Salmonella enteritidis in eggs, cloacal swab specimens, and internal organs of experimentally infected White Leghorn chickens.
OBJECTIVE
To investigate prevalence of Salmonella enteritidis-positive eggs, excretion of the organism in fecal droppings, and infection of internal organs after oral inoculation of White Leghorn hens with S enteritidis phage type 8.


METHODS
30 White Leghorn laying hens.


METHODS
At 25 weeks of age, hens were each inoculated orally with 10(10) colony-forming units of S enteritidis, then were observed for 8 weeks.


RESULTS
Salmonella enteritidis Y-BP2 did not cause any clinical signs of disease or decrease in egg production. However, at 1 week after inoculation, 63.9% of the eggs collected from inoculated hens were culture positive for S enteritidis. The organism was isolated from the shell washings, egg shells, yolk, and albumen. A total of 592 eggs from S enteritidis-inoculated hens were examined. Of these eggs, 157 (26.5%) were positive for S enteritidis on external shell washings alone, 17 (2.9%) were positive for S enteritidis internally, and 44 (7.4%) were positive for S enteritidis externally and internally. The percentage of culture-positive eggs gradually decreased between postinoculation weeks 2 and 5, then gradually increased to a high of 76% at week B. At 3, 7, and 10 days after S enteritidis inoculation, cloacal swab specimens from 3 hens were positive for S enteritidis. Salmonella enteritidis was recovered from ovary, oviduct, liver, and cecal junction from S enteritidis-inoculated hens.


CONCLUSIONS
Our results indicated that birds infected with this isolate produced S enteritidis-positive eggs at high frequencies initially, that decreased over time. When S enteritidis antibody began to decrease, reaching geometric mean titer < or = 40, the frequency of S enteritidis-positive eggs increased.
Bichler
L A
LA
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.
Nagaraja
K V
KV
Halvorson
D A
DA
D000704:Analysis of Variance; D000821:Animal Feed / Q000382:microbiology; D000818:Animals; D002645:Chickens; D002988:Cloaca / Q000382:microbiology*; D004528:Egg Shell / Q000382:microbiology; D004529:Egg White / Q000382:microbiology; D004530:Egg Yolk / Q000382:microbiology; D004531:Eggs / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D008099:Liver / Q000382:microbiology; D010053:Ovary / Q000382:microbiology; D010057:Oviducts / Q000382:microbiology; D010058:Oviposition; D011201:Poultry Diseases; D012481:Salmonella Infections, Animal / Q000503:physiopathology*; D012477:Salmonella enteritidis / Q000302:isolation & purification*; D013154:Spleen / Q000382:microbiology; D013997:Time Factors