A simple membrane filtration-elution method for the enumeration of F-RNA, F-DNA and somatic coliphages in 100-ml water samples

1996 ◽  
Vol 25 (3) ◽  
pp. 257-269 ◽  
Author(s):  
L.W. Sinton ◽  
R.K. Finlay ◽  
A.J. Reid
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Somatic Coliphages ◽  
Elution Method

A Most Probable Number Method for the Enumeration of Legionella Bacteria in Water

1991 ◽  
Vol 24 (2) ◽  
pp. 143-147 ◽  
Author(s):  
N. A. Grabow ◽  
R. Kfir ◽  
W. O. K. Grabow
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Quantitative Method ◽  
Fluorescent Antibody ◽  
Most Probable Number ◽  
Probable Number ◽  
Comparative Tests ◽  
Antibody Staining ◽  
Direct Fluorescent Antibody ◽  
Yeast Extract Agar

A new quantitative method for the enumeration of Legionella bacteria in water is described. Appropriate tenfold serial dilutions of water samples concentrated by membrane filtration are plated in triplicate on buffered charcoal yeast extract agar. After incubation for 3 days representative smears from individual plates are tested for the presence of Legionella by direct fluorescent antibody staining. The number of positive plates in each dilution is used to calculate the Legionella count by means of conventional most probable number statistics. In comparative tests on a variety of water samples this method yielded significantly higher counts than previously used procedures.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

scholarly journals Assessment of Giardia and Cryptosporidium Assemblages/ Species and Their Viability in Potable Tap Water in Beni-Suef, Egypt Using Nested PCR/RFLP and Staining

2019 ◽  
Author(s):  
Doaa HAMDY ◽  
Ayman El-BADRY ◽  
Wegdan ABD EL WAHAB
Keyword(s):  
Water Samples ◽  
Rural Areas ◽  
Nested Pcr ◽  
Membrane Filtration ◽  
Tap Water ◽  
Significant Risk ◽  
Waterborne Diseases ◽  
Filtration Method ◽  
Pcr Rflp ◽  
Blue Stain

Background: The protozoan Giardia and Cryptosporidium are responsible for most water-borne diseases all over the world. The extent and number of outbreaks of waterborne diseases suggests a significant risk of their potential transmission via drinking water. This study aimed to document the prevalence and viability of Giardia and Cryptosporidium (oo) cysts in tap water samples in Beni-Suef Governorate, Egypt and to detect the predominant Giardia and Cryptosporidium assemblages/species using nested PCR/ Restriction Fragment Length Polymorphism (RFLP) confirmed by further sequencing of positive samples. Methods: A total of 80 tap water samples were collected throughout a year from four big centers and filtered using the membrane filtration method. Samples were stained by Lugol’s iodine, Modified Zeihl-Neelsen (MZN) (to detect prevalence) and trypan blue stain (to detect viability). Nested PCR-RFLP and sequencing were used for molecular characterizations and genotyping of the detected Giardia and Cryptosporidium. Results: Giardia and Cryptosporidium DNA was detected in 20 (25%) and 29 (36.3%) samples respectively, with predominance of Giardia assemblage B (85%) and C. hominis (75.9%). The prevalence and viability of both parasites (oo) cysts showed seasonality which peaked in summer and were greater in Beba center and in rural areas. Conclusion: To our knowledge, no studies have been done in these areas before. The anthroponotic transmission has an important role in giardiasis and crypto­sporidiosis epidemiology in this studied area.

scholarly journals Bluephage, a method for efficient detection of somatic coliphages in one hundred milliliter water samples

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javier Méndez ◽  
Daniel Toribio-Avedillo ◽  
Raquel Mangas-Casas ◽  
Judit Martínez-González
Keyword(s):  
Water Samples ◽  
Somatic Coliphages ◽  
Efficient Detection

Optimisation of the ISO-method on enumeration of somatic coliphages (draft ISO 10705-2)

2001 ◽  
Vol 43 (12) ◽  
pp. 205-208 ◽  
Author(s):  
K. A. Mooijman ◽  
M. Bahar ◽  
N. Contreras ◽  
A. H. Havelaar
Keyword(s):  
Membrane Filtration ◽  
Viable Count ◽  
Somatic Coliphages ◽  
Layer Method ◽  
Bathing Waters ◽  
Agar Layer ◽  
Eu Project ◽  
Single Agar ◽  
Filtration Technique ◽  
The Eu

As part of the EU project “Bacteriophages in Bathing Waters” (January 1996 - June 1999) research was carried out to optimise the method for detection and enumeration of somatic coliphages in water as described in ISO/CD 10705-2 of August 1995. It was concluded that this draft ISO standard needed to be amended in certain aspects. For determining the viable count of the host culture WG5 Escherichia coli, a membrane filtration technique should be used instead of spread plate technique as the latter gives lower and less reproducible results. A freshly prepared inoculum culture of host strain WG5 should be used instead of a frozen inoculum culture as freezing of the inoculum culture is found to negatively influence the phage counts. The double agar layer method (DAL) is preferred to the single agar layer method (SAL) for performing the phage analysis as the DAL method gives higher phage counts than the SAL method.

