Bacteriophage is the phage which causes the microbial host to infect and COLIPHAGE is the bacteriophage which in fects Escherichia coli. The presence of COLIPHAGE in surface waters is the indication of fecal contamination (enteric viruses). The objective of this study was evaluation of enteric viruses recovery from farmed fish using Male specific COLIPHAGE (MS2) as an indicator bacteriophage for enteric viruses due to stable connection to surfaces. MS2 COLIPHAGE was used to contaminate farmed Salmon fish in three concentrations (103, 105 and 108 pfu/ml) all around Mashhad city. After phage spiked, COLIPHAGE recovery was evaluated using double agar layer technique from three different parts of Salmon fish (gills, skin flesh and interceptive) according to the best procedure (glycine- threonine- polyethylene glycol). The highest COLIPHAGE recovery in the lowest spiked concentration (103pfu/ml) was in skin-flesh of Salmon fish while interceptive of Salmon fish had the highest recovery in 105pfu/ml of spiked concentration.

In this study somatic COLIPHAGEs were enumerated by double agar layer method, using Escherichia coli (ATCC 13706) as the host strain. Two standard methods for determination of fecal coliforms (most probable number) and membrane filtration, and numerated spores of Clostridium perfringes (by membrane filter method) were also made to compare the fluctuations. Thirty samples of surface and ground waters were collected from Tehran city. Regeneration coefficient (r) values obtained from correlation analysis between the concentration of the COLIPHAGEs, and the others (fecal coliforms by MNP, fecal coliphorms by membrane filter and spores of Clostridium perfringes). The r-value of colliphages and coliforms by MNP method was the lowest correlation (r=0.19) and that was not significant. This value for COLIPHAGEs and coliforms by membrane filter method was r = 0.43 and that was a little significant. The highest correlation coefficient was obtained with COLIPHAGEs and spores of Clostridium perfringes, r=0.62, and it was significant. Therefore, colliphages would be considered as an optimal indicator of pollution of natural waters by the spores of Clostridium perfringes, but not for colliform.  

Nowadays, presence of enteric viruses in water and some foods is proved as a cause for infectious diseases. Raw milk can transmit enteric viruses potentially. Lack of distinct protocol for recovery and extraction of these viruses from raw milk made us to evaluate the effect of dry matter amount on quality and amount of viral RNA yield. Therefore according to reverse of routine protocols in separating of milk components, we prepared four milk model solutions in different combinations and ratios based on natural raw milk components. Then, each milk model solution was spiked with five levels of MS2 COLIPHAGE (1.3×104, 1.3×102, 1.3, 1.3×10-2, 1.3×10-4 pfu/ml). We isolated the viral RNA from each milk model solution using phenol - guanidine thiocyanat - chloroform method. Also we measured quality and RNA extraction Yield in twelve frequencies by nanodrop spectrophotometer. The results showed that in the equal viral concentration, the most amount of viral RNA was extracted from whole milk model solution (including fat). Whereas casein and whey proteins had the most inhibition in the viral RNA extraction .Also the highest quality of the extracted RNA for molecular detection was related to whole milk model solution. Based on response surface model (polynomial) RNA extraction yield and quality of the extracted RNA were closely correlated to the amount of dry matter of milk model together with COLIPHAGE concentration (R=0.96 and R=0.92 respectively).

A total of 114 samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and COLIPHAGEs. Sorbitol MacConkey agar is mainly used in the detection of E. coli O157:H7. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of 20 different genera, 38 species of non-sorbitol fermenting bacteria were isolated. Escherichia coli O157 could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O157. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals` wastewaters samples. The correlation between COLIPHAGEs and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O157, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries.