Occurrence of heterotrophic bacteria and fungi in cold and hot water distribution systems using water of different quality

1995 ◽  
Vol 41 (12) ◽  
pp. 1088-1094 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Surface Water ◽  
Water Samples ◽  
Distribution Systems ◽  
Heterotrophic Bacteria ◽  
Cold Water ◽  
Hot Water ◽  
Thermophilic Fungi ◽  
Cell Counts ◽  
Bacteria And Fungi ◽  
Water Plants

The microbiological quality of cold and hot water samples of 67 Finnish buildings was studied. Most of the buildings were apartment buildings receiving their cold water from municipal groundwater or surface water plants. Disinfection with chlorine was applied in all the surface water plants and 33% of the groundwater plants. Water samples in buildings were taken from incoming cold water, from the hot water main just before and after the heat exchanger, and from a tap or shower in an apartment. The viable counts of mesophilic bacteria and fungi and total cell counts were higher in cold than in hot water samples. In hot water, the microbial counts were higher in samples from taps and showers than from the mains. In taps and showers, the decrease in hot water temperature probably increased the microbial numbers. Thermophilic bacteria appeared with high numbers in all the hot water samples, but thermophilic fungi were found in only one sample. Bacterial biomass and mean cell volume were greater in processed surface water than in processed groundwater samples. Disinfection with chlorine reduced the viable plate counts, although the chlorine concentration was extremely low in the water samples studied.Key words: heterotrophic bacteria, fungi, distribution system, groundwater, surface water.

Occurrence of legionellae in hot water distribution systems of Finnish apartment buildings

1994 ◽  
Vol 40 (12) ◽  
pp. 993-999 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Surface Water ◽  
Ground Water ◽  
Water Temperature ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Water Systems ◽  
Hot Water ◽  
Apartment Buildings ◽  
Water Plants

The occurrence of legionellae in the hot water distribution systems of 67 buildings located in different parts of Finland was studied. Most of the buildings were apartment buildings. They had different hot water temperatures, and some received their cold potable water from surface water plants and some from ground water plants. Hot water samples were taken from taps, showers, and water mains just before and after the heat exchanger. Legionella pneumophila was isolated from 30% of the distribution systems. In the legionella-positive samples the legionella concentration varied from < 50 to 3.2 × 105 colony-forming units (cfu)/L (mean 2.7 × 103 cfu/L). The highest concentration of legionellae was found in the shower water. Legionellae appeared more often and with higher concentrations in hot water systems using cold water processed in surface water plants than in hot water systems associated with ground water plants. A high organic matter content in surface waters might favor the occurrence of legionellae and also the growth of other heterotrophic microbes. Mean water temperature just after heating was slightly higher in the legionella-negative systems than in the legionella-positive systems (53.5 vs. 51.5 °C).Key words: Legionella, organic carbon, hot water distribution system, water temperature.

Determinants of Legionella pneumophila Contamination of Water Distribution Systems: 15-Hospital Prospective Study

1987 ◽  
Vol 8 (9) ◽  
pp. 357-363 ◽  
Author(s):  
Richard M. Vickers ◽  
Victor L. Yu ◽  
S. Sue Hanna ◽  
Paul Muraca ◽  
Warren Diven ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Cold Water ◽  
Physicochemical Characteristics ◽  
Hot Water ◽  
Environmental Study ◽  
Water Tank ◽  
One Year

AbstractWe conducted a prospective environmental study for Legionella pneumophila in 15 hospitals in Pennsylvania. Hot water tanks, cold water sites, faucets, and show-erheads were surveyed four times over a one-year period. Sixty percent (9/15) of hospitals surveyed were contaminated with L pneumophila. Although contamination could not be linked to a specific municipal water supplier, most of the contaminated supplies came from rivers. Parameters found to be significantly associated with contamination included elevated hot water temperature, vertical configuration of the hot water tank, older tanks, and elevated calcium and magnesium concentrations of the water (P < 0.05). This study suggests that L pneumophila contamination could be predicted based on design of the distribution system, as well as physicochemical characteristics of the water.

Microbial Quality of Drinking Water in Some Finnish Distribution Systems

1993 ◽  
Vol 27 (3-4) ◽  
pp. 151-154 ◽  
Author(s):  
Kirsti Lahti
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Surface Water ◽  
Distribution Systems ◽  
Heterotrophic Bacteria ◽  
Biochemical Tests ◽  
Gram Negative ◽  
Total Coliforms ◽  
Groundwater Supply ◽  
Sampling Points ◽  
Faecal Streptococci

The occurrence of heterotrophic bacteria, Pseudomonas aeruginosa, Aeromonas, total coliforms, faecal streptococci, molds and yeasts in distribution systems of two surface water, two artificial groundwater and two groundwater supplies was examined three times during one year. All water samples studied were free of Pseudomonas aeruginosa and faecal streptococci in 100 ml. Total coliforms were detected in water distributed from one groundwater supply. Aeromonas hydrophila/caviae in the concentration range &lt;1 - 32 cfu/100 ml also occurred in distributed water from the same supply. Molds and yeasts were frequently found in piped water from all watenvorks. The concentration of molds exceeded 100 cfu/100 ml in two sampling points. The differences in heterotrophic plate counts were greater between different sampling points of the same surface water supplies than between waterworks with different raw water origins. Over 80 % of the isolated strains of heterotrophic bacteria from different sampling locations were gram-negative and 57 % were oxidase-negative. The identified gram-negative strains belonged to the genera Pseudomonas, Moraxella, Alcaiigenes and Flavobacterium. The majority of strains (64 %) remained unidentified with the biochemical tests used.

