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Kostic A, Cukovic K, Stankovic L, Raskovic Z, Nestorovic J, Savic D, Simovic A, Prodanovic T, Zivojinovic S, Andrejevic S, Erovic I, Djordjevic Z, Rsovac S, Sazdanovic P, Stojkovic A. The Different Clinical Courses of Legionnaires’ Disease in Newborns from the Same Maternity Hospital. Medicina (B Aires) 2022; 58:medicina58091150. [PMID: 36143827 PMCID: PMC9502702 DOI: 10.3390/medicina58091150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/01/2022] [Accepted: 08/09/2022] [Indexed: 11/27/2022] Open
Abstract
In children, the incidence of Legionnaires’ disease (LD) is unknown, hospital-acquired LD is associated with clinical risk factors and environmental risk, and children with cell-mediated immune deficiency are at high risk of infection. Both newborns were born in the same delivery room; stayed in the same hospital room where they were cared for, bathed, and breastfed; were male; were born on time, with normal birth weight, and with high Apgar score at birth; and survived this severe infection (L. pneumophila, serogroup 2-15) but with different clinical courses. In neonate 1, bleeding in the brain, thrombosis of deep pelvic veins, and necrosis of the lungs, which left behind cystic and cavernous changes in the lungs, were found, while neonate 2 suffered from pneumonia alone. The only difference in risk factors for LD between these two newborns is the number of days of illness until the start of azithromycin treatment (sixth versus the third day of illness). We suggest that a change in the guidelines for diagnosing and treating community-acquired pneumonia and hospital-acquired pneumonia in newborns is needed in terms of mandatory routine testing for Legionella pneumophila. Early initiation of macrolide therapy is crucial for the outcome of LD in the newborn.
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Affiliation(s)
- Andrijana Kostic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Katarina Cukovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Lidija Stankovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Zorica Raskovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Jelena Nestorovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Dragana Savic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Aleksandra Simovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Tijana Prodanovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Suzana Zivojinovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | - Sladjana Andrejevic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
| | | | - Zorana Djordjevic
- Department of Epidemiology, University Clinical Center, 34000 Kragujevac, Serbia
| | - Snezana Rsovac
- University Children’s Clinic Tirsova, Pediatric and Neonatal Intensive Care, 11000 Belgrade, Serbia
- Department of Pediatrics, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Predrag Sazdanovic
- University Clinical Center, Clinic of Gynecology and Obstetrics, 34000 Kragujevac, Serbia
- Department of Anatomy, Faculty of Medical Sciences, University of Kragujevac, 11000 Belgrade, Serbia
| | - Andjelka Stojkovic
- University Clinical Center, Clinic of Pediatrics, 34000 Kragujevac, Serbia
- Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia
- Correspondence: ; Tel.: +381-63-615434
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Djordjevic Z, Folic M, Petrovic I, Zornic S, Stojkovic A, Miljanovic A, Randjelovic S, Jovanovic S, Jovanovic M, Jankovic S. An outbreak of Legionnaires' disease in newborns in Serbia. Paediatr Int Child Health 2022; 42:59-66. [PMID: 35944175 DOI: 10.1080/20469047.2022.2108672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Legionnaires' disease is an atypical pneumonia caused by inhaling small droplets of water containing the bacterium Legionella spp. In newborns, it is a rare event, usually associated with water births and the use of air conditioning systems or air humidifiers. A nosocomial outbreak of Legionnaires' disease in the maternity ward of a secondary-care hospital in Arandjelovac, Serbia is described.Two male newborns were found to be infected with Legionnella pneumophila. On Days 7 and 6 of life, respectively, they were transferred to a tertiary-care hospital with signs of severe pneumonia which was radiologically confirmed. L. pneumophila was detected in tracheal secretions from both infants by RT-PCR, and its antigens were also positive in urine samples. The source of infection in the secondary-care hospital was the internal hot water heating system, and the main contributory factor to the emergence of the infection was the low temperature of the hot water which did not kill the bacteria during the available exposure time.These two cases highlight the importance of being cautious about possible Legionnaires' disease in maternity wards with outdated or irregularly maintained internal water supply systems. The adoption of official guidelines for the control and regular maintenance of water supply systems, including the multidisciplinary cooperation of all relevant parties, forms the basis for direct monitoring for Legionella and the prevention of new outbreaks.Abbreviations: BCYE: buffered charcoal yeast extract agar; GVPC: glycine vancomycin polymyxin cycloheximide agar; LD - Legionnaires' disease; TR-PCR: Reverse transcription polymerase chain reaction.
