Project description:H9N2 subtype avian influenza virus (H9N2 AIV) is a low pathogenic virus that is widely prevalent all over the world. H9N2 AIV causes immunosuppression in the host and often leads to high rates of mortality due to secondary infection with Escherichia. Due to the drug resistance of bacteria, many antibiotics are not effective in the treatment of secondary bacterial infection. Therefore, the purpose of this study is to find effective nonantibiotic drugs for the treatment of H9N2 AIV infection-induced secondary bacterial infection and inflammation. This study proves, for the first time, that baicalin, a Chinese herbal medicine, can regulate <i>Lactobacillus</i> to replace <i>Escherichia</i> induced by H9N2 AIV, so as to resolve the intestinal flora disorder. In addition, baicalin can effectively prevent intestinal bacterial translocation of SPF chickens' post-H9N2 AIV infection, thus inhibiting secondary bacterial infection. Furthermore, baicalin can effectively treat H9N2 AIV-induced inflammation by inhibiting intestinal structural damage, inhibiting damage to ileal mucus layer construction and tight junctions, improving antioxidant capacity, affecting blood biochemical indexes, and inhibiting the production of inflammatory cytokines. Taken together, these results provide a new theoretical basis for clinical prevention and control of H9N2 AIV infection-induced secondary bacterial infection and inflammation.
Project description:Avian influenza viruses represent a growing threat of an influenza pandemic. The co-circulation of multiple H9N2 genotypes over the past decade has been replaced by one predominant genotype-G57 genotype, which displays a changed antigenicity and improved adaptability in chickens. Effective H9N2 subtype avian influenza virus vaccines for poultry are urgently needed.In this study, we constructed H9N2 subtype avian influenza virus-like particle (VLP) and evaluated its protective efficacy in specific pathogen-free (SPF) chickens to lay the foundation for developing an effective vaccine against influenza viruses.Expression of influenza proteins in VLPs was confirmed by Western blot, hemagglutination inhibition (HI), and neuraminidase inhibition (NI). The morphology was observed by electron microscopy. A group of 15 three-week-old SPF chickens was divided into three subgroups of five chickens immunized with VLP, commercial vaccine, and PBS. Challenge study was performed to evaluate efficacy of VLP vaccine.The hemagglutinin (HA) and neuraminidase (NA) proteins were co-expressed in the infected cells, self-assembled, and were released into the culture medium in the form of VLPs of diameter ~80 nm. The VLPs exhibited some functional characteristics of a full influenza virus, including hemagglutination and neuraminidase activity. In SPF chickens, the VLPs elicited serum antibodies specific for H9N2 and induced a higher HI titer (as detected by a homologous antigen) than did a commercial H9N2 vaccine (A/chicken/Shanghai/F/1998). Viral shedding from VLP vaccine subgroup was reduced compared with commercial vaccine subgroup and control subgroup.
Project description:Since 2007, most areas of China have seen outbreaks of poultry airsacculitis, which causes hugely economic losses to the poultry industry. However, there are no effective measures to combat the problem. In this study, 105 rations were collected to isolate Aspergillus spp. from the diseased farms. In subsequent experiments, SPF chickens were inoculated with Ornithobacterium rhinotracheale (ORT), Chlamydia psittaci (C. psittaci) and Aspergillus fumigatus (A. fumigatus), and mortality rate, body weight gain and lesion score were evaluated. Of these ration samples, 63 (60.0%) were A. fumigates, 21 (20.0%) were Aspergillus niger (A. niger) and 11 (10.5%) were Aspergillus candidus (A. candidus). Furthermore, SPF birds infected with C. psittaci, ORT, H9N2 virus and A. fumigatus conidia exhibited a mortality rate of 40%, while simultaneous co-infection with C. psittaci, ORT and A. fumigatus resulted in a mortality rate of 20%. The avian airsacculitis was manifested in the C. psittaci + ORT/A. fumigatus, C. psittaci + H9N2 + ORT/A. fumigatus and C. psittaci + H9N2/A. fumigatus groups while others had transient respiratory diseases without mortality. Our survey indicates that feed-borne A. fumigatus is prevalent in poultry rations. The combination of C. psittaci, ORT, H9N2 and A. fumigatus conidia contributes to the replication of avian airsacculitis by aggravating the severe damage to the air sacs and lungs of chickens.
Project description:BACKGROUND:As a low pathogenic influenza virus, avian influenza virus subtype H9N2 (H9N2 AIV) often induces high morbidity in association with secondary bacterial infections in chickens or mammals. To explore this phenomenon, the relationship between intestinal microflora changes and bacterial translocations was studied post H9N2 AIV challenge and post AIV infection plus Ageratum-liquid treatment. METHODS:Illumina sequencing, histological examination and Neongreen-tagged bacteria were used in this study to research the microbiota composition, intestinal barrier, and bacterial translocation in six weeks of BALB/c mice. RESULTS:H9N2 AIV infection caused intestinal dysbacteriosis and mucosal barrier damages. Notably, the villus length was significantly reduced (p < 0.01) at 12 dpi and the crypt depth was significantly increased (p < 0.01) at 5 dpi and 12 dpi with infection, resulting in the mucosal regular villus-length/crypt-depth (V/C) was significantly reduced (p < 0.01) at 5 dpi and 12 dpi. Moreover, degeneration and dissolution of the mucosal epithelial cells, loose of the connective tissue and partial glandular atrophy were found in infection group, indicating that intestinal barrier function was weakened. Eventually, intestinal microbiota (Staphylococcus, E. coli, etc.) overrun the intestinal barrier and migrated to liver and lung tissues of the mice at 5 and 12 dpi. Furthermore, the bacteria transferred in mesentery tissue sites from intestine at 36 h through tracking the Neongreen-tagged bacteria. Then the Neongreen-tagged bacteria were isolated from liver at 48 h post intragastrical administration. Simultaneously, Ageratum-liquid could inhibit the intestinal microbiota disorder post H9N2 AIV challenge via the respiratory tract. In addition, this study also illustrated that Ageratum-liquid could effectively prevent intestinal bacterial translocation post H9N2 AIV infection in mice. CONCLUSION:In this study, we report the discovery that H9N2 AIV infection could damage the ileal mucosal barrier and induce the disturbance of the intestinal flora in BALB/c mice resulting in translocation of intestinal bacteria. In addition, this study indicated that Ageratum-liquid can effectively prevent bacterial translocation following H9N2 infection. These findings are of important theoretical and practical significance in prevention and control of H9N2 AIV infection.
