Brucella melitensis Differs from B. suis in Growth and Urease Activity In-Vitro, and Infectivity in Fisher-344 Rats In-Vivo

Aloka B. Bandara, Stephen M. Boyle, Araceli Contreras-Rodriguez, Ana M. Martins, Rajiv Prasad, Christopher M. Reilly

12 Virginia Bioinformatics Institute, Virginia Polytechnic Institute & State University, Blacksburg, USA.
The Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute & State University, Blacksburg, USA.

DOI: 10.4236/aid.2013.31008                

Abstract

Importance of urease activity on pathogenic differences among Brucella species was evaluated. In cell-free extracts, the B. suis urease showed 12 times greater specific activity than the B. melitensis urease. When Fisher-344 rats were inoculated intraperitoneally (IP), at 1 week post-inoculation (PI), B. melitensis wild type 16 M was recovered from spleens and livers in greater numbers than B. suis wild type 1330. At 8 weeks PI, spleens were clear of B. melitensis, whereas B. suis remained. The wild type and the urease deficient strains of B. suis did not differ from each other in terms of recovery from spleen or liver. Our observations suggest that B. melitensis induces greater acute infectivity in Fisher-344 rats, whereas B. suis causes chronic infectivity; and urease activity has no influence on Brucella infection using an IP route.

Keywords

Brucella; Urease Activity; Splenomegaly; Infectivity; Pathogenicity

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W. J. Morgan, “Brucella Classification and Regional Distribution,” Developments in Biological Standardization, Vol. 56, 1984, pp. 43-53.
[2]	M. J. Corbel, “Brucellosis: An Overview,” Emerging Infectious Diseases, Vol. 3, No. 2, 1997, pp. 213-221.
[3]	M. J. Corbel, “Recent Advances in Brucellosis,” Journal of Medical Microbiology, Vol. 46, No. 2, 1997, pp. 101-103.
[4]	H. C. Scholz, K. Nockler, C. Gollner, P. Bahn, G. Vergnaud, H. Tomaso, S. Al Dahouk, P. Kampfer, A. Cloeckaert, M. Maquart, M. S. Zygmunt, A. M. Whatmore, M. Pfeffer, B. Huber, H. J. Busse and B. K. De, “Brucella inopinata sp. nov., Isolated from a Breast Implant Infection,” International Journal of Systematic and Evolutionary Microbiology, Vol. 60, No. 4, 2010, pp. 801-808. doi:10.1099/ijs.0.011148-0
[5]	E. Sanders and J. Warner, “A Study of Urease Activity in Cells of the Genus Brucella,” Journal of Bacteriology, Vol. 62, No. 5, 1951, pp. 591-598.
[6]	A. B. Bandara, A. Contreras, A. Contreras-Rodriguez, A. M. Martins, V. Dobrean, S. Poff-Reichow, P. Rajasekaran, N. Sriranganathan, G. G. Schurig and S. M. Boyle, “Brucella suis Urease Encoded by Ure1 but Not Ure2 is Necessary for Intestinal Infection of BALB/c Mice,” BMC Microbiology, Vol. 7, 19 June 2007, p. 57.
[7]	A. B. Bandara, N. Sriranganathan, G. G. Schurig and S. M. Boyle, “Carboxyl-Terminal Protease Regulates Brucella suis Morphology in Culture and Persistence in Macrophages and Mice,” Journal of Bacteriology, Vol. 187, No. 16, 2005, pp. 5767-5775.
[8]	G. G. Schurig, R. M. 2nd Roop, T. Bagchi, S. Boyle, D. Buhrman and N. Sriranganathan, “Biological Properties of RB51; a Stable Rough Strain of Brucella abortus,” Veterinary Microbiology, Vol. 28, No. 2, 1991, pp. 171-188.
[9]	D. M. Monack and S. Falkow, “Cloning of Bordetella Bronchiseptica Urease Genes and Analysis of Colonization by a Urease-Negative Mutant Strain in a Guinea-Pig Model,” Molecular Microbiology, Vol. 10, No. 3, 1993, pp. 545-553.
[10]	E. J. Young, C. I. Gomez, D. H. Yawn and D. M. Musher, “Comparison of Brucella abortus and Brucella melitensis Infections of Mice and Their Effect on Acquired Cellular Resistance,” Infection and Immunity, Vol. 26, No. 2, 1979, pp. 680-685.