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Affiliation(s)
- Zorana Djordjevic
- Department of Hospital Infection Control, University Clinical Centre Kragujevac, Kragujevac, Serbia
| | - Marko Folic
- Department of Clinical Pharmacology, University Clinical Centre of Kragujevac and Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Ivana Petrovic
- Department of Clinical Microbiology, University of Kragujevac Clinical Centre, Kragujevac, Serbia
| | - Sanja Zornic
- Department of Clinical Microbiology, University of Kragujevac Clinical Centre, Kragujevac, Serbia
| | - Andjelka Stojkovic
- Institute of Public Health Kragujevac, Centre for Disease Control and Prevention, Kragujevac, Serbia
| | - Ana Miljanovic
- Paediatric Clinic, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Sladjana Randjelovic
- Human Ecology and Ecotoxicology Laboratory, City Institute for Public Health Belgrade, Belgrade, Serbia
| | - Snezana Jovanovic
- Department of Medical Microbiology, University Clinical Centre of Serbia, Belgrade, Serbia
| | - Milica Jovanovic
- Department of Medical Microbiology, University Clinical Centre of Serbia, Belgrade, Serbia
| | - Slobodan Jankovic
- Department of Clinical Pharmacology, University Clinical Centre of Kragujevac and Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
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Cazals M, Bédard E, Doberva M, Faucher S, Prévost M. Compromised Effectiveness of Thermal Inactivation of Legionella pneumophila in Water Heater Sediments and Water, and Influence of the Presence of Vermamoeba vermiformis. Microorganisms 2022; 10:microorganisms10020443. [PMID: 35208896 PMCID: PMC8874534 DOI: 10.3390/microorganisms10020443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 11/21/2022] Open
Abstract
Intermittent reduction of temperature set-points and periodic shutdowns of water heaters have been proposed to reduce energy consumption in buildings. However, the consequences of such measures on the occurrence and proliferation of Legionella pneumophila (Lp) in hot water systems have not been documented. The impact of single and repeated heat shocks was investigated using an environmental strain of L. pneumophila and a reference strain of V. vermiformis. Heat shocks at temperatures ranging from 50 °C to 70 °C were applied for 1 h and 4 h in water and water heaters loose deposits (sludge). The regrowth potential of heat-treated culturable L. pneumophila in presence of V. vermiformis in water heaters sludges was evaluated. A 2.5-log loss of culturability of L. pneumophila was observed in simulated drinking water at 60 °C while a 4-log reduction was reached in water heaters loose deposits. Persistence of Lp after 4 h at 55 °C was shown and the presence of V. vermiformis in water heater’s loose deposits resulted in a drastic amplification (5-log). Results show that thermal inactivation by heat shock is only efficient at elevated temperatures (50 °C) in both water and loose deposits. The few remaining organisms can rapidly proliferate during storage at lower temperature in the presence of hosts.
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Affiliation(s)
- Margot Cazals
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
- Correspondence:
| | - Emilie Bédard
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
| | - Margot Doberva
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
| | - Sébastien Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada;
| | - Michèle Prévost
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
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Genetic Diversity of the Legionella pneumophila dotA Gene Detected on Surfaces of Respiratory Therapy Equipment. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2021. [DOI: 10.22207/jpam.15.2.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Legionellosis is a neglected disease due to the absence of well-defined clinical symptoms and difficulties in isolating the causal organism. Legionella spp. is known to colonize the lumen of respiratory therapy equipment(RTE) and evade conventional detection by entering the viable but non-culturable state. Monitoring these surfaces for Legionella pneumophila in addition to routine monitoring of water could aid in decreasing incidences of hospital-acquired infections by this pathogen. In this study swabs of different respiratory therapy equipment were tested for the presence of Legionella by conventional culture-based methods versus molecular detection of culture-independent template by polymerase chain reaction (PCR). Genetic diversity of the genes amplified were studied using bioinformatic tools. The dotA genes were genetically diverse indicating no clonality. This communication highlights that the persistence of virulence genes like dotA on abiotic surfaces can result in the mobilization of these genes to other species and give rise to virulent forms especially in a healthcare setting.
