scholarly journals Rapid Detection and Enumeration of Legionella pneumophila in Hot Water Systems by Solid-Phase Cytometry

2004 ◽  
Vol 70 (3) ◽  
pp. 1651-1657 ◽  
Author(s):  
Helena Aurell ◽  
Philippe Catala ◽  
Pierre Farge ◽  
France Wallet ◽  
Matthieu Le Brun ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Natural Waters ◽  
Solid Phase ◽  
Tap Water ◽  
Culture Method ◽  
Water Systems ◽  
Cross Reactivity ◽  
Hot Water ◽  
Standard Culture ◽  
Direct Counts

ABSTRACT A new method for the rapid and sensitive detection of Legionella pneumophila in hot water systems has been developed. The method is based on an IF assay combined with detection by solid-phase cytometry. This method allowed the enumeration of L. pneumophila serogroup 1 and L. pneumophila serogroups 2 to 6, 8 to 10, and 12 to 15 in tap water samples within 3 to 4 h. The sensitivity of the method was between 10 and 100 bacteria per liter and was principally limited by the filtration capacity of membranes. The specificity of the antibody was evaluated against 15 non-Legionella strains, and no cross-reactivity was observed. When the method was applied to natural waters, direct counts of L. pneumophila were compared with the number of CFU obtained by the standard culture method. Direct counts were always higher than culturable counts, and the ratio between the two methods ranged from 1.4 to 325. Solid-phase cytometry offers a fast and sensitive alternative to the culture method for L. pneumophila screening in hot water systems.

scholarly journals Integrated Real-Time PCR for Detection and Monitoring of Legionella pneumophila in Water Systems

2006 ◽  
Vol 73 (5) ◽  
pp. 1452-1456 ◽  
Author(s):  
Diaraf Farba Yaradou ◽  
Sylvie Hallier-Soulier ◽  
Sophie Moreau ◽  
Florence Poty ◽  
Yves Hillion ◽  
...  
Keyword(s):  
Real Time ◽  
Legionella Pneumophila ◽  
Cooling Tower ◽  
Water System ◽  
Culture Method ◽  
Hot Water ◽  
Pcr Assay ◽  
Standard Culture ◽  
Serial Samples ◽  
Over Time

ABSTRACT We evaluated a ready-to-use real-time quantitative Legionella pneumophila PCR assay system by testing 136 hot-water-system samples collected from 55 sites as well as 49 cooling tower samples collected from 20 different sites, in parallel with the standard culture method. The PCR assay was reproducible and suitable for routine quantification of L. pneumophila. An acceptable correlation between PCR and culture results was obtained for sanitary hot-water samples but not for cooling tower samples. We also monitored the same L. pneumophila-contaminated cooling tower for 13 months by analyzing 104 serial samples. The culture and PCR results were extremely variable over time, but the curves were similar. The differences between the PCR and culture results did not change over time and were not affected by regular biocide treatment. This ready-to-use PCR assay for L. pneumophila quantification could permit more timely disinfection of cooling towers.

scholarly journals Total and Viable Legionella pneumophila Cells in Hot and Natural Waters as Measured by Immunofluorescence-Based Assays and Solid-Phase Cytometry

2011 ◽  
Vol 77 (17) ◽  
pp. 6225-6232 ◽  
Author(s):  
N. Parthuisot ◽  
M. Binet ◽  
A. Touron-Bodilis ◽  
C. Pougnard ◽  
P. Lebaron ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Water Samples ◽  
Natural Waters ◽  
Solid Phase ◽  
Environmental Water ◽  
Thermal Spring ◽  
Hot Water ◽  
Content Type ◽  
Thermal Spring Water ◽  
Plate Counts

