Comparison of Different Enrichment Broth and Plating Media Used to Isolating Salmonella from Chicken Carcasses and Poultry Faeces Samples

This study was undertaken to compare selenite-cystine-novobiocin (SCN) broth, tetrationate-novobiocin (TN) broth and Rappaport-Vassiliadisnovobiocin (RVN) broth as enrichment and MacConkey (MC) agar, brilliant green (BG) agar, Hektoen (HE) agar, Salmonella-Shigella (SS) agar and xylose Iysine desoxycholate (XLD) agar as plating media for isolating Salmonella from broiler carcasses and chicken feces. The carcasses were washed with 300mL of Buffer Peptone Water 0.1% (BPW). The BPW solation was incubated 6h at ambient temperature and up to 24 h/43ºC. From this, 2 mL were inoculate in 20 mL of enrichment broth, incubated at 43ºC/24h. The enrichment broth was plated on the five tested selective agars, also incubated at 43ºC/24h. Up to five colonies from each plate were inoculated in TSI agar and LIA agar, incubated at 37ºC/24h. The genus of Salmonella was confirmed by slide agglutination test using poly serum anti-somatic Salmonella antigens (O) and poly serum anti-fiagellar (H) Salmonella antigens. The feces were experimentally contaminated with eight Salmonella serotypos (Agona, Anatum, Enteritidis, Havana, Intantis, Owakam, Schwazengrundand Typhimurium). Each serotype was tested five times. Salmonella serotypes were added in the sample of feces individually so that the final concentration of the bacterium was 1,2 x iO³ ufclg. Two grams of each sample were inoculated in 20 mL of the enrichment broth. The proceduring from this point wes the same adopted to carcasses examination. To broiler carcasses there was no statistic difference (p>0, 001) among the enrichment broth and among plating media. However the use of two enrichment broth (SCN and TN) and two agars between XLD agar, SS agar and HE agar gave the bost results. The assay done with feces showed that the TN broth was much better than the others and, in this case it can be plated either HE agar, or VB agar or SS agar The results from the broiler carcasses examination and the feces examination showed that it is not easy to determine the better bacteriologic routine to search for Salmonella and suggest that the association of two eorichments broth and two plating media may improve the test.

Salmonella; enrichment broth; plating media; isolating; broiler carcasses; chicken feces