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Papagianeli SD, Aspridou Z, Didos S, Chochlakis D, Psaroulaki A, Koutsoumanis K. Dynamic modelling of Legionella pneumophila thermal inactivation in water. WATER RESEARCH 2021; 190:116743. [PMID: 33352528 DOI: 10.1016/j.watres.2020.116743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
A predictive mathematical model describing the effect of temperature on the inactivation of Legionella pneumophila in water was developed. Thermal inactivation of L. pneumophila was monitored under isothermal conditions (51 - 61°C). A primary log-linear model was fitted to the inactivation data and the estimated D values ranged from 0.23 to 25.31 min for water temperatures from 61 to 51°C, respectively. The effect of temperature on L. pneumophila inactivation was described using a secondary model, and the model parameters z value and Dref (D-value at 55°C) were estimated at 5.54°C and 3.47 min, respectively. The developed model was further validated under dynamic temperature conditions mimicking various conditions of water thermal disinfection in plumbing systems. The results indicated that the model can satisfactorily predict thermal inactivation of the pathogen at dynamic temperature environments and effectively translate water temperature profiles to cell number reduction. The application of the model in combination with effective temperature monitoring could provide the basis of an integrated preventive approach for the effective control of L. pneumophila in plumbing systems.
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Affiliation(s)
- Styliani Dimitra Papagianeli
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Zafeiro Aspridou
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Spyros Didos
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Dimosthenis Chochlakis
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, Unit of Water, Food and Environmental Microbiology, School of Medicine, University of Crete, Heraklion, 71110, Greece
| | - Anna Psaroulaki
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, Unit of Water, Food and Environmental Microbiology, School of Medicine, University of Crete, Heraklion, 71110, Greece
| | - Konstantinos Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
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6
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Abstract
Energy usage in buildings is coming increasingly under the spotlight as carbon policy focus shifts towards the utilization of thermal energy. In the UK, heating and hot water accounts for around 40% of energy consumption and 20% of greenhouse gas emissions. Heating is typically produced onsite, making widescale carbon or energetic improvements challenging. District heating networks (DHNs) can offer significant carbon reduction for many users but can only be implemented if the end user buildings have good thermal energy efficiency. This greatly limits the ability to implement advancing 4th and 5th generation DHNs, which are the most advanced systems available. We elucidate the current state of thermal efficiency in buildings in the UK and provide recommendations for necessary building requirements and modifications in order to accommodate 4th and 5th generation district heating. We conclude that key sectors must be addressed including creating a skilled workforce, producing relevant metrics and benchmarks, and providing financial support for early stage design exploration.
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8
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Kao PM, Tung MC, Hsu BM, Chiu YC, She CY, Shen SM, Huang YL, Huang WC. Identification and quantitative detection of Legionella spp. in various aquatic environments by real-time PCR assay. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:6128-6137. [PMID: 23536272 DOI: 10.1007/s11356-013-1534-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/29/2013] [Indexed: 06/02/2023]
Abstract
In this study, a SYBR green quantitative real-time PCR was developed to quantify and detect the Legionella spp. in various environmental water samples. The water samples were taken from watershed, water treatment plant, and thermal spring area in Taiwan. Legionella was detected in 13.6 % (24/176), and the detection rate for river water, raw drinking water, and thermal spring water was 10, 21.4, and 16.6 %, respectively. Using real-time PCR, concentration of Legionella spp. in detected samples ranged between 9.75 × 10(4) and 3.47 × 10(5) cells/L in river water, 6.92 × 10(4) and 4.29 × 10(5) cells/L in raw drinking water, and 5.71 × 10(4) and 2.12 × 10(6) cells/L for thermal spring water samples. The identified species included Legionella pneumophila (20.8 %), Legionella jordanis (4.2 %), Legionella nautarum (4.2 %), Legionella sp. (4.2 %), and uncultured Legionella sp. (66.6 %). The presence of L. pneumophila in aquatic environments suggested a potential public health threat that must be further examined.
