Avian Insight - Volume 2, 2011

8/6/2019 Avian Insight - Volume 2, 2011

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avianinsightA L O H M A N N A N I M A L H E A L T H N E W S B R

Fowl Cholera Bacterins: Tissue Reactionand Protection against Challenge

Introduction

Fowl cholera is a highly contagious and economicallysignificant disease caused by Pasteurella multocida,a gram negative bacteria. Several avian species,such as chickens, turkeys, ducks and quails, can beaffected. The disease can be manifested as an acutesepticemic form, characterized by rapid colonizationof internal organs and mortality, or a more benignchronic form, with typical inflammation of wattles,face and/or joints.

The organism can be introduced into commercialpoultry operations by direct contact with sick birds,asymptomatic carriers (birds recovered from previ-ous infections) or other potential animal reservoirs (4,7). P. multocida has been isolated from the oral cavityof dogs, cats, pigs and rodents species commonlyfound in close proximity to poultry operations. Since P.multocida has a natural ability to multiply to very highlevels in the blood stream of chickens, carcasses of

infected birds also constitute a very important sourceof contamination and spread of the disease (4).

Prevention and Control

Prevention against infection relies on avoiding thecontact of susceptible flocks with sick or recoveredbirds or any other possible animal reservoir. This canbe achieved by the implementation of adequatebiosecurity programs and the use of all-in all-ouproduction systems (7). In areas where fowcholera is considered endemic, the use of vaccinationprograms to minimize the presence of clinical signsdrops in egg production and mortality is highlyrecommended. Several factors, such as prevalenceof particular serotypes, age of the birds at infection

and control of animal reservoirs, should be carefullyevaluated before designing a vaccinationprogram. Even though effective, vaccination programshould never be considered as a substitute for goodmanagement and sanitation practices.

Vaccines

Live and inactivated vaccines are commonly used inbroiler breeders and turkeys. Live vaccines currentlyavailable in the U.S. belong to the 3X4 serotypeHowever, they exhibit a variable degree of virulencewith the CU, PM-1 and M-9 classified from high to lowaccording to their degree of virulence (3, 4). All live

vaccines can effectively infect turkeys orally, howeverin chickens, their administration by wing web transfixion is essential for the development of an adequateimmune response (1, 2, 3, 7). Due to their capacity tomultiply and produce a wider spectrum of immunogens, live vaccines induce a non serotype-specifictype of immunity, providing cross protection againstdifferent serotypes. However, they have the potentia

By Ivn R. Alvarado, DVM, M.S., Ph.D.,

ACPV, Technical Service Manager,

Lohmann Animal Health International

By Drew Parker, DVM, MAM

Volume 2, 2011

inside

The use of the water-

oil-water type of

emulsion preserves

the capacity of the

inactivated antigens

to simulate the

development of a

humoral immune

response while

inducing a milder

tissue reaction at the

site of the inoculation.

Fowl Cholera Bacterins: Tissue Reaction

and Protection against Challenge,p.1

Notes from the

CEO,p.4


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to induce chronic fowl cholera in chickensand turkeys with increased mortality duringproduction (1, 4, 5). In broiler breeders, liveattenuated vaccines are commonly adminis-

tered around 10 and 16 weeks of age whilein turkeys, the administration of several livevaccines (at least three doses) is required toinduce an adequate protection.

In broiler breeders, vaccination programsbased on the use of a fowl cholera bacte-rin before or after the administration of alive vaccine (usually PM-1 for females andM9 for males) provide adequate protectionagainst challenge with different serotypeswhile minimizing the risk of chronic fowlcholera associated with live vaccines (1,5). Research studies evaluating the level ofprotection provided by different vaccinationprograms in broiler breeders seem to cor-roborate such observation (5). In one study,significant levels of protection againstmortality were observed after challenginghens under different vaccination programs.Whereas no mortality was observed in hensvaccinated with a live CU strain and a bac-terin (containing serotypes 1, 3 and 4), 77%mortality was observed in non vaccinatedhens. Furthermore, a vaccination programbased on the use of a bacterin at 10 weeksfollowed by the live vaccine at 19 weekswas considered effective in protecting hensagainst virulent challenge and possiblyreducing the incidence of chronic fowl choleraobserved in hens vaccinated twice with theCU strain (5). In turkeys, the inclusion of twobacterins after the administration of at leastthree live vaccines is also common.

