a preliminary protocol for induction of tuberculosis spondylitis by mycobacterium tuberculosis strain h37r: in-vivo new zealand white rrabbits model

Background: proper animal model is a critical prerequisite of any experimental study, while it is a lack for tuberculosis spondylitis. this study aimed to validate a protocol for induction of tuberculosis spondylitis in an animal model. methods: ten new zealand white rabbits were used and divided randomly into four experimental groups (n = 8), with 2 rabbits in each group, and the control group (n = 2). a 0.2 ml suspension of 108 cfu/ml h37rv strain m. tuberculosis was delivered into the drilled hole with a depth of 6-10 mm at the midpoint of the 12th thoracal corpus compared with the saline in the control group. evaluation of imaging examination by using plain x-ray was done within the targeted time followed by euthanasia protocol. results: a survival rate of 100% was observed in the present study with all rabbits having stable vital signs during the incubation period. group 3 with an incubation period of 6 weeks showed the highest success rate for inoculation of m. tuberculosis bacteria in which 7 samples were positive. this was followed by group 2 (75%, incubation 4 weeks), group 1 (37.5%, incubation 2 weeks), and group 4 (12.5%, incubation 8 weeks). the high positive rates were also reported by using culture and pcr staining, 62.5% and 75%, respectively. a slight destruction of the vertebral body was observed in both groups 2 and 3 starting at 4 weeks, postoperatively. histopathology specimen exhibited an infiltration of numerous inflammatory cells. conclusions: establishment of spondylitis tuberculosis model by using new zealand white rabbit could be successfully formed through 0.2 ml suspension of 108 cfu/ml m. tuberculosis strain h37rv with a direct inoculation method towards the midpoint of the 12th thoracal vertebral body. in addition, this model showed a high positive rate with a 100% survival rate in both control and 4 treatment groups.