ABSTRACTA new method was developed for the rapid and sensitive detection of viableLegionella pneumophila. The method combines specific immunofluorescence (IF) staining using monoclonal antibodies with a bacterial viability marker (ChemChrome V6 cellular esterase activity marker) by means of solid-phase cytometry (SPC). IF methods were applied to the detection and enumeration of both the total and viableL. pneumophilacells in water samples. The sensitivity of the IF methods coupled to SPC was 34 cells liter−1, and the reproducibility was good, with the coefficient of variation generally falling below 30%. IF methods were applied to the enumeration of total and viableL. pneumophilacells in 46 domestic hot water samples as well as in cooling tower water and natural water samples, such as thermal spring water and freshwater samples. Comparison with standard plate counts showed that (i) the total direct counts were always higher than the plate counts and (ii) the viable counts were higher than or close to the plate counts. With domestic hot waters, when the IF assay was combined with the viability test, SPC detected up to 3.4 × 103viable but nonculturableL. pneumophilacells per liter. These direct IF methods could be a powerful tool for high-frequency monitoring of domestic hot waters or for investigating the occurrence of viableL. pneumophilain both man-made water systems and environmental water samples.

Detection and quantification ofLegionella pneumophilain water samples using competitive PCR

2006 ◽  
Vol 52 (6) ◽  
pp. 584-590 ◽  
Author(s):  
Priscilla Declerck ◽  
Jonas Behets ◽  
Elke Lammertyn ◽  
Ilya Lebeau ◽  
Jozef Anné ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Water Samples ◽  
Cooling Tower ◽  
Tap Water ◽  
Cost Effective ◽  
Culture Method ◽  
Environmental Water ◽  
Competitive Pcr ◽  
Promising Alternative ◽  
Standard Culture

The presence of high levels of Legionella pneumophila in man-made aquatic systems correlates with the incidence of nosocomial Legionnaires' disease. This requires a rapid, reliable, and sensitive quantification of L. pneumophila concentrations in suspected water systems. In this research, a homologous competitor was developed and evaluated in a L. pneumophila competitive polymerase chain reaction (cPCR) to quantify this human pathogen in a quick, cost-effective, and reliable way. Accuracy of cPCR was evaluated by analyzing cooling tower and tap water samples spiked with known concentrations of L. pneumophila bacteria, in parallel with the standard culture method. Legionella pneumophila amounts detected and calculated from cPCR and culture correlated very well: r = 0.998, P = 0.002 for tap water and r = 0.990, P = 0.009 for cooling tower water. Nevertheless, for both kinds of water samples, mean numbers of L. pneumophila calculated from cPCR results were always higher than those obtained by culture. This study makes it clear that the rapid, sensitive, and cost-effective L. pneumophila cPCR is a promising alternative to the standard time-consuming culture method and expensive real-time PCR to enumerate L. pneumophila bacteria in environmental water samples.Key words: Legionella pneumophila, competitive PCR, cost-effective, cooling tower water, tap water, sensitive detection.

A simple method for the eradication ofLegionella pneumophilafrom potable water systems

1997 ◽  
Vol 43 (12) ◽  
pp. 1189-1196 ◽  
Author(s):  
Carmen Moreno ◽  
Isabel de Blas ◽  
Francisca Miralles ◽  
David Apraiz ◽  
Vicente Catalan
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Residual Chlorine ◽  
Water Heater ◽  
Simple Method

In this paper we describe a simple method, noncorrosive to pipes, for the eradication of Legionella pneumophila from potable water systems. This method is based on the systematic purging of the pipe networks with cold water containing 1 – 1.5 mg residual chlorine/L. In the hot water system, a new pipe bypassing the water heater was installed, whereas in the air conditioning system, the circuit is purged with water from the tap water system. The feasibility of this method was studied in two hotels in which the presence of Legionella was detected despite treatment of the water by the hyperchlorination method. The evolution of the presence of Legionella was studied by culture and polymerase chain reaction. Eighty samples from hotel A and sixty-seven samples from hotel B were analyzed during the time that the eradication method was applied. Our results showed that this method permitted the effective elimination of L. pneumophila after 5 months in hotel A and 7 months in hotel B.Key words: Legionella pneumophila, eradication.

scholarly journals Detection and Quantification ofLegionella pneumophilafrom Water Systems in Kuwait Residential Facilities

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Qadreyah A. Al-Matawah ◽  
Sameer F. Al-Zenki ◽  
Jafer A. Qasem ◽  
Tahani E. Al-Waalan ◽  
Ahmed H. Ben Heji
Keyword(s):  
Legionella Pneumophila ◽  
Culture Method ◽  
Water Systems ◽  
Residential Facilities ◽  
Rt Pcr ◽  
Serological Typing ◽  
Standard Culture ◽  
Polymerase Chain ◽  
Water Tanks