Inactivated bacterins contain whole cellsuspensions ofP. multocidaorganism emulsifiedin highly purified oils or adsorbed in aluminumhydroxide. Commercially available bacterinscontain the most commonly found serotypes

(1, 3, 4 and/or 3X4), with serotype 3X4 sharingsome antigenic characteristics with serotype 3and 4 P. multocida strains. Bacterins provideprotection against clinical signs, drops in eggproduction and mortality. However, they inducea serotype specific type of immune response,directed only against P. multocida strains strainsthat belong to the same serotypes includedin the bacterin (4, 6, 7). Vaccination programsbased on the use of inactivated vaccinesrequire the administration of at least twodoses, usually 4 weeks apart.

The presence of tissue reaction at the siteof inoculation is normally observed afterthe administration of inactivated vaccinesand is essential for the development of a

strong and long lasting humoral immuneresponse. In the case of fowl cholera bac-terins, a variable degree of tissue reactionpost-vaccination has been associated withthe concentration of gram negative bacte-rial components (i.e. endotoxins, exotoxins,LPS) and the type of emulsion used.Bacterins are effectively administered bythe intramuscular (breast, leg and wing)or subcutaneous (under the skin of theneck) routes. Although breast injection iscommonly favored over other routes ofinoculation, due to a more consistent

administration (coverage) and the lowerrisk of self injection by the vaccinationpersonnel, strong tissue reactions mightoccur. Such reactions have been morefrequently observed after the off-labeladministration of bacterins presented inthe traditional water in oil (WO) type ofemulsion, resulting in increased condemna-tions at the spent fowl processing plant.

At Lohmann Animal Health International,a novel formulation containing inactivatedserotype 1, 4 and 3X4 P. multocida strainsresuspended in a water-oil-water (WOW)type of emulsion (AviPro FC3 Platinum)has been developed. The use of the water-oil-water type of emulsion preserves thecapacity of the inactivated antigens tostimulate the development of a humoral

immune response while inducing a mildetissue reaction at the site of inoculation. Aresearch study, conducted in 2010 by Parkeet alat the University of Georgia, evaluated

the local reaction at the site of inoculationand the level of protection against challenge provided by the WOW AviPro FC3Platinum when compared with a traditional WO fowl cholera bacterin (AviPro FC4)AviPro FC3 Platinum is currently approvedfor subcutaneous or intramuscular administration (0.25 ml per dose) while AviPro FC4is only recommended for subcutaneousadministration (0.5 ml per dose). In theexperimental design, broiler breedepullets were equally divided in three groupand kept in floor pens under standard feed

restriction and lighting programs. Pulletsin two groups were intramuscularly vaccinated (left side of the breast) at 10 and16 weeks of age with AviPro FC3 Platinumor AviPro FC4 (off-label) bacterins. The thirdgroup was not vaccinated and remained asa positive challenge control group.

At 22 weeks of age, half of the pullets ineach of the vaccinated and control groupswere intramuscularly challenged with ahighly virulent serotype 1 P. multocida strain(4.75 x 10^2 CFU/dose). Vaccinated and nonvaccinated pullets were evaluated fothe presence of clinical signs (torticollisunthriftiness, facial inflammation and/olameness) and mortality until the end of thetrial. A significant level of protection againstclinical signs and mortality was observed in

Figure 1

Control AviPro FC4 AviPro FC3 Platinum

%A

ffectedBirds

100

80

60

40

20

0

Clinical Signs Mortality


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both vaccinated groups when comparedwith the non vaccinated controls (Fig. 1).Furthermore, no significant difference inthe level of protection provided by Avipro

FC4 and AviPro FC3 Platinum against chal-lenge was observed.

At 27 weeks of age, tissue reaction in bothvaccinated groups was also evaluated. Asignificantly milder local reaction at thesite of inoculation was observed in pulletsvaccinated with the AviPro FC3 Platinumbacterin (Fig. A and B) when compared withthe tissue reaction observed in pullets afterthe off-label administration of the AviProFC4 bacterin (Fig. C and D).

