Highest Total Coliform Count Research Articles

Microbiological Quality of Unpeeled Fruits Sold in the Local Market of Tangail District, Bangladesh, and Assessment of Health Impacts

Introduction: Fruits are good source of vitamins, nutrients, minerals, micronutrients, and fiber. However, fruits are usually eaten uncooked and this is hazardous for health as fruits are highly susceptible to microbial contamination during harvesting or postharvest processing. Methods: Nine fruits that we usually eat without peeling were tested by applying different standard microbiological methods. Biochemical and antibiogram tests were performed to confirm bacterial isolates and antibiotic-resistant patterns, respectively. We also performed an anthropometric assessment to evaluate if local common fruits caused any prevalent digestive disorders. Results: The highest Total Viable Count (TVC) was found in guava (1.95×105 CFU/gm), whereas the highest Total Coliform Count (TCC) was in grape (3.39×104 CFU/g). The mean value of TVC of all fruits was 7.112×103 CFU/g and TCC was 6.02×102 CFU/g, respectively. Escherichia coli, Salmonella spp., Shigella spp., and Vibrio spp. were confirmed by biochemical tests. Antibiogram study shows that these bacterial isolates were resistant to commercially available antibiotics. E. coli isolates were resistant to penicillin (73.3%); Salmonella spp. Isolates were resistant to Penicillin (80%), and Amoxicillin (80%). In case of Vibrio spp. isolates, they were resistant to Penicillin (66.67%), Amoxicillin and Erythromycin (60%). The anthropometric assessment showed that acidity occurred more frequently than abdominal pain and digestive disorder among the correspondents. In the case of both male and female respondents, black plum and apple were mostly responsible for gastric acidity and the frequencies were 41% to 45%, respectively. Conclusion: Fruit is a natural source of vitamins and minerals essential for our health, at the same time steps must be taken to ensure that they are free from pathogenic microbes. Therefore, public awareness is necessary for proper hygiene and good health.

Evaluation of physicochemical and microbiological quality of drinking water in the distribution system of Dharan, Nepal

Dharan has been facing drinking water-related problems for a very long time now and this research was conducted in order to determine whether the quality of water being distributed throughout the city was one of them. Hence, 31 samples were taken from the drinking water distribution system of Dharan in the spring of 2022 for evaluating the physicochemical and microbiological quality of drinking water being distributed across the sub-metropolitan city. Though public knowledge and adequate management of watershed and reservoir premises were insufficient, the physicochemical characteristics were determined to be within the National Drinking Water Quality Standards (NDWQS) for drinking water with temperatures ranging from 23.6 °C to 25.6 °C, pH 7.7 to 8.5, conductivity 38.2 to 38.7 µS/cm, Dissolved Oxygen (DO) 7.7 to 9.0 mg/L, Biological Oxygen Demand (BOD) 0.8 to 1.8 mg/L, chloride 29.82 to 34.08 mg/L, nitrite 10 mg/L and ammonia <0.5 mg/L. However, the coliform bacteria levels were significant, with the highest TCC (Total Coliform Count) being 137 CFU/100mL, the highest FCC (Fecal Coliform Count) being 85 CFU/100mL and the highest TPC (Total Plate Count) being TMTC (Too Many To Count). The water was found to be unsafe to drink without disinfection treatments. It may be necessary to carry out treatment procedures like chlorination as advised by WHO (World Health Organization) as soon as possible while also taking into account the proper application of filtration techniques for distributing safe drinking water to the residents of Dharan.

Comparative Study of Indicator Organisms in Different Water Sources in North Bank Area of Makurdi

This study compared the presence of indicator organisms in different domestic water sources in the North Bank area of Makurdi. The water sources included stream waters, well waters, and borehole waters. Total bacteria count, total coliform count, microscopic examination, and biochemical tests were the parameters measured. The results obtained showed that all the different water sources had the presence of total bacteria and coliforms except the borehole water along Ter Guma Street (B1) which only showed the presence of total bacteria. The total bacteria count was found to be more (2.91 x 107 cfu/ml) in the stream water samples along University of Agriculture Road (ST2) and least in B2 water samples (6.76 x 106 cfu/ml) with no significant difference (p>0.05). Total coliform counts were found in all the water sources except in B1 water sample, while, the well water sample from Old Lafia Road (W2), had the highest total coliform count (1600 MPN/100 ml). Coliform isolates including Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Salmonella spp, Pseudomonas aeruginosa, and Klebsiella pneumoniae were found in the water samples, with well water from Old Lafia Road (W2), having more of the isolates. This study reveals that all the water sources studied were contaminated by the presence of microorganisms including indicator organisms, above the recommended by WHO, for a domestic water source. Further study to investigate the physicochemical parameters of these water sources is suggested.

