Nested PCR and Conventional Techniques for Detection of Salmonella< /i>spp. in River Nile Water, Egypt

THIS STUDY aimed to detect salmonellae group using most probable number (MPN), membrane filtration (MF) and nested PCR techniques from River Nile at Cairo segment and Rossita branch so, 74 samples were collected and analyzed to count the total viable bacteria/ml and total salmonellae. Total viable bacterial counts ranged from 1.0x102 to 1.6x108 cfu/m1 during the study. Using MPN technique salmonellae were detected in 64 samples out of 74 samples (86.4% recovery), with the MF technique, salmonellae were detected in 73 samples out of 74 samples and with PCR technique salmonellae were detected in all samples. It can be concluded that MF technique is more suitable to detect salmonellae as it allows to filter or pass the relatively larger amount of water sample rather than MPN which measure salmonellae presence in fixed amount of water while nested PCR technique is more rapid, sensitive and specific than conventional techniques (i.e., MF and MPN). Statistical analysis was done only between MF and MPN techniques due to PCR technique doesn't provide counts to be involved in statistical analysis (provide only positive and negative results). Results indicated that counts of Salmonella showed significant differences between sites using both techniques MF and MPN at Cairo segment. Wherever, no significant difference between sites at Rossita branch.