Cytopathogenicity and molecular subtyping ofLegionella pneumophilaenvironmental isolates from 17 hospitals

2008 ◽  
Vol 137 (2) ◽  
pp. 188-193 ◽  
Author(s):  
M. GARCIA-NUÑEZ ◽  
M. L. PEDRO-BOTET ◽  
S. RAGULL ◽  
N. SOPENA ◽  
J. MORERA ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Cytopathic Effect ◽  
Water Distribution System ◽  
Water Reservoir ◽  
Pfge Pattern ◽  
Contaminated Water ◽  
Legionnaires Disease ◽  
Hospital Acquired

SUMMARYThe cytopathogenicity of 22Legionella pneumophilaisolates from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (CPED50) in U937 human-derived macrophages. All isolates were able to infect and grow in macrophage-like cells (range log10CPED50: 2·67–6·73 c.f.u./ml). Five groups were established and related to the serogroup, the number of PFGE patterns coexisting in the same hospital water distribution system, and the possible reporting of hospital-acquired Legionnaires' disease cases.L. pneumophilaserogroup 1 isolates had the highest cytopathogenicity (P=0·003). Moreover, a trend to more cytopathogenic groups (groups 1–3) in hospitals with more than one PFGE pattern ofL. pneumophilain the water distribution system (60%vs. 17%) and in hospitals reporting cases of hospital-acquired Legionnaires' disease (36·3%vs. 16·6%) was observed. We conclude that the cytopathogenicty of environmentalL. pneumophilashould be taken into account in evaluating the risk of a contaminated water reservoir in a hospital and hospital acquisition of Legionnaires' disease.

Safety and Efficacy of Chlorine Dioxide for Legionella Control in a Hospital Water System

2007 ◽  
Vol 28 (8) ◽  
pp. 1009-1012 ◽  
Author(s):  
Zhe Zhang ◽  
Carole McCann ◽  
Janet E. Stout ◽  
Steve Piesczynski ◽  
Robert Hawks ◽  
...  
Keyword(s):  
Chlorine Dioxide ◽  
Environmental Protection Agency ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water System ◽  
Hot Water ◽  
Skilled Nursing ◽  
Legionnaires Disease ◽  
Hospital Acquired

In a 30-month prospective study, we evaluated the efficacy of chlorine dioxide to control Legionella organisms in a water distribution system of a hospital with 364 patient beds and 74 skilled nursing beds. The number of hot water specimens positive for Legionella organisms decreased from 12 (60%) of 20 to 2 (10%) of 20. An extended time (18 months) was needed to achieve a significant reduction in the rate of Legionella positivity among hot water specimens. At the time of writing, no cases of hospital-acquired Legionnaires disease have been detected at the hospital since the chlorine dioxide system was installed in January 2003. Use of chlorine dioxide was safe, based on Environmental Protection Agency limits regarding maximum concentrations of chlorine dioxide and chlorite.

scholarly journals Outbreak of Legionnaires' disease in a nursing home, Slovenia, August 2010: preliminary report

2010 ◽  
Vol 15 (39) ◽  
Author(s):  
A Trop Skaza ◽  
L Beskovnik ◽  
A Storman ◽  
S Ursic ◽  
B Groboljsek ◽  
...  
Keyword(s):  
Nursing Home ◽  
Distribution System ◽  
Preliminary Report ◽  
Water Distribution ◽  
Water Distribution System ◽  
Source Of Infection ◽  
Dead End ◽  
Probable Source ◽  
Legionnaires Disease

We report an outbreak of Legionnaires' disease in a nursing home in Slovenia in August 2010 affecting 15 of 234 residents. To date, Legionnaires' disease has been confirmed in four patients. Further serum analyses and genotyping of isolates are ongoing. The building's water distribution system with dead end sections has been identified as the probable source of infection.

scholarly journals Near-optimal scheduling of device activation in water distribution systems to reduce the impact of a contamination event

2011 ◽  
Vol 14 (2) ◽  
pp. 345-365 ◽  
Author(s):  
S. Alvisi ◽  
M. Franchini ◽  
M. Gavanelli ◽  
M. Nonato
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Optimal Scheduling ◽  
Mixed Integer ◽  
Maximum Speed ◽  
Contaminated Water ◽  
Flow Control Devices ◽  
The Impact

This paper proposes an innovative procedure for identifying, in the event of accidental or intentional contamination of a water distribution system, the optimal scheduling of activation of a pre-selected set of flow control devices which will serve to minimise the volume of contaminated water consumed by users after the detection of the contaminant in the system. The constraints are represented by the number of available response teams and the maximum speed at which these teams can travel along the roadway. The optimal scheduling of device activation is sought by means of an optimisation process based on a genetic algorithm (GA) which interacts with a mixed integer linear programming (MILP) solver in order to ensure the feasibility of the scheduling identified. The optimisation procedure is coupled to a hydraulic and quality simulator, which enables a calculation of the volumes of contaminated water consumed by users, and a dynamic cache memory, which, by storing information on the system's behaviour as the optimisation process progresses, serves to limit the computational times. The application of the procedure to a highly complex real water distribution system shows that the optimisation process is robust and efficacious and produces a smaller volume of contaminated water consumed by the users than when the activation of all the devices was completed in the shortest amount of time.

