Incidence of nontuberculous mycobacteria in four hot water systems using various types of disinfection

2008 ◽  
Vol 54 (11) ◽  
pp. 891-898 ◽  
Author(s):  
Helena Sebakova ◽  
Frantisek Kozisek ◽  
Radim Mudra ◽  
Jarmila Kaustova ◽  
Marie Fiedorova ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Nontuberculous Mycobacteria ◽  
Water Systems ◽  
Hot Water ◽  
Mycobacterium Fortuitum ◽  
Mycobacterium Xenopi ◽  
High Incidence ◽  
Low Incidence ◽  
Thermal Disinfection

The objective of this study was to determine the incidence of nontuberculous mycobacteria (NTM) in hot water systems of 4 selected hospital settings. The hospitals provided the following types of disinfection for their hot water systems: hydrogen peroxide and silver, thermal disinfection, chlorine dioxide, and no treatment (control). In each building, 6 samples were collected from 5 sites during a 3 month period. NTM were detected in 56 (46.7%) of 120 samples; the CFU counts ranged from 10 to 1625 CFU/L. The detected NTM species were the pathogens Mycobacterium kansasii , Mycobacterium xenopi , and Mycobacterium fortuitum and the saprophyte Mycobacterium gordonae. The most common to be isolated was M. xenopi, which was present in 51 samples. The hot water systems differed significantly in the incidence of NTM. NTM were not detected in the system treated by thermal disinfection, and a relatively low incidence (20% positive samples) was found in the system disinfected with chlorine dioxide. However, a high incidence was found in the control system with no additional disinfection (70% positives) and in the system using hydrogen peroxide and silver (97% positives). Water temperatures above 50 °C significantly limited the occurrence of NTM.

scholarly journals Diseases of Sugarcane and their Control in Puerto Rico

1969 ◽  
Vol 55 (2) ◽  
pp. 139-146
Author(s):  
Lii-Jang Liu ◽  
José Adsuar ◽  
Enrique Pérez
Keyword(s):  
Puerto Rico ◽  
Root Rot ◽  
Economic Importance ◽  
Hot Water ◽  
Root Rots ◽  
High Incidence ◽  
Disease Survey ◽  
Sugar Mills ◽  
Low Incidence ◽  
Methods Of Control

A sugarcane disease survey was conducted over different mill zones of Puerto Rico during the fall of 1969 and the spring of 1970. It covered the plantations of 10 sugar mills. The results obtained to date indicate that the diseases of major importance are ratoon stunting, chlorotic streak, pineapple disease, and root rot caused by a complex of Pythium, Fusarium and nematodes. The specific disease problems are identified in each area. Special attention was given to disease distribution, economic importance, and possible methods of control. Although in general low incidence of ratoon stunting was observed in commercial plantings, data obtained from previous variety tests indicate this malady to be potentially dangerous. Hot water treatment of seedpieces should be conducted to prevent its further spread. The significance of chlorotic streak disease as a factor in yield decline in Puerto Rico has not yet been completely evaluated. The high incidence of this disease, under present conditions, has given rise to concern. Pineapple disease caused by Thielaviopsis paradoxa greatly affects the germination of P.R. 980, especially in areas with poor drainage. Root rots caused by Pythium, Fusarium and nematodes reduced germination of P.O.J. 2878 and H. 328560 by as much as 40 percent in poorly-drained areas.

scholarly journals Isolation ofMycobacterium aviumfrom Potable Water in Homes and Institutions of Patients with HIV Infection in Finland and the United States

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Matti Ristola ◽  
Robert D. Arbeit ◽  
C. Fordham von Reyn ◽  
C. Robert Horsburgh
Keyword(s):  
United States ◽  
Hiv Infection ◽  
Potable Water ◽  
Nontuberculous Mycobacteria ◽  
The United States ◽  
Common Species ◽  
Water Systems ◽  
Human Infection ◽  
Hot Water ◽  
Symptomatic Disease

Symptomatic disease by nontuberculous mycobacteria has been linked to potable water from institutional and domestic potable water systems. Potable water samples were collected from homes and institutions of patients with AIDS. Colonization of potable water with nontuberculous mycobacteria was demonstrated in 230 (15%) of 1489 samples collected from domestic and institutional water systems of patients with HIV infection in the United States and Finland.Mycobacterium aviumwas the most common species and colonization was favored at temperatures of 40–50°C in recirculating hot water systems. Such systems are a plausible source of human infection and disease.

scholarly journals Effect of ClO2 on the distribution of Legionella pneumophila serogroups in a Teaching Hospital

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Vincenti ◽  
D I La Milia ◽  
F Boninti ◽  
E Marchetti ◽  
M Wachocka ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Chlorine Dioxide ◽  
Legionella Pneumophila ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Systematic Sampling ◽  
National Guidelines ◽  
High Increase ◽  
Percentage Decrease