Effects of Backwashing on the Characteristics of Sand Filtration Effluents: Organic and Microbial Analyses

2013 ◽  
Vol 353-356 ◽  
pp. 2921-2925
Author(s):  
Jian Li Lin ◽  
Chih Ming Kao ◽  
Jen Jeng Chen ◽  
Shao Wei Liao ◽  
Chung Yi Chung ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Water Samples ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Head Loss ◽  
Sand Particle ◽  
Sand Filtration ◽  
Sand Filter ◽  
Continuous Increase

In this study, the head loss, turbidity, particle size, and zeta potential were monitored from the effluent of the sand filtration system after backwashing located in Cheng-Ching Lake (CCL) Water Treatment Plant. Moreover, the non-purgeable dissolved organic matter (NPDOC) and excitation emission fluorescent matrix (EEFM) were measured for the collected water samples with or without the pretreatment process. Results indicate that the turbidity of the influent dropped to 0.06 NTU and remained stable after flowing through the sand filter during the 4-hr operation period. However, a continuous increase of the head loss and sand particle size for the sand filter was observed. This phenomenon was opposite with the absolute value of zeta potential. The water samples were collected from the effluent of the sand filter and were treated by a 0.2 μm membrane filter. Thus, higher NPDOC values of sample without pretreatment were observed in comparison with sample with treatment. Results indicate that the sand filter was able to remove NPDOC, and bacteria might proliferate among the sand filter in rapid filtration. Results from the EEFM analyses show that effluents without membrane filtration pretreatment contained a higher percentage of aromatic protein. Compared to the water samples without pretreatment, more humic-like substance was found in the effluent. This reveals that microbial products or bacteria were detached from the fillers after the backwashing process.

scholarly journals Membrane filtration media for the enumeration of coliform organisms and Escherichia coli in water: comparison of Tergitol 7 and lauryl sulphate with Teepol 610

1980 ◽  
Vol 85 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
False Positive ◽  
Membrane Filtration ◽  
Sodium Lauryl Sulphate ◽  
Standard Medium ◽  
E Coli ◽  
Laboratory Trial ◽  
Positive Results ◽  
Filtration Technique

SUMMARYIn a multi-laboratory trial with the mombrane filtration technique, three surfactants – Teepol 610 (T610), Tergitol 7 (T7) and sodium lauryl sulphate (LS) – were compared in media for the enumeration of coliform organisms and Escherichia coli in water. A total of 170 samples of water (87 raw and 92 marginally chlorinated) were examined for colony counts of coliform organisms, and 185 water samples (94 raw and 91 marginally chlorinated) for E. coli. Slight differences in the confirmed colony counts between the three media were noted, but few of these were observed consistently in every laboratory. In most laboratories, T7 gave slightly higher counts of E. coli than LS with chlorinated waters; a higher incidence of false-positive results for E. coli at 44 °C was also noted with T7. As there were no outstanding differences in the trial, sodium lauryl sulphate, which is chemically defined, cheap and readily available, is therefore recommended for use at a concentration of 0·1% instead of Teepol 610 in the standard medium for the enumeration of coliform organisms and E. coli in water by the membrane filtration technique.

scholarly journals Comparative Microbiological Assessment of Drinking Water Collected from Different Areas of Kathmandu Valley

2019 ◽  
Vol 6 ◽  
pp. 39-43
Author(s):  
Aman Thapa Magar ◽  
Mamata Khakurel ◽  
Shree Laxmi Pandey ◽  
Kalyan Subedi ◽  
Umesh Kaji Manandhar ◽  
...  
Keyword(s):  
Ground Water ◽  
Water Samples ◽  
Membrane Filtration ◽  
Tap Water ◽  
Bacterial Load ◽  
Total Coliform ◽  
Bottled Water ◽  
Plate Count ◽  
Aerobic Plate Count ◽  
Filtration Technique

Objectives: This study was aimed to evaluate different water samples in terms of Total bacterial load and Total Coliform Load in comparison with different parameters such as pH, type of samples, chlorination status, turbidity, temperature and collection areas. Methods: Altogether 250 water samples were collected; 110(44%) were ground water samples, 60(24%) were public tap water samples and 80(32%) were bottled water samples. Total Coliform load was evaluated using Membrane Filtration Technique and Total Bacterial Load was evaluated using Aerobic Plate Count Technique. pH was measured using pH meter, turbidity was measured using nephelometer, temperature was measured using temperature probe and bottled water were considered chlorinated. Results: Among these 250 samples, the highest mean bacterial load was seen in public tap water samples (137×103 cfu/ml) and least mean bacterial load was seen on bottled water sample (28×103). Similarly, highest mean coliform load was seen on ground water samples (81 cfu/ml) and least mean coliform load was seen on bottled water samples (6 cfu/ml). Conclusion: This study has concluded that ground water samples contain large number of coliforms which suggest it might be fecally contaminated. Also the result had shown even bottled water contained coliforms. Therefore, it is recommended to treat ground water before using. Proper care must be taken during manufacture of bottled water.

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