Risk Assessment of Heterotrophic Plate Count (HPC) Bacteria in Potable Water Sources PDF Download

Author: Zuzanne G. Martinez
Publisher:
ISBN:
Category : Heterotrophic bacteria
Languages : en
Pages : 148

View

Book Description

Author: Bartram J.
Publisher: World Health Organization
ISBN: 9241562269
Category : Medical
Languages : en
Pages : 273

View

Book Description
This text prepared by an international group of experts addresses the 'heterotrophic plate count' test which is widely used in drinking-water assessment: what it detects (and what it does not detect) its direct and indirect health significance and its use in the safety management of drinking water supplies. It includes the consensus statement from an expert review meeting and takes account of the presentations and posters at an international conference on the theme co-sponsored by WHO and NSF-International. It provides valuable information on the utility and the limitations of HPC data in the management and operation of piped water systems as well as other means of providing drinking water to the public. It is of particular value to piped public water suppliers and bottled water suppliers manufacturers and users of water treatment and transmission equipment and inline treatment devices water engineers sanitary and clinical microbiologists and national and local public health officials and regulators of drinking water quality. ...The book will be of great value to the piped public water suppliers bottled water suppliers manufacturers users of water treatment and transmission equipment and online treatment device makers water supply engineers sanitary engineers clinical and water microbiologists national and local public health officials and regulators of drinking-water quality. - Indian Journal of Medical Research

Author: A. Dufour
Publisher: IWA Publishing
ISBN: 1843390361
Category : Science
Languages : en
Pages : 296

View

Book Description
Inadequate drinking water quality and poor sanitation have remained the world's major causes of preventable morbidity and mortality. In 1996 the OECD called for concerted action to improve the assessment and management of the world's sources of drinking water. This guidance document seeks to respond to this call. It is the product of a shared initiative between the OECD and the World Health Organization. It is a state-of-the-art review that will contribute to the revisions of the WHO's Guidelines for Drinking Water Quality. Assessing Microbial Safety Of Drinking-water has elements of both revolution and evolution. It is revolutionary in that it supports a rapidly emerging approach for a broader, system-wide management perspective. This is based on a risk management framework that has evolved from the traditional indicator concept to include multiple parameters and where consideration is also given to tolerable risk, water quality targets and public health status.

Author: Dobromir Nicolov Pavlov
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Heterotrophic plate counts (HPCs) are commonly used to assess the general microbiological quality of drinking water. Drinking water quality specifications world-wide recommend HPC limits from 100 to 500 cfu.m1-1. However, a number of recent studies revealed evidence that commonly used indicator bacteria may not be as harmless as generally accepted. It appears that immuno-compromised individuals, which represent increasing components of many consumer populations, are particularly at risk. This would include the very young and very old, patients with diseases such as AIDS, and patients on therapy after organ transplantations and cancer treatment. Since, epidemiological and animal infectivity studies are complex and difficult to control, attempts have been made by researchers to examine HPCs directly in order to assess health risks. These analyses included: cytotoxicity, invasiveness, enzyme analyses, antibiotic susceptibility and identification. In this study, 339 bacterial colonies were isolated at random from selected drinking water supplies in South Africa using heterotrophic plate count tests. In a first step to screen for potentially pathogenic properties, 188 (55.5%) of the isolates showed ; - and ;?-haemolysis on human- and horse-blood agar media. Subsequent analysis of the haemolytic isolates for enzymatic properties associated with pathogenicity revealed the presence of chondroitinase in 5.3% of the isolates, coagulase in 16.0%, DNase in 60.6%, elastase in 33 .0%, fibrinolysin in 53.7%, gelatinase in 62.2%, hyaluronidase in 21. 3 %, lecithinase in 47.9%, lipase in 54.8%, and proteinase in 64.4%. Fluorescein and pyocyanin were not produced by any of the isolates. The Kirby-Bauer quality controlled disc diffusion method was applied in the demonstration of antibiotic resistance by the HPC isolates. Among the haemolytic isolates 77.7% were resistant to oxacillin (1 ; g), 59.6% to penicillin G (2 units), 47.3% to penicillin G (10 units), 54.3% to ampicillin (10 ; g) and 43.1% to ampicillin (25 ; g). Cell culture studies revealed that 96% of haemolytic isolates were cytotoxic to HEp-2 cells and 98.9% of the 181 cytotoxic isolates adhered to HEp-2 or Caco-2 cells. Gram-negative isolates tended to adhere in larger numbers than gram-positive isolates. The average index of adherence for Gram-negative bacteria was 20-30 bacteria per HEp-2 cell, compared to 3-7 for Gram-positive bacteria. HEp-2 cells were invaded by 43.6% and Caco-2 cells by 49.7% of the 181 cytotoxic isolates. The invasion index on HEp-2 cells was 1.9xlO-1 to 8.9xl0-6, compared to 7.7xl0-2 to 8.3xlO-6 on Caco-2 cells. The most commonly isolated genera showing potentially pathogenic features were: Aeromonas, Acinetobacter, Aureobacterium, Bacillus, Chryseobacterium, Corynebacterium, Klebsiella, Moraxella, Pseudomonas, Staphylococcus, Tsukamurella and Vibrio. All these genera are known to contain opportunistic pathogens. Our results support earlier findings on potentially pathogenic features of bacteria detected by heterotrophic plate counts on drinking water. These findings seem to be in agreement with some epidemiological studies, which indicated an association between HPCs of drinking water and the incidence of gastroenteritis in consumers. However, the extent of the health risk concerned needs to be defined in detail for meaningful revision of quality guidelines for HPCs in drinking water.