Summary

Prevention of fowl cholera in a poultryoperation must include the design andimplementation of biosecurity programsdirected to avoid the contact of suscep-tible flocks with the numerous sources ofinfection, especially vectors able to harborand amplify P. multocida. However, inendemic areas where a free status is difficultto achieve, intensive vaccination programs

must be established. Both live and inactivatedvaccines have inherent advantages anddisadvantages. However, when properlyadministered, they are able to provide an

adequate level of protection against fieldchallenge. Vaccination programs based onthe use of a bacterin before or after theadministration of a live attenuated vaccineprovide not only cross protection againstdifferent serotypes but also reduce the pos-sible risk of live vaccine induced chronicfowl cholera. Such programs are able tostimulate all the three major componentsof the immune response humoral, localand cellular immunity (5, 6, 7). Since breast

injection offers the possibility of a moreconsistent administration of a completeantigenic dose and lowers the risk of

self injection, the use of highly immu-nogenic fowl cholera strains presentedin a water-oil-water type of emulsion isvery convenient. The presence of an externalaqueous phase allows for a betterdistribution of the inactivated antigens inthe breast tissue, with a consequent milder

tissue reaction post-vaccination.

References

1. Bierer. B. W, and W. T. Derieux. 1972. Immunologic response of turkeys to an avirulenPasteurella multocida vaccine in thedrinking water. Poult Sci. 51:408-416.

2. Derieux, W. T. 1978. Responses of youngchickens and turkeys to virulent and avirulent Pasteurella multocida administered byvarious routes. Avian Dis. 22:131-139.

3. Derieux, W. T, and B. W. Bierer. 1975. The CUstrain of Pasteurella multocida. Proc 24thWest Poult Dis Conf. 64-66.

4. Glisson, J. R. 1998. Bacterial respiratory

diseases in poultry. Poult Sci. 77:1139-1142

5. Hofacre, C. L., J. R. Glisson, and S. H. Kleven1986. Comparison of vaccination protocolsof broiler breeder hens for Pasteurellamultocida utilizing enzyme-linked immnosorbent assay and virulent challengeAvian Dis. 31:260-263.

6. Dick, J. W, and J. W. Johnson. 1985. Fowl chol-era immunity in broiler breeder chickensdetermined by the enzyme-linked immunosorbent assay. Avian Dis. 29:706-714.

7. Glisson, J. R., C. L. Hofacre, and J. P. Christensen. 2003. Fowl Cholera. In: Diseases ofPoultry. 11th ed. H. J. Barnes, A. M. Fadley, JR. Glisson, L. R. McDougald and D. E. Swayneed. Iowa State University Press, Ames, IA658-676.


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At Lohmann Animal Health

International, we have completed the

recent expansion of our facility which

increased capacity in fermentationfor live and killed bacterial vaccines,

AviPro Megan Vac 1 & Megan Egg

and AviPro SE4. The new facility is

already getting a workout as Lohmann

live and killed Salmonella vaccines

have more than doubled previous

years volumes. New customers and

improved vaccination programs

have worked together to make this

significant increase happen.

AviPro FC3 Platinum also is contributing to increased volume

of fermented bacterial products. This new vaccine, developed by

Lohmann Animal Health International R&D, is a low dose, low

reactivity, no residue, IM application Pasteurella bacterin that has

found much success in the marketplace. We are proud of AviPro

FC3 Platinum.

In addition to the additional fermentation capacity, we increased

live vaccine harvest areas and completely renovated our QC testing

laboratories. We also added a spacious, modern employee area.

The highlight of the expansion is our new, state-of-the-art, Research

and Development Center. This new addition is evidence of ou

continued commitment to the poultry industry.

We appreciate the support of the industry, which has resulted in

strong growth for the past three years. Our work remains centered

on the poultry industry now and into the future. As always, thank youfor your business.

Notes from the CEO

for more information:

avianinsight(+1) 207-873 3989 (+1) 800-655 1342 www.lahinternational.com

Dave Zacek

CEO,Lohmann Animal Health

Lohmann Animal Health Int375 China Road

Winslow, Maine 04901, USA

Documents

Avian Insight - Volume 2, 2011