Physicochemical and Microbiological Analyses of Bacterial Isolates from Drinking Water Distribution Systems of Some Higher Institutions in Edo State, Nigeria (original) (raw)
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J.Appl.Sci.Environ.Manage., 2019
ABSTACT: In drinking water systems, a large number of microorganisms live in complex communities in a self-produced extracellular polymeric matrix associated with inner surfaces of pipes, walls and floors of storage tanks, joints and faucets. This study was aimed at analyzing the physicochemical and microbiological characteristics of bacterial isolates of drinking water distribution systems in some higher institutions in Edo State. The physicochemical parameters were determined by using standard protocol and microbiological water quality was conducted using the standard microbiological methods. The results of the physicochemical analysis showed that, the pH values ranged between 4.17 and 5.89. The highest (5.89) was recorded with samples from OK-R and the least (4.17) was obtained from UB-T. The electrical conductivity (EC) values for SA-R (104.8µS/cm), AA-R (105.5 µS/cm) and OKR (114.8 µS/cm) exceeded the permissible threshold value of 100µS/cm. Concentrations of lead for AA-R (0.02 mg/L) and OK-R (0.03 mg/L) were significantly higher than the acceptable level of 0.01mg/L. The mean total heterotrophic bacterial counts ranged from 3.3 ± 0.3 x 10 2 cfu/mL to 9.3 ± 0.3 x 10 2 cfu/mL, with the least and highest counts recorded for UB-R and AA-R. Phenotypically identified bacteria were the Citrobacter, Klebsiella, Bacillus, Pseudomonas, Proteus and Providencia species. The study revealed that drinking water system of biofilms is a reservoir for microorganisms that could cause public health concerns which is impacted by the presence of available nutrient, environmental conditions and heavy metals.
Water Research, 1998
ÐIn Germany, bank-®ltered raw water and ground water is mainly used for drinking water conditioning. Microorganisms, which are neither retarded by the subsoil passage of the bank-®ltration, nor by the dierent ®ltration and disinfection steps at the water works, cause the growth of bio®lms on dierent materials originally used in drinking water distribution systems. The development, the phylogenetical diversity and the bacterial metabolic activities of bio®lms on polyethylen (PE-HD), polyvinylchlorid (PVC), steel and copper were analyzed at dierent sampling points. The incubation experiments were performed under natural conditions using a¯ow device technique. The devices were installed after the activated carbon ®lters and disinfection step at the water works and at two dierent house branch connections within the distribution system of the conditioned drinking water of the water works. The synthetic materials were colonized very rapidly within a few days in signi®cant higher densities than steel and copper. The total bacterial cell counts of the bio®lms were measured by DAPI (4',6-diamidino-2-phenylindole) staining. The metabolic activities of the bacteria were quanti®ed by the use of the redox dye CTC (5-cyano-2,3-ditolyl tetrazolium chloride), which is frequently described as an indicator for respiration. The highest respiratory activities were observed in bio®lms from synthetic materials grown after the activated carbon ®lters at the water works. A signi®cant reduction of the total bacterial cell counts and respiratory activities of about 80% was measured due to the disinfection at the water works. A time dependent growth of bacteria in bio®lms was observed at the two sampling points within the distribution system, whereas the percentage of CTC-reducing cells stabilized at 35%. The in situ-hybridizations with¯uorescence labelled, group-speci®c rRNA targeted oligonucleotide probes revealed the following: (i) bacteria of the Beta-and Gamma-subclass of Proteobacteria were found most frequently within the bio®lm population, (ii) the percentage of the dierent subclasses depended on the used material, (iii) there were no signi®cant changes in bacterial subclass composition of the bio®lms taken from the water works and house branch connections. In addition, polymerase chain reaction (PCR), southern blot hybridization and in situ hybridization were used to detect facultative pathogenic bacteria in bio®lms. Non-pneumophila Legionella were found in a relative high percentage up to about 7% in many bio®lms, whereas fecal streptococci were detected only in few bio®lms of the drinking water distribution systems
Prevalence of bacterial pathogens in biofilms of drinking water distribution systems
Journal of water and health, 2007
Water for human consumption is required to be free from any bacteria that might pose a health risk. The presence of biofilms in the drinking water distribution system may play a role in the presence of potential pathogens in the drinking water supply. Ninety-five biofilm samples from various parts of South Africa were tested for the presence of Escherichia coli, Aeromonas, Pseudomonas, Salmonella, Shigella and Vibrio spp. Members of these genera were quantified by the three-tube most probable number (MPN) approach using enrichment broths and plating on selective agars. The heterotrophic culturable counts were determined for both the planktonic and biofilm phases of the samples. Biofilm density varied between 10 and 1.9 x 10(9) colony forming units cm(-2). The 16S rRNA identity of the putative pathogenic isolates revealed that high numbers of Aeromonas, Pseudomonas, Klebsiella and Enterobacter were present, but no putative Salmonella and Shigella could be confirmed. None of the Pseud...
