture method

Sanden

Morrill

Fields

et al. 1992

Appl Environ Microbiol

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Some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. We studied the effect of incubating water samples containing amoebae on the sensitivity of culture for legionellae. Samples collected during investigations of legionellosis epidemics and shown by conventional culture procedures to contain amoebae, but not legionellae, were incubated at 35°C and replated. Legionellae were recovered from 59 of 144 such samples. Species isolated included L. pneumophila, L. anisa, L. bozemanii, L. gornanii, L. micdadei, L. rubrilucens, L. sainthelensi, L. steigerwaltii, and an unnamed species. Acanthamoeba polyphaga, Acanthamoeba hatcheffi, a Rosculus sp., Hartmannella vermiformis, and Vahlkampfia spp. were among the autochthonous amoebae identified. Legionellae were recovered by this procedure from only 3 of 63 samples that were negative for amoebae by conventional culture procedures. These results show that water samples negative for legionellae, but positive for amoebae, by standard culture techniques should be incubated and replated to maximize the sensitivity of culture for legionellae.

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Section: Discussionmentioning

confidence: 99%

“…Routine sample treatment. The procedures used to treat and culture water samples are described elsewhere (5). Briefly, 0.1-ml volumes of incubated samples were inoculated onto buffered charcoal yeast extract agar with ox-ketoglutarate (BCYEa), BCYEa with antimicrobial drugs, and BCYEa with antimicrobial drugs and glycine.…”

Section: Methodsmentioning

confidence: 99%

Incubation of water samples containing amoebae improves detection of legionellae by the culture method

Sanden

Morrill

Fields

et al. 1992

Appl Environ Microbiol

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“…Amoebal coculture. Acanthamoeba castellanii ATCC 30234 was grown in Proteose Peptone glucose broth for 4 days at 30ЊC in 75-cm 2 Corning tissue culture flasks in air, without agitation. At this stage, more than 95% of the amoebae were trophozoites.…”

Section: Methodsmentioning

confidence: 99%

Precision and accuracy of recovery of Legionella pneumophila from seeded tap water by filtration and centrifugation

Boulanger

Edelstein

1995

Appl Environ Microbiol

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Determination of the concentration of Legionella pneumophila in environmental water sites may be useful for the prediction of the risk of a particular site's causing Legionnaires' disease as well as for experimental studies of environmental growth or remediation. The precision and accuracy of recovery of two different L. pneumophila strains from seeded tap water samples were studied, with either filtration or centrifugation used to concentrate the bacteria. L. pneumophila grown on BCYE␣ agar or in Acanthamoeba castellanii was used to seed sterile tap water. Water samples were then either filtered (0.2-m pore size) or centrifuged. An average of 53% (95% confidence interval [CI], 47 to 58%; n ‫؍‬ 45) of the seeded L. pneumophila organisms were recovered by filtration with flat polycarbonate membranes. This recovery was significantly higher (P < 0.01) than that obtained by filtration with cast membranes (mean, 13%; 95% CI, 11 to 38%; n ‫؍‬ 4) or by centrifugation at 3,800 ؋ g for 30 min (mean, 14%; 95% CI, 2 to 25%; n ‫؍‬ 9) or at 8,150 ؋ g for 15 min (mean, 32%; 95% CI, 28 to 36%; n ‫؍‬ 19). Recovery of L. pneumophila was not significantly different whether the bacteria were grown on plates or in amoebae. Use of a selective medium did not decrease the recovery efficiency, but preplating acid treatment of specimens caused an Ϸ30% bacterial loss. The lower limit of detection of L. pneumophila from 50 ml of seeded tap water was highly variable and was in the range of 1 to 10 CFU/ml when filtration was performed with single-layer membranes and the membranes were either plated directly or first minced and suspended in water before plating. Filtration with single-layer membranes is the superior method for the recovery of L. pneumophila from seeded tap water. All concentration methods have highly variable recovery rates, making accurate quantification of low concentrations of L. pneumophila difficult. Even the most efficient recovery method can be very inaccurate.

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“…5,6 Results Prior to the initiation of the control program Legionella species were frequently detected in water samples drawn from various sites in the hospital in concentrations ranging form 20 to 1400 cfu/100 ml. the hospital initiated various control programs including superheating the hot water tanks to 70 º C and shock treatment with chlorine doses up to 2000 ppm.…”

Section: Control Of Legionella In Hospital Hot Water Systems Shuvalmentioning

confidence: 99%

An Innovative Method for the Control of Legionella Infections in the Hospital Hot Water Systems with a Stabilized Hydrogen Peroxide-Silver Formulation

Shuval¹,

Yarom²,

Shenman³

2009

Int. j. infect. control

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Legionella pneumophila contamination of hot water systems are particularly difficult to control due to the optimal growth conditions, protection by biofilms and the fact that chlorine and many other disinfectants are less effective at high temperatures. this paper reports on a 24 month study using an innovative method to control Legionella pneumophila in the closed loop hot water system of a major hospital in Israel which has suffered a serious out-break of Legionaires disease in their BMt unit. they had failed to control the Legionella infections by the conventional use of repeated shock treatments with chlorine up to 2000 ppm and by raising the water temperature to 70 º C. During the period between october 2005 and September 2007 an innovative disinfectant process, based on a patented, stabilized, non-toxic, taste free, bactericidal/bacteriostatic, heat resistant formulation of hydrogen peroxide containing a minute amount of oligodynamic silver was used to effectively disinfect the hot water system and achieve total long term control of Legionella pneumophila. the combined formulation of H 2 O 2 and silver and other metals is some 100 times more powerful as a disinfectant than hydrogen peroxide alone and can provide a long lasting effective disinfectant residual. our studies show that the formulation's disinfection power increases significantly as water temperature increases which contributes to its effective control of Legionalla bacteria in hot water systems which normally operate at temperatures up to 40-50 0 C. the silver ion deposit on the pipe walls have a bacteriostatic effect. At the end of the 24 month test period it can be stated that the stabilized H 2 O 2 -silver formulation effectively controlled Legionella pneumophila in the hospital ward's hot water system for the first time after years of chronic problems and has proved to be a promising and economical option for the long term control of Legionella bacteria in closed loop hot water systems.

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Detection and recovery of Legionella in water

Cited by 14 publications

References 17 publications

Incubation of water samples containing amoebae improves detection of legionellae by the culture method

Incubation of water samples containing amoebae improves detection of legionellae by the culture method

Precision and accuracy of recovery of Legionella pneumophila from seeded tap water by filtration and centrifugation

An Innovative Method for the Control of Legionella Infections in the Hospital Hot Water Systems with a Stabilized Hydrogen Peroxide-Silver Formulation

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