الفهرس 
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Abstract
This study investigates the epidemiology and molecular characterization of salmonella isolates in broiler chicks during 1st week of life.
A total of (n=1000) samples including liver, intestine, yolk sac, spleen and heart blood were collected from El-Gharbia, El-Behera, Kafr-Elshikh ,Alexandria and Matroh Province in Egypt and tested through bacteriological, biochemical, serological and molecular examinations.
1-The obtained results revealed that:
A total of 75 samples out 1000 collected samples were positive for salmonella with a percentage of 7.5.
2-Incidence of Salmonella in different organs:
Prevalence of salmonella isolated from internal organs of newly hatched chicks was highest from yolk sacs (10%), followed by liver and intestines (9%) followed by the spleen (7.5%) then heart blood (2%).
3-Serological identification of the isolated organisms:
The serotyping revealed that 24 isolates belonging to S. enteritidis (1,9,12 g.m 1,7), while, 14 isolates belonging to S. virchow (6,7 r 1,2 ), in addition to, 12 isolates belonging to S. typhimurium (1,4,5,12.i.1,2) and 8 isolates belonging to S. kentucky (6,8.I,z).
4- Incidence of Salmonella in some provinces:
The isolated salmonella strains in El-Gharbia province was 1.9% (1% S. Enteritidis ,0.6% S.Kentucky and 0.3% Un typable) , in Kafr-Elshikh province was 1.5% (0.6% S. Enteritidis ,0.6% S. Typhimurium and 0.3% Un typable), in El-Behera province was 1.3% (0.2% S. Typhimurium ,0.7% S. Virchow and 0.4% Un typable), in Alexandria province was 1.7% (0.8% S. Enteritidis ,0.4% S. Typhimurium and 0.5% Un typable) and in Matroh province was 1.1% (0.7% S. virchow ,0.2% S. kentucky and 0.2% Un typable) .
5-Experimental infection:
Experimental infection of broiler chickens at 28 days old infected with S.enteritidis , S. Typhimurium and S. Kentucky in comparison with vaccinated and treated groups either with probiotic or prebiotic showed that:
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
The Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age).
he Measured Parameters for Evaluation of the Bacterin Efficacy in Comparison with the Probiotic
2.8.1 Clinical Signs, Mortalities and Gross Lesions
Birds in the challenged groups were observed daily for three weeks 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 lesions of
S. Enteritidis (O’Brien 1988).
2.8.2 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 free from S. Enteritidis infection. Weekly after the challenge up to 6 weeks of age, cloacal
swabs were collected from each of the infected as well as control group and examined bacteriologically for the
presence of S. Enteritidis organism. Sterile cotton swab was inserted into the cloaca of each bird and rotated
gently to collect the clocal contents. Each swab was transferred to 10 ml tube of tetrathionate broth and
incubated 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.
2.8.3 Re-isolation of S. Enteritidis
Ten birds from each group post challenge were weekly randomly selected, sacrificed and the liver, heart, spleen
and caecum were collected for S. Enteritidis re-isolation. Samples were inoculated into tetrathionate broth,
incubated at 37°C for 24 hr, streaked onto S.S agar and incubated at 37°C for 24 hr. Suspected colonies were
identified morphologically and biochemically.
2.8.4 The Performance
At arrival, the chicks were weighed and then the birds in each group were subjected to weekly determination of
the production parameters that include; the body weight (BW), the cumulative feed conversion (CFC) and the
European Production Efficiency Factor (EPEF) according to Sainsbury (1984). These measures were taken till
the end of the study (6 weeks of age)
The use of vaccine and the probiotic are effective in reducing signs, mortalities, gross lesions, the shedding rate and the re-isolation of S.enteritidis , S. Typhimurium and S. Kentucky and also increasing in the performance of chickens.
Using Live and killed salmonella vaccine with probiotic or prebiotic were highly protective for broiler chicken flocks when using signs, mortalities and post-mortem lesions as criteria for measuring the protective index.
The results of this study allow to conclude that:
1-Although the incidence of salmonella infection examined from the samples was found to be 7.5% it has been considered high and required a stric eradication program.
2- Probiotic and /or prebiotic in poultry ration as substitute for antibiotics so that it would be a potential strategy for economic poultry production which would be saves for human consumption.
4- Both inactivated and live attenuated vaccine with probiotic or prebiotic are effective and safe methods for prevention of Salmonella infection in broiler chickens.
5- The use of probiotics or prebiotic improve the performance parameters which including weekly feed consumption, weekly body weight gain, main weekly body weights and FCR and improve the immune response of birds against Salmonella infection.
6- It should be taken in consideration that the vaccine, the probiotic or prebiotic must be go parallel to bio-security measures and good management practices to eradicate Salmonella infection in poultry flocks.
7- The use of probiotics or prebiotic eliminated using of antibiotics in ration which cause antibiotic residue and development of drug-resistant bacteria and additionally a reduction in the ability to cure bacterial infections in humans.
8- Local vaccine is economic, effective and gives protection nearly similar to imported salmonella vaccine.