scholarly journals Legionellaceae in the potable water of Nova Scotia hospitals and Halifax residences

1994 ◽  
Vol 112 (1) ◽  
pp. 143-150 ◽  
Author(s):  
T. Marrie ◽  
P. Green ◽  
S. Burbridge ◽  
G. Bezanson ◽  
S. Neale ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Potable Water ◽  
Calcium Content ◽  
Potassium Nitrate ◽  
Hot Water ◽  
Total System ◽  
Single Family ◽  
Water Heaters

SummaryWater was cultured from 39 of 48 hospitals (7 Halifax hospitals and 32 non-Halifax hospitals) in the province of Nova Scotia and from 90 residences (74 private dwellings, 16 apartments) in Halifax to determine the frequency of legionella contamination. Six of seven Halifax hospitals had Legionellaceae isolated from their potable water compared with 3 of 32 non-Halifax hospitals (P < 0.0001). Overall. 19 of 59 (32%) of the water samples from Halifax hospitals were positive for legionellae compared with 5 of 480 (1%) samples from non-Halifax hospitals (P < 0.0000). Five of the six positive Halifax hospitals hadLegionella pneumophilaserogroup 1 and 1 hadL. longbeachaeserogroup 2 recovered from their potable water. Legionella contamination was associated with older, larger (> 50 beds) hospitals with total system recirculation. These hospitals also had water with a higher pH and calcium content but lower sodium, potassium, nitrate, iron and copper content.Fourteen of the 225 (6.2%) water samples from Halifax residences were positive for legionellae – 8% (6/74) of the single family dwellings were positive, compared with 25% (4/16) apartments. The positivity rate of 15.7% for the 19 electric hot-water heaters in Halifax homes was not significantly different from the 32% positivity for Halifax hospitals.L. longbeachaeaccounted for 2 of the 14 isolates of legionellae from Halifax homes.

scholarly journals Performance of Legiolert Test vs. ISO 11731 to Confirm Legionella pneumophila Contamination in Potable Water Samples

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 690 ◽  
Author(s):  
Maria Scaturro ◽  
Matteo Buffoni ◽  
Antonietta Girolamo ◽  
Sandra Cristino ◽  
Luna Girolamini ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Gold Standard ◽  
Liquid Culture ◽  
Potable Water ◽  
Culture Method ◽  
Alternative Methods ◽  
Significant Difference

Detection and enumeration of Legionella in water samples is of great importance for risk assessment analysis. The plate culture method is the gold standard, but has received several well-known criticisms, which have induced researchers to develop alternative methods. The purpose of this study was to compare Legionella counts obtained by the analysis of potable water samples through the plate culture method and through the IDEXX liquid culture Legiolert method. Legionella plate culture, according to ISO 11731:1998, was performed using 1 L of water. Legiolert was performed using both the 10 mL and 100 mL Legiolert protocols. Overall, 123 potable water samples were analyzed. Thirty-seven (30%) of them, positive for L. pneumophila, serogroups 1 or 2–14 by plate culture, were used for comparison with the Legiolert results. The Legiolert 10 mL test detected 34 positive samples (27.6%) and the Legiolert 100 mL test detected 37 positive samples, 27.6% and 30% respectively, out of the total samples analyzed. No significant difference was found between either the Legiolert 10 mL and Legiolert 100 mL vs. the plate culture (p = 0.9 and p = 0.3, respectively) or between the Legiolert 10 mL and Legiolert 100 mL tests (p = 0.83). This study confirms the reliability of the IDEXX Legiolert test for Legionella pneumophila detection and enumeration, as already shown in similar studies. Like the plate culture method, the Legiolert assay is also suitable for obtaining isolates for typing purposes, relevant for epidemiological investigations.

scholarly journals Introduction of Monochloramine into a Municipal Water System: Impact on Colonization of Buildings by Legionella spp

2006 ◽  
Vol 72 (1) ◽  
pp. 378-383 ◽  
Author(s):  
Matthew R. Moore ◽  
Marsha Pryor ◽  
Barry Fields ◽  
Claressa Lucas ◽  
Maureen Phelan ◽  
...  
Keyword(s):  
Potable Water ◽  
Sampling Site ◽  
Water System ◽  
Water Source ◽  
Water Systems ◽  
Hot Water ◽  
County Government ◽  
Single Family ◽  
Pinellas County ◽  
Municipal Water