The prevalence ofLegionella pneumophiliain water systems of residential facilities in Kuwait was performed during the period from November 2007 to November 2011. A total of 204 water samples collected from faucets and showerheads in bathrooms (n= 82), taps in kitchens (n= 51), and water tanks (n= 71), from different locations of residential facilities in Kuwait were screened forLegionella pneumophilaby the standard culture method and by real time polymerase chain reaction (RT-PCR). Out of the 204 samples, 89 (43.6%) samples were positive forLegionellaspp., 48 (23.5%) samples were detected by the standard culture method, and 85 (41.7%) were detected by RT-PCR. Of the culture positiveLegionellasamples, counts ranged between 10 to 2250 CFU/L. Serological typing of 48Legionellaisolates revealed that 6 (12.5%) of these isolates belonged toLegionella pneumophilaserogroup 1, 37 (77.1%) isolates toLegionella pneumophilaserogroup 3, and 1 isolate each (2.1%) belonged to serogroups 4, 7, and 10. The minimum inhibitory concentration (MICs) of the 46 environmentalL. pneumophilaisolates against the 10 antimicrobials commonly used forLegionellainfection treatments were determined. Rifampicin was found to be the most active againstL. pneumophilaserogroups isolatesin vitro.

Computational framework for evaluating risk trade-offs in costs associated with Legionnaires’ Disease risk, energy, and scalding risk for hospital hot water systems

2021 ◽  
Author(s):  
Ashley Heida ◽  
Alexis Mraz ◽  
Mark Hamilton ◽  
Mark Weir ◽  
Kerry A Hamilton
Keyword(s):  
Legionella Pneumophila ◽  
Disease Risk ◽  
Disease Outbreaks ◽  
Febrile Illness ◽  
Water Systems ◽  
Hot Water ◽  
Computational Framework ◽  
Trade Offs ◽  
Pontiac Fever ◽  
Legionnaires Disease

Legionella pneumophila are bacteria that when inhaled cause Legionnaires’ Disease (LD) and febrile illness Pontiac Fever. As of 2014, LD is the most frequent cause of waterborne disease outbreaks due...

scholarly journals Antimycobacterial potential of the juniper berry essential oil in tap water

2018 ◽  
Vol 69 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Dolores Peruč ◽  
Ivana Gobin ◽  
Maja Abram ◽  
Dalibor Broznić ◽  
Tomislav Svalina ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Mycobacterium Avium ◽  
Morphological Changes ◽  
Tap Water ◽  
Microscopic Analysis ◽  
Water Systems ◽  
Hot Water ◽  
Gas Chromatography Mass Spectrometry ◽  
Mediterranean Plants ◽  
Common Juniper

Abstract Mycobacterium avium complex-related diseases are often associated with poorly maintained hot water systems. This calls for the development of new control strategies. The aim of this study was to investigate the activity of essential oils (EOs) from the Mediterranean plants, common juniper, immortelle, sage, lavandin, laurel, and white cedar against Mycobacterium avium ssp. avium, Mycobacterium intracellulare, and Mycobacterium gordonae in culturing broth and freshwater as their most common habitat. To do that, we developed a new method of water microdilution to determine their minimal effective concentrations (MEC). The most active EO was the one from the common juniper with the MEC of 1.6 mg mL-1. Gas chromatography / mass spectrometry the juniper EO identified monoterpenes (70.54 %) and sesquiterpenes (25.9 %) as dominant component groups. The main monoterpene hydrocarbons were α-pinene, sabinene, and β-pinene. The juniper EO significantly reduced the cell viability of M. intracellulare and M. gordonae at MEC, and of M. avium at 2xMEC. Microscopic analysis confirmed its inhibitory effect by revealing significant morphological changes in the cell membrane and cytoplasm of all three bacteria. The mode of action of the juniper EO on the cell membrane was confirmed by a marked leakage of intracellular material. Juniper EO has a great practical potential as a complementary or alternative water disinfectant in hot water systems such as baths, swimming pools, spa pools, hot tubs, or even foot baths/whirlpools.

