ISSN 1673-6184 CN 31-1966/R
The largest ever Ebola virus epidemic in the history, which is currently affecting some Western Africa countries, has resulted in major losses in the region, and is posing a threat to the public health of countries all over the world. This review summarizes the history of Ebola virus epidemics, the research advances in understanding the pattern of the epidemics, the natural reservoir host, and the transmission of the virus, along with issues that need further attentions.
Since the first outbreak in 1976, Ebola hemorrhagic fever has attracted great attention due to its high fatality rate. The 2014 epidemic has caused more than 6 800 deaths. The impact of Ebola is not only related to etiology and epidemiology in West Africa, but also to regional and global politics, economy, culture, health status as well. With global support, including from China, the joint efforts led by international organizations and West Africa are making progress on effective measures to control and treat the epidemic.
To investigate the role of PTEN protein in dengue virus type 2 (DENV2) infection and the related autophagy process, human umbilical vein endothelial cells (HUVECs) were challenged with the virus. PTEN expression and autophagy were checked by Western blotting and the level of LC3 type conversions respectively. The pLentiPTEN and pLentishPTEN expression plasmids were constructed and packaged into lentiviruses to establish PTEN and shPTENexpressing HUVEC cell lines for further detecting the effects of PTEN overexpression and downexpression on autophagy, especially ratio of LC3II/LC3I. The effects of PTEN on DENV2 capsid expression and mRNA level as well as infectivity of progeny viruses were also examined. The data showed that the downexpression of PTEN inhibited autophagy and as a result, reduced the expression of DENV2 capsid protein and the release of progeny virus particles. It is suggested that the downexpression of PTEN by DENV2 infection in HUVECs is likely a host protective response against dengue virus infection.
The Mycobacterium tuberculosis DNA vaccine pVAX1/Ag85ARv3425Rv2029c (A39) plasmid was constructed and its immunogenicity was then investigated. Ag85A gene was firstly amplified by polymerase chain reaction (PCR) and then cloned into pVAX1 to construct the recombinant plasmid pVAX1/Ag85A (A). Ag85ARv3425 gene segment was amplified by PCR and then cloned into pVAX1 to construct the recombinant plasmid pVAX1/Ag85ARv3425 (A3). Rv2029c gene was amplified by PCR and then cloned into plasmid A3 to construct the recombinant plasmid A39. HEK293T cells were transfected with the recombinant plasmids and the protein expression was detected by Western blotting. The proteins Ag85A, Rv3425 and Rv2029c were expressed in Escherichia coli BL21. C57BL/6 mice were divided into five groups named phosphate buffered saline (PBS), pVAX1, A, A3 and A39. The mice were immunized with plasmids mediated by in vivo electroporation (EP) 3 times at an interval of 2 weeks. The levels of cellular immunity and humoral immunity were detected by enzymelinked immunospot assay (ELISPOT), enzymelinked immunosorbent assay (ELISA) and flow cytometry. In the immunized mice, A39 could cause stronger cellular immunity: the highlevel secretion of IFNγ， IL2 and TNFα， and the increase in the proportion of CD4＋/CD8＋ T cells and CD8＋ perforin＋ T cells. Therefore, the constructed A39 DNA vaccine could induce stronger cellular immunity in mice and it may be used as a new tuberculosis vaccine against latent tuberculosis infection.
The purpose of the present study is to investigate the performance of interferon γ release assay (IGRA) and tuberculin skin test (TST) in household contacts of tuberculosis patients, and to evaluate the predictive values of the two tests for disease progression from latent tuberculosis infection (LTBI) to active tuberculosis in China. Household contacts of active pulmonary tuberculosis patients were offered both IGRA (TSPOT.TB) and TST, and then followed up for 6 years. The final cohort comprised 121 household contacts. TSPOT.TB was positive in 49.6% of the contacts; the positive rate was associated with increasing age ﹝OR＝1.03 (95% CI 1.001.05)，P＝0.032﹞ and contacting with smearpositive patients ﹝OR＝2.13 (95% CI 1.014.51)，P＝0.048﹞. TST≥5 mm and TST≥10 mm accounted for 57.5% and 37.2% of the contacts, respectively. TST≥10 mm was positively associated with contacting with smearpositive patients ﹝OR＝2.30 (95% CI 1.055.06)，P＝0.038﹞. Seven cases progressed to tuberculosis within 626 personyears of followup, showing an overall incidence rate of 11.0 per 1 000 personyears. The positive predictive value (PPV) and negative predictive value (NPV) was 8.3% and 96.7% for TSPOT.TB. The PPVs for TST≥5 mm and TST≥10 mm were 7.7% and 9.5% respectively; NPVs were both 95.8%. In conclusion, there is a high incidence rate of active tuberculosis among household contacts compared to general population in China. The predictive values of IGRA and TST for progression to active tuberculosis among household contacts are comparable.
