[01] Mst Minara Khatun, Department of Veterinary Public Health, College of Veterinary Medicine, Chonbuk National University, Jeonju, Republic of Korea;Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh. [02] Md Ariful Islam, Department of Veterinary Public Health, College of Veterinary Medicine, Chonbuk National University, Jeonju, Republic of Korea;Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh. [03] Beyong-Kirl Baek, Department of Veterinary Public Health, College of Veterinary Medicine, Chonbuk National University, Jeonju, Republic of Korea.

Background: Brucellosis is an important zoonotic disease in animals and humans caused by Brucella abortus. The pathogenesis and immune responses of B. abortus is mainly studied in mice and cattle. The serologic responses as well as the kinetics and distribution of bacteria were measured for 8 weeks after infection of Sprague-Dawley (SD) rats with B. abortus biotype 1. Methodology: Thirty-two SD rats received an intraperitoneal dose of 1×1010 colony-forming units (CFU) of B. abortus biovar 1 isolated from cattle in Korea. At regular intervals after infection the rats were randomly bled for serologic studies and euthanatized for bacteriological examinations. Results: Sera were found positive for B. abortus specific antibody response by rose bengal plate test (RBPT), tube agglutination test (TAT) and plate agglutination test (PAT) at one week after infection. The peak antibody titers were recorded at 5 weeks after infection by the TAT and PAT then the titer gradually decreased until the end of the study. After experimental infection B. abortus was disseminated in blood and lymphoid tissues (spleen, liver and kidney). The persistence of B. abortus in blood was noted for short time, up to 5 weeks of infection. Bacterial persistence was recorded in the spleen throughout the experiment. No bacteria were cultured from the liver and kidney at 6 weeks after infection. Conclusion: The serologic responses and distribution of B. abortus in SD rats following experimental infection suggests that SD rats can clear the infection after a single exposure which will be helpful for the diagnosis of brucellosis.