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Affiliation(s)
- Po-Min Kao
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, Republic of China
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Kao PM, Tung MC, Hsu BM, Hsu SY, Huang JT, Liu JH, Huang YL. Differential Legionella spp. survival between intracellular and extracellular forms in thermal spring environments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:3098-3106. [PMID: 23054762 DOI: 10.1007/s11356-012-1159-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
Legionella are commonly found in natural and man-made aquatic environments and are able to inhabit various species of protozoa. The relationship between the occurrence of Legionella spp. within protozoa and human legionellosis has been demonstrated; however, the proportions of intracellular and extracellular Legionella spp. in the aquatic environment were rarely reported. In this study, we developed a new method to differentiate intracellular and extracellular Legionella spp. in the aquatic environment. Water samples from three thermal spring recreational areas in southeastern Taiwan were collected and analyzed. For each water sample, concurrent measurements were performed for Legionella spp. and their free-living amoebae hosts. The overall detection rate was 32 % (16/50) for intracellular Legionella spp. and 12 % (6/50) for extracellular Legionella spp. The most prevalent host of Legionella spp. was Hartmannella vermiformis. The identified Legionella spp. differed substantially between intracellular and extracellular forms. The results showed that it may be necessary to differentiate intracellular and extracellular forms of Legionella spp.
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Affiliation(s)
- Po-Min Kao
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, Republic of China
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Hsu BM, Huang CC, Chen JS, Chen NH, Huang JT. Comparison of potentially pathogenic free-living amoeba hosts by Legionella spp. in substrate-associated biofilms and floating biofilms from spring environments. WATER RESEARCH 2011; 45:5171-5183. [PMID: 21831404 DOI: 10.1016/j.watres.2011.07.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/24/2011] [Accepted: 07/15/2011] [Indexed: 05/31/2023]
Abstract
This study compares five genera of free-living amoebae (FLA) hosts by Legionella spp. in the fixed and floating biofilm samples from spring environments. Detection rate of Legionella spp. was 26.9% for the floating biofilms and 3.1% for the fixed biofilms. Acanthamoeba spp., Hartmanella vermiformis, and Naegleria spp. were more frequently detected in floating biofilm than in fixed biofilm samples. The percentage of pathogenic Acanthamoeba spp. among all the genus Acanthamoeba detected positive samples was 19.6%. The potential pathogenic Naegleria spp. (for example, Naegleria australiensis, Naegleria philippinensis, and Naegleria italica) was 54.2% to all the Naegleria detected positive samples. In the study, 12 serotypes of possible pneumonia causing Legionella spp. were detected, and their percentage in all the Legionella containing samples was 42.4%. The FLA parasitized by Legionella included unnamed Acanthamoeba genotype, Acanthamoeba griffini, Acanthamoeba jacobsi, H. vermiformis, and N. australiensis. Significant differences were also observed between the presence/absence of H. vermiformis and Legionella parasitism in FLA. Comparisons between the culture-confirmed method and the PCR-based detection method for detecting FLA and Legionella in biofilms showed great variation. Therefore, using these analysis methods together to detect FLA and Legionella is recommended.
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Affiliation(s)
- Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Minhsiung Township, Chiayi County 62102, Taiwan, ROC.
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NICOLELLA CRISTIANO, CASINI BEATRICE, ROSSI FRANCESCO, CHERICONI ALESSIO, PARDINI GIANLUCA. THERMAL SANITIZING IN A COMMERCIAL DISHWASHING MACHINE. J Food Saf 2010. [DOI: 10.1111/j.1745-4565.2010.00270.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Gerba CP. Disinfection. Environ Microbiol 2009. [DOI: 10.1016/b978-0-12-370519-8.00026-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Delaedt Y, Daneels A, Declerck P, Behets J, Ryckeboer J, Peters E, Ollevier F. The impact of electrochemical disinfection on Escherichia coli and Legionella pneumophila in tap water. Microbiol Res 2008; 163:192-9. [PMID: 16793247 DOI: 10.1016/j.micres.2006.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 04/13/2006] [Accepted: 05/02/2006] [Indexed: 10/24/2022]
Abstract
In order to reduce the risks of Legionnaires' disease, caused by the bacterium Legionella pneumophila, disinfection of tap water systems contaminated with this bacterium is a necessity. This study investigates if electrochemical disinfection is able to eliminate such contamination. Hereto, water spiked with bacteria (10(4)CFU Escherichia coli or L. pneumophila/ml) was passed through an electrolysis cell (direct effect) or bacteria were added to tap water after passage through such disinfection unit (residual effect). The spiked tap water was completely disinfected, during passage through the electrolysis cell, even when only a residual free oxidant concentration of 0.07 mg/l is left (L. pneumophila). The residual effect leads to a complete eradication of cultivable E. coli, if after reaction time at least a free oxidant concentration of 0.08 mg/l is still present. Similar conditions reduce substantially L. pneumophila, but a complete killing is not realised.
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Affiliation(s)
- Yasmine Delaedt
- Laboratory of Aquatic Ecology, Katholieke Universiteit Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium.
