Characterization of virulence of Leptospira isolates in a hamster model.
Effort has been made to identify protective antigens in order to develop a recombinant vaccine against leptospirosis. Several attempts failed to conclusively demonstrate efficacy of vaccine candidates due to the lack of an appropriate model of lethal leptospirosis. The purposes of our study were: (i) to test the virulence of leptospiral isolates from Brazil, which are representative of important serogroups that cause disease in humans and animals; and (ii) to standardize the lethal dose 50% (LD(50)) for each of the virulent strains using a hamster (Mesocricetus auratus) model. Five of seven Brazilian isolates induced lethality in a hamster model, with inocula lower than 200 leptospires. Histopathological examination of infected animals showed typical lesions found in both natural and experimental leptospirosis. Results described here demonstrated the potential use of Brazilian isolates as highly virulent strains in challenge experiments using hamster as an appropriate animal model for leptospirosis. Furthermore these strains may be useful in heterologous challenge studies which aim to evaluate cross-protective responses induced by sub-unit vaccine candidates.
Silva
Everton F
EF
Centro de Biotecnologia, Universidade Federal de Pelotas, UFPel, Brazil.
Santos
Cleiton S
CS
Athanazio
Daniel A
DA
Seyffert
Núbia
N
Seixas
Fabiana K
FK
Cerqueira
Gustavo M
GM
Fagundes
Michel Q
MQ
Brod
Claudiomar S
CS
Reis
Mitermayer G
MG
Dellagostin
Odir A
OA
Ko
Albert I
AI
D000818:Animals; D001938:Brazil; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology; D007919:Leptospira / Q000472:pathogenicity*; D007922:Leptospirosis / Q000382:microbiology*; D007928:Lethal Dose 50; D008168:Lung / Q000473:pathology; D008297:Male; D008647:Mesocricetus; D016019:Survival Analysis; D014774:Virulence