Comparison of two molecular methods used for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply

2008 ◽  
Vol 58 (3) ◽  
pp. 683-688 ◽  
Author(s):  
B. Casini ◽  
P. Valentini ◽  
A. Baggiani ◽  
F. Torracca ◽  
C. Lorenzini ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Potable Water ◽  
Water System ◽  
Epidemiological Studies ◽  
Molecular Methods ◽  
Pfge Analysis ◽  
Typing Method ◽  
Electrophoretic Patterns ◽  
Low Degree

The results of the pulsed-field gel electrophoresis and the sequence-based typing (using the loci flaA, pilE, asd, mip, mompS and proA) were compared for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply. Molecular typing was carried out on 61 isolates (38% of the positive samples) selected on space and temporal criteria in order to follow the evolution of the water-system colonization. For all the 61 isolates, the sequence of the amplified mip gene fragment identified Legionella pneumophila strain Wadsworth. Genotype testing by PFGE analysis showed three different patterns, correspondent to three SBT types according to the allelic profiles. Both PFGE and SBT indicated the circulation and the persistence in the hospital potable water-system of three types randomly distributed in space and time. The two molecular methods adopted showed a 100% concordance, although a low degree of genetic heterogeneity characterized the isolates. The electrophoretic patterns were sufficiently unambiguous to consider PFGE a highly discriminatory typing method, but the SBT technique besides accurately characterizing isolates, was able to identify Legionella strains through analysis of the mip gene. A typing method with this level of discriminatory power has great potential for assisting in epidemiological studies.

scholarly journals Lessons From an Outbreak of Legionnaires’ Disease on a Hematology-Oncology Unit

2016 ◽  
Vol 38 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Louise K. Francois Watkins ◽  
Karrie-Ann E. Toews ◽  
Aaron M. Harris ◽  
Sherri Davidson ◽  
Stephanie Ayers-Millsap ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Single Case ◽  
Healthcare Providers ◽  
Water System ◽  
Positive Sequence ◽  
Environmental Isolates ◽  
Legionnaires Disease ◽  
Oncology Unit ◽  
Healthcare Associated

OBJECTIVESTo define the scope of an outbreak of Legionnaires’ disease (LD), to identify the source, and to stop transmission.DESIGN AND SETTINGEpidemiologic investigation of an LD outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit.METHODSAn LD case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture forLegionellaand exposure to the hematology-oncology unit after February 20, 2014. Cases were classified as definitely or probably healthcare-associated based on whether they were exposed to the unit for all or part of the incubation period (2–10 days). We conducted an environmental assessment and collected water samples for culture. Clinical and environmental isolates were compared by monoclonal antibody (MAb) and sequence-based typing.RESULTSOver a 12-week period, 10 cases were identified, including 6 definite and 4 probable cases. Environmental sampling revealedLegionella pneumophilaserogroup 1 (Lp1) in the potable water at 9 of 10 unit sites (90%), including all patient rooms tested. The 3 clinical isolates were identical to environmental isolates from the unit (MAb2-positive, sequence type ST36). No cases occurred with exposure after the implementation of water restrictions followed by point-of-use filters.CONCLUSIONSContamination of the unit’s potable water system with Lp1 strain ST36 was the likely source of this outbreak. Healthcare providers should routinely test patients who develop pneumonia at least 2 days after hospital admission for LD. A single case of LD that is definitely healthcare associated should prompt a full investigation.Infect Control Hosp Epidemiol2017;38:306–313

Fatal NosocomialLegionella pneumophilaInfection Due to Exposure to Contaminated Water From a Washbasin in a Hematology Unit

2008 ◽  
Vol 29 (11) ◽  
pp. 1091-1093 ◽  
Author(s):  
Alexandre Brûlet ◽  
Marie-Christine Nicolle ◽  
Marine Giard ◽  
Franck-Emmanuel Nicolini ◽  
Mauricette Michallet ◽  
...  
Keyword(s):  
Nosocomial Infection ◽  
Water Supply ◽  
Legionella Pneumophila ◽  
Potable Water ◽  
Contaminated Water ◽  
Genomic Profile ◽  
Source Of Infection ◽  
Potable Water Supply

A fatal nosocomial infection withLegionella pneumophilaserogroup 5 occurred in a patient with leukemia. Isolates recovered from both the potable water supply and the patient showed an identical genomic profile. With no other exposure identified, the water from the washbasin was evidently the source of infection.

scholarly journals emm typing, antibiotic resistance and PFGE analysis of Streptococcus pyogenes in Lebanon

2011 ◽  
Vol 60 (1) ◽  
pp. 98-101 ◽  
Author(s):  
Wael Bahnan ◽  
Fuad Hashwa ◽  
George Araj ◽  
Sima Tokajian
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pyogenes ◽  
Epidemiological Studies ◽  
Pfge Pattern ◽  
Penicillin G ◽  
Pfge Analysis ◽  
Typing Method ◽  
Pfge Typing

One hundred and three Streptococcus pyogenes isolates recovered mainly from streptococcal throat infections in Lebanon were characterized by emm and PFGE typing. Thirty-three emm types and subtypes were detected among the isolates. PFGE was more discriminatory as a typing method. The prevalent emm types were emm1 (12.6 %), emm22 (8.7 %), emm28 (7.7 %), emm88 (7.7 %) and emm4 (6.8 %) and all isolates were susceptible to vancomycin and penicillin G. Ten per cent of the isolates were resistant to erythromycin and 3 % were resistant to erythromycin and clindamycin, showing the macrolide–lincosamide–streptogramin B phenotype. The emm sequences and PFGE pattern database that were generated in this study will serve as a basis for information for long-term evolutionary and epidemiological studies of local S. pyogenes recovered not only in Lebanon, but also in neighbouring countries.

Point-of-Use Membrane Filtration and Hyperchlorination to Prevent Patient Exposure to Rapidly Growing Mycobacteria in the Potable Water Supply of a Skilled Nursing Facility

2011 ◽  
Vol 32 (9) ◽  
pp. 837-844 ◽  
Author(s):  
Margaret M. Williams ◽  
Tai-Ho Chen ◽  
Tim Keane ◽  
Nadege Toney ◽  
Sean Toney ◽  
...  
Keyword(s):  
Water Supply ◽  
Potable Water ◽  
Skilled Nursing Facility ◽  
Water System ◽  
Nursing Facility ◽  
Mycobacterium Chelonae ◽  
Skilled Nursing ◽  
Rapidly Growing Mycobacteria ◽  
Membrane Filters ◽  
Point Of Use

Background.Healthcare-associated outbreaks and pseudo-outbreaks of rapidly growing mycobacteria (RGM) are frequently associated with contaminated tap water. A pseudo-outbreak ofMycobacterium chelonae–M. abscessusin patients undergoing bronchoscopy was identified by 2 acute care hospitals. RGM was identified in bronchoscopy specimens of 28 patients, 25 of whom resided in the same skilled nursing facility (SNF). An investigation ruled out bronchoscopy procedures, specimen collection, and scope reprocessing at the hospitals as sources of transmission.Objective.To identify the reservoir for RGM within the SNF and evaluate 2 water system treatments, hyperchlorination and point-of-use (POU) membrane filters, to reduce RGM.Design.A comparative in situ study of 2 water system treatments to prevent RGM transmission.Setting.An SNF specializing in care of patients requiring ventilator support.Methods.RGM and heterotrophic plate count (HPC) bacteria were examined in facility water before and after hyperchlorination and in a subsequent 24-week assessment of filtered water by colony enumeration on Middlebrook and R2A media.Results.Mycobacterium chelonaewas consistently isolated from the SNF water supply. Hyperchlorination reduced RGM by 1.5 log10initially, but the population returned to original levels within 90 days. Concentration of HPC bacteria also decreased temporarily. RGM were reduced below detection level in filtered water, a 3-log10reduction. HPC bacteria were not recovered from newly installed filters, although low quantities were found in water from 2-week-old filters.Conclusion.POU membrane filters may be a feasible prevention measure for healthcare facilities to limit exposure of sensitive individuals to RGM in potable water systems.

