Background: Waste water contains microorganisms which are continuously shed in the feces. These microorganisms especially bacteria might acquire antibiotic resistance and pose a significant threat to human health. Therefore, this work aims at isolating bacteriophage capable of infecting the isolated bacteria. Methodology: For this purpose, the grab sampling was performed at the Guheswori sewage treatment plant from the inlet in the primary treatment plant and from the outlet of the secondary treatment plant. For the isolation of bacteriophage, bacteriophage in the sewage was first enriched in an isolated pathogen, then filtered and then subjected to the isolates in the nutrient agar. Results: Pathogens like Escherichia coli, Salmonella Typhi, Enterococcus faecalis, Staphylococcus aureus, Coagulase negative Staphylococcus (CONS), Citrobacter fruendii, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Pseudomonas aeruginosa were screened. Bacteriophage was able to infect E. coli (p < 0.001), S. Typhi (p < 0.001), E. faecalis (p = 0.182); and unable to infect S. aureus, CONS, C. fruendii, E. aerogenes, P. mirabilis, P. vulgaris, P. aeruginosa. Conclusion: Bacteriophage are able to infect and kill pathogens like E. coli, S. Typhi, E. faecalis and unable to infect S. aureus, CONS, C. fruendii, E. aerogenes, P. mirabilis, P. vulgaris, P. aeruginosa. Among all other reasons of lowering bacterial load, bacteriophages could also be one of the confounding factor. Such bacteriophage able to infect and undergo lytic cycle could be used in phage typing.

In recent years, we are having mixed feelings regarding the use of polyethylene terephthalate (PET) bottles for storing water. The aim of this study is to determine any associations between bacterial load and the physical condition of the water bottle. For this study, bottled water was purchased, and parameters like pH, electrical conductivity (EC), total dissolved solids (TDS), heterotrophic plate count (HPC), total coliform count, and Pseudomonas spp. count were determined as per the American Public Health Association, 2005. The pH value of water samples tested ranged from 5.2 to 6.8. The majority of samples (96%) were found to contain pH values that were unacceptable as per the Department of Food Technology and Quality Control (DFTQC) guideline. Value of electrical conductivity (EC) ranged from 5 to 199 μS/cm. HPC revealed that, out of 100 samples, 48 (48%) samples were found to be acceptable as per the DFTQC guideline value (<25 cfu/mL). Among 100 samples, Pseudomonas spp. was found to be present in 23% of bottled water. Acidic pH and elevated concentrations of TDS and EC may lead to the survival of extremophiles present in HPC which may lead to degradation of PET. Extremophile bacteria that survive in bottled water for a long time rely on several survival mechanisms including evolutionary development (evo-devo) and solely survive on complex polymers like PET.

Sales of bottled water have been increasing around the globe. This study was carried out to assess the trace elements present in bottled water. For the study of bottled water, a total of 100 samples of different volumes (20 L and 1 L) were selected. The physicochemical assessments were performed as per the methods described in the American Public Health Association, 2005. Average values of pH, electrical conductivity, total dissolved solids, and turbidity were found to be 5.96 ± 0.54, 59.97 ± 58.65, 4.42 ± 3.69, and 0.408 ± 0.19, respectively. Likewise, average values of total hardness (as CaCO3), calcium (as CaCO3), magnesium (as CaCO3), chlorine, iron, copper, cobalt, nickel, fluoride, sodium, and potassium were found to be 14.78 ± 8.43, 3.26 ± 1.55, 11.51 ± 7.92, 7.51 ± 3.21, 0.0032 ± 0.0017, 0.0091 ± 0.0116, 0.2520 ± 0.0127, 0.0080 ± 0.0082, 0.047 ± 0.0139, 12.65 ± 10.90, and 1.41 ± 2.00, respectively; meanwhile residual chlorine, zinc, silver, cadmium, and lead were below detection limit. All the physicochemical characteristics of bottled water were found to be within International Bottled Water Association (IBWA) guidelines. From the physicochemical aspects, the bottled water was found to be within the permissible value set by IBWA. Pearson’s correlation revealed significant association between trace elements. Levene’s test for equity of variances indicated that the majority (iron, copper, cobalt, nickel, fluoride, sodium, and potassium) of trace elements and seasons (monsoon and postmonsoon) demonstrated a statistically significant distribution (at 95% confidence interval). At elevated concentrations, some elements can be harmful to human health and can cause morphological abnormalities, mutagenic effects, reduced growth, and increased morbidity and mortality in humans but it all depends upon a person’s metabolic factors, genetic factors, and ability to excrete trace elements through different routes, etc. Water could have percolated down from the surface to the ground water and as such the difference in concentration of trace elements in monsoon and postmonsoon seasons could be noticeable.

Background: Water sources such as lakes, ponds, river etc. have been continuously contaminated by the   micro organisms and chemicals. The former can pose a significant threat to human health. This work aims at detecting the bacterial load before and after the sewage treatment and hence isolating pathogens from the sewage before primary treatment and secondary treated effluent. Methods: Grab sampling (50mL sewage before primary treatment and secondary treated effluent) was performed for 20 days in the Guheswori  sewage treatment plant. The reduction in microbial load was determined through heterotrophic plate count. Pathogens were screened from the effluent obtained from the secondary treatment plant. Results: Bacterial load reduction was found to be about 48.02% on average. The observed bacterial load reduction might have been caused by bacteriophage flocculation and sedimentation. Pathogens isolated from the treated effluent were Escherichia coli, Salmonella Typhi, Enterococcus faecalis, Staphylococcus aureus, Coagulase negative Staphylococcus (CONS), Citrobacter fruendii, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Pseudomonas  aeruginosa. Conclusions: It has been found that the sewage treatment plant helps to reduce the bacterial load which is, however, not capable of effluent polishing where all pathogens are killed.

Introduction: Membrane filtration (MF) is one of the widely used technique on a routine basis. On the other hand, replica plate (RP) technique can be used to transfer existing bacterial colonies in two plates which even allows pinpointing the original colony. The aim of this study is to comparatively detect the cfu/100 mL of fecal coliform using membrane filtration and replica plate techniques.Methods: In the study, a total of 25 bottled water were selected from the local market in Kathmandu valley. The total coliform count was detected using MF, while fecal coliform was detected using both MF and RP technique.Results: It was found that the average cfu/100 mL for total coliform, fecal coliform (MF) and fecal coliform (RP) were 143.38, 49.82 and 51.00 respectively. Pearson correlation coefficient calculated between total coliform and fecal coliform (MF), total coliform and fecal coliform (RP), fecal coliform (MF) and fecal coliform (RP) were found to be 0.695, 0.733 and 0.990 respectively; implying a positive correlation Conclusions: It has been demonstrated that intrinsic and extrinsic factors influence colony forming units. Furthermore, RP is a more sensitive method for screening fecal coliforms although both MF and RP can be efficiently used.