Live and inactivated vaccine regimens against caecal Salmonella Typhimurium colonisation in laying hens.
OBJECTIVE
In Australia, Salmonella serovar Typhimurium (S. Typhimurium) is the predominant zoonotic serovar in humans and is frequently isolated from layer hens. Vaccination against this serovar has been previously shown to be effective in broilers and the aim of this current study was to assess and determine the best vaccination strategy (live or inactivated) to minimise caecal colonisation by S. Typhimurium.


METHODS
A long-term experiment (56 weeks) was conducted on ISABROWN pullets using a commercial live aroA deleted mutant S. Typhimurium vaccine and an autogenous inactivated multivalent Salmonella vaccine (containing serovars Typhimurium, Infantis, Montevideo and Zanzibar). These vaccines were administered PO or by SC or IM injection, either alone or in combination. Pullets were vaccinated throughout rearing (to 18 weeks of age) and sequentially bled for antibody titre levels. The birds, vaccinated and controls, were challenged orally with a field isolate of S. Typhimurium at different ages, held for 21 days post-challenge, then euthanased and their caeca cultured for the presence of Salmonella.


RESULTS
None of the oral live-vaccinated groups exhibited lasting protection. When administered twice, the inactivated vaccine gave significant protection at 17 weeks of age and the live vaccine given by SC injection given twice produced significant protection at 17, 25 and 34 weeks.


CONCLUSIONS
Vaccination regimens that included parenteral administration of live or inactivated vaccines and thus achieved positive serum antibody levels were able to provide protection against challenge. Hence, vaccination may play a useful role in a management strategy for Salmonella carriage in layer flocks.
Faculty of Veterinary Science, The University of Sydney, 425 Werombi Rd, Camden, New South Wales, 2570, Australia. peter.groves@sydney.edu.au.
P J
PJ
Groves
University of New South Wales, Kensington, NSW, Australia.|Birling Avian Laboratories, Bringelly, NSW, Australia.
S M
SM
Sharpe
Faculty of Veterinary Science, The University of Sydney, 425 Werombi Rd, Camden, New South Wales, 2570, Australia.
W I
WI
Muir
Birling Avian Laboratories, Bringelly, NSW, Australia.
A
A
Pavic
University of New South Wales, Kensington, NSW, Australia.
J M
JM
Cox
D000818:Animals; D001315:Australia; D002432:Cecum / Q000382:microbiology; D002645:Chickens; D005260:Female; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control*; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology; D012486:Salmonella typhimurium / Q000276:immunology*; D013997:Time Factors; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated
Salmonella Typhimurium; layer chickens; poultry; vaccines
Berl Munch Tierarztl Wochenschr. 2000 Jun;113(6):246-52
10925515
Avian Dis. 2009 Jun;53(2):281-6
19630237
Infect Immun. 2005 May;73(5):2986-90
15845505
Appl Environ Microbiol. 2010 Dec;76(23):7820-5
20889797
Infect Immun. 2001 Dec;69(12):7950-4
11705984
Poult Sci. 2008 Nov;87(11):2399-403
18931193
Avian Dis. 1991 Jul-Sep;35(3):435-42
1953573
Avian Dis. 1997 Oct-Dec;41(4):783-91
9454910
Avian Pathol. 2002 Aug;31(4):383-92
12396340
Avian Pathol. 2011 Oct;40(5):429-36
21879803
Avian Pathol. 2010 Feb;39(1):31-9
20390534
Vet Microbiol. 2002 Oct 22;89(2-3):167-79
12243894
Epidemiol Infect. 1992 Dec;109(3):361-9
1468521
Avian Dis. 1993 Jan-Mar;37(1):19-26
8452496
J Food Prot. 2011 May;74(5):727-34
21549042
Aust Vet J. 1994 Mar;71(3):78-81
8198512