B. abortus Biotype 1, Sprague-Dawley Rat, Acute Infection, Bacterial Persistence, Serologic Response

[01] Pappas, G., Papadimitriou, P., Akritidis, N., Christou, L. and Tsianos, E. V. (2006). The new global map of human brucellosis. Lancet Infectious Diseases, 6: 91–99. [02] Boschiroli, M. L., Foulongne, V. and O’Callaghan, D. (2001). Brucellosis: a world –wide zoonosis. Current Opinion in Microbiology, 4: 58-64. [03] Allen, A., Breadon, E., Byrne, A., Mallon, T., Skuce, R., Groussaud, P., Dainty, A., Graham, J., Jones, K., Pollock, L. and Whatmore, A. (2015). Molecular Epidemiology of Brucella abortus in Northern Ireland-1991 to 2012. Molecular epidemiology of Brucella abortus in Northern Ireland-1991 to 2012. PLoS One, 10(9): e0136721. [04] Madkour, M. M. (2001). Madkour’s brucellosis, Springer-Verlag, New York, N. Y. 150–151. [05] Memish, Z. A. and Balkhy, H. H. (2004). Brucellosis and international travel. Journal of Travel Medicine, 11: 49-55. [06] Park, M. Y., Lee, C. S., Choi, Y. S., Park, S. J., Lee, J. S. and Lee, H. B. (2005). A sporadic outbreak of human brucellosis in Korea. Journal of Korean Medical Science, 20: 941-946. [07] Zavala, I., Nava, A., Guerra, J. and Quiros, C. (1994). Brucellosis. Infectious Disease Clinics of North America, 8: 225-241. [08] Davis, D. S. and Elzer, P. H. (2002). Brucella vaccines in wildlife. Veterinary Microbiology, 90:533-544. [09] Moore, C. G. and Schnurrenberger, P. R. (1981). A review of naturally occurring Brucella abortus infections in wild mammals. Journal of American Veterinary Association, 179:1105-1112. [10] Oliakova, N. V. and Antoniuk, V. I. (1989). The gray rat as a carrier of infectious agents in Siberia and the Far East. Medical Parasitology, 3:73-77. [11] Silva, T. M. A, Costa, E. A., Paixao, T. A., Tsolis, R. M and Santos, R. L (2011). Laboratory animal model for brucellosis research. Journal of Biomedicine and Biotechnology, Article ID 518323, doi:10.1155/2011/518323. [12] Garcia-Carrillo, C. (1990). Laboratory animal models for brucellosis studies. In: Nielsen, K., Duncan, J. R. (Eds.), Animal Brucellosis. CRC Press, Boca Raton, 423-442. [13] Corbel, M. J. (1997). Brucellosis: an overview. Emerging Infectious Diseases, 3: 213-221. [14] Araya, L. N. and Winter, A. J. (1990). Comparative protection of mice against virulent and attenuated strains of Brucella abortus by passive transfer of immune T cells or serum. Infection and Immunity, 58: 254-256. [15] Alton, G. G., Jones, L. M., Angus, R. D. and Verger, J. M. (1988). Techniques for the brucellosis laboratory. Institut National de la Recherche Agronomique, Paris, 17-113. [16] MacMillan, A. P. and Stack, J. (2000). Bovine brucellosis. In: OIE manual of standards for diagnostic tests and vaccines, 4th ed, OIE, Paris: 328-345. [17] Bricker, B. J. and Halling, S. M. (1994). Differentiation of Brucella abortus bv. 1, 2, and 4, Brucella melitensis, Brucella ovis, and Brucella suis bv. 1 by PCR. Journal of Clinical Microbiology, 32: 2660-2666. [18] MacMillan, A. (1990). Conventional serological tests. In Nielsen K, Duncan JR, editors. Animal Brucellosis. CRC Press, Inc. Boca Raton, Florida, 33431. 153-197 [19] Beh, K. J. (1973). Distribution of Brucella antibody among immunoglobulin classes and a low molecular weight antibody fraction in serum and whey of cattle. Research in Veterinary Science, 14: 381-384. [20] Jenness, R. and Anderson, R. K. (1971). Immunological response of cows to Brucella antigens. Journal of Dairy Science 54: 13-29. [21] Blasco, J. M., Garin-Bastuji, B., Marin, C. M., Gerbier, G., Fanlo, J., Jimenez de Bagues, M. P. and Cau, C. (1994). Efficacy of different Rose Bengal and complement fixation antigens for the diagnosis of Brucella melitensis infection in sheep and goats. Veterinary Records, 134: 415-420. [22] Lucero, N. E. and Bolpe, J. E. (1998). Buffered plate antigen test as a screening test for diagnosis of human brucellosis. Journal of Clinical Microbiology, 36:1425-1427. [23] George, W. B. (1994). Handbook of Zoonoses, second edition, Section A: Bacterial, Rickettsial, Chlamydial and Mycotic, CRC Press, Inc., 2000 Corporate Blvd., Boca Raton, Florida 33431. [24] Blood, D. C., Henderson, J. A. and Radostits, O. M. (1979). Veterinary Medicine. A Text Book of the Diseases of Cattle, Sheep, Pigs and Horses, 5th edn, (Bailliere Tindall, London). [25] MacMillan, A. P., Baskerviile, A., Hambleton, P. and Corbel, M. J. (1982). Experimental Brucella abortus infection in the horse: Observations during the three months following inoculation. Research in Veterinary Science, 33:351-359. [26] Memish, Z., Mah, M. W., Al-Mahmoud, S., Al-Shaalan, M. and Khan, M.Y. (2000). Brucella bacteremia. Clinical and laboratory observations in 160 patients. Journal of Infection, 40: 59-63. [27] Young, E. J, Gomez, C. I., Yawn, D. H. and Musher, D. M. (1979). Comparison of Brucella abortus and Brucella melitensis infections of mice and their effect on acquired cellular resistance. Infection and Immunity, 26: 680-685. [28] High, K. P., Prasad, R., Marion, C. R., Schurig, G. G., Boyle, S. M. and Sriranganathan, N. (2007). Outcome and immune responses after Brucella abortus infection in young adult and aged mice. Biogerontology, 8:583-593. [29] Damir, H. A., Tageldin, M. H., Kenyon, S. J. and Idris, O. F. (1989). Isolation of Brucella abortus from experimentally infected dromedary camels in Sudan: A preliminary report. Veterinary Research communications, 13:403-406. [30] Stevens, M. G., Olsen, S. C., Pugh, G. W. and Palmer, M. V. (1994). Immune and pathologic responses in mice infected with Brucella abortus 19, RB51, or 2308. Infection and Immunity, 62: 3206-3212. [31] Tessaro, S. V. and Forbes, L. B. (2004). Experimental Brucella abortus infection in wolves. Journal of Wildlife Diseases, 40:60-65.