Project description:The goal of the study was testing the effects of chlorogenic acid (CA) supplementation on small intestine healthiness, growth performance, oxidative stress, inflammatory response, and blood biochemical indices in specific-pathogen-free (SPF) chickens after infection with Clostridium perfringens (CP) type A. In this study, 324 1-day-old male SPF chickens were randomly distributed into 6 groups: control group; CA group; CP infection group; CA + CP group; antibiotic group; antibiotic + CP group. All 1-day-old chickens were fed with CA or antibiotic in corresponding treatment group for 13 d. On the 14 d, the chickens in corresponding infection group were challenged with CP type A for 3 d. Samples in each group were collected when the chickens were 17 and 21 d old. This study proves for the first time that CA, a Chinese herbal medicine, can effectively improve growth performance, inhibit small intestine structural damage, improve antioxidant capacity, inhibit damage to ileal mucosal layer construction and tight junctions, inhibit inflammatory cytokines, and ameliorate blood biochemical indices. Therefore, this study provides data for CA being able to effectively alleviate small intestine damage caused by CP type A infection in chickens.
Project description:In the present study, virus-like particles (VLPs) were evaluated as a candidate poultry vaccine against avian influenza virus (AIV) subtype H9N2. Specific pathogen-free chickens received a single injection of the VLP vaccine expressing HA and M1 protein of AIV H9N2 (H9 HA VLP) at escalating doses in the presence or absence of ISA70 water-in-oil adjuvant. At 3 weeks post vaccination, we performed hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay (ELISA) to determine serological immune responses, and challenge studies using SPF chickens. A single dose of H9 HA VLP vaccine induced high levels of HI antibodies and lowered frequencies of virus isolation after the wild-type virus challenge. The addition of ISA70 adjuvant significantly increased the immunogenicity of H9 HA VLP vaccines. Furthermore, it allows differentiation of AIV-infected chickens from vaccinated chickens with an ELISA using nucleocapsid antigen, which offers a promising strategy to differentiate infected from vaccinated animals (DIVA). These results provide support for continued development of the VLP as an animal vaccine against influenza virus.
Project description:Avian influenza virus subtype H9N2 is identified in chickens with respiratory disease while Bacillus cereus (B. cereus) has been frequently isolated from chicken feed in China. However, the roles of co-infection with these two pathogens remain unclear. In the present study, SPF chicks were intragastrically administered with 108?CFU/mL of B. cereus for 7 days and then inoculated intranasally with 100 EID50 of H9N2 three days later. Alternatively, chickens were initially inoculated with H9N2 and then with B. cereus for one week. Post administration, typical respiratory distress persisted for 5 days in both co-infection groups. Gizzard erosions developed in the groups B. cereus/H9N2 and B. cereus group on 7th day while in group H9N2/B. cereus on 14th day. More importantly, both air-sac lesions and lung damage increased significantly in the co-infection group. Significant inflammatory changes were observed in the B. cereus group from day 7 to day 21. Moreover, higher loads of H9N2 virus were found in the co-infected groups than in the H9N2 group. Newcastle Disease Virus (NDV) specific antibodies were decreased significantly in the H9N2/B. cereus group compared to the B. cereus and the B. cereus/H9N2 groups. Nonspecific IgA titers were reduced significantly in the B. cereus group and the H9N2/B. cereus group compared to the control group. In addition to this, lower lymphocyte proliferation was found in the con-infection groups and the H9N2 group. Hence, feed-borne B. cereus contamination potentially exacerbates gizzard ulceration and aggravates H9N2-induced respiratory distress by inhibiting antibody-mediated immunity and pathogen clearance. Thus controlling the B. cereus contamination in poultry feed is immediately needed.
Project description:Influenza H9N2 is considered to be a low pathogenicity avian influenza (LPAI) virus that commonly infects avian species and can also infect humans. In 1996, the influenza virus, A/chicken/Korea/MS96-CE6/1996/H9N2 (MS96) was isolated from an outbreak in multiple farms in South Korea that resulted in upwards of 30% mortality in infected chickens, with the virus infecting a number of extrapulmonary tissues, indicating internal spread. However, in experimental infections, complete recovery of specific pathogen free (SPF) chickens occurred. Such a discrepancy indicated an alternative pathway for MS96 virus to gain virulence in farmed chickens. A key determinant of influenza pