Middle East respiratory syndrome (MERS) is a viral infection caused by a novel coronavirus (MERS­-CoV). In this review, we focus on the classification, molecular structure and the proteins related to tissue tropisms and host range of MERS­-CoV. The efforts on development of drugs and vaccines for the control of MERS­-CoV are also discussed.

Middle East respiratory syndrome (MERS) is caused by MERS coronavirus (MERS­-CoV). Most people with confirmed MERS-­CoV infection develop to severe acute respiratory syndrome, and the severe patients may progress to kidney failure resulting in death. MERS was first reported in Saudi Arabia in 2012. So far, all the cases have been linked to over 20 countries in and near the Arabian Peninsula, which poses a great threat to global public health. Here the research progress on MERS clinical control is summarized.

Middle East respiratory syndrome (MERS) is an acute respiratory infectious disease caused by Middle East respiratory syndrome coronavirus (MERS­-CoV). Its clinical diagnosis is based on pathogen detection in the laboratory. In this review, we summarize the latest research progress on the methodology of nucleic acid detection, serological detection, virus isolation and genetic variation monitoring of MERS-­CoV.

In this study, the structure of indole-3-glycerol phosphate synthase (IGPS) from Mycobacterium tuberculosis (M. tuberculosis) H37Rv was obtained by homologous modeling. Based on the IGPS structure, virtual screening was carried out to select novel inhibitors  from  the Maybridge database with about sixty thousands organic compounds. Through biological selection, one compound, named ATB26, was identified as a potential inhibitor of IGPS, which showed potent antimycobacterial activity not only against M. tuberculosis H37Rv, but also against clinical isolates of multidrug-resistant M. tuberculosis strains with (minimal inhibition concentration, MIC) of 0.1 μg/ml. ATB26 could bound tightly to IGPS in vitro and obviously inhibited activity of IGPS. These results suggest that ATB26 is a novel potent inhibit of IGPS, and that IGPS might be a potential target for the development of new anti-tuberculosis drugs.

Mycobacterium cell wall is rich in lipid components, and some of the lipids may have antigenicity or play an important role in the process of immune regulation. To investigate the effects of the lipids from Mycobacterium cell wall in tuberculosis subunit vaccine, the total lipids were extracted from bacillus Calmette­Guérin (BCG) cell wall and separated by silica column into three different groups: the nonpolar lipids, the intermediate polar lipids and the polar lipids. The lipids were used as the antigen to screen the immune responses in general population. Furthermore, the total lipids and the three groups of lipids were mixed with fusion protein LT70(ESAT6­-Ag85B­MPT64<190­1-98>­Mtb8.4­-Rv2626c) in adjuvant of N, N′­dimethyl­N, N′­dioctadecylammonium(DDA) and Poly (I:C) respectively. The subunit vaccines containing lipids were used to immunize mice and the protective efficacy were evaluated by challenging with BCG. The results showed that the level of lipid­specific IgG in tuberculosis patients was significantly higher than that in healthy people (P＜0.05). For the protective efficacy, the number of bacteria harbored in mice immunized with LT70­total lipids significantly declined compared with BCG vaccination (P＜0.05). In BCG prime­subunit vaccine boost strategy, LT70­total lipids and LT70­intermediate polar lipids vaccines resulted in significantly low bacterial number than BCG (P＜0.01) and LT70 (P＜0.05). In conclusion, lipids from Mycobacterium cell wall have high immunogenicity; combination of them, especially the total lipids or intermediate polar lipids, with fusion protein antigen can enhance the antimycobacterial protective efficacy of subunit vaccine.

