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Waterborne disease has changed a basic challenge in human population. recently, the use of nanotechnology and application of nanomaterials for the control of pathogens in water is widely increased in research. Common indicator for microbial quality of water are determine presence of total and fecal coliforms. The purpose of this study was to evaluate the effect of Silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs) and combination of them in removing total and fecal coliform bacteria from contaminated water. In this experimental study a synthetic solution was made by adding effluent to distilled water. In each run, the nano silver (20-100 μg /L) and ZnO NPs (0.25-2 mg/L) were added to contaminated water. The samples were tested by 15-tube series method based on the instruction 9221-B of 21th edition of standard method book on water and wastewater experiments. Bacteria removal efficiency were examined in contact times (15, 30,60, 90 and 120) minutes. Our data indicate a decrease in the number of bacteria (MPN) in the presence of the nanoparticles. Results revealed that the removal percentage of coliform bacteria removal increased with increasing the contact time and concentrations of nanoparticles. Ag NPs at a concentration of 100 μg /L and ZnO NPs at a concentration of 2 mg/L showed the highest percentage of removal bacteria and the combination of ZnO and Ag NPs have been high synergistic behavior against coliform bacteria in contaminated water. therefore, using a combination of ZnO and Ag NPs can become a new and efficient method for the removal of indicator bacteria from contaminated water.

Background: Today, bottled water is used in many countries of the world due to its relatively low cost, better taste, ease of access and low levels of impurities. In unfavorable conditions, the maintenance of microorganisms due to hydrophobicity and adherence to bottles and as a result of increased lipolytic activity can lead to undesirable changes in color, taste and odor, and in cases of more severe load, microbial contamination may cause unhealthy water and flooding. In this study, the presence or absence of coliform in a number of bottled water brands was examined. Methods: The microbial quality of 10 markers of bottled water present in the market of Sari that was randomly selected from each mark and three samples was examined. The samples were analyzed using the coliform-presence/absence (P-A) test. The results were compared with national standards and the World Health Organization (WHO) guidelines. Data were analyzed using SPSS version 24 and EXCEL. Results: Samples showed no microbial contamination Also, coliform and fecal coliforms were not observed in any of the samples. Finally, it was revealed that all cases were in accordance with national standards and WHO guidelines. Conclusion: Increasing the health indexes of places, food supply and distribution centers, and maintaining health conditions and measures that have been considered especially in the recent years on the health of bottled water, have greatly reduced the problems.

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Background & objectives: Flies are found worldwide because of adapting to different environments. Synanthropic flies are able to transfer a variety spectrum of pathogens and pathogenic factors to humans because of their close relationship with human life. The present study was aimed to determine the bacterial contamination of Musca domestica and Lucilia sericata as the main type of synanthropic flies in the Ghaem-Shahr city. Methods: Samples were collected from four locations in Ghaem-Shahr city, on a monthly basis and using a bait trap. A total of 384 flies were recruited from two species of Musca domestica and Lucilia sericata in the sterile conditions to determine bacterial contamination in different bacteria medium. Results: Out of 260 samples infected with pathogenic bacteria, 61.1% were related to household flies and 38.8% were related to the Lucilia Sericata. The highest rate of contamination with gram-positive bacilli (22.6%) and gram-positive cocci (26.7%) were related to household flies and Lucilia sericata, respectively. Escherichia coli was the dominant species and the lowest contamination rate was related to Klebsiella sp. Conclusion:To prevent the spread of bacterial infections by flies and providing public health and creating a healthy and safe environment, control measures are required at landfills, hospitals and slaughterhouses.