Treatment of aLegionella pneumophila-Colonized Water Distribution System Using Copper-Silver Ionization and Continuous Chlorination

1999 ◽  
Vol 20 (6) ◽  
pp. 426-428 ◽  
Author(s):  
Amaya Biurrun ◽  
Luis Caballero ◽  
Carmen Pelaz ◽  
Elena León ◽  
Alberto Gago
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Cold Water ◽  
Conventional Methods

AbstractThe detection in April 1997 of a case of nosocomial legionellosis in our hospital led to the discovery that both our hot- and cold-water circuits were heavily colonized withLegionella pneumophila. Conventional methods for eradication of the organisms were unsuccessful, so a copper-silver (Cu-Ag) ionization system and a continuous chlorination system were installed. Five months later, the number of colonized sites decreased from an initial 58.3% to 16.7%.

scholarly journals KESEPANCARAN (HOMOLOGI) LEGIONELLA PNEUMOPHILA JARINGAN DISTRIBUSI AIR DAN PNEUMONIA NOSOKOMIAL

2018 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
Noormartany .
Keyword(s):  
New Species ◽  
16S Rrna ◽  
Nosocomial Pneumonia ◽  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Base Sequence ◽  
A New Species

L. pneumophila is one of the nosocomial pneumonia causes that contaminated hospital water distribution system. The aim of this study was to determine the homology between L. pneumophila 16S rRNA base sequence found in the water distribution systemand the sequence derived from the sputum of nosocomial pneumonia patients identified at RSHS Bandung as well as the homology of L. pneumophila 16S rRNA found in the same system network. The study also include the nosocomial pneumonia patients at RSHSBandung with L. pneumophila from GenBank. The research using descriptive bioinformatics BLAST method by comparative analyticapproach, which performed from April 2006 to February 2008. The material consists of 60 biofilm samples from water distributionsystem and pneumonia nosocomial patient’s sputum is positive L.pneumophila from water distribution system in her/his room. Inthe result was found: out of the 60 biofilm samples from the water distribution system, there are seven (7) L. pneumophila positivePCR and culture. During the 12 months of observation, there is only one (1) out of 31 pneumonia nosocomial patients with positively L. pneumophila PCR and culture. The conclusion so far can be mentioned that: The water distribution system in RSHS for patient roomsmay become the source for nosocomial pneumonia transmission of L. pneumophila and also was detected a new species of L. pneumophilathat is genetically different from that has been found in GenBank.

scholarly journals Accumulation and Fate of Microorganisms and Microspheres in Biofilms Formed in a Pilot-Scale Water Distribution System

2005 ◽  
Vol 71 (2) ◽  
pp. 706-712 ◽  
Author(s):  
Jonas Långmark ◽  
Michael V. Storey ◽  
Nicholas J. Ashbolt ◽  
Thor-Axel Stenström
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Residence Time ◽  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Pilot Scale ◽  
Microbial Pathogens

ABSTRACT The accumulation and fate of model microbial “pathogens” within a drinking-water distribution system was investigated in naturally grown biofilms formed in a novel pilot-scale water distribution system provided with chlorinated and UV-treated water. Biofilms were exposed to 1-μm hydrophilic and hydrophobic microspheres, Salmonella bacteriophages 28B, and Legionella pneumophila bacteria, and their fate was monitored over a 38-day period. The accumulation of model pathogens was generally independent of the biofilm cell density and was shown to be dependent on particle surface properties, where hydrophilic spheres accumulated to a larger extent than hydrophobic ones. A higher accumulation of culturable legionellae was measured in the chlorinated system compared to the UV-treated system with increasing residence time. The fate of spheres and fluorescence in situ hybridization-positive legionellae was similar and independent of the primary disinfectant applied and water residence time. The more rapid loss of culturable legionellae compared to the fluorescence in situ hybridization-positive legionellae was attributed to a loss in culturability rather than physical desorption. Loss of bacteriophage 28B plaque-forming ability together with erosion may have affected their fate within biofilms in the pilot-scale distribution system. The current study has demonstrated that desorption was one of the primary mechanisms affecting the loss of microspheres, legionellae, and bacteriophage from biofilms within a pilot-scale distribution system as well as disinfection and biological grazing. In general, two primary disinfection regimens (chlorination and UV treatment) were not shown to have a measurable impact on the accumulation and fate of model microbial pathogens within a water distribution system.

Sign in / Sign up

Export Citation Format

Share Document