avian salmonella inactivated vaccine against probiotics

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.