Journal of Environmental Biology, 2018
Potable water can be contaminated with variety of bacterial pathogens during the distribution process. The aim of this study was to analyze the bacterial risks associated with drinking water supply system of the city Kasur, Pakistan. Water analysis was accomplished by following the most probable number (MPN) method. Bacterial diversity was determined by 16S rRNA gene sequencing. Screening for O157 antigen was conducted for all the identified strains of. Strains were also screened for antibiotic susceptibility and biofilm formation. Analysis showed 2400 MPN index for few water samples. 16S rRNA sequencing confirmed the presence of bacterial strains belonging to the genera of and Serological analysis also detected the presence of pathogenic strains of O157. Antibiotic sensitivity pattern showed the resistance of strains against nitrofurantoin, cephalexin, nalidixic acid and ampicillin. For biofilm formation, DG1 and J4 were the most active biofilm producer in single cultures. Majority of the water samples were contaminated in terms of coliforms. Biofilm formation by bacterial strains indicated that water distribution network might be colonized by potential human pathogens.
Journal of Advances in Microbiology, 2019
This study evaluated the physico-chemical and the bacteriological quality of five different sources of drinking water in Calabar metropolis, Nigeria, to give a fair geographical representative of the town and to contribute to our understanding of the quality of drinking water in the metropolis. The physicochemical characteristics such as pH, temperature, turbidity, conductivity, colour, Iron, dissolved oxygen, Calcium, Magnesium, alkalinity, total hardness, Manganese, Sulphate, Chloride, Phosphate, Sodium, Zinc, Copper, total dissolved solid, Nitrate, Nitrite, Ammonia, Ammonium and Potassium were determined following the procedures prescribed by American Public Health Association Standard Method. The bacteriological analysis was carried out using the standard microbiological standard for analysis of water for total and faecal coliform count. The mean temperature of the evaluated waters ranged from 23.03°C-29.3°C, mean pH ranged from 4.37-6.76, while turbidity had a mean range of 0.16 NTU-4.13 NTU. Conductivity ranged between 39.29 μs/cm - 120.7 μs/cm, dissolved oxygen with 13.30 mg/L - 4.19 mg/L, total dissolved solids ranged from 72.4 mg/L -23.5 mg/L, while the mean for iron concentration ranged from 0.12 mg/L - 0.99 mg/L. Similarly, the mean for total hardness was 34.2 mg/L - 17.1 mg/L and 7.93 mg/L - 6.71 mg/L for total alkalinity. Others includes Manganese (0.88 mg/L - 0.02 mg/L), Magnesium (16.5 mg/L - 9.9 mg/L), Calcium (9.77 mg/L - 7.20 mg/L, Nitrate (14.6 mg/L - 3.66 mg/L), Nitrite (0.076 mg/L -0.009 mg/L), Ammonia (0.89 mg/L - 0.25 mg/L), Ammonium (0.52 mg/L - 0.013 mg/L), Zinc (1.01 mg/L - 0.34 mg/L), Chloride (5.73 mg/L - 0.364 mg/L), Fluoride (0.76 mg/L - 0.277 mg/L), Copper (0.61 mg/L - 0.18 mg/L), Sodium (2.73 mg/L - 0.180 mg/L), potassium (5.73 mg/L - 2.0 mg/L), Sulphate (14.8 mg/L - 3.69 mg/L and Phosphate with 4.8 mg/L - 3.69 mg/L. The total coliform count for bottled water ranged between 2.00 cfu/100 mL – 19.00 cfu/100 mL, the total coliform range for sachet water were 6.00 cfu/100 mL and 15.00 cfu/100 mL