scholarly journals Legionella Colonization of Hotel Water Systems in Touristic Places of Greece: Association with System Characteristics and Physicochemical Parameters

2018 ◽  
Vol 15 (12) ◽  
pp. 2707 ◽  
Author(s):  
Maria A. Kyritsi ◽  
Varvara A. Mouchtouri ◽  
Antonis Katsioulis ◽  
Elina Kostara ◽  
Vasileios Nakoulas ◽  
...  
Keyword(s):  
Water Samples ◽  
Physicochemical Parameters ◽  
Cold Water ◽  
Protective Role ◽  
Water Systems ◽  
Free Chlorine ◽  
Hot Water ◽  
Chlorine Concentration ◽  
P Value ◽  
European Guidelines

This study aimed to assess the colonization of hotel water systems in central Greece and Corfu by Legionella, and to investigate the association between physicochemical parameters and Legionella colonization. Standardized hygiene inspection was conducted in 51 hotels, and 556 water samples were analyzed for Legionella spp. Free chlorine concentration, pH, hardness, conductivity, and trace metals were defined in cold water samples. The results of inspections and chemical analyses were associated with the microbiological results using univariate and logistic regression analysis. According to the score of the checklist used for the inspections, 17.6% of the hotels were classified as satisfactory, 15.7% as adequate, and 66.7% as unsatisfactory. Moreover, 74.5% of the hotels were colonized by Legionella spp. and 31.4% required remedial measures according to the European guidelines. Legionella spp. were isolated in 28% of the samples. Unsatisfactory results of inspections were associated with Legionella presence (relative risk (RR) = 7.67, p-value = 0.043). In hot-water systems, <50 °C temperatures increased the risk of Legionella colonization (RR = 5.36, p-value < 0.001). In cold-water systems, free chlorine concentration <0.375 mg/L (odds ratio (OR) = 9.76, p-value = 0.001), pH ≥ 7.45 (OR = 4.05, p-value = 0.007), and hardness ≥321 mgCaCO3/L (OR = 5.63, p-value = 0.003) increased the risk, whereas copper pipes demonstrated a protective role (OR = 0.29, p-value = 0.0024). The majority of the hotels inspected were colonized with Legionella. Supplementary monitoring of the risk factors that were identified should be considered.

scholarly journals Legionella sp. in water systems in public teaching and education facilities in Małopolskie voivodeship in 2016

2019 ◽  
pp. 227-237
Author(s):  
Jacek Żak ◽  
Karolina Orlińska ◽  
Magdalena Koperny ◽  
Jarosław Foremny ◽  
Katarzyna Bandoła ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Water Samples ◽  
Distribution Systems ◽  
Water Distribution ◽  
Objective Assessment ◽  
Water Systems ◽  
Hot Water ◽  
Water Spray ◽  
Taking Action

INTRODUCTION. Bacteria Legionella sp. found in water distribution systems, especially warm, transferred to water spray devices for aerators and showers in the form of aerosols infected with them become a threat to the human inhaler. OBJECTIVE. Assessment of colonization of the water supply network with Legionella bacteria in teaching and education facilities in Małopolska in 2016 year. MATERIAL AND METHODS. The results of water samples taken from plumbing installations were analyzed in teaching and education facilities by employees of the State Sanitary Inspection of the Lesser Poland Voivodeship. RESULTS. The results of 366 testing hot water samples in 111 teaching and education centers in Małopolska have shown that in 123 testing samples (33,6%) in 48 centers (43,2%) the water sample was colonized with Legionella sp. and the water quality did not meet the requirements of the current ordinance of the Minister of Health. CONCLUSIONS. It is justified to periodically monitor the presence of Legionella sp. in water supply installations in teaching and education centers and taking action to reduce the colonization of these bacteria.

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.

scholarly journals Analysis of physico-chemical and bacteriological quality of drinking water in Mafikeng, South Africa

2015 ◽  
Vol 13 (4) ◽  
pp. 1143-1152 ◽  
Author(s):  
Suma George Mulamattathil ◽  
Carlos Bezuidenhout ◽  
Moses Mbewe
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Distribution Systems ◽  
Heterotrophic Bacteria ◽  
Significant Finding ◽  
Pseudomonas Spp ◽  
Bacteriological Quality ◽  
Physico Chemical

