II. MATERIALS AND METHODS
Collection of samples:
A total of 121frozen samples including 81
carcasses ,10 breast muscle ,14thighs and 16wings
were collected from grocery in 4 localities in
Khartoum State namely Khartoum,Bahry
,Omdurman and East nile .Samples were collected
directly from storage devices at temperature ± -18ºC ( the temperature of most domestic freezers)
then transported on ice bags to the lab .
Preparation of samples:
Rinse technique was used to enumerate the total
viable count [13]. The frozen samples were thawed
at 2-5° C and the mass of each sample was
recorded, sample and any fluids in the original
packaging bag were transferred to a sterile plastic
bag of a suitable size, 400 ml sterile peptone water
was added and vigorously shaken and massaged for
1-2 minute to ensure through rinsing of all sample
surfaces, then the rinsed fluids were aseptically
collected in a sterile containers.
Total viable count:
The total viable count was applied according to
Miles and Misra [11]. The concentration of viable
bacteria per ml in initial sample was calculated and
expressed in CFU / ml and then converted to CFU
/cm2 using the formula described previously [12].
Plates with more than 300 colonies were calculated
as 6.5×10 6 EAPC/ml [13].
Identification of the isolates:
The rinsed fluid samples were cultured onto
nutrient, Mac Conkey and blood agar plates. For
the detection of salmonella 10 ml of the rinsed
fluids were added to 100 ml selenite broth,
incubated at 37ºC for 24 hours, then subculture on
Bismuth sulphite, XLD and SS agar incubated at
37ºC for 72 hours . Biochemical test was carried
out for suspected colonies.Isolated bacteria were
identified by colonial morphology microscopic
examination of stained smear in addition to
biochemical tests using API 20E strips and Vitek 2
automated system.