Human immunodeficiency virus (HIV) is a global threat to health with high morbidity and mortality, and 50% of all HIV-related death is associated with invasive fungal infection. Highly active antiretroviral therapy (HAART) is used to treat HIV infection and can significantly reduce incidence of HIV-related opportunistic fungal infection. In this article, the epidemiology, diagnosis and treatment of HIV-related fungal infection are reviewed, giving an insight into study of deep fungal infection and a reference for clinic practice.

Previous study suggested that primate animal model infected by Coxsackievirus A16 (CA16) can display a significant viremia phase. This study was conducted for further analyzing the relationship between viremia and viral proliferation in peripheral blood mononuclear cell (PBMC) population. Firstly, the rhesus monkeys infected with CA16 were detected for the viral loads in CD4^＋， CD8^＋， CD20^＋， CD11c^＋， CD16 ^＋ and CD14^＋ cells from the PBMCs at different infectious stages, and the results revealed that CA16 could only propagate in some CD14^＋ cells. Secondly, in the dendritic cells (DCs) derived from CD14^＋ cells induced by granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 4 (IL-4), a significant viral proliferation dynamics could be observed with a viral load peak at 12-36 h post-infection (hpi). These findings will likely provide important information on the pathogenesis of CA16 infection.

Eukaryotic expression vector containing different proteins (C, M, E and NS1-­5) of dengue virus serotype 2 (DENV­-2) were constructed and intramuscularly injected directly to mice for developing antibodies against DENV-­2. Two weeks after the fourth immunization, sera were collected and the immune effects were evaluated by enzyme­linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA) and Western blotting. Specific antibodies could be obtained by DNA immunization, and the titers of these antibodies fluctuated between 1:400­ - 1:16 127. Of those, the antibody against protein E showed the highest titer at 1:16 127 whereas the antibodies against proteins NS3, NS4b and NS5 had the lowest titer at 1:400. The results showed that all antibodies acquired by DNA immunization could produce specific immunofluorescent reactions when tested using DENV­-2-infected Vero cells, suggesting that antibodies prepared by DNA immunization could specifically identify naturally infected DENV­-2. Antibodies against proteins E, NS1, NS4b and NS5 could also identify heat­denatured proteins. The results generated from this study provided the base for further research.

To investigate whether the non-structural protein 2B of rhinovirus 16 induces endoplasmic reticulum stress (ERS) and apoptosis, BHK-21 cells were transfected with a plasmid p2B-GFP expressing rhinovirus 16 2B protein. Biomarkers of ERS and apoptosis were detected respectively. The results showed that 2B protein was localized to the ER apparatus. 2B protein increased the expressions of ERS marker proteins Grp78 and CHOP and the transcriptional activity of activating transcription factor 6 (ATF6). We also found 2B protein induced nuclear condensation associated with apoptosis and degradation of marker protein PARP in BHK-21 cells. In conclusion, the rhinovirus 16 2B protein induces both ERS and apoptosis.

The present paper aims to establish a RAW264.7 macrophage model to investigate the effects of CD36 and extracellular regulated kinase (ERK) signaling pathway on the secretion of inflammation-related cytokines induced by lipopolysaccharide (LPS). Firstly, the macrophages with or without CD36 knockdown were stimulated with 100 ng/ml LPS for 16 h. Then the activation of ERK and secretion of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and IL-10 were analyzed. Secondly, the cells were incubated with 20 nmol/L ERK inhibitor, and LPS was added for further stimulation. The changes in the above indexes were investigated. The relationship between the secretion of inflammatory cytokines and ERK signaling pathway was studied. The results showed that in normal RAW264.7 cells, LPS treatment stimulated the activation of ERK and secretion of TNF-α and IL-6 significantly, and had no significant effects on IL-10 level. CD36 knockdown inhibited the activation of ERK and secretion of TNF-α and IL-6, and increased IL-10 level upon LPS treatment. The pharmaceutical inhibition of ERK decreased TNF-α and IL-6 secretion and enhanced IL-10 secretion upon LPS treatment. The results suggest that both CD36 and ERK pathway are involved in LPS-mediated secretion of proinflammatory cytokines.