CONCORDANCE OF METHYLENE BLUE REDUCTION AND MICROBIOLOGICAL TECHNIQUES IN THE ANALYSIS OF RAW AND PROCESSED MILK QUALITY: A COMPARATIVE STUDY

Raw milk is a milk that has not undergone pasteurization for an effective pathogen elimination, thus having a reduced shelf life due to microbial activities. Microorganisms such as bacteria can affect the quality of diary products, hence the need to assess the microbial quality of natural cow milk, pasteurized milk and processed tin-milk which are consumed on daily basis in Nigeria, Africa and the world at large. In this study, raw (unpasteurized) and processed milk samples from two locations (Bogobiri and Watt market) in Calabar municipal were analyzed using methylene blue reduction test (MBRT), total heterotrophic bacterial count (THBC) and total coliform count (TCC). The total Heterotrophic bacterial count ranged from too numerous to count (TNTC) to 3.86 x 106 colony forming unit (CFU)/milliliter (ml) in samples MA (Unpasteurized/Raw cow milk) and MB (Pasteurized cow milk) respectively. There was no fungal growth in five of the samples except MA that had a fungal count that was TNTC. The highest TCC was obtained from sample MA, with a value of 2.96 x 106 CFU/mL while sample MD had the lowest count of one colony. The total microbial count from sample MA was extremely high and above the standard signifying that it is unfit for human consumption. The MBRT result revealed that MD (Processed liquid tin-milk) and MC (Processed liquid tin-milk) gave no methylene blue reduction (excellent quality) while MB (Pasteurized cow milk), ME (Processed liquid tin-milk) and MF (Processed liquid tin-milk) were of fair quality. However, MA gave a poor quality based on the MBR time of between 30 m to 2 h corroborating with the high value of its THBC which was above the standard. Milk being a vital protein source and an excellent medium for microbial growth should be thoroughly treated by sterilization in a bottle as the study revealed that the milk microbial load can be greatly reduced by pasteurization, with sterilization in bottle having a greater bactericidal effect than pasteurization.

Microbial Quality Assessment of Raw Freshwater Fish Sold in Local Markets of Kathmandu Valley

Microbial quality of Labeo rohita, Cyprinus carpio and Clarias batrachus collected from the markets of Kathmandu valley was evaluated. 9 freshwater fish (skin, gills, intestine) were sampled and were analyzed for Total Plate Count (TPC), Total Coliform Count (TCC) and Total Fecal Coliform Count (TFCC). The average TPC ranged from 4.1 x 107 to 1.02 x 108 cfu/gm, with the highest count in C. batrachus and the lowest in C. carpio, whereas the organ wise load was the highest in intestine with 1.3 x 108 cfu/gm and the lowest in skin with 1.02 x 107 cfu/gm. The highest TCC and TFCC was found in C. carpio and C. batrachus respectively, whereas organ wise distribution showed the highest count in intestine for both TCC and TFCC. The pathogens isolated from the samples were Escherichia coli, Staphylococcus aureus, Coagulase negative Staphylococcus (CoNS), Vibrio cholerae, Salmonella Typhi and S. Paratyphi. E. coli was isolated from 67% of L. rohita, 44.44% of C. carpio and 66.67% of C. batrachus. S. aureus was isolated from 44.44% of both L. rohita and C. batrachus whereas 55.55% of C. carpio. CoNS were isolated from 33.33% of L. rohita, 22.22% of C. carpio and 33.33% of C. batrachus. S. Typhi was isolated from 11.11% of C. carpio and 22.22% of C. batrachus. S. Paratyphi was isolated from 11.11% of both L. rohita and C. batrachus, V. cholerae was isolated from 11.11% of L. rohita, 33.33% of C. carpio and 22.22% of C. batrachus. The observation of this study showed higher bacterial load in all of the fishes above the acceptance level and presence of Total Coliform, Fecal Coliform and potential human pathogens suggests that the microbial quality of the fish available in the market is not satisfactory. Hence, the fishes possess a threat to public health safety and there is an urgent need to improve the Quality Control and Quality Assurance Systems for fish markets of Kathmandu valley.

