Evaluation of novel Brucella melitensis unmarked deletion mutants for safety and efficacy in the goat model of brucellosis.
Pregnant goats were employed to assess unmarked deletion mutant vaccine candidates BMDeltaasp24, BMDeltacydBA, and BMDeltavirB2, as the target host species naturally infected with Brucella melitensis. Goats were assessed for the degree of pathology associated with the vaccine strains as well as the protective immunity afforded by each strain against abortion and infection after challenge with wild-type Brucella melitensis 16M. Both BMDeltaasp24 and BMDeltavirB2 were considered safe vaccine candidates in the pregnant goat model because they did not cause abortion or colonize fetal tissues. BMDeltaasp24 was isolated from the maternal tissues only, indicating a slower rate of clearance of the vaccine strain than for BMDeltavirB2, which was not isolated from any maternal or fetal tissues. Both strains were protective against abortion and against infection in the majority of pregnant goats, although BMDeltaasp24 was more efficacious than BMDeltavirB2 against challenge infection.
Kahl-McDonagh
Melissa M
MM
Department of Veterinary Pathobiology, Texas A&M University and Texas Agricultural Experiment Station, College Station, TX 77843-4467, United States. mkahl@cvm.tamu.edu
Elzer
Philip H
PH
Hagius
Sue D
SD
Walker
Joel V
JV
Perry
Quinesha L
QL
Seabury
Christopher M
CM
den Hartigh
Andreas B
AB
Tsolis
Renee M
RM
Adams
L Garry
LG
Davis
Donald S
DS
Ficht
Thomas A
TA
D000818:Animals; D002004:Brucella Vaccine / Q000009:adverse effects / Q000276:immunology*; D017347:Brucella melitensis / Q000276:immunology*; D002006:Brucellosis / Q000517:prevention & control*; D004195:Disease Models, Animal; D005260:Female; D006041:Goats; D009154:Mutation; D011247:Pregnancy; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology*
D002004:Brucella Vaccine; D014614:Vaccines, Synthetic