Microbiological Evaluation of Copper : Silver Disinfection Units for Use in Swimming Pools

1989 ◽  
Vol 21 (3) ◽  
pp. 267-270 ◽  
Author(s):  
Lee K. Landeen ◽  
Moyasar T. Yahya ◽  
Susan M. Kutz ◽  
Charles P. Gerba
Keyword(s):  
Pathogenic Bacteria ◽  
Silver Ions ◽  
Free Chlorine ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Bactericidal Effects ◽  
Pure Cultures ◽  
Bactericidal Activities ◽  
Low Levels ◽  
Hot Tubs

The bactericidal effects of electrolytically generated copper:silver ions on pathogenic bacteria of concern in swimming pools, hot tubs and cooling towers were evaluated in disinfection experiments. Copper:silver ion concentrations generated in well water were 400:40 µg/L, respectively. Pure cultures of Legionellapneumophila, Staphylococcusaureus, Pseudomonasaeruginosa, Escherichiacoli, and Streptococcusfaecalis, were individually tested in water containing copper:silver ions alone, copper:silver ions with free chlorine, and free chlorine alone. Greater numbers of organisms were killed after exposure to copper: silver ions with 0.2 mg/L free chlorine than in either the copper:silver ions or free chlorine alone. L. pneumophlla showed greater than a 5 log10 reduction in numbers after 7 minutes exposure to copper:silver ions with 0.2 mg/L free chlorine. In comparison, less than a 2 log10 decrease was obtained after exposure to free chlorine alone. E.coli numbers decreased over 4 log10 after 1 minute exposure to copper:silver ions with 0.2 mg/L free chlorine and less than a 3 log10 decrease after exposure to free chlorine alone. The majority of the other organisms tested showed the same effect. Electrolytically generated copper:silver ions with low levels of free chlorine appear to have greater bactericidal activities than either disinfectant alone.

Efficacy of a combined system of copper and silver and free chlorine for inactivation of Naegleria fowleri amoebas in water

1995 ◽  
Vol 31 (5-6) ◽  
pp. 119-122 ◽  
Author(s):  
J. M. Cassells ◽  
M. T. Yahya ◽  
C. P. Gerba ◽  
J. B. Rose
Keyword(s):  
Synergistic Effect ◽  
Exposure Time ◽  
Silver Ions ◽  
Free Chlorine ◽  
Log10 Reduction ◽  
Naegleria Fowleri ◽  
Combined System ◽  
Water Ph ◽  
Nægleria Fowleri ◽  
Time Required

Electrolytically generated copper and silver ions (400:40 and 800:80 μg/l) were evaluated, separately and combined with 1.0 mg/l free chlorine, for their efficacy in reducing the viable numbers of Naegleria fowleri amoebas in water (pH 7.3 and 23-25°C). Inactivation rates (k = log10 reduction/min) and T99 values (exposure time required to achieve a 99% or a 2 log10 reduction) of the disinfectants were determined. Copper and silver alone, at ratio of 400:40 to 800:80 μg/l caused no significant inactivation of N. fowleri even after 72 hours of exposure (k = 0.00017 and 0.00013, respectively). Addition of 1.0 mg/l free chlorine to water which contained 400:40 or 800:80 μg/l copper and silver resulted in enhanced inactivation rates (k = 0.458 and 0.515, respectively) compared to either chlorine alone (k = 0.33) or the metals alone. Water containing 800:80 μg/l copper and silver with 1.0 mg/l chlorine showed a T99 value of 3.9 minutes, while chlorine alone showed a T99 of 6.1 minutes. Enhanced inactivation of N. fowleri by a combined system of free chlorine and copper and silver may be attributed to the different mechanism that each disinfectant utilizes in inactivating the amoebas, and may suggest a synergistic effect.

scholarly journals The effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum in 20-ppm free chlorine

2008 ◽  
Vol 7 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Joan M. Shields ◽  
Michael J. Arrowood ◽  
Vincent R. Hill ◽  
Michael J. Beach
Keyword(s):  
Public Health ◽  
Cryptosporidium Parvum ◽  
Cyanuric Acid ◽  
Free Chlorine ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Chlorine Residual ◽  
Cryptosporidium Oocysts ◽  
Reduction Current