How much spatial and temporal variation in groundwater microbiology can occur following open dumping of municipal solid waste?

Abstract The effects of open dumping of municipal solid waste on local groundwater microbiology were assessed in Ranchi, India. Both the spatial and temporal variations of groundwater microbiology were studied. Groundwater was analyzed to determine heterotrophic plate count (HPC), total coliforms (TC) and faecal coliforms (FC). Highest HPC was 4.5 × 104 CFU/mL and the highest total coliform count was 3.7 × 104 CFU/mL. Faecal coliforms were detected in most of the groundwater samples. The highest faecal coliform count of 2.1 × 104 CFU/mL was from a hand pump located adjacent to the dumping site. Spatial variations revealed dispersion of bacterial contamination up to 5 km from the periphery of the municipal solid waste dump. The level of bacterial contamination decreased with an increase in distance from the municipal solid waste dump. The maximum bacterial count was detected in the monsoon whereas the lowest count was found in summer. Molecular characterization of morphologically similar faecal coliform colonies indicated the presence of Klebsiella pneumoniae (Klebsiella ssnkbit, KU647674) in one of the groundwater samples that showed maximum faecal coliform count. Results of this study indicated that groundwater in the area is highly contaminated with a bacterial load which can be a major health risk.

Physico-chemical and microbiological assessment of drinking water of the selected restaurants in Mymensingh district of Bangladesh

Water is essential for living organisms for their survival. Access of adequate and safe water is a basic need of human beings. In adequacy and unsafe water supply may cause various health problems. This study was designed with a view to assessing physicochemical properties of drinking water collected from different restaurants at Mymensingh sadar. In this case, electrical conductivity (EC), total dissolved solids (TDS), pH, dissolved oxygen (DO), biological oxygen demand (BOD), arsenic (As), iron (Fe) and lead (Pb) were measured. Furthermore, Microbiological assessments of drinking water samples were carried out. For achieving the microbiological assessment, methods of heterotrophic plate count (HPC) and total coliform count (TCC) were applied. The mean value of EC, TDS, pH, DO, BOD, As, Fe, Pb were 682.38 µS cm-1, 201ppm, 7.11, 4.98 mg/L, 1.72 mg/L, 0.005 ppm, 0.181 ppm and 0.000 ppm, respectively. According to the standard of drinking water the EC, TDS, pH, DO, BOD, As, Fe, Pb toxicity were not detected in all samples. All of above mentioned parameters were present in water within permissible limits. In most cases the concentrations of Pb and in some cases the concentrations of Fe were considered as toxicants due to the higher concentrations noted. The highest heterotrophic plate count was found in water of Ganginapar sample (1.2×107 CFU/ml) and the highest total coliform count was noted in C. K. Ghosh road sample (13 coliforms/100 ml). Therefore, the examined water quality parameters indicate that water quality of the restaurants at Mymensingh sadar is suitable for drinking. Although some of the samples identified as the presence of fecal coliforms that indicates contamination of feces with water. One sample among the studied drinking water samples was contaminated with fecal coliform which is very harmful for health and this water is not suitable for drinking. It may be concluded that hygienic and quality water need to supply for human drinking purposes.
 Progressive Agriculture 32 (2): 84-95, 2021

Impact of Indian almond leaves on aquarium water quality

There are very few studies done to understand the impact of Indian almond leaves (IAL) on aquarium water quality. Therefore, in this study, Indian almond leaves (IAL) were used to investigate the impacts on water quality in an aquarium with Betta fish as they are hardy fish, tolerant to changes in water quality, comparatively cheaper and more readily available in tropical countries. For this study, the powdered form of IAL was used for faster dilution or mixing. As for the aquarium tank, smaller tanks with a capacity of 4.5 litres are used since Betta fish is small in size and it is easy to be accommodated in the aquarium. The various dosage of IAL in power form (0-200 mg/L) was used to determine physical, chemical and biological parameters of aquarium water quality in the presence of Betta fish. The parameters were Biochemical Oxygen Demand (BOD5), Dissolved Oxygen (DO), turbidity, pH, chlorine and survivability test and tests were conducted on day 1, 3, 7, 14, 21 and 28. All experiments had an increasing value of DO until Day 21 and gradually decreased, while BOD5 increased with increased IAL dosage. Ammonia concentration increased between day 5-10 and then started to decline at day 21 and pH values were decreasing with increased IAL dosage. The total coliform test has the highest total coliform count on day 28 for IAL dosage. The study revealed that Betta fish could survive for 28 days without any application of de-chlorinator. The optimum dosage of 50 mg/L of IAL can eliminate any requirement for de-chlorination for Betta fish.

