Open AccessRole in Virulence of aBrucella abortusProtein Exhibiting Lectin-Like Activity
Author(s) -
Tracy H Vemulapalli,
Ramesh Vemulapalli,
Gerhardt G. Schurig,
Stephen M. Boyle,
Nammalwar Sriranganathan
Publication year - 2006
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.74.1.183-191.2006
Subject(s) - virulence , biology , brucella abortus , microbiology and biotechnology , lectin , brucellosis , brucella , virology , immunology , genetics , gene
Brucella abortus is a facultative, intracellular zoonotic pathogen which can cause undulant fever in humans and abortions in cattle. A 14-kDa protein ofB. abortus was previously identified to be immunogenic in animals infected withBrucella spp. In this study, we discovered that the 14-kDa protein possessed immunoglobulin binding and hemagglutination properties that appeared to be based on the protein's lectin-like properties. Hemagglutination inhibition experiments suggested that the 14-kDa protein has affinity towards mannose. Disruption of the gene encoding the 14-kDa protein in virulentB. abortus strain 2308 induced a rough-like phenotype with an altered smooth lipopolysaccharide (LPS) immunoblot profile and a significant reduction in the bacterium's ability to replicate in mouse spleens. However, the mutant strain was stably maintained in mouse spleens at 2.0 to 2.6 log10 CFU/spleen from day 1 to week 6 after intraperitoneal inoculation with 4.65 log10 CFU. In contrast to the case for the smooth virulent strain 2308, in the rough attenuated strain RB51 disruption of the 14-kDa protein's gene had no effect on the mouse clearance pattern. These findings indicate that the 14-kDa protein ofB. abortus possesses lectin-like properties and is essential for the virulence of the species, probably because of its direct or indirect role in the synthesis of smooth LPS.