Effect of heat flushing on the concentrations of Legionella pneumophila and other heterotrophic microbes in hot water systems of apartment buildings

1996 ◽  
Vol 42 (8) ◽  
pp. 811-818 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Water Temperature ◽  
Legionella Pneumophila ◽  
Heterotrophic Bacteria ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Circulating Water ◽  
Heterotrophic Microbes ◽  
Before And After ◽  
Circulating Water System

The decontamination of Legionella pneumophila and other heterotrophic microbes by heat flushing in four legionellae-positive hot water systems was studied. Before the decontamination procedure, the concentration of legionellae varied from 3.0 × 10−3 to 3.5 × 10−5 cfu/L and the hot water temperature from 43.6 to 51.5 °C. During the contamination the temperature was raised to 60–70 °C. All taps and showers were cleaned from sediments and flushed with hot water twice a day for several minutes. The decontamination lasted for 2–4 weeks. In a few weeks the heat-flushing method reduced the concentration of legionellae below the detection limit (50 cfu/L) in the hot circulating water system just before and after the heat exchanger. The high hot water temperature also decreased the viable counts of heterotrophic bacteria, fungi, and total microbial cells determined by the epifluorescent microscopy. However, the eradication of legionellae failed in a water system where the water temperature remained below 60 °C in some parts of the system. After the decontamination, the temperature of hot water was lowered to 55 °C. Thereafter, all the studied hot water systems were recolonized by legionellae within a few months, showing that the decontamination by heat flushing was temporary. Also, the contamination of other bacteria increased in a few months to the level before decontamination.Key words: legionellae, hot water system, decontamination, water temperature, heterotrophic bacteria.

scholarly journals Is a Proactive Approach to Controlling Legionella in the Environment Justified?

2021 ◽  
Vol 59 (3) ◽  
Author(s):  
Daniela Glažar Ivče ◽  
Dobrica Rončević ◽  
Marina Šantić ◽  
Arijana Cenov ◽  
Dijana Tomić Linšak ◽  
...  
Keyword(s):  
Drinking Water ◽  
Legionella Pneumophila ◽  
Cold Water ◽  
Aged Care ◽  
Water Systems ◽  
Hot Water ◽  
Plate Count ◽  
Surveillance Program ◽  
Adequate Treatment ◽  
Proactive Approach

Research background. Legionella are Gram-negative bacteria that are ubiquitous in the natural environment. Contaminated water in manmade water systems is a potential source of transmission of Legionnaires’ disease (LD). The aim of this study was to explore the prevalence of Legionella pneumophila (L. pneumophila) in the drinking water distribution system (DWDS) of Primorje-Gorski Kotar County (PGK County), Croatia, for the period 2013-2019, coupled with the incidence of LD. A number of L. pneumophila-positive samples (>100 CFU/L), serogroup distribution, and the degree of contamination of specific facilities (health & aged care, tourism, sports) were assessed. Based on the results obtained, the reasoning for the implementation of a mandatory Legionella environmental surveillance program was assessed. Experimental approach. Sample testing for Legionella was carried out according to ISO 1173. A Heterotrophic Plate Count (HPC) and P. aeruginosa were analysed along with the basic physico-chemical indicators of drinking water quality. The research period was divided into two parts, namely, the 2013-2018 period (before implementation of the prevention program, after the outbreak of LD), and year 2019 (proactive approach, no LD cases recorded). Results and conclusion. During the 7-year observation period in PGK County, an increase in the number of samples tested for Legionella was found. An increase in Legionella-positive samples (particularly pronounced during the warmer part of the year) was recorded, along with a growing trend in the number of reported LD cases. In addition to hot water systems, the risk of Legionella colonization also applies to cold water systems. Health & aged care facilities appear to be at highest risk. In addition to the higher proportion of positive samples and a higher degree of microbiological load at these facilities, the highest proportion of L. pneumophila SGs 2-14 was identified. Due to the diagnostic limitations of the applied tests, the number of LD cases is underdiagnosed. Novelty and scientific contribution. The introduction of a mandatory preventive approach to monitoring Legionella in DWDS water samples, along with the definition of national criteria for the interpretation of results, will create the preconditions for diagnosis and adequate treatment of larger numbers of LD cases.

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