Bacterial YycFG two-component signal transduction system plays a major role in controlling cell wall synthesis, metabolism and biofilm formation of Staphylococcus. The extracellular PAS domain of YycG histidine kinase can sense various environmental signals. Therefore, a monoclonal antibody targeting PAS domain of Staphylococcus epidermidis (S. epidermidis) was produced (YycG-PAS MAb). Enzyme-linked immunosorbent assay (ELISA) indicated that YycG-PAS MAb belonged to IgG2a subclass and antibody titer was log 2¹⁵. Western blotting suggested that YycG-PAS MAb had the ability to bind both recombinant YycG-PAS protein and protein extracted from cells. Further investigation exhibited inhibitory effect of YycG-PAS MAb (80 μg/ml) against biofilm formation after co-incubation with S. epidermidis and the inhibitory rate was 46.5%. The anti-biofilm activity of YycG-PAS MAb was improved when combined with low-concentration of vancomycin (1 μg/ml). The inhibitory rate was increased from 57.6% to 93.0% (P<0.01). No significant effects of YycG-PAS MAb on viability and growth of planktonic bacterial cells were observed. This study indicated that YycG-PAS MAb is a promising candidate antibody for biofilm-related infections.

A Mycobacterium marinum random mutant library using MycoMarT7 phage system was constructed. After screening, a mutant whose transposon insertion site was in MMAR_0994 (mkl) gene was obtained. The adult zebrafish were infected with the wild-type and the mutant strains respectively and the survival rates of the zebrafish were compared. The potential impact of the mutant on host innate immune system was tested by infecting the 48-hour post-fertilization zebrafish larvae using caudal vein injection. In vivo distribution of the bacteria was monitored by following green fluorescence in the larvae. The impact of the mutant on mouse macrophage cell line was tested. In addition, the acid tolerance level was also checked. The results showed that mkl mutant displayed attenuated virulence in the zebrafish infection model. The attenuated phenotypes in the zebrafish larvae and mouse macrophage cell line were observed. The invasion rates of the mutant and the wild-type were similar. The growth of the mutant was more sensitive to low pH. These results indicated that mkl may play a functional role in the interaction with host immune system.

To study the toxin-antitoxin system mazEF6 of Mycobacterium tuberculosis (M. tuberculosis), deletion mutants were constructed and subjected to phenotype analysis. First, the flanking (homology arms) of mazEF6 gene from H37Rv and kanamycin resistance gene (kan gene) from plasmid PUC-19K were amplified by polymerase chain reaction (PCR) respectively. Second, fusion PCR was used for the hybrid splicing of mazEF6 homology arms and kan gene, and the desired fusion fragment was obtained. Then the fragment was cloned into pMD-19T (simple) vector to form a suicide plasmid (pMD-19T-ΔmazEF6-kan), and the suicide plasmid was transformed into Escherichia coli (E. coli) DH5α. At last, the constructed plasmid was transformed into H37Rv by electroporation. Single colonies of M. tuberculosis were screened on L-J medium with kanamycin, the genomic DNA of positive strains were extracted, and the targeted fragments were amplified by PCR and sequenced. The genetic stability and other phenotypes of the H37Rv ΔmazEF6 deletion mutant were studied. The results showed that the deletion mutant strains did not present reverse mutant within 15 generations. Compared with the wild-type strains, H37Rv ΔmazEF6 deletion mutant strains grew more slowly and the bacterial cell was relatively shorter. This study demonstrated that it is practical to obtain M. tuberculosis deletion mutant by fusion PCR technology, and the survival ability of M. tuberculosis without toxin-antitoxin mazEF6 gene is decreased.

Brucellosis is a systemic infectious disease with a broad spectrum of clinical manifestations. It may go unnoticed, particularly in the areas with low incidence. Osteoarthicular manifestations are often seen in brucellosis but most of brucellar monoarthritis cases are reactive rather than being septic. Here we report the clinical manifestation, diagnosis and treatment of a case of brucellar septic monoarthritis of the knee joint.

Respiratory syncytial virus (RSV) is the most important pathogen responsible for children’s severe lower respiratory tract infection worldwide. However, no vaccine has been licensed to prevent RSV infection as the inactivated RSV vaccine could enhance disease severity. The exact mechanism of RSV vaccine-enhanced disease (RVED) remains unclear. Since Toll-like receptors (TLRs) and their signal pathways play crucial roles in both innate and adaptive immunity, TLR-associated RVED mechanism has been proposed and is attracting more and more attentions of researchers. In this review, we summarized the main progress on the roles of TLRs in anti-RSV immunity and their signal pathways in affecting the immune status of mice with RVED, which may enlighten the vaccine design and development.

Rickettsia is an obligate intracellular parasitic bacterium which has been included in the list of biowarfare agents. Rickettsial diseases are zoonotic, natural focal diseases, and also threats to human health seriously. Different from the standard detection methods for other bacteria, the diagnosis of rickettsial diseases needs a collective consideration of the epidemiological data, clinical symptoms and laboratory test results. Although Rickettsia detection technology has been developed for more than 100 years, early rapid diagnosis is still difficult. Current progresses on Rickettsia and rickettsial disease detection, including pathogen isolation and molecular detections, are reviewed in this paper.