and no faecal coliform was detected. Public water had no growth at all, the stream and borehole bacteriological analysis ranged from 27x101 cfu/ mL - 55x101 cfu/mL and 12 cfu/100 mL - 33 cfu/100 mL for total coliform respectively. Faecal coliform ranged from 15x101 cfu/ mL - 52x101 cfu/ mL for stream and 9.00 cfu100/ mL – 16.00 cfu/100 mL for borehole. A total of seven (7) different bacteria species were isolated from the sampled drinking water sources. These included Proteus spp., Streptococcus spp., Enterobacter spp., Pseudomonas spp., E.coli, Chromobacter spp., Salmonella spp. and Enterococcus spp. This study reveals a high level of poor quality sources of water in the metropolis and makes need for urgent health intervention.
Ceylon Journal of Science, 2021
Several water-related disease outbreaks have been attributed to deficiencies in water distribution systems (WDS). This study determined the relationship between biofilmproducing bacteria and their antibiotic resistance in WDS in Ilorin Metropolis, Nigeria through the assessment of the quality of water, the virulence factors possessed and susceptibility to some antibiotics. The physicochemical and bacteriological quality of the water samples were analyzed using standard methods. A total of 60 samples were collected from seven different locations within Ilorin metropolis. The pH of the water samples ranged from 6.58 – 7.22, turbidity 0.14 – 2.07 NTU and free residual chlorine ranged from 0.00 – 1.14 mg/L. A total of eleven bacteria isolates were identified by biochemical and molecular methods. They included genera of Pseudomonas, Escherichia, Staphylococcus, Klebsiella, Citrobacter, Shigella, Proteus, Yersinia and Serratia. The total bacterial counts were 1.10 – 7.20 × 102 cfu/mL. The isolates consisted of 72.7% biofilm producers using the tube method and 63.6% biofilm producers using the congo red method. Both biofilm and non-biofilm isolates displayed complete resistance to ceftriazone, amoxicillin, tetracycline, and cotrimoxazole. Biofilm producers showed stronger relationship with antibiotic resistance (p < 0.0001) than non-biofilms, thus suggesting the use of bacterial biofilm counts as indicators of water quality.
Impact of Biofilms on Water Distribution System of a Tertiary Institution in Northern Nigeria
Equity Journal of Science and Technology
The aim of this research was to determine the impact of biofilms on water distribution system of FederalUniversity Birnin Kebbi. Samples were collected from different water distribution pipelines in the University.Total heterotrophic count was carried out to determine the microbial load and Most Probable Method (MPN)was used to detect the presence of fecal coliforms in the water. Total heterotrophic bacterial count rangedbetween 1.6×103 to 3.9×103 cfu/ml. Escherichia Coli showed the highest frequency (25%) of occurrence, whilethe least frequency of occurrence (5%) was recorded for Klebsiella spp and Enterobacter spp respectively. Theisolates identified were Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella spp,Enterobacteria Spp, Salmonella Spp and Bacillus Spp. Presence of these isolates is of significant concern andmay cause some water borne diseases like diarrhea, dysentery etc. It is therefore recommended that water boardtreatment plant should use disin...
