**2.5 Salmonella detection**

One gram of the sample was diluted in 9 ml 1% NaCl to a dilution up to 5-10 times. One ml from each dilution was transferred into another five tubes containing buffered peptone water (9 ml). The inoculated tubes were incubated at 37° C for 24 h, then 0.1 ml from each tube showing bacterial growth (turbidity) was transferred into 10 ml of Rappaport-Vassiliadis (RV) broth. The inoculated tubes were incubated at 43.5 ± 1°C for 24 h, then three loops from each tube were taken, the first was streaked out onto bismuth sulfite agar according to [51]. The plates incubated up to about 48 h at 37 ± 0.5°C. Growth of Salmonella on bismuth sulfite agar plates showed are black center, light edges surrounded by a black precipitate with metallic sheen (so-called

*Perspective Chapter: Removal of Heavy Metals and Salmonella Pathogens from Sewage Sludge… DOI: http://dx.doi.org/10.5772/intechopen.109224*

rabbits or fish- eye). A typical colony was collected and streaked on slants of tryptic soya agar (TSA) (contains 10% glycerol) and stored at 4°C not more than 1 year. Confirmation of Salmonella was carried out using the API E20 Enterobacteriaceae test system and RISA molecular profiling [52].