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.

Persistence ofLegionella Pneumophilain a Hospital's Water System: A 13-Year Survey

1999 ◽  
Vol 20 (12) ◽  
pp. 793-797 ◽  
Author(s):  
M. Sigfrido Rangel-Frausto ◽  
Paul Rhomberg ◽  
Richard J. Hollis ◽  
Michael A. Pfaller ◽  
Richard P. Wenzel ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Water System ◽  
University Teaching ◽  
University Of Iowa ◽  
System A ◽  
Sporadic Cases ◽  
Iowa Hospital ◽  
Different Strains ◽  
The University

AbstractObjective:To describe the molecular epidemiology ofLegionella pneumophilainfections in the University of Iowa Hospitals and Clinics (UIHC).Design:Molecular epidemiological study using pulsed-field gel electrophoresis (PFGE).Setting:A large university teaching hospital.Isolates:All surviving isolates obtained from culture-proven nosocomialL pneumophilainfections and all surviving isolates obtained from the University of Iowa Hospital and Clinics' water supply between 1981 and 1993.Results:Thirty-three isolates from culture-proven nosocomial cases ofL pneumophilapneumonia were available for typing. PFGE of genomic DNA from the clinical isolates identified six different strains. However, only strain C (16 cases) and strain D (13 cases) caused more than 1 case. Strain C caused clusters of nosocomial infection in 1981, 1986, and 1993 and also caused 4 sporadic cases. Strain D caused a cluster in 1987 and 1988 plus 4 sporadic cases. Of the six strains causing clinical infections, only strains C and D were identified in water samples. PFGE identified three strains in the water supply, of which strains C and D caused clinical disease and also persisted in the water supply during most of the study period.Conclusion:Specific strains ofL pneumophilacan colonize hospital water supplies and cause nosocomial infections over long periods of time.

Nosocomial Outbreak of Legionnaires' Disease: Molecular Epidemiology and Disease Control Measures

1987 ◽  
Vol 8 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Jeffrey M. Johnston ◽  
Robert H. Latham ◽  
Frederick A. Meier ◽  
Jon A. Green ◽  
Rebecca Boshard ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cooling Tower ◽  
Water System ◽  
Hot Water ◽  
Control Measures ◽  
Laboratory Techniques ◽  
Legionnaires Disease ◽  
Water Holding ◽  
Methods Of Control

AbstractMolecular laboratory techniques were used to study the epidemiology of an outbreak of nosocomial Legionnaires' disease. All patient isolates were Legionella pneumophila serogroup 1 and showed identical plasmid profiles and reactions with serogroup-specific monoclonal antibodies. L pneumophila was also cultured from four of five cooling tower water samples; however, the isolate from only one tower was serogroup 1 of the same sub-type as patient isolates. Since the cases were temporally clustered and epidemiologically associated with exposure to cooling tower aerosols, the single cooling tower implicated by molecular analysis was the most likely source of the outbreak. Chlorination of cooling tower ponds has eradicated the epidemic strain. Since potable water also harbored the infecting organism and was the probable source for cooling tower contamination, decontamination of the hospital water system was also undertaken. Superchlorination of hot water holding tanks to 17 ppm on a weekly basis has effectively eradicated L pneumophila from the potable water system and appears to be a reasonable, simple, and relatively inexpensive alternative to previously described methods of control.

scholarly journals High-Throughput Typing Method To Identify a Non-Outbreak-Involved Legionella pneumophila Strain Colonizing the Entire Water Supply System in the Town of Rennes, France

2011 ◽  
Vol 77 (19) ◽  
pp. 6899-6907 ◽  
Author(s):  
D. Sobral ◽  
P. Le Cann ◽  
A. Gerard ◽  
S. Jarraud ◽  
B. Lebeau ◽  
...  
Keyword(s):  
Water Supply ◽  
High Throughput ◽  
Legionella Pneumophila ◽  
Variable Number Tandem Repeat ◽  
Hot Water ◽  
Clinical Isolates ◽  
Water Supply Systems ◽  
Environmental Isolates ◽  
Typing Method ◽  
The City

