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Salmonella Bacterin Against Probiotic
Salmonella Enteritidis Infection in Broiler
Trial Aim
This study was carried out to investigate the efficacy of thelocally prepared autogenous Salmonella Enteritidis (S.Enteritidis) bacterin as well as a probiotic preparation in theprevention of broiler chickens from S. Enteritidis infection.
Experimental Chickens
310, day-old Hubbardbroiler chicks of mixed sex.
Obtained from CairoPoultry Company in 10thRamadan city.
Breeder flock free fromsalmonellosis.
Experimental Design
At arrival, randomly 10 chicks were sacrificed and thenexamined bacteriologically to prove their freedom from S.Enteritidis infection.
Experimental Chickens
The birds were kept under complete observation for six weeksexperimental period) in separate thoroughly cleaned anddisinfected houses.
Vaccination Program
ND IB AI IBD
Day 6: HB1Day 19: L aSota
Day 6: H120 Day 7: H5N1 RG Day 14: 228E
Salmonella Vaccination Program
Inactivated S. Enteritidis bacterin was given IM in the thighmuscle for the experimental chicks at:
1. First day of age in a dose of 0.2 ml/bird
2. Second dose at 10 days of age in a dose 0.5 ml/bird.
The Used Probiotic
Commercial preparation containing:– (Lactobacillus acidophilus, Enterococcus faecium, Lactobacillus
plantarum and Lactobacillus casei)
– Potassium
– Vitamins A, D3, E and K,
– Riboflavin, pantothenic acid, thiamine and niacinamide.
That product was manufactured by Bomac Vets Plus, USA.Batch No., A704.
It was given in the drinking water at the age of one day for 5consecutive days in a dose of 1gm/ 4 liter of the drinkingwater as recommended by manufacturer.
The Challenge Inoculum
Broth culture of S. Enteritidis field strain was centrifuged at3000 r.p.m for 10 min.
Sediment was diluted with sterile buffer saline and adjustedusing Mac Ferland matching tube to contain 10 log 9 CFU/ml.
The challenge inoculum was prepared according to themethod of Timms et al., (1990).
At 20 days of age, each bird in the experimentally infectedgroups was inoculated orally with 0.5 ml/ containing 10 log 9CFU/ml S. Enteritidis (Okamoto et al., 2007).
4 Groups, each of 75 chicks:
Non-VaccinatedNon-Challenged
1
InfectedNot Treated
2
VaccinatedInfected
3
ProbioticInfected
4
Evaluation
1. Clinical Signs
2. Mortalities
3. Performance
4. Gross Lesions
5. Detection of the Shedding of S. Enteritidis
Birds in the challenged groups were observed daily for threeweeks post challenge till the end of the study (6 weeks of age)for the clinical signs or deaths.
Dead birds were subjected to necropsy for recording the lesionsof S. Enteritidis (O'Brien 1988).
Cont. …
Detection of the Shedding of S. Enteritidis Cloacal swabs were taken from birds in each group just before
experimental infection (at 20 days of age) to ensure that the birds freefrom S. Enteritidis infection.
Weekly after the challenge up to 6 weeks of age, cloacal swabs werecollected from each of the infected as well as control group and examinedbacteriologically for the presence of S. Enteritidis organism.
Sterile cotton swab was inserted into the cloaca of each bird and rotatedgently to collect the clocal contents.
Each swab was transferred to 10 ml tube of tetrathionate broth andincubated overnight at 37°C.
A loopful from the broth was streaked on S.S agar for Salmonella isolation.
Suspected colonies were identified morphologically and biochemically.
Cont. …
Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weeklyrandomly selected, sacrificed and the liver, heart, spleen andcaecum were collected for S. Enteritidis re-isolation.
Samples were inoculated into tetrathionate broth, incubatedat 37°C for 24 hr, streaked onto S.S agar and incubated at 37°Cfor 24 hr. Suspected colonies were identified morphologicallyand biochemically.
Cont. …
Performance
At arrival, the chicks were weighed and then the birds in eachgroup were subjected to weekly determination of the productionparameters that include;
1. Body weight (BW)
2. Cumulative feed conversion (CFC)
3. European production efficiency factor (EPEF) according tosainsbury (1984).
These measures were taken till the end of the study (6 weeks ofage).
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0
23
4
9
Number of Dead Birds
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
31%
5%
12%
Mortality Rate %
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
52%
18%
26%
SE Faecal Shedding Week 1
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
37%
7%
18%
SE Faecal Shedding Week 2
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
25%
0%
4%
SE Faecal Shedding Week 3
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
41%
9%
18%
SE Faecal Shedding Total
SE Faecal Shedding Total
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
0%
47%
12%
22%
Re-isolation rate of S. Enteritidis from different organs
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
2.03
2.43
1.781.89
Cumulative Feed Conversion
Results
Control Non-treated -Infected
Vaccinated -Infected
Probiotic -Infected
1,580
1,355
1,705 1,640
Average body weight after 6 weeks
Conclusion
From this study, it could be concluded that both the locallyprepared autogenous S. Enteritidis bacterin in double doses andthe probiotic preparation are effective and safe methods forprevention of S. Enteritidis infection in broiler chickens.
