Abstract # I-17

Transmission of Borrelia burgdorferi from Experimentally Infected Mating Pairs to Offsprings in a Murine Model. S.S. Altaie1,3, S. Mookherjee2 E. Assian2, F. Al-Taie2, S.M. Nakeeb3, and S.Y. Siddiqui3.   1CDER, FDA, Rockville, MD, 2CHOB, Buffalo, NY, 3State University of New York at Buffalo, NY

In an effort to develop a murine model for studying other modes of transmission of B. burgdorferi (Bb), we started with the well studied C3H/HeJ mouse. Splenectomized 6-8 week-old mice were divided into 4 groups. Groups A, B, and C had 23, 24, and 26 mating pairs respectively. Prior to mating, in group A female, in group B male, and in group C both female & male were infected subcutaneously with 106-107 (Bb) in 250 ml SKB II media. The control group D had 12 mating pairs in which both male & female received sterile media. Resulting pups were sacrificed at 1, 7, 14, and 21 days of age. Milk content of the stomach, sections from ear, skin, heart, liver, spleen, brain, bladder, and kidney of the 1, 7, and 14 day-old pups were cultured for Bb. The above mentioned tissues except milk were also cultured from sacrificed 21 day-old weanlings. Transmission to offsprings was indicated when Bb was isolated from any tissue from a given pup. From the experimentally infected female in which the milk was cultured, 2 (8%) transmitted Bb to their pups on day one via their milk. Among 49 infected female from groups A and C, 5 (10.2%) transmitted Bb to their pups either in utero or intrapartum.. Four of the litters from the mating pairs in group B had infected pups. These results indicate that Bb can transmit by other modes than the tick bite. The described mouse model with further modifications may provide a tool for studying such transmission modes and treatment strategies.