Cyanuric acid is used to stabilize free chlorine to reduce photodegradation in outdoor swimming pools. While there have been numerous studies examining its effect on the disinfection rates of bacteria and viruses, it is not known whether cyanuric acid can significantly impact the effectiveness of hyperchlorination for inactivating Cryptosporidium oocysts present in fecally-contaminated swimming pools. This study examined the effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum under swimming pool hyperchlorination conditions (20 mg/ml free chlorine). When 50 mg/L cyanuric acid was present there was a 0.70-log10 reduction in oocyst viability after 10 hours as compared to a 3.7-log10 reduction without cyanuric acid. Aids to remediation, such as decreasing the pH to enhance the germicidal efficiency of the free chlorine and doubling the amount of free chlorine residual, were still unable to achieve a 3-log10 reduction. Current public health recommendations for hyperchlorination and pool remediation are insufficient for pools using cyanurate-stabilized chlorine to achieve a three log inactivation of the parasite.

Inactivation of coliphage MS-2 and poliovirus by copper, silver, and chlorine

1992 ◽  
Vol 38 (5) ◽  
pp. 430-435 ◽  
Author(s):  
Moyasar T. Yahya ◽  
Timothy M. Straub ◽  
Charles P. Gerba
Keyword(s):  
Key Words ◽  
Enteric Viruses ◽  
Silver Ions ◽  
Water Systems ◽  
Free Chlorine ◽  
Inactivation Rate ◽  
Swimming Pools ◽  
Poliovirus Type ◽  
Test Systems

The efficacy of electrolytically generated copper and silver ions (400 and 40 μg/L, respectively) was evaluated separately and in combination with free chlorine (0.2 and 0.3 mg/L) for the inactivation of coliphage MS-2 and poliovirus type 1 in water at pH 7.3. The inactivation rate was calculated as log10 reduction/min: k = −(log10Ct/C0)/t. The inactivation of both viruses was at least 100 times slower in water containing 400 and 40 μg/L copper and silver, respectively (k = 0.023 and 0.0006 for MS-2 and poliovirus, respectively), compared with water containing 0.3 mg/L free chlorine (k = 4.88 and 0.036). Significant increases in the inactivation rates of both viruses were observed in test systems containing 400 and 40 μg/L copper and silver, respectively, with 0.3 mg/L free chlorine when compared with the water systems containing either metals or free chlorine alone. Poliovirus was approximately 10 times more resistant to the disinfectants than coliphage MS-2. This observation suggests either a synergistic or an additive effect between the metals and chlorine for inactivation of enteric viruses. Use of copper and silver ions in water systems currently used in swimming pools and spas may provide an alternative to high levels of chlorination. Key words: enteric viruses, poliovirus, coliphage MS-2, bacteriophage, disinfection, inactivation, copper, silver, chlorine.

Disinfection of Human Enteric Viruses in Water by Copper: Silver and Reduced Levels of Chlorine

1993 ◽  
Vol 27 (3-4) ◽  
pp. 351-355 ◽  
Author(s):  
Albert Bosch ◽  
José M. Díez ◽  
F. Xavier Abad
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Silver Ions ◽  
Water Systems ◽  
Free Chlorine ◽  
Viral Pathogens ◽  
Human Rotavirus ◽  
Low Levels ◽  
Total Elimination

Electrolytically generated copper: silver ions were evaluated in combination with low levels of chlorine for their ability to reduce the infectivity of hepatitis A virus, human rotavirus, adenovirus and poliovirus seeded in well and tap water. Overall, hepatitis A virus and rotavirus showed less than 2.6 log10 titre reduction for concentrations of 1 mg/l of free chlorine. For free chlorine concentrations of 0.5 mg/l or lower, with or without copper: silver ions, both of these viral strains suffered little inactivation. Poliovirus showed more than 4 log10 titre reduction in the presence of copper: silver combined with 0.5 mg/l of free chlorine, or 1 mg/l of free chlorine alone. Copper: silver ions (700:70 µg/l) reduced the infectivity of poliovirus. Although adenovirus was more efficiently inactivated than rotavirus or hepatitis A virus, it persisted longer than poliovirus under the same treatments, and its infectivity was never completely removed. The addition of copper: silver ions to reduce the levels of free chlorine do not ensure the total elimination of viral pathogens from water systems.

scholarly journals Chemical preservatives in foodstuffs VI. The effect of silver ions on microbes, in particular on the flora of fresh fish

1966 ◽  
Vol 38 (4) ◽  
pp. 198-209
Author(s):  
Olavi E. Nikkilä ◽  
Alpo Siiriä ◽  
Jorma J. Laine
Keyword(s):  
Aqueous Solution ◽  
Silver Ions ◽  
Mixed Cultures ◽  
Fresh Fish ◽  
Baltic Herring ◽  
Pure Cultures ◽  
Chemical Preservatives