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15
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Spinks AT, Dunstan RH, Harrison T, Coombes P, Kuczera G. Thermal inactivation of water-borne pathogenic and indicator bacteria at sub-boiling temperatures. WATER RESEARCH 2006; 40:1326-32. [PMID: 16524613 DOI: 10.1016/j.watres.2006.01.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/22/2006] [Accepted: 01/23/2006] [Indexed: 05/07/2023]
Abstract
The use of harvested rainwater in domestic hot water systems can result in optimised environmental and economic benefits to urban water cycle management, however, the water quality and health risks of such a scenario have not been adequately investigated. Thermal inactivation analyses were carried out on eight species of non-spore-forming bacteria in a water medium at temperatures relevant to domestic hot water systems (55-65 degrees C), and susceptibilities to heat stress were compared using D-values. The D-value was defined as the time required to reduce a bacterial population by 90% or 1 log reduction. The results found that both tested strains of Enterococcus faecalis were the most heat resistant of the bacteria studied, followed by the pathogens Shigella sonnei biotype A and Escherichia coli O157:H7, and the non-pathogenic E. coli O3:H6. Pseudomonas aeruginosa was found to be less resistant to heat, while Salmonella typhimurium, Serratia marcescens, Klebsiella pneumoniae and Aeromonas hydrophila displayed minimal heat resistance capacities. At 65 degrees C, little thermal resistance was demonstrated by any species, with log reductions in concentration occurring within seconds. The results of this study suggested that the temperature range from 55 to 65 degrees C was critical for effective elimination of enteric/pathogenic bacterial components and supported the thesis that hot water systems should operate at a minimum of 60 degrees C.
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Affiliation(s)
- Anthony T Spinks
- School of Environmental & Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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Kusnetsov J, Torvinen E, Perola O, Nousiainen T, Katila ML. Colonization of hospital water systems by legionellae, mycobacteria and other heterotrophic bacteria potentially hazardous to risk group patients. APMIS 2003; 111:546-56. [PMID: 12887506 DOI: 10.1034/j.1600-0463.2003.1110503.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Occurrences of legionellae and nontuberculous mycobacteria were followed in water systems of a tertiary care hospital where nosocomial infections due to the two genera had been verified. The aim was to examine whether their occurrence in the circulating hot water can be controlled by addition of a heat-shock unit in the circulation system, and by intensified cleaning of the tap and shower heads. One hot water system examined had an inbuilt heat-shock system causing a temporary increase of temperature to 80 degrees C, the other was an ordinary system (60 degrees C). The heat-shock unit decreased legionella colony counts in the circulating hot water (mean 35 cfu/l) compared to the ordinary system (mean 3.6 x 10(3) cfu/l). Mycobacteria constantly present in the incoming cold water (mean 260 cfu/l) were never isolated from the circulating hot water. Water sampled at peripheral sites such as taps and showers contained higher concentrations of legionellae, mycobacteria, and mesophilic and Gram-negative heterotrophs than the circulating waters. The shower water samples contained the highest bacterial loads. The results indicate the need to develop more efficient prevention methods than the ones presently used. Prevention of mycobacteria should also be extended to incoming cold water.
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Affiliation(s)
- Jaana Kusnetsov
- Laboratory of Environmental Microbiology, National Public Health Institute, Kuopio, Finland.
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17
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Abstract
Legionella pneumophila is naturally found in fresh water were the bacteria parasitize within protozoa. It also survives planctonically in water or biofilms. Upon aerosol formation via man-made water systems, L. pneumophila can enter the human lung and cause a severe form of pneumonia, called Legionnaires' disease. The pathogenesis of Legionnaires' disease is largely due to the ability of L. pneumophila to invade and grow within macrophages. An important characteristic of the intracellular survival strategy is the replication within the host vacuole that does not fuse with endosomes or lysosomes. In recent times a great number of bacterial virulence factors which affect growth of L. pneumophila in both macrophages and protozoa have been identified. The ongoing Legionella genome project and the use of genetically tractable surrogate hosts are expected to significantly contribute to the understanding of bacterium-host interactions and the regulation of virulence traits during the infection cycle. Since person-to-person transmission of legionellosis has never been observed, the measures for disease prevention have concentrated on eliminating the pathogen from water supplies. In this respect detection and analysis of Legionella in complex environmental consortia become increasingly important. With the availability of new molecular tools this area of applied research has gained new momentum.
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Affiliation(s)
- Michael Steinert
- Institut für Molekulare Infektionsbiologie, Universität Würzburg, Würzburg, Germany.
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18
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Abstract
Emerging pathogens in drinking water have become increasingly important during the decade. These include newly-recognized pathogens from fecal sources such as Cryptosporidium parvum, Campylobacter spp., and rotavirus, as well as pathogens that are able to grow in water distribution systems, like Legionella spp., mycobacteria, and aeromonads. To perform a risk analysis for the pathogens in drinking water, it is necessary to understand the ecology of these organisms. The ecology of the drinking-water distribution system has to be evaluated in detail, especially the diversity and physiological properties of water bacteria. The interactions between water bacteria and (potential) pathogens in such diverse habitats as free water and biofilms are essential for the survival or growth of hygienically relevant organisms in drinking water. Results of epidemiological studies together with ecological data are the basis for effective resource protection, water treatment, and risk assessment.
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Affiliation(s)
- U Szewzyk
- Technical University Berlin, Microbial Ecology Group, Secr. OE 5, Berlin, 10587 Germany.
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Kusnetsov J, Ottoila E, Martikainen P. Growth, respiration and survival of Legionella pneumophila at high temperatures. J Appl Microbiol 1996. [DOI: 10.1111/j.1365-2672.1996.tb01924.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Kusnetsov JM, Ottoila E, Martikainen PJ. Growth, respiration and survival of Legionella pneumophila at high temperatures. THE JOURNAL OF APPLIED BACTERIOLOGY 1996; 81:341-7. [PMID: 8896348 DOI: 10.1111/j.1365-2672.1996.tb03517.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The optimum temperature for multiplication of legionella strains in culture media is around 37 degrees C. The effect of high temperatures on the growth of strains isolated from various environments is poorly known. We studied the growth (cell multiplication, respiration) of clinical and environmental Legionella pneumophila strains in liquid media at intervals of 0.5 degrees C in the temperature range from 41.6 to 51.6 degrees C using a temperature gradient incubator. Cell multiplication and CO2 production decreased markedly with all the strains at temperatures above 44-45 degrees C. CO2 continued to be produced up to 51.6 degrees C even if cell multiplication generally stopped at around 48.4-50.0 degrees C. Thus, legionella retained its metabolic activity beyond the maximum temperature for cell multiplication. The CO2 production per bacterial cell (metabolic quotient, qCO2) increased with increasing temperature up to 45 degrees C, whereafter it decreased, the turning point being almost at the same at which the rate of cell multiplication decreased. The difference in qCO2 between the strains] may reflect their different physiological capacities for tolerating high temperatures.
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Affiliation(s)
- J M Kusnetsov
- Laboratory of Environmental Microbiology, National Public Health Institute (KTL), Kuopio, Finland. Faanna.
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21
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Tablan OC, Anderson LJ, Arden NH, Breiman RF, Butler JC, McNeil MM. Guideline for Prevention of Nosocomial Pneumonia. Infect Control Hosp Epidemiol 1994. [DOI: 10.2307/30147436] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Venezia RA, Agresta MD, Hanley EM, Urquhart K, Schoonmaker D. Nosocomial Legionellosis Associated with Aspiration of Nasogastric Feedings Diluted in Tap Water. Infect Control Hosp Epidemiol 1994. [DOI: 10.2307/30148403] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Makin T, Hart CA. The effect of a self-regulating trace heating element on Legionella within a shower. THE JOURNAL OF APPLIED BACTERIOLOGY 1991; 70:258-64. [PMID: 2030099 DOI: 10.1111/j.1365-2672.1991.tb02934.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A self-regulating trace heating element was assessed for its ability to maintain a temperature of 50 degrees C in the mixer valve and dead-legs of a shower, and for its effect on legionellas colonizing the shower. The trace heating element maintained a temperature of 50 degrees C +/- 1.5 degrees C in dead-legs when the circulating hot water supply remained above 45 degrees C. Legionellas appeared in a trace heated dead-leg when the temperature of the dead-leg reached 45 degrees C and the hot water supply dropped below this temperature. Legionellas were eradicated or significantly reduced in sections of the shower where a temperature of 50 degrees C was consistently achieved. The mixer valve which was trace heated but not insulated remained colonized with Legionellas. Legionellas were found in shower water throughout the study.
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Affiliation(s)
- T Makin
- Department of Medical Microbiology, University of Liverpool, UK
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