Brucella ovis lacking a species-specific putative ATP-binding cassette transporter is attenuated but immunogenic in rams.
Ovine brucellosis caused by Brucella ovis is considered one of the most important reproductive diseases of rams worldwide. This study aimed to characterize the kinetics of infection of a ΔabcAB B. ovis mutant strain in rams. Twelve 1-year-old crossbred rams were used. Six rams were challenged with 2 mL of a suspension containing 1.2×10(9) CFU/mL of B. ovis strain ATCC25840 (wild type) by intraprepucial inoculation and additional 50 μL in each conjunctival sac of a suspension containing 1.2×10(10) CFU/mL of the same strain. The other six rams were challenged with an equivalent number of CFU of the mutant strain ΔabcAB B. ovis through the same routes. Serum samples for serology and semen and urine samples for bacteriologic culture and PCR were collected weekly during 24 weeks. At 24 weeks post infection, tissue samples were collected for bacteriologic culture and PCR. All rams inoculated with wild type or the ΔabcAB strain seroconverted at the fourth week post infection, remaining positive up to the 16th week post infection. PCR and bacteriology demonstrated that only rams inoculated with the wild type strain shed the organism in semen and urine. Lymphocytes from rams inoculated with wild type or ΔabcAB B. ovis had significantly higher proliferation in response to B. ovis antigens when compared with unstimulated controls. Tissue bacteriology and PCR detected B. ovis in all rams challenged with the wild type strain, whereas only one ΔabcAB-infected ram had a positive iliac lymph node sample by PCR.
Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil.
Ana Patrícia C
AP
Silva
Auricélio A
AA
Macêdo
Luciana F
LF
Costa
Andréia P
AP
Turchetti
Valquíria
V
Bull
Moisés S
MS
Pessoa
Márcio S S
MS
Araújo
Ernane F
EF
Nascimento
Olindo A
OA
Martins-Filho
Tatiane A
TA
Paixão
Renato L
RL
Santos
D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000276:immunology; D000818:Animals; D000942:Antigens, Bacterial / Q000494:pharmacology; D042061:Brucella ovis / Q000235:genetics* / Q000276:immunology*; D002006:Brucellosis / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D049109:Cell Proliferation / Q000187:drug effects; D056724:Immunity, Humoral; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D008297:Male; D009154:Mutation; D012661:Semen / Q000382:microbiology; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000382:microbiology*; D014556:Urine / Q000382:microbiology
D018528:ATP-Binding Cassette Transporters; D000942:Antigens, Bacterial
Brucella ovis; Immunogenic potential; Kinetics; Rams; ΔabcAB