A study has been made of the effect of silver ions upon microbes in water, in rinsing and washing experiments, and in the storage of fresh Baltic herring in ice containing silver ions. It was observed that silver ions were microbicidic in all experiments except in those with stored fish. Even in this case, silver ions were effective in killing bacteria when they were isolated and kept in an aqueous solution. In all the experiments the pure cultures were less resistant than the natural mixed cultures.

scholarly journals Occurrence of Bacterial Stem Rot, Caused by Erwinia chrysanthemi, on Field-Grown Tomato in Florida

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 831-831 ◽  
Author(s):  
D. O. Chellemi ◽  
H. A. Dankers ◽  
K. Hill ◽  
R. E. Cullen ◽  
G. W. Simone ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Methyl Esters ◽  
Sole Source ◽  
Erwinia Chrysanthemi ◽  
Identification System ◽  
Bacterial Cells ◽  
Sterile Water ◽  
Microbial Identification ◽  
Pure Cultures ◽  
Tomato Isolate

In September 1997, wilted 4-week-old tomato (Lycopersicon esculentum Mill.) plants were observed in a commercial production field in St. Lucie County, FL. Closer inspection of affected plants revealed hollow stems and petioles with dark, water-soaked lesions. Diseased tissue was macerated and streaked onto nutrient agar (NA) and crystal violet pectate (CVP) agar. After incubation for 2 days at 30°C, isolates produced pits on the CVP agar. Isolates were transferred onto NA and the incubation and transfer procedure was performed two additional times to obtain pure cultures. Suspensions of bacterial cells were injected into tomato and tobacco leaves to test for a hypersensitive or pathogenic reaction. Isolates produced collapsed necrotic tissue on tomato while no reaction was observed on tobacco. Tests for differentiating species and subspecies in the ‘carotovora’ group of Erwinia were conducted following the protocol of Dickey and Kelman (1). With known cultures of E. carotovora subsp. carotovora and E. chrysanthemi as controls, the isolate from tomato was determined to function as a facultative anaerobe, utilize asparagine as a sole source of carbon and nitrogen, and give positive reactions for pectate degradation, phosphatase, and growth at 37°C. Known cultures of E. carotovora subsp. carotovora, E. chrysanthemi, and the tomato isolate were grown on trypticase soy broth agar for 24 h at 28°C and their cellular fatty acids derivatized to fatty acid methyl esters (FAMEs). Statistical analyses of FAME profile data (MIDI Microbial Identification System, Newark, DE, version 3.60) identified the tomato isolate as Erwinia chrysanthemi. Pathogenicity was determined by inoculating 50-day-old tomato plants (cv. SunPride) with a suspension of E. chrysanthemi obtained from nutrient broth plates incubated at 24°C for 60 h. Three plants each were inoculated with the E. chrysanthemi identified from tomato, sterile water, and known cultures of E. chrysanthemi and E. carotovora subsp. carotovora by placing a drop at the junction of the petiole and stem and passing a sterile needle through the drop into the stem. Plants were maintained in a greenhouse. Dark, water-soaked cankers were observed on the stems of plants inoculated with E. chrysanthemi, including the tomato isolate and E. carotovora subsp. carotovora, after 7 days. No symptoms were observed on plants inoculated with sterile water. Reisolation of the pathogen and identification was performed with tissue from one of the symptomatic inoculated plants. Analyses of FAMEs confirmed E. chrysanthemi as the causal agent. This is the first report of E. chrysanthemi causing a vascular disease of field-grown tomato in Florida. Reference: (1) R. S. Dickey and A. Kelman. 1988. Pages 44–59 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. N. W. Schaad, ed. American Phytopathological Society, St. Paul, MN.

scholarly journals Certain Aspects of Silver and Silver Nanoparticles in Wound Care: A Minireview

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Marek Konop ◽  
Tatsiana Damps ◽  
Aleksandra Misicka ◽  
Lidia Rudnicka
Keyword(s):  
Silver Nanoparticles ◽  
Clinical Practice ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Wound Care ◽  
Wound Dressings ◽  
Major Health Problem ◽  
Major Health ◽  
Bactericidal Effects

Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. In this context silver and silver nanoparticles (AgNP) have been known to have inhibitory and bactericidal effects and was used throughout history for treatment of skin ulcer, bone fracture, and supporting wound healing. In all of these applications prevention and treatment of bacterial colonized/infected wounds are critical. In this context silver and its derivatives play an important role in health care. Silver is widely used in clinical practice in the form of silver nitrate and/or silver sulfadiazine. In the last few years silver nanoparticles entered into clinical practice as both antimicrobial and antifungal agents. In addition, nanosilver is used in coating medical devices (catheters) and as component of wound dressings. In this paper we present summarized information about silver and nanoparticles made of silver in the context of their useful properties, especially antibacterial ones, being of a great interest for researchers and clinicians.