This study aims to investigate the function of Rv3425 in Mycobacterium tuberculosis (M. tuberculosis) by screening its interacting proteins in bacillus Calmette­Guérin (BCG) via co-­immunoprecipitation coupled with mass spectrometry. Regions coding for Rv3425 were amplified by polymerase chain reaction (PCR) and cloned into the pMV261 vector. The recombinant vector was transformed into BCG, and the expression of the fusion protein was verified by Western blotting analysis. The Rv3425 protein complex formed in BCG (rBCG) were obtained by co-­immunoprecipitation combined with anti­-His specific antibody. Mass spectrometry was used to identify protein components in the complex; the function of each protein was obtained from the National Center for Biotechnology Information (NCBI). The candidate proteins interacting with Rv3425 were verified by glutathione S­-transferase (GST) pulldown assay. Ten proteins interacted with Rv3425 were obtained. Rv3425 could coordinate with a variety of proteins implicated in intermediary metabolism and respiration, cell wall and cell processes as well as latent infections. The results also demonstrated that Rv3614c protein implicated in ESX­1 secretion system and possible pathogenic mechanism could bind to Rv3425 in vitro.

This study aims to isolate lytic bacteriophages from Enterococcus faecalis (E. faecalis)，analyze its biological characteristics and to establish the research basis for a phage­based therapy against Enterococcus infections. A lytic bacteriophage (named φEn­-ZZ8) was isolated from the sewage using double­agar method and its basic biological characteristics were analyzed. The results showed that φEn­-ZZ8 had an icosahedral head of 40 nm in diameter and a filamentous tail of 200 nm in length. The adsorption rate of φEn-­ZZ8 reached 90% in 10 min. One­step growth showed that φEn­-ZZ8 had a short latency period of 15 min, a rise period of 40 min, and a burst size of 150 pfu/cell. The genome of φEn­-ZZ8 was sensitive to HindIII, EcoRV, NdeI, PstI, Xba I and Sac II, and the size of the genome was estimated to be 42 kb. Sodium dodecyl sulfate­polyacrylamide gel electrophoresis (SDS­-PAGE) revealed that at least 14 proteins were observed on the gel, ranging from 11 000 to 130 000. The bacteriophage specifically infected and lysed 30.8% E. faecalis isolates. The φEn­-ZZ8 also exhibited stability to the wide range of pH and temperature. The data suggest that phage φEn-­ZZ8 may be a candidate therapeutic agent to control Enterococcus infections.

The drug resistance of Candida albicans (C. albicans), resulted from gradual application of advanced medical treatments and the widespread use of antifungals, has become a severe problem in clinic. C. albicans is one of the major opportunistic human fungal pathogens. The transition from yeast to hypha is a necessary process in its pathogenic activity, and inhibiting the hypha formation can decrease its infective ability. Quorum sensing signal BDSF (short­-chain fatty acid) from Burkholderiacenocepacia can inhibit the yeast­to­hypha transition and hinder the virulence of C. albicans. The drug susceptibility of 60 C.albicans clinical isolates to fluconazole and BDSF were determined respectively. The results showed there were 8 strains (13.3%) resistant to fluconazole, with the minimum inhibitory concentration (MIC) ≥64 μg/ml, but BDSF showed efficiently inhibitory effect on all the clinical isolates no matter the isolates were resistant to fluconazole or not. The results suggest that BDSF might be a new clinical option to treat C. albicans infection.

Breast cancer is the most common malignant carcinomas for females in the world. Recently, potential viral factors for breast cancer have been emphasized, as human papillomavirus, Epstein­-Barr virus and the others were detected in breast carcinomas. There is no clear conclusion for the relationship between viruses and breast carcinogenesis for discrepancy among the data reported from different studies. The main obstacles and bottleneck of studies are analyzed in this review.

Helicobacter pylori (H. pylori) is a chronic infectious pathogen with high prevalence. H. pylori infection is closely related to chronic gastritis, dyspepsia, iron deficiency, anemia and growth retardation in children. It is a lifetime health issue for children. Therefore, finding a safe, efficient and convenient detection method suitable for children is very important. Currently, the commonly used detection methods in children include rapid urease test (RUT), histological examination, bacterial culture, urea breath test (UBT), serum H. pylori­Ig-IgG antibodies, H. pylori stool antigen, etc. In general, a non­invasive, efficient, operation friendly and economic H. pylori detection method is needed. Therefore suitable method should be chosen according to the diagnosis purpose. This review summarizes various detection methods and their clinical value for H. pylori infection in children.