Salmonella Isolation from Blood and Stool

Blood cultures were collected and processed as previously described [4 (link),15 (link)]. About 1 g of stool was suspended in 10 ml selenite broth (Oxoid, Basingstoke, UK and BD Difco^TM, Becton, Dickinson and Company, Franklin Lakes, NJ, U.S.), and incubated at 36°C for 18–24 hours. Next, 10 μl of selenite broth was inoculated on two plates of Salmonella-Shigella (SS) agar (Oxoid) which were incubated at 36°C for 18–24 hours. In case of absence of growth on the SS plate, the plate was re-incubated for another 24 hours. Two colonies suspected of Salmonella per SS plate were inoculated on a Kligler Iron Agar (KIA) tube (Oxoid) and incubated at 36°C for 18–24 hours. KIA tubes suggestive of Salmonella species were further identified by their biochemical characteristics [2 (link),16 (link)]. Salmonella spp. isolates from blood and stool were stored in tubes with Tryptone Soy Agar (Oxoid) and shipped to INRB for serotyping and ITM for confirmation and molecular testing. Salmonella spp. isolates were serotyped using commercial antisera (Sifin, Berlin, Germany; and Vision^TM, Pro-Lab Diagnostics, Richmond Hill, Canada) according to the Kaufman-White scheme [17 ].