Microbiological safety of a small water distribution system: evaluating potentially pathogenic bacteria using advanced sequencing techniques

2017 ◽  
Vol 18 (2) ◽  
pp. 391-398 ◽  
Author(s):  
A. M. M. Batista ◽  
P. Meynet ◽  
G. P. P. Garcia ◽  
S. A. V. Costa ◽  
J. C. Araujo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Relative Abundance ◽  
Distribution System ◽  
Water Distribution ◽  
Pathogenic Bacteria ◽  
Water Distribution System ◽  
Free Chlorine ◽  
Intermediate Point ◽  
Microbiological Safety ◽  
The City

Abstract This study evaluated the microbiological safety of the water distribution system of a city in the state of Minas Gerais (Brazil), population 120,000 inhabitants. During the study, the city suffered a severe drought that had a significant impact on water availability and quality in the river that supplies water to the city. Samples (2 liters) were collected from the distribution system over a period of six months, which included wet and dry months, from three points: the point with the lowest altitude in the distribution network, the farthest point from the water treatment works, and an intermediate point. Free chlorine was measured in situ using a Hach kit. DNA was extracted using a FastDNA Spin Kit Soil (Qbiogene). Advanced sequencing techniques (Ion Torrent) were used to identify and quantify the relative abundance of potentially pathogenic bacteria present in the samples. Coliforms and Escherichia coli, indicators currently used worldwide to assess microbiological safety of drinking water, were measured on all samples using an enzyme substrate method (ONPG-MUG Colilert®). Next generation sequencing results retrieved 16SrRNA sequences of E. coli and some potentially pathogenic bacteria, even in the presence of free chlorine. Operational taxonomic units related to pathogenic bacteria were present in all samples from the drinking water distribution system (DWS) and, in general, at high relative abundance (up to 5%). A total of 19 species related to bacterial pathogens were detected. Inadequate operational practices that could affect the microbiological safety of the DWS were identified and discussed. The current paper is the first to evaluate the community of potentially pathogenic bacteria in a real DWS.

Contamination of swimming pools and hot tubs biofilms with Acanthamoeba

2018 ◽  
Vol 63 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Behroz Mahdavi Poor ◽  
Abdolhossein Dalimi ◽  
Fatemeh Ghafarifar ◽  
Fariba Khoshzaban ◽  
Jalal Abdolalizadeh
Keyword(s):  
Pcr Amplification ◽  
Cross Sectional Study ◽  
Recreational Water ◽  
Swimming Pools ◽  
Cross Sectional ◽  
Swimming Pool Water ◽  
Specific Fragment ◽  
Hot Tubs ◽  
High Degree ◽  
Tabriz City

Abstract The members of Acanthamoeba genus are ubiquitous amoeba which could be a pathogenic parasite. The amoeba is resistant to the common chlorine concentration that used for disinfecting the swimming pool water. Therefore, the pools can be suitable environments for the survival and multiplication of the amoeba. In this cross sectional study, 10 indoor recreational water centers from different regions of Tabriz city were selected and sampling was done from fixed and floating biofilms of the swimming pools and hot tubs. The samples were cultured and monitored for the presence of amoeba cyst or trophozoite. For molecular identification of Acanthamoeba, PCR (polymerase chain reaction) and sequencing were conducted based on genus specific fragment of 18S ribosomal DNA (Rns). Acanthamoeba contamination was observed in 6 centers of 10 recreational centers. Based on the amoeba isolation from fixed and floating biofilms, 2 (20%) swimming pools, and 5 (50%) hot tubs were contaminated. Based on the type of the sample, the highest contamination was found in the hot tub water (40%) and the least was found in the swimming pools water (10%) and fixed biofilms of the swimming pools (10%). Out of 8 isolates, 5 (62.5%) were shown expected product in PCR amplification. Sequence analysis showed that Acanthamoeba isolates belonged to the T3 and T4 genotypes. The study revealed a high degree of contamination in the indoor recreational water centers in Tabriz city. So, it is essential to pay closer attention to the hygiene of swimming pools and hot tubs.

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