Abstract The prevention of Legionella colonization of water systems is one of the goals of hospital management. Among chemical disinfection methods, chlorine dioxide (ClO2) has been largely used to control Legionella in water systems. We analysed the distribution of Legionella pneumophila serogroups (sg) and Legionella other spp before (PRE) and after (POST) installation of chlorine dioxide (ClO2) continuous disinfection systems in a Teaching Hospital in Rome. According to the Italian National Guidelines, our surveillance plan involved a systematic sampling of the water system. The sampling was performed from Jan. 2010 to Dec. 2019. From 2011 to 2019, ClO2 continuous disinfection systems were installed in all hot water system of the hospital, and maintained at a concentration of 0.25 mg/l at the end point. The isolated strains of Legionella were first serotyped using a kit that identifies sg1, other species and that discriminate sg from 2 to 15. 1505 hot water samples were collected from the Hospital and analysed. 363 samples are PRE and 1142 are POST activation of ClO2. Only the 16.74% of monitored sampling points were colonized by Legionella during the study period. This percentage decrease from 31.40% of PRE samples, to 12.08% of POST samples (p ≤ 0.000). The sg isolated were: sg3 (60.31%), sg8 (17.12%), sg1 (16.73%), sg6 (1.95%) and other species (3.89%). Comparing the distribution of sg between the PRE and POST samples, the sg8 showed a high increase (+136.84%) and the sg3 a slight decrease (-17.94%). These variations were statistically significative. The results showed a predominance of Legionella pneumophila sg3, compared to what was observed in a multicenter study conducted between different hospitals of various regions of Italy, where sg6 was the major isolate. The ClO2 affect the distribution of sg, in particular for sg8. This interesting result will be further investigated. Key messages Our data deriving from an environmental monitoring plan, show that the ClO2 affects the distribution of Legionella’s serogroups. The ClO2 reduces the percentage of samples colonized by Legionella. The ClO2 reduces the percentage of samples colonized by Legionella.

Chemical disinfection of Legionella in hot water systems biofilm: a pilot-scale 1 study

2011 ◽  
Vol 64 (3) ◽  
pp. 708-714 ◽  
Author(s):  
Maha Farhat ◽  
Marie-Cécile Trouilhé ◽  
Christophe Forêt ◽  
Wolfgang Hater ◽  
Marina Moletta-Denat ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Contact Time ◽  
Pilot Scale ◽  
Water Systems ◽  
Hot Water ◽  
The Other ◽  
Cooling Towers ◽  
Test Loop ◽  
Growing Conditions ◽  
Chemical Disinfection

Legionella bacteria encounter optimum growing conditions in hot water systems and cooling towers. A pilot-scale 1 unit was built in order to study the biofilm disinfection. It consisted of two identical loops, one used as a control and the other as a ‘Test Loop’. A combination of a bio-detergent and a biocide (hydrogen peroxide + peracetic acid) was applied in the Test Loop three times under the same conditions at 100 and 1,000 mg/L with a contact time of 24 and 3–6 hours, respectively. Each treatment test was preceded by a three week period of biofilm re-colonization. Initial concentrations of culturable Legionella into biofilm were close to 103 CFU/cm2. Results showed that culturable Legionella spp. in biofilm were no longer detectable three days following each treatment. Nevertheless, initial Legionella spp. concentrations were recovered 7 days after the treatments (in two cases). Before the tests, Legionella spp. and L. pneumophila PCR counts were both about 104 GU/cm2 in biofilm and they both decreased by 1 to 2 log units 72 hours after each treatment. The three tests had a good but transient efficiency on Legionella disinfection in biofilm.

scholarly journals Nontuberculous mycobacteria in hospital water systems: application of HPLC for identification of environmental mycobacteria

2003 ◽  
Vol 1 (3) ◽  
pp. 133-139 ◽  
Author(s):  
L. Galassi ◽  
R. Donato ◽  
E. Tortoli ◽  
D. Burrini ◽  
D. Santianni ◽  
...  
Keyword(s):  
High Performance ◽  
Nontuberculous Mycobacteria ◽  
Water System ◽  
Water Systems ◽  
Mycobacterium Fortuitum ◽  
Mycolic Acids ◽  
Environmental Mycobacteria ◽  
First Choice ◽  
One Year ◽  
Choice Method

Nontuberculous mycobacteria (NTM), ubiquitous in water environments, are increasingly recognized as nosocomial pathogens. Our study reports a one-year survey of the water system of two hospitals, A and B, in a small town near Florence, Italy. NTM were found throughout the study period in both settings, but B showed a significantly higher mycobacterial load. Mycobacterium gordonae and Mycobacterium fortuitum were the most frequent species isolated. Identification was carried out by conventional techniques and by high performance liquid chromatography (HPLC) analysis of cell wall mycolic acids. HPLC profiling could be used as a first-choice method for identification of environmental mycobacteria.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

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