A specific reverse complement sequence for distinguishing Brucella canis from other Brucella species.

Canine brucellosis is primarily caused by Brucella canis, but other Brucella species can also cause the disease. Identifying sequences specific to B. canis and establishing PCR assays that can distinguish between B. canis and other Brucella species is essential to determine the etiology of canine brucellosis and the source of infection and to achieve effective control. We analyzed the gaps and SNPs of genomes I and II from B. canis strain RM6/66 and B. melitensis strain 16M using the Mauve genome alignment software, and the specificity of each of these differential regions was analyzed by BLAST. A 132 bp specific sequence was found between the DK60_915 (glycosyl hydrolase 108 family protein) and DK60_917 (aldose 1-epimerase) loci in B. canis chromosome 1. Further comparative analysis revealed that this is a reverse complement sequence between B. canis and other Brucella species. Then, three primers were designed based on the sequence that could detect B. canis with a 310 bp amplification product or other Brucella species with a 413 bp product. The PCR based on these primers had reasonable specificity and a sensitivity of 100 copies of Brucella DNA. The detection results for the blood samples of the aborted dogs showed a favorable accordance with the Bruce-ladder multiplex PCR assay. In conclusion, we found a specific reverse complement sequence between B. canis and other Brucella and developed a PCR method that allows a more comprehensive identification of the pathogen involved in canine brucellosis. These findings provide an effective means for preventing and controlling brucellosis.

Synthesis, interaction with DNA and antiproliferative activities of two novel Cu(II) complexes with norcantharidin and benzimidazole derivatives.

Two novel complexes [Cu(L)2(Ac)2]·3H2O (1) (L=N-2-methyl benzimidazole demethylcantharate imide, C16H15N3O3, Ac=acetate, C2H3O2) and [Cu(bimz)2(DCA)] (2) (bimz=benzimidazole, C7H6N2; DCA=demethylcantharate, C8H8O5) were synthesized and characterized by elemental analysis, infrared spectra and X-ray diffraction techniques. Cu(II) ion was four-coordinated in complex 1, Cu(II) ion was five-coordinated in complex 2. A large amount of intermolecular hydrogen-bonding and π-π stacking interactions were observed in these complex structures. The DNA-binding properties of these complexes were investigated using electronic absorption spectra, fluorescence spectra, viscosity measurements and agarose gel electrophoresis. The interactions between the complexes and bovine serum albumin (BSA) were investigated by fluorescence spectra. The antiproliferative activities of the complexes against human hepatoma cells (SMMC7721) were tested in vitro. And the results showed that these complexes could bind to DNA in moderate intensity via partial intercalation, and complexes 1 and 2 could cleave plasmid DNA through hydroxyl radical mechanism. Title complexes could effectively quench the fluorescence of BSA through static quenching. Meanwhile, title complexes had stronger antiproliferative effect compared to L and Na2(DCA) within the tested concentration range. And complex 1 possessed more antiproliferative active than complex 2.