ABSTRACT Legionnaires' disease (LD) outbreaks are often traced to colonized potable water systems. We collected water samples from potable water systems of 96 buildings in Pinellas County, Florida, between January and April 2002, during a time when chlorine was the primary residual disinfectant, and from the same buildings between June and September 2002, immediately after monochloramine was introduced into the municipal water system. Samples were cultured for legionellae and amoebae using standard methods. We determined predictors of Legionella colonization of individual buildings and of individual sampling sites. During the chlorine phase, 19 (19.8%) buildings were colonized with legionellae in at least one sampling site. During the monochloramine phase, six (6.2%) buildings were colonized. In the chlorine phase, predictors of Legionella colonization included water source (source B compared to all others, adjusted odds ratio [aOR], 6.7; 95% confidence interval [CI], 2.0 to 23) and the presence of a system with continuously circulating hot water (aOR, 9.8; 95% CI, 1.9 to 51). In the monochloramine phase, there were no predictors of individual building colonization, although we observed a trend toward greater effectiveness of monochloramine in hotels and single-family homes than in county government buildings. The presence of amoebae predicted Legionella colonization at individual sampling sites in both phases (OR ranged from 15 to 46, depending on the phase and sampling site). The routine introduction of monochloramine into a municipal drinking water system appears to have reduced colonization by Legionella spp. in buildings served by the system. Monochloramine may hold promise as community-wide intervention for the prevention of LD.

scholarly journals Nosocomial legionella pneumonia: demonstration of potable water as the source of infection

1988 ◽  
Vol 101 (3) ◽  
pp. 647-654 ◽  
Author(s):  
B. Ruf ◽  
D. Schürmann ◽  
I. Horbrach ◽  
K. Seodel ◽  
H. D. Pohle
Keyword(s):  
Monoclonal Antibodies ◽  
Water Supply ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Potable Water ◽  
Supply System ◽  
University Hospital ◽  
Environmental Isolates ◽  
Legionella Pneumonia ◽  
Source Of Infection

SUMMARYFrom January 1983 until December 1985, 35 cases of sporadic nosocomial legionella pneumonia, all caused byLegionella pneumophila, were diagnosed in a university hospital.L. pneumophilaserogroup (SG) 1 was cultured from 12 of the 35 cases and compared to correspondingL. pneumophilaSG 1 isolates from water outlets in the patients' immediate environment by subtyping with monoclonal antibodies. The corresponding environmental isolates were identical to 9 out of 12 (75%) of those from the cases. However, even in the remaining three cases identical subtypes were found distributed throughout the hospital water supply. From the hospital water supply four different subtypes ofL. pneumophilaSG 1 were isolated, three of which were implicated in legionella pneumonia. Of 453 water samples taken during the study 298 (65.8%) were positive for legionellae. Species ofLegionellaother thanL. pneumophilahave not been isolated. This may explain the exclusiveness ofL.pneumophilaas the legionella pneumonia-causing agent. Our results suggest that the water supply system was the source of infection.

scholarly journals Multiple Types of Legionella pneumophilaSerogroup 6 in a Hospital Heated-Water System Associated with Sporadic Infections

1999 ◽  
Vol 37 (7) ◽  
pp. 2189-2196 ◽  
Author(s):  
Paolo Visca ◽  
Paola Goldoni ◽  
P. Christian Lück ◽  
Jürgen H. Helbig ◽  
Lorena Cattani ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Water Samples ◽  
Water System ◽  
Hot Water ◽  
Control Measures ◽  
Hospital Environment ◽  
Modes Of Transmission ◽  
Sequence Of Events ◽  
Single Clone ◽  
Arbitrarily Primed Pcr

Five sporadic cases of nosocomial Legionnaires’ disease were documented from 1989 to 1997 in a hospital in northern Italy. Two of them, which occurred in a 75-year-old man suffering from ischemic cardiopathy and in an 8-year-old girl suffering from acute leukemia, had fatal outcomes. Legionella pneumophila serogroup 6 was isolated from both patients and from hot-water samples taken at different sites in the hospital. These facts led us to consider the possibility that a single clone of L. pneumophila serogroup 6 had persisted in the hospital environment for 8 years and had caused sporadic infections. Comparison of clinical and environmental strains by monoclonal subtyping, macrorestriction analysis (MRA), and arbitrarily primed PCR (AP-PCR) showed that the strains were clustered into three different epidemiological types, of which only two types caused infection. An excellent correspondence between the MRA and AP-PCR results was observed, with both techniques having high discriminatory powers. However, it was not possible to differentiate the isolates by means of ribotyping and analysis of rrnoperon polymorphism. Environmental strains that antigenically and chromosomally matched the infecting organism were present at the time of infection in hot-water samples taken from the ward where the patients had stayed. Interpretation of the temporal sequence of events on the basis of the typing results for clinical and environmental isolates enabled the identification of the ward where the patients became infected and the modes of transmission of Legionellainfection. The long-term persistence in the hot-water system of different clones of L. pneumophila serogroup 6 indicates that repeated heat-based control measures were ineffective in eradicating the organism.

scholarly journals Environmental Surveillance of Legionellosis within an Italian University Hospital—Results of 15 Years of Analysis

2019 ◽  
Vol 16 (7) ◽  
pp. 1103 ◽  
Author(s):  
Pasqualina Laganà ◽  
Alessio Facciolà ◽  
Roberta Palermo ◽  
Santi Delia
Keyword(s):  
Potential Risk ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Continuous Monitoring ◽  
Water System ◽  
Hot Water ◽  
University Hospital ◽  
Environmental Surveillance ◽  
Standard Procedures ◽  
Legionnaires Disease

Legionnaires’ disease is normally acquired by inhalation of legionellae from a contaminated environmental source. Water systems of large and old buildings, such as hospitals, can be contaminated with legionellae and therefore represent a potential risk for the hospital population. In this study, we demonstrated the constant presence of Legionella in water samples from the water system of a large university hospital in Messina (Sicily, Italy) consisting of 11 separate pavilions during a period of 15 years (2004–2018). In total, 1346 hot water samples were collected between January 2004 and December 2018. During this period, to recover Legionella spp. from water samples, the standard procedures reported by the 2000 Italian Guidelines were adopted; from May 2015 to 2018 Italian Guidelines revised in 2015 (ISS, 2015) were used. Most water samples (72%) were positive to L. pneumophila serogroups 2–14, whereas L. pneumophila serogroup 1 accounted for 18% and non-Legionella pneumophila spp. Accounted for 15%. Most of the positive samples were found in the buildings where the following critical wards are situated: (Intensive Care Unit) ICU, Neurosurgery, Surgeries, Pneumology, and Neonatal Intensive Unit Care. This study highlights the importance of the continuous monitoring of hospital water samples to prevent the potential risk of nosocomial legionellosis.

scholarly journals Evaluation of a most probable number method for the enumeration of Legionella pneumophila from North American potable and nonpotable water samples

2017 ◽  
Vol 16 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Ray Petrisek ◽  
Jonathon Hall
Keyword(s):  
Legionella Pneumophila ◽  
Water Samples ◽  
Potable Water ◽  
High Specificity ◽  
Most Probable Number ◽  
Water Type ◽  
Probable Number ◽  
Standard Methods ◽  
Water And Wastewater ◽  
Higher Sensitivity

Abstract This study compares the performance of a novel most probable number (MPN) method (Legiolert™/Quanti-Tray®) with Standard Methods for the Examination of Water and Wastewater 9260 J for the enumeration of Legionella pneumophila from potable and nonpotable waters. Data from the study showed that Legiolert exhibited higher sensitivity for the detection of L. pneumophila for potable water and equivalent sensitivity for nonpotable water. The Legiolert medium had a high specificity with no false positive signals reported for either water type. The new method represents a significant improvement in usability and accuracy in the enumeration of L. pneumophila.

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.

scholarly journals Contamination of Water Sources of Karaj Hospitals with Legionella pneumophila and Campylobacter jejuni

2020 ◽  
Vol 8 (4) ◽  
pp. 142-146
Author(s):  
Niloofar Ghomimaghsad ◽  
Somayeh Yaslianifard ◽  
Mohammad Mohammadzadeh ◽  
Masoud Dadashi ◽  
Mohammad Noorisepehr
Keyword(s):  
Campylobacter Jejuni ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
High Efficiency ◽  
Cold Water ◽  
Bacterial Species ◽  
Water Sources ◽  
Hot Water ◽  
Water Supply Systems ◽  
Contaminated Water

Background: One of the most common routes of infection development in humans is contaminated water. Legionella pneumophila and Campylobacter jejuni are the important causes of community- and hospital-acquired pneumonia and gastroenteritis that are transmitted to humans via the inhalation of contaminated water droplets and consumption of contaminated water, respectively. Thus, continuous monitoring of the water supply systems for these pathogens has great importance in public health. Objective: This study aimed to evaluate the water contamination of Karaj hospitals with these two bacterial species. Materials and Methods: In this study, 62 water samples were obtained from different parts of the hospitals of Karaj from April to September 2019, including air conditioning systems, dialysis equipment, ventilation tanks, and different wards of a hospital such as infectious diseases, pediatrics, gastroenterology, dialysis, and intensive and neonatal intensive care units. The samples were collected in sterile containers and immediately transferred to the laboratory for further analysis. The culture on specific media, staining, and biochemical tests were performed to identify the L. pneumophila and C. jejuni. Results: Out of 62 water samples, 25.8% (16 samples) were positive for L. pneumophila; 68.75% were observed in hot water samples, and 31.25% were attributed to cold water samples. Among 62 samples, 4.84% (3 samples) were positive for C. jejuni, which were all detected in hot water samples. Conclusion: Considering that the methods of water refinery of municipal water have no high efficiency, the quality improvement of the water sources of hospitals seems to be necessary.

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