Mafikeng, the capital of the North West Province, receives water from two sources, namely the Molopo eye and the Modimola dam. Once treated, the potable water is mixed and supplied to the city via distribution systems. This study was designed to assess the quality of drinking water in Mafikeng and also to determine whether the water from the two sources has an impact on the mixed water quality. Physico-chemical parameters and bacteriological quality (faecal coliforms (FCs), total coliforms (TCs), heterotrophic bacteria and Peudomonas spp.) was monitored at three drinking water sites weekly for 4 months. The results revealed that the physico-chemical quality of the water was generally acceptable. The pH ranged from 5.7 ± 0.18 to 8.6 ± 0.14, the temperature ranged from 18.3 ± 0.69 to 25.1 ± 0.69 °C and the total dissolved solids (TDS) ranged from 159.9 ± 22.44 to 364.4 ± 12.44 mg/l. These values are within the target water quality range for drinking water as prescribed by WHO, Department of Water Affairs and SANS 241. What is of concern was the microbial quality of the water. FCs, TCs, heterotrophic bacteria and Pseudomonas spp. were present in some of the treated water samples. The most significant finding of this study is that all drinking water samples were positive for Pseudomonas spp. (&gt;100/100 ml).

scholarly journals Co-Occurrence of Free-Living Amoeba and Legionella in Drinking Water Supply Systems

Medicina ◽  
2019 ◽  
Vol 55 (8) ◽  
pp. 492 ◽  
Author(s):  
Valciņa ◽  
Pūle ◽  
Mališevs ◽  
Trofimova ◽  
Makarova ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Samples ◽  
Cold Water ◽  
Hot Water ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Free Living ◽  
Free Living Amoeba ◽  
Supply Systems

Background and Objectives: Legionella is one of the most important water-related pathogens. Inside the water supply systems and the biofilms, Legionella interact with other bacteria and free-living amoeba (FLA). Several amoebas may serve as hosts for bacteria in aquatic systems. This study aimed to investigate the co-occurrence of Legionella spp. and FLA in drinking water supply systems. Materials and Methods: A total of 268 water samples were collected from apartment buildings, hotels, and public buildings. Detection of Legionella spp. was performed in accordance with ISO 11731:2017 standard. Three different polymerase chain reaction (PCR) protocols were used to identify FLA. Results: Occurrence of Legionella varied from an average of 12.5% in cold water samples with the most frequent occurrence observed in hot water, in areas receiving untreated groundwater, where 54.0% of the samples were Legionella positive. The occurrence of FLA was significantly higher. On average, 77.2% of samples contained at least one genus of FLA and, depending on the type of sample, the occurrence of FLA could reach 95%. In the samples collected during the study, Legionella was always isolated along with FLA, no samples containing Legionella in the absence of FLA were observed. Conclusions: The data obtained in our study can help to focus on the extensive distribution, close interaction, and long-term persistence of Legionella and FLA. Lack of Legionella risk management plans and control procedures may promote further spread of Legionella in water supply systems. In addition, the high incidence of Legionella-related FLA suggests that traditional monitoring methods may not be sufficient for Legionella control.

scholarly journals Legionella spp. in Polish hospitals in 2009–2013 and 2014–2016: An epidemiological analysis

2021 ◽  
Vol 75 ◽  
pp. 85-90
Author(s):  
Iwona Gładysz ◽  
Agnieszka Sikora ◽  
Małgorzata Wójtowicz-Bobin ◽  
Jan Karczewski
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Distribution Systems ◽  
Water Distribution ◽  
Hot Water ◽  
Water Supply Systems ◽  
Atypical Pneumonia ◽  
Epidemiological Analysis ◽  
Pontiac Fever ◽  
Supply Systems

Introduction: Bacteria of the genus Legionella cause Legionnaires’ disease (atypical pneumonia, often with a severe clinical course) and Pontiac fever (self-limiting infection with flu-like symptoms). Legionella spp. are commonly found in natural aquatic environments and artificial water distribution systems. Material&Methods: An epidemiological analysis of Legionella spp. in hospital water supply systems was based on the results obtained from Sanitary-Epidemiological Stations of Poland. The materials for this study were hot water samples collected from 346 hospitals in 2009–2013 and from 221 hospitals in 2014–2016. Results: Between 2014 and 2016, there was a decrease in the percentage of the number of water samples in Group A (<100 CFU/100 ml). In other groups: B (>100 CFU/100 ml), C (>1000 CFU/100 ml), D (>10 000 CFU/100 ml) was observed an increase in the percentage of the number of water samples, which was a negative phenomenon. The mean number of L. pneumophila colonies in analyzed periods 2009–2013 and 2014–2016 were different. In 2009–2013, the most virulent L. pneumophila serogroup 1 (SG 1) was detected in 3 hospitals (0.9%), and L. pneumophila SG 2-14 were isolated in 20 (5.5%). Between 2014 and 2016, L. pneumophila SG 1 and L. pneumophila SG 2-14 were found in 5 hospitals (2.2%) and 18 hospitals (8.1%), respectively. Disscusion: In this study a comparative epidemiological analysis was performed on the prevalence of L. pneumophila in hospital water supply systems in Poland in the following two periods: 2009 –2013 and 2014–2016. The study demonstrated that the water supply systems of Polish hospitals were colonized by L. pneumophila at different levels. However, between 2014 and 2016 an upward trend was observed in comparison with 2009–2013.

Sign in / Sign up

Export Citation Format

Share Document