Assessment of Some Bacteriological Quality of Streams of Upper Awash River, Central Ethiopia

Supply of safe and adequate drinking water is very essential for the health of human beings. But water safety and sanitations in the developing countries has been a serious problem threatening the community of these nations. The major objective of this article is to communicate the microbial quality of water of streams of upper Awash River. The indicator microbial quality of the water samples from streams of upper Awash River was analyzed using membrane filtration techniques, while heterotrophic bacteria, Bacillus spp and Staphylococcus aureus count were done by using specific isolation techniques for the particular organisms. From the five different sampling sites site 1 and 4 showed highest total coliform count ranging from 17300 to 22000 cfu/100ml. Escherichia coli count ranged from 200to 11300 cfu/100ml; Entrococcus count ranged from 178to 2300 cfu/100ml; Clostridium perfringes ranged from 66- to 201 cfu/100ml. Hetrotrophic plate count ranged from 350-2380 cfu/100ml. Bacillus spp count ranged from320-990 cfu/100ml. Staphylococcus aureus count ranged 300-1950 cfu/100ml.The result of this investigation indicated that all the indicator microorganisms and other bacterial species were found to be above the minimum number of the specific group of the organisms showing that the water of streams of upper Awash river is highly exposed to certain pollution and it need some means of purification before it used for the intended purposes. Keywords/ phrases: bacteriological; indicator microorganisms, Streams; water quality DOI: 10.7176/JNSR/10-9-01 Publication date: May 31 st 2020

Effect of variations in heterotrophic plate count methods on bacterial estimation in some sachet water in Calabar Metropolis

Heterotrophic plate count (HPC) or standard plate count is a standardized method for determining the density of aerobic and facultative anaerobic heterotrophic microorganisms in water. In this study, water samples were analyzed to ascertain the effects of temperature, media, and incubation time in HPC methods of bacterial estimation. The samples were analyzed using the membrane filtration and direct plating methods. No faecal coliform was detected in all the samples and at all temperature. However, some coliforms and heterotrophic bacteria were present in the water samples. The organisms were isolated at 4 °C, 28 °C and 37 °C after 24-72 h. The heterotrophic bacterial isolates include: Enterobacter spp., Staphylococcus aureus, S. epidermidis, Bacillus sphericus, B. cereus, Micrococcus roseus, Pseudomonas aeruginosa and Klebsiella pneumonia. It was observed that yeast extract agar gave a higher heterotrophic plate count at 28 °C while EMB agar yielded the highest total coliform count at 37 °C. The result of the physicochemical analysis showed that the water samples met the World Health Organization (WHO) and Standards Organization of Nigeria (SON) standards for drinking water while the bacteriological quality based on the total coliform count result indicates the need for improvement in the treatment systems.

Diarrhoeal Disease in Relation to Possible Household Risk Factors in South African Villages.

Diarrhoeal disease is a significant contributor to child morbidity and mortality, particularly in the developing world. Poor sanitation, a lack of personal hygiene and inadequate water supplies are known risk factors for diarrhoeal disease. Since risk factors may vary by population or setting, we evaluated the prevalence of diarrhoeal disease at the household level using a questionnaire to better understand household-level risk factors for diarrhoea in selected rural areas in South Africa. In a sub-sample of dwellings, we measured the microbial quality of drinking water. One in five households had at least one case of diarrhoea during the previous summer. The most widespread source of drinking water was a stand-pipe (inside yard) (45%) followed by an indoor tap inside the dwelling (29%). Storage of water was common (97%) with around half of households storing water in plastic containers with an opening large enough to fit a hand through. After adjusting for confounders, the occurrence of diarrhoea was statistically significantly associated with sourcing water from an indoor tap (Adjusted Odds Ratio (AOR): 2.73, 95% CI: 2.73, 1.14–6.56) and storing cooked/perishable food in non-refrigerated conditions (AOR: 2.17, 95% CI: 2.17, 1.44–3.26). The highest total coliform counts were found in water samples from kitchen containers followed by stand-pipes. Escherichia coli were most often detected in samples from stand-pipes and kitchen containers. One in four households were at risk of exposure to contaminated drinking water, increasing the susceptibility of the study participants to episodes of diarrhoea. It is imperative that water quality meets guideline values and routine monitoring of quality of drinking water is done to minimise diarrhoea risk in relevant rural communities. The security of water supply in rural areas should be addressed as a matter of public health urgency to avoid the need for water storage.

