Liposomal delivery of p-ialB and p-omp25 DNA vaccines improves immunogenicity but fails to provide full protection against B. melitensis challenge.

Background: We have previously demonstrated protective efficacy against B. melitensis using formulations of naked DNA vaccines encoding genes ialB and omp25. The present study was undertaken to further understand the immune response generated by the protective vaccination regimens and to evaluate cationic liposome adsorption as a delivery method to improve vaccine utility.

Evaluation of azithromycin, trovafloxacin and grepafloxacin as prophylaxis against experimental murine Brucella melitensis infection.

The prophylactic potential of the azalide azithromycin as well as the fluoroquinolones trovafloxacin and grepafloxacin was assessed for the control of infection with Brucella melitensis in an experimental mouse model, determined by reduction in splenic bacterial burden. Trovafloxacin showed limited protective efficacy when administered 2h following a low-dose B. melitensis challenge, whereas grepafloxacin was ineffective.

Efficacy of moxifloxacin or gatifloxacin as prophylaxis against experimental murine Brucella melitensis infection.

The prophylactic potential of moxifloxacin and gatifloxacin was assessed in comparison with doxycycline, an established therapeutic antibiotic, to limit or control infection by Brucella melitensis in an experimental mouse model, determined by reduced bacterial burden in the spleen. Although moxifloxacin was found to have a small protective effect when administered 6 h following infection, neither moxifloxacin nor gatifloxacin showed significant efficacy in vivo. In comparison, doxycycline provided significant protection when prophylaxis was started at 6 h, 7 days or 14 days following infection.

Efficacy of ciprofloxacin versus doxycycline as prophylaxis against experimental murine Brucella melitensis infection.

The prophylactic potential of ciprofloxacin was assessed in comparison with doxycycline, an established therapeutic antibiotic, to limit or control infection by Brucella melitensis in an experimental mouse model. Ciprofloxacin treatment reduced bacterial loads in the spleens of challenged mice when administered prior to or at the same time as the bacterial challenge. In comparison, doxycycline provided much greater reductions in bacterial counts, even when treatment was initiated after infection.

Phenotypic and molecular characterisation of Brucella isolates from marine mammals.

Background: Bacteria of the genus Brucella are the causative organisms of brucellosis in animals and man. Previous characterisation of Brucella strains originating from marine mammals showed them to be distinct from the terrestrial species and likely to comprise one or more new taxa. Recently two new species comprising Brucella isolates from marine mammals, B.

Characterisation of the genetic diversity of Brucella by multilocus sequencing.

Background: Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus.

The identification of two protective DNA vaccines from a panel of five plasmid constructs encoding Brucella melitensis 16M genes.

Five candidate genes from the Brucella melitensis 16M genome were selected. Eukaryotic expression plasmids encoding these antigens were constructed and expression was verified in vitro from transfected Cos7 cells. Each vaccine was assessed for protective efficacy in a BALB/c mouse brucellosis infection model.

Serologic survey for Brucella spp., phocid herpesvirus-1, phocid herpesvirus-2, and phocine distemper virus in harbor seals from Alaska, 1976-1999.

Harbor seals (Phoca vitulina richardsi) were captured in the coastal regions of Southeast Alaska, Gulf of Alaska, Prince William Sound (PWS), and Kodiak Island during 1976-1999. Blood was collected from 286 seals. Sera were tested for evidence of exposure to Brucella spp.

Identification and characterization of variable-number tandem-repeat markers for typing of Brucella spp.

Members of the genus Brucella infect many domesticated and wild animals and cause serious zoonotic infection in humans. The availability of discriminatory molecular typing tools to inform and assist conventional epidemiological approaches would be invaluable in controlling these infections, but efforts have been hampered by the genetic homogeneity of the genus. We report here on a molecular subtyping system based on 21 variable-number tandem-repeat (VNTR) loci consisting of 13 previously unreported loci and 8 loci previously reported elsewhere.

Use of amplified fragment length polymorphism to identify and type Brucella isolates of medical and veterinary interest.

Amplified fragment length polymorphism (AFLP) is a whole-genome fingerprinting method that relies on the selective PCR amplification of restriction fragments. The potential of this approach for the discrimination of Brucella isolates at the species and intraspecies level was assessed. A number of different combinations of restriction enzymes and selective primers were examined, and one, using EcoRI and MseI with additional selective TC bases on the MseI primer, was selected for full assessment against a panel of Brucella isolates.

Generation of the Brucella melitensis ORFeome version 1.1.

The bacteria of the Brucella genus are responsible for a worldwide zoonosis called brucellosis. They belong to the alpha-proteobacteria group, as many other bacteria that live in close association with a eukaryotic host. Importantly, the Brucellae are mainly intracellular pathogens, and the molecular mechanisms of their virulence are still poorly understood.