Biofouling, 2006
Monitoring of biofilms subjected to different operating conditions was performed using a flow cell system. The system was fed by chlorine-free tap water, with and without added nutrients (0.5 mg l 71 carbon, 0.1 mg l 71 nitrogen and 0.01 mg l 71 phosphorus), and biofilms were grown on polyvinyl chloride (PVC) and stainless steel (SS) coupons, both in laminar and turbulent flow. The parameters analysed were culturable cells, using R2A, and total bacteria, which was assessed using the 4,6-diamino-2-phenylindole (DAPI) staining method. The impact of the different operating conditions in the studied parameters was established using Multivariate Analysis of Variance (MANOVA). From the most relevant to the least relevant factor, the total and culturable bacteria in biofilms increased due to the addition of nutrients to water (F ¼ 20.005; p 5 0.001); the use of turbulent (Re ¼ 11000) instead of laminar (Re ¼ 2000) hydrodynamic flows (F ¼ 9.173; p 5 0.001); and the use of PVC instead of SS as the support material (F ¼ 2.848; p ¼ 0.060). Interactions between these conditions, namely between surface and flow (F ¼ 8.235; p 5 0.001) and also flow and nutrients (F ¼ 5.498; p 5 0.05) have also proved to significantly influence biofilm formation. This work highlights the need for a deeper understanding of how the large spectrum of conditions interact and affect biofilm formation potential and accumulation with the final purpose of predicting the total and culturable bacteria attached to real drinking water distribution pipes based on the system characteristics.
Microbial Analysis of Drinking Water And Water Distribution System
The discharge of wastes from municipal sewers is one of the most important water quality issues world-wide. It is of particular significance to sources of drinking-water. Municipal sewage contains human faeces and water contaminated with these effluents may contain pathogenic (disease-causing) organisms and, consequently, may be hazardous to human health if used as drinking-water or in food preparation. Faecal contamination of water is routinely detected by microbiological analysis. It is impractical to attempt the routine isolation of pathogens because they are present in relatively small numbers compared with other types of micro-organism. Moreover, there are many types of pathogen and each requires a unique microbiological isolation technique. The approach that has been adopted is to analyse for indicator organisms that inhabit the gut in large numbers and are excreted in human faeces. The presence of these indicator organisms in water is evidence of faecal contamination and, therefore, of a risk that pathogens are present. If indicator organisms are present in large numbers, the contamination is considered to be recent and/or severe. Bacteria in water are, in general, not present individually, but as clumps or in association with particulate matter. When enumerating bacteria in water it is not the number of individual bacteria present which are counted, but the number of clumps of bacteria or the particles and their associated bacteria. Each clump or particle may have many bacteria associated with it.
2022
The aim of this study is to comparatively analyze the bacterial load and physiochemical parameters of water samples from various sources used by the students of Federal University, Dutsinma Katsina State. Samples from tap, well, dam, rain, sachet and boreholes were collected at different locations where students reside. There were 6 sources of water, namely; tap water, dam water, well water, borehole water, sachet water and rain water from which 10 samples were obtained each, making a total of 60 samples for analysis. The physicochemical parameters of each water samples were detected. According the technique adopted by Chessbrough. (2000), the samples were serially diluted, 3 test tubes were sterilized and distilled water of 9ml were Pipette into these test tubes, 1ml of the water sample was pipette into the first test tube and was shaken vigorously to have a homogeneous mixture (stock). Bacterial count of each water sample was carried out and presence of Escherichia coli, P.aeruginosa, S.aureus, S.typhi, K.pneumoniae, B.subtilis, Proteus sp, Shigella sp, and E.aerogenes were identified. Biochemical tests were carried out for accurate characterization of the isolates. The pattern of occurrence the studied physico-chemical parameters (except pH) of borehole water, sachet water, Dam, Rain, well, tap water were within the permissible limit set by World Health Organization. The pH of all samples of sachet water were within the permissible limit set by World Health Organization However, the pH of 7 out of 10 samples of borehole water and 8 out of 10 samples of tap water were within the permissible limit set by World Health Organization. The prevalence of indicator organisms in water samples are as follows; Klebsiella pneumoniae (Dam water=100%, Sachet water=0, Tap water=80%, Borehole=70%, Rain=20%, Well=100%), Escherichia coli(Dam water=100%, Sachet water=0, Tap water=20%, Borehole=10%, Rain=0, Well=100%), Pseudomonas aeruginosa (Dam water=100%, Sachet All rights reserved. No reuse allowed without permission.