Microbiota/microbiome has been one of the lead topics in science these years, and its impact on host health and disease became a frontier scientific issue. Albeit a large number of laboratories around the world are focusing on this task, most of the researches are lack of detailed mechanisms. In this review, we clarify and illustrate the concepts of microbiota/microbiome. We sketch the interaction mode of human microbiota with the host, and list the diseases which have been reported in the past. In addition, six critical issues are put forward, and the direction of this field is prospected.

The collective of microflora inhabiting human mouth is called oral microbiota. Increasing evidence has proven that oral microbiota is highly associated with not only oral but also systematic diseases. Comprehensive knowledge of oral microbiota has been obtained after the launch of Human Microbiome Project, as well as some other microbial metagenomic projects. This paper reviewed the latest research on composition, succession, and potential impacts of oral microbiota on systemic diseases and health.

To analyze the microbial composition and the distribution of tetracycline resistant bacteria in the feces of chickens from small farmhouse and big feedlot, eight chickens from a small farmhouse and ten chickens from a big feedlot were enrolled. Fecal microbiota was analyzed through 454 pyrosequencing of 16S rRNA V3 region. Fourteen reported tetracycline resistance genes were tested by polymerase chain reaction (PCR). The mean Shannon diversity indexes of microbiota in chickens from a small farmhouse and a big feedlot were 5.321±0.590 and 4.398 ±0.440, respectively, with significant difference (Mann-Whitney U test, P＝0.008). Moreover, 69 and 65 tetracycline resistant isolates were randomly selected from chicken feces in small farmhouse and big feedlot, respectively. The species of tetracycline resistant bacteria isolated from chicken feces in the big feedlot were more diverse than those in the small farmhouse. The data concluded the wider dissemination of tetracycline resistant bacteria in the chickens from big feedlot, suggesting that more attentions should be paid to the changes in the microbiota and tetracycline resistant bacteria in the chickens from big feedlot and their influences on human health.

Tumor necrosis factor α(TNF-α) is an important inflammatory cytokine implicated in the pathogenesis of rheumatoid arthritis, septic shock and other diseases. In order to investigate the functional role of host TNF-α in Mycobacterium marinum (M. marinum) infection, clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) technology was utilized to mutate the TNF-α gene in wild type (WT) zebrafish. A zebrafish containing a frame-shift mutation was successfully constructed, isolated, and named as TNF-α^－/－. It was found that the expression of TNF-α mRNA was significantly reduced in TNF-α^－/－ zebrafish by in situ hybridization (ISH). The proliferation of M. marinum in TNF-α^－/－ zebrafish was significantly elevated compared to WT zebrafish. The construction of TNF-α^－/－ zebrafish will allow further in-depth study on the function of TNF-α in mycobacterial infection and related immune regulation.

The early results of our laboratory showed that BA2380 protein may be related to the virulence of Bacillus anthracis (B. anthracis). The goal of this study is to knock out the BA2380 gene in B．anthracis A16D2 strain. The downstream and upstream sequences of BA2380 and spectinomycin resistance gene (spc) were obtained with polymerase chain reaction (PCR) respectively and used in the construction of plasmid pK2380usd for gene replacement. pK2380usd was introduced into B. anthracis A16D2 competent cells, and the BA2380 gene deletion was obtained by antibiotic screening and PCR identification. The results laid a foundation for the subsequent exploration of gene function.

Coxsackievirus B3 (CVB3) mainly infects the heart, and the timing and distribution of viral RNA polymerase (3D protein) expression in the myocardium are currently unclear. In this study, the CVB3 3D gene was obtained by polymerase chain reaction (PCR) and cloned into the prokaryotic expression vector pET28a(＋). The expression of 3D was induced by isopropyl β-D-1-thiogalactopyranoside (IPTG), and the 3D-His protein was purified and used to immunize New Zealand white rabbits for antiserum against the 3D protein. An anti-CVB3 3D antibody with high titer and specificity was obtained, and it can be used for future functional study of CVB3 3D protein.

Hepatitis B virus (HBV) regulatory protein HBx is required to initiate and maintain productive virus replication. HBx is thought to achieve these functions by hijacking Cullin-RING ubiquitin E3 ligase 4 (CRL4) to target the SMC5/6 complex, a restriction factor for extrachromosomal viral DNA degradation. Studies also indicated that DNA damage-binding protein 1 (DDB1), an adaptor protein within CRL4 complex, may stimulate HBV transcription via a mechanism that does not involve an interaction with HBx. In the present study, using a model system of recombinant covalently closed circular DNA (rcccDNA) of HBV, it was confirmed that CRL4 could upregulate the secretion of HBV antigens in the absence of HBx (rcccDNA^X-null) in cultured hepatoma cell lines. However, this effect of CRL4 was abolished by serum deprivation in the cell culture. In addition, it was found that CRL4 failed to stimulate the expression of rcccDNA^X-null in non-proliferating hepatocytes in a mouse model with DNA hydrodynamic injection. Thus, the HBx-independent, CRL4-upregulated HBV expression is likely to be closely related to rapid proliferation of cultured hepatoma cell lines. The study thus revealed a previously unappreciated role of CRL4 in HBV virology, and would be helpful for better understanding of the biological significance of HBx.

Acquired immunodeficiency syndrome dementia complex (ADC) is a human immunodeficiency virus (HIV)-related brain syndrome, which is caused by HIV invading the central nervous system. ADC may have impacts on patient’s consciousness, behavior and exercise ability. Although cognitive deficit is associated with around 50% of HIV-infected people, the pathogenesis of ADC has not been clarified, and the diagnosis is still unclear. Proteomic technology can provide new clues for the diagnosis, pathogenesis, prevention and treatment of ADC due to its high sensitivity and high throughput capacity. In this paper, the progress of proteomic studies on ADC in the last 5 years is reviewed.

Pyroptosis is a new form of programmed cell death depending on cysteinyl aspartate specific proteinase 1 (caspase-1). Inflammasome plays a significant role in regulating pyroptosis. Intracellular pattern recognition proteins such as nucleotide-binding oligomerization domain-like receptor (NLR) and absent in melanoma 2 (AIM2) act to their ligands and promote the assembly of inflammasome as well as the activation of caspase-1/caspase-11, then induce pyroptosis. The in-depth research on the mechanisms and correlation between pyroptosis and inflammasome contributes to the understanding of the occurrence and development of pyroptosis-related inflammatory diseases.