ABSTRACTTwo legionellosis outbreaks occurred in the city of Rennes, France, during the past decade, requiring in-depth monitoring ofLegionella pneumophilain the water network and the cooling towers in the city. In order to characterize the resulting large collection of isolates, an automated low-cost typing method was developed. The multiplex capillary-based variable-number tandem repeat (VNTR) (multiple-locus VNTR analysis [MLVA]) assay requiring only one PCR amplification per isolate ensures a high level of discrimination and reduces hands-on and time requirements. In less than 2 days and using one 4-capillary apparatus, 217 environmental isolates collected between 2000 and 2009 and 5 clinical isolates obtained during outbreaks in 2000 and 2006 in Rennes were analyzed, and 15 different genotypes were identified. A large cluster of isolates with closely related genotypes and representing 77% of the population was composed exclusively of environmental isolates extracted from hot water supply systems. It was not responsible for the known Rennes epidemic cases, although strains showing a similar MLVA profile have regularly been involved in European outbreaks. The clinical isolates in Rennes had the same genotype as isolates contaminating a mall's cooling tower. This study further demonstrates that unknown environmental or genetic factors contribute to the pathogenicity of some strains. This work illustrates the potential of the high-throughput MLVA typing method to investigate the origin of legionellosis cases by allowing the systematic typing of any new isolate and inclusion of data in shared databases.

scholarly journals Blackwater Event: Water Management and Remediation at a Major Medical Center

2020 ◽  
Vol 41 (S1) ◽  
pp. s140-s140
Author(s):  
Priya Sampathkumar ◽  
Debra Apenhorst ◽  
Al Kubly ◽  
Mark Keller ◽  
Alan Wright
Keyword(s):  
Water Management ◽  
Water Supply ◽  
Potable Water ◽  
Water System ◽  
Bottled Water ◽  
Alternative Methods ◽  
Infection Prevention And Control ◽  
Water Testing ◽  
Municipal Water ◽  
The Impact

Background: The CMS and the CDC recommend that all healthcare facilities have an effective water management program (WMP). Our WMP has been in place since 2010; it includes members from facilities operations, infection prevention and control, environmental services, and industrial hygiene. The team meets regularly to discuss current water issues, reviews validation data and water testing reports. Description of event: In April 2018, we suddenly experienced discolored water and sediment at multiple water fixtures throughout the 3.3 million square-foot hospital campus. The hospital incident command structure (HICS) was activated to assist in investigating and managing the situation. Immediate response: Water was deemed unsafe while the cause was being investigated. Bottled water was distributed to 950 hospital patients, and >8,000 staff and visitors. The impact included alternative methods for hand hygiene, the use of bottled water for food preparation and drinking, and the elimination of showers for patients and staff. The dialysis unit used an independent water supply that was not affected. Investigation and remediation: The hospital had 2 sources of domestic cold water: municipal water and a private well that had been in use since 1912. An investigation revealed that the well pump had malfunctioned, drawing gravel into the potable water supply. This overwhelmed the plumbing, blocked toilets and likely dislodged biofilm from the pipes. Early testing showed high levels of corrosion byproducts (ie, iron, copper, and lead) and bacterial contamination in the water, including presence of Legionella. Remediation involved isolating the well, switching to municipal water as the sole source of potable water, flushing the system, and retesting. Overall, 105 technicians flushed the water system including 6,000 water fixtures, 125 drinking fountains, and 95 emergency showers and eyewashes; they sanitized and cleaned 130 ice machines and tested 240 backflow preventers. We retested 437 water samples after remediation; all parameters had returned to the normal range. The existing water process flow diagrams were used to guide sampling for water testing. Conclusions: The hospital’s water system was brought back on line in 78 hours after the first report of “black water.” An active, mature WMP with multiple facilities technicians trained in water sampling enabled a quick response. Coordination through the HICS structure streamlined the response and enabled clear communication throughout the process.Funding: NoneDisclosures: None

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