A case report of spontaneous abortion caused by Brucella melitensis biovar 3.

BACKGROUND: Brucellosis is a worldwide zoonotic disease caused by Brucella spp. Brucella invades the body through the skin mucosa, digestive tract, and respiratory tract. However, only a few studies on human spontaneous abortion attributable to Brucella have been reported. In this work, the patient living in Shanxi Province in China who had suffered a spontaneous abortion was underwent pathogen detection and Brucella melitensis biovar 3 was identified. CASE PRESENTATION: The patient in this study was 22 years old. On July 16, 2015, she was admitted to Shanxi Grand Hospital, Shanxi Province, China because of one day of vaginal bleeding and three days of abdominal distension accompanied by fever after five months of amenorrhea. A serum tube agglutination test for brucellosis and blood culture were positive. At the time of discharge, she was prescribed oral doxycycline (100 mg/dose, twice a day) and rifampicin (600 mg/dose, once daily) for 6 weeks as recommended by the World Health Organization (WHO). No recurrence was observed during the six months of follow-up after the cessation of antibiotic treatment. CONCLUSIONS: This is the first reported case of miscarriage resulting from Brucella melitensis biovar 3 isolated from a pregnant woman who was infected through unpasteurized milk in China. Brucellosis infection was overlooked in the Maternity Hospital because of physician unawareness. Early recognition and prompt treatment of brucellosis infection are crucial for a successful outcome in pregnancy.

[RelE toxin protein of Mycobacterium tuberculosis induces growth inhibition of lung cancer A-549 cell].

OBJECTIVE: To investigate whether the RelE toxin protein of mycobacterium tuberculosis has a growth inhibition effect on lung cancer A-549 cell. METHODS: The complete open-reading frame sequences of RelE, RelB and RelBE genes were amplified by PCR with using M. tuberculosis H37Rv genomic DNA as the template. The RelE, RelB and RelBE genes were subcloned into PcDNA3. 1 (+). After being verified with restriction endonuclease digestion and DNA sequence determination, the recombinant vectors were applied to transfect lung cancer A-549 cells by liposome transfection method. By determining the growth curve and protein level of living cells, MTT cell proliferation assay, the apoptosis of cells with HE staining and the apoptosis rate of transient transfection cells detected by Flow Microfluorimetry, it was observed and analyzed whether the RelE toxin protein of mycobacterium tuberculosis had a growth inhibition and apoptosis effects on lung cancer A-549 cell. RESULTS: The cell proliferation rate of lung cancer A-549 cells effected by the RelE toxin protein of mycobacterium tuberculosis was lower than that of the other groups, and this group cells with RelE protein effect showed more sensitive to nutrition starving. HE staining revealed that this group cells which included the transient transfection with RelE expression plasmid appeared to have more apoptosis cells and higher apoptotic rate than other groups did (P < 0.05). CONCLUSION: The RelE toxin protein of mycobacterium tuberculosis has growth inhibition and apoptotic effect on lung cancer A-549 cell.

[Protein-protein interaction between hypothetical protein Rv1246c and Rv1247c of Mycobacterium tuberculosis].

OBJECTIVE: To investigate the protein-protein interaction between hypothetical protein Rv1246c and Rv1247c of Mycobacterium tuberculosis. METHODS: By PCR technique, the complete open-reading frame sequences of Rv1246c and Rv1247c gene were amplified from the M. tuberculosis H37Rv genomic DNA as template. The PCR-amplified cDNAs of Rv1247c and Rv1246c gene were subcloned into pGBKT7 and pGADT7-Rec vector respectively for constructing recombinant plasmids pGBKT7-Rv1247c and pGADT7-Rv1246c. After verified by restriction endonuclease digestion and DNA sequence determination, the recombinant vectors were used to transform the yeast cell AH109 by lithium acetate method. RESULTS: The yeast cells co-transformed with pGBKT7-Rv1247c and pGADT7-Rv1246c grew on SD/-Ade/-His/-Leu/-Trp plates, and the beta-galactosidase activity assays showed the positive signal. CONCLUSION: The hypothetical protein Rv1246c and Rv1247c could interact with each other in yeast cells.

[Effect of transfected Rv0901 gene on the activity of mice macrophages].

OBJECTIVE: To test the effect of Rv0901 gene of Mycobacterium tuberculosis on the activity of mice macrophages. METHODS: Peritoneal macrophages of mice were isolated and transfected with pcDNA3. 1 or pcDNA3. 1-Rv0901 plasmid DNA, along with the GFP DNA. The effectiveness of the transfection was detected by RT-PCR. The expression of the GFP and the apoptosis ratio of the macrophages were detected by FCM 72 hours after the transfection. The level of nitric oxide and IFN-gamma in cultural supernatant were also measured 72 hours after transfection. RESULTS: All of the macrophages being transfected had the expression of GFP. After being transfected with pcDNA3. 1-Rv0901, the 528 bp gene of Rv0901 was amplified by RT-PCR. The macrophages transfected with pcDNA3. 1-Rv0901 had higher apoptosis ratio [(56.4 +/- 2.0)% vs (19.9 +/- 1.5)%] and released more nitric oxide [(40.4 +/- 3.0) micromol/L vs (27.5 +/- 3.2) micromol/L] and IFN-gamma [(2.11 +/- 0.031) ng/mL vs (0.62 +/- 0.025) ng/mL] in the cultural supernatants than those transfected with pcDNA3. 1 (P < 0.05). CONCLUSION: Transient transfection of pcDNA3. 1-Rv0901 increases the apoptosis ratio of the macrophages, which could increase the release of nitric oxide and IFN-gamma.

[Molecular cloning and expression of hypothetical proteins Rv1494 and Rv1495 of M.tuberculosis H37Rv strain].

OBJECTIVE: The mechanism by which M.tuberculosis persists and survives in host macrophage is not fully understood, however, the M. tuberculosis chromosome-encoded TA loci perform functions possibly of signaling to these processes. To explore the biological functions of M. tuberculosis chromosome-encoded TA loci, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and expressed. METHODS: The hypothetical proteins Rv1494 and Rv1495 were bioinformatically analyzed by means of Bioedit software, Dnaman software and Pfam database. The complete open-reading frame sequences of Rv1494 and Rv1495 genes were amplified by PCR using M.tuberculosis H37Rv genomic DNA as the template, and the PCR products were cloned into prokaryotic expression vector pET32a(+), respectively. After induction of expressions in E.coli host strain BL21 (DE3), the recombinant proteins were purified and detected by Western blotting. RESULTS: According to bioinformatic analysis, the hypothetical proteins of Rv1494 and Rv1495 genes shared some homologies with mazEF family, one of E. coli chromosomal TA loci (homology at 26% and 29.5%). Sequence analysis showed that the inserted target genes and its reading frames were completely correct. The recombinant plasmids were induced with IPTG to effectively express the fusion proteins with relative molecular mass coincident with prediction. The specific positive signals were identified from the immunoblots. CONCLUSION: For the first time, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and its prokaryotic expression vectors were constructed successfully in this experiment, which may facilitate further functional study of this mazEF-like gene pair.