Author: Tapio Katko
Publisher: IWA Publishing
ISBN: 1780408684
Category : Science
Languages : en
Pages : 334

View

Book Description
The book addresses the interdisciplinary area of water quality monitoring and binds together interests and competences within sensing technology, system behaviour, business needs, legislation, education, data handling, and artificial response algorithms.

Author: Donald J. Reasoner
Publisher:
ISBN:
Category : Drinking water
Languages : en
Pages : 57

View

Book Description

Author: World Health Organization
Publisher:
ISBN:
Category : Drinking water
Languages : en
Pages : 144

View

Book Description
Contents: v.1. Recommendations -- v.2. Health criteria and other supporting information -- v.3. Drinking-water quality control in small-community supplies.

Author: Susumu Kawamura
Publisher: John Wiley & Sons
ISBN: 9780471350934
Category : Technology & Engineering
Languages : en
Pages : 724

View

Book Description
Completely up-to-date coverage of water treatment facility design and operation This Second Edition of Susumu Kawamura's landmark volume offerscomprehensive coverage of water treatment facility design, from thebasic principles to the latest innovations. It covers a broadspectrum of water treatment process designs in detail and offersclear guidelines on how to choose the unit, process, and equipmentthat will maximize overall efficiency and minimize maintenancecosts. This book also explores many important operational issuesthat affect today's plant operators and facility designers. This new edition introduces several new subjects, including valueengineering, watershed management, dissolved air flotation process,filtered reservoir (clearwell) design, and electrical systemdesign. It provides expanded and updated coverage of objectives forfinished water quality, instrumentation and control, disinfectionprocess, ozonation, disinfection by-product control, the GACprocess, and the membrane filtration process. Other importantfeatures of this Second Edition include: * Practical guidance on the design of every water treatment plantcomponent * New information on plant layout, cost estimation, sedimentationissues, and more * English and SI units throughout * Help in designing for compliance with water treatment-relatedgovernment regulations Supplemented with hundreds of illustrations, charts, and tables,Integrated Design and Operation of Water Treatment Facilities,Second Edition is an indispensable, hands-on resource for civilengineers and managers, whether working on new facilities orredesigning and rebuilding existing facilities.

Author: Dick van der Kooij
Publisher: IWA Publishing
ISBN: 1780400403
Category : Science
Languages : en
Pages : 484

View

Book Description
Maintaining the microbial quality in distribution systems and connected installations remains a challenge for the water supply companies all over the world, despite many years of research. This book identifies the main concerns and knowledge gaps related to regrowth and stimulates cooperation in future research. Microbial Growth in Drinking Water Supplies provides an overview of the regrowth issue in different countries and the water quality problems related to regrowth. The book assesses the causes of regrowth in drinking water and the prevention of regrowth by water treatment and distribution. Editors: Dirk van der Kooij and Paul W.J.J. van der Wielen, KWR Watercycle Research Institute, The Netherlands

Author: Sunette Walter
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

View

Book Description
Heterotrophic plate count bacteria -- Drinking water quality -- Biofilms -- Red-copper coupons -- Drinking water distribution systems -- Heterotrofiese plaattellings bakterie?e -- Drinkwater kwaliteit -- Rooikoper koeponne -- Drinkwater verspreidingssisteme.