The present paper aims to determine the prevalence of Beijing strains of Mycobacterium tuberculosis isolated from visa applicants in Shanghai Port, to define the probability of drug resistance and to evaluate the underlying risks of dissemination of Mycobacterium tuberculosis and tuberculosis burden for Chinese tuberculosis surveillance system. From January 2009 to May 2013, a total of 193 visa applicants who received medical examinations in Shanghai Port were suspected of infectious tuberculosis by detected abnormalities in the chest radiology. Smear and culture examination from 3 consecutive early morning sputum specimens collected from them were performed. Isolated Mycobacterium tuberculosis complex strains were subjected for genotyping using deletiontargeted multiplex polymerase chain reaction (DTMPCR). Fifty of them were positive for Mycobacterium tuberculosis complex. Forty isolates were genotyped by DTMPCR, 23 of the isolates (57.5%) belonged to Beijing genotype. The ratio was significantly lower than that in the local people going abroad (37/41, 90.2%). In all imported cases with Beijing genotype, 5 were from SouthEast Asia Region and 16 were from Western Pacific Region. Of 23 Beijing strains, 7 (30.4%) were resistant to at least one firstline antituberculosis drug, which was similar to the drug resistance rate (34.1%) in the local people going abroad. No multidrugresistant Beijing strain was found. The drug resistance rate to pyrazinamide was much higher in visa applicants (16.7%) than that in the local people going abroad (2.4%)．
A bibliometric analysis based on the articles in the field of microbiology collected in Essential Science Indicators (ESI) database with a special emphasis on the distribution of countries, institutions, journals of high significance and impact was performed. The highly cited papers and papers on hot topics in microbiology were also analyzed. It is shown that the current productivity of scientific research in the field of microbiology in China has improved and China has become one of contributors of the international microbiological world. However, gaps still exist in terms of influence.
A case of penicilliosis marneffei complicated with lymph node tuberculosis was reported. The boy was born in December 2010 and admitted for swollen lymph nodes behind the ear lasting for more than two years and aggravation with recurrent fever for 5 months. The human immunodeficiency virus (HIV) test was negative. He was treated with a variety of antibiotics but ineffective. After administration of antituberculosis drugs, his body temperature temporarily returned to normal, but recurrent fever appeared. We considered the presence of fungal infections and treated him with voriconazole. The condition of the child was improved significantly. The culture of his bone marrow sample turned positive for Penicillium marneffei. The boy was diagnosed lymph node tuberculosis by lymph node biopsy. The clinical presentation, diagnosis and treatment of penicilliosis marneffei complicated with tuberculosis were discussed in the context of the literatures.
Brucellosis is a zoonosis caused by Brucella, with an acute or chronic clinical infection. Clinical manifestations of brucellosis is various or atypical, which is easily misdiagnosed and miss-diagnosed. The case we have reported had an onset of fever and abdominal pain, associated with arthralgia, headache and rashes during the course, and was initially misdiagnosed as “acute cholangitis, associated with biliary pancreatitis”. According to epidemiology survey, radiological evidence, as well as blood culture and agglutination test showing Brucella positive, the diagnosis of brucellosis associated with splenic infarction and multiple organ involvement including lungs, skin and brain was made. After regular anti-brucellosis treatment, the patient’s symptoms were significantly improved. Brucellosis associated with splenic infarction is rare, which is possibly due to vasculitis resulting from Brucella infection.
Tuberculosis caused by Mycobacterium tuberculosis (M. tuberculosis) is the second important infectious disease in the world, and nextgeneration sequencing technology provides an effective research method to study the genome of M. tuberculosis. The current applications of nextgeneration sequencing technology in the study of M. tuberculosis from the aspects of epidemiology, drug resistance, evolution and related bioinformatics are reviewed.
It was believed that apoptosis was the only programmed cell death in the development and homeostasis of vertebrate. Meanwhile, necrosis was considered to be unprogrammed. However, growing evidences have demonstrated that some types of necrosis can also be regulated by signaling molecules, and these types of necrosis could be defined as programmed necrosis or necroptosis. In this review, the morphological characteristics of necroptosis, and the relationships between necroptotic signaling pathway and the immune system’s function and inflammatory response are summarized.