Microbiological and Antimicrobial Analysis of Hospital Wastewater Discharged into the Soil Environment

This study evaluated the microbiological effects of hospital wastewater discharged into the soil environment using standard microbiological procedures. The highest total bacterial count (8.3±0.5×1010 cfu/ml) of the wastewater samples was observed in the collation point sample while the laundry wastewater sample had the least number of 5.4±0.5×107 cfu/ml. The collation point wastewater sample had the highest total coliform count (4.1±0.1×108 cfu/ml)while the laundry wastewater sample produced the least count of 2.3±0.1×101 cfu/ml. The highest total coliform faecal count of 4.2±0.3×105 cfu/ml was observed in the collation point wastewater sample while the least count of 2.4±1.2×103 cfu/ml was seen in the laundry wastewater sample. The mortuary wastewater had the highest total fungal count of 3.1±0.2×105 cfu/ml while the least count was seen in the collation point wastewater 2.9±0.2×102 cfu/ml. The total viable numbers of the soil samples ranged from 5.0±0.0×108 cfu/g (200m away from the point of discharge) to 8.4±1.6×1012 cfu/g (point of release) while the total coliform counts ranged from 2.3±0.0×104 cfu/g (200m away from the point of discharge) to 3.9±0.8×108 cfu/g (point of discharge). The highest total faecal count of 3.7±0.5×104 cfu/g was observed in the sample from the point of discharge while the least count was seen in the sample collected 200m away from point of discharge 2.3±0.1×102 cfu/g. Total fungal count ranged from 2.4±0.5×107 cfu/g (200m away from the point of discharge) to 3.4±0.5×108 cfu/g (point of discharge). The bacterial species isolated were Escherichia coli, Erwinia, Serratia, Enterococcus, Staphylococcus, Streptococcus, and Salmonella. Others were Pseudomonas aeruginosa, Proteus, Neisseria, Actinomycetes, Shigella, Bacillus and Enterobacter species. The fungi isolated include Aspergillus niger, Aspergillus fumigatus, Trichophyton rubrum, Candida, Penicillium and Rhizopus species. Bacillus spp., Staphylococcus epidermidis, Penicillium spp. and Rhizopus species were the most frequently distributed (100%), followed by S. species, Enterococcus spp., E. coli, Pseudomonas aeruginosa, Proteus spp. and Candida spp. (80%). Salmonella spp., Shigella spp., Enterobacter spp. and Trichophyton rubrum had the same rate of 60%, respectively while the least occurrence was seen in Streptococcus spp., Neisseria spp., Actinomyces spp. and Aspergillus niger with the rate of 40%, respectively. The high microbial loads of the isolates and the high densities of the coliforms indicate there is, therefore, contamination of the soil environment as a result of the discharged hospital wastewater, which could probably be hazardous to human health.

Effect of quality of colostrum on health, growth and immunoglobulin G concentration in Holstein calves in a hot environment.

The aim of this study was to determine the effect of ingestion of pasteurized and subsequently frozen–thawed pooled colostrum (≥50 mg Ig/mL) with different bacterial counts and immunoglobulin concentration (IgC) on the occurrence of diarrhea and pneumonia in 306 neonatal Holstein calves in a hot environment. Calves were assigned to be fed colostrum with total bacterial counts (TBC) lower or greater than 100 000 colony‐forming units (cfu)/mL, total coliform counts (TCC) greater or lower than 10 000 cfu/mL, and IgC lower or higher than 85 mg Ig/mL. Calves fed colostrum with TBC ≥100 000 cfu/mL were more likely (risk ratio 1.34, confidence interval 1.05–1.71; P < 0.05) to present pneumonia than calves receiving colostrum with lower TBC (incidence 53.2 vs. 39.8%). Calves fed colostrum with high TCC had increased chances of suffering pneumonia (51.4 vs. 42.1%; P < 0.05) than calves fed colostrum with lower TCC. Calves fed colostrum with ≥85 mg Ig/mL tended to present higher daily weight gain (505 ± 113 vs. 484 ± 126 g; P = 0.09). TBC and TCC in colostrum did not influence the incidence rate of diarrhea. It was concluded that under the conditions of the present study, heavy contamination of on‐farm pasteurized frozen–thawed colostrum is seemingly unavoidable and this contamination poses a threat for pneumonia, but not for diarrhea.

Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico.

Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.

A comparison of the boating and swimming microbial water quality of Calabar River and cross river estuary, Nigeria

Calabar River Estuary is often used by both locals and tourists for boating and swimming making it necessary to assess the microbial recreational water quality of this water body. Five sampling stations were established – 3 in Calabar River and 2 in the Estuary. Calabar River stations were inshore while the estuarine stations were outshore. Sampling was fortnightly and twice on sampling days to cover flood and ebb tides. Water samples were analyzed for total coliform, fecal coliform and intestinal Enterococci . The highest count of intestinal Enterococci (191cfu/100ml) was recorded in station 3 during flood tide in July. Station 2 had the lowest count (17cfu/100ml) of intestinal Enterococci and this was in November during the dry season and during low tide. The 95 th percentile of the highest and lowest count of intestinal Enterococci was 190/100ml and 14/100ml respectively. The highest total coliform count (1900cfu/100ml) was recorded at station 3 in July during flood tide while the lowest (163cfu/100ml) was recorded also station2 during ebb tide in November. Almost the same scenario was observed for fecal coliform. The highest count (250cfu/100ml) was recorded at station 3 in July during flood tide while the lowest count (27cfu/100ml.) was recorded at station 2 in February during ebb tide. Statistical analysis using t- test indicated that there is no significant difference in microbial water quality between Calabar River and the Estuary. All the sampled stations met the WHO, and EC standards for safe recreational waters. Keywords: Boating, Swimming, Water quality, Total coliform, Fecal coliform, Enterococci

English

Food safety issues are of growing concern to consumers globally because of the risk associated with consumption of foods contaminated with pathogens in irrigated vegetables. The study was conducted to assess the extent of bacterial contamination of vegetables due to irrigation with polluted Awash River water. Three leafy vegetable samples, namely, cabbage (Brassica oleracea L. var. capitata), lettuce (Lactuca sativa L. longifolia) and spinach (Spinacea oleracea) from both farms were examined for bacterial contaminants. The results show that spinach was found to be the most heavily contaminated vegetable in both farms by aerobic bacteria. The aerobic mesophilic bacterial count on this vegetable was 2.2×108 and 2.0×108 CFU/g, for spinach sampled from Melka Hida and Wonji Gefersa vegetable farms, respectively. The highest total coliform count (6.6×106) was also recorded from lettuce in Melka Hida vegetable farm. The mean fecal coliform values of all the three vegetable samples exceed the International Commission on Microbiological Specifications for Foods (ICMSF) recommended level. The highest faecal coliform count (5.7×105) was recorded in cabbage sampled from Wonji Gefersa. The high microbial contamination rates associated with these vegetable samples indicated poor water quality for irrigation employed in the overall production of vegetables in the study area. Key words: Indicator bacteria, pathogen, vegetables.

Groundwater contamination in Agbowo community, Ibadan Nigeria: Impact of septic tanks distances to wells

In Nigeria, inadequate supply of pipe borne water is a major concern; hence many homes have wells as a source of water for household uses. The groundwater of forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts (TABC) and Total Coliform Counts (TCC). The location and distances of wells from septic tanks were determined using the Global Positioning System (GPS) device and a tape rule respectively. All the wells sampled had high TABC (4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFU/mL) counts which exceeded the international standard of 0 per 100 mL of potable water. There were no significant differences in the bacterial counts between covered and uncovered wells (p>0.05). The mean distance (8.93±3.61m) of wells from the septic tanks was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TABC increased with a decrease in distance between the wells and septic tanks though not significant (p<0.05). A very weak positive correlation (r 2 =0.021) ensued between the distance from septic tank and CC, while a weak negative correlation (r 2 = ‒0.261) was obtained between the TCC and TABC. This study accentuates the need to set standards for the siting of wells from septic tanks while considering all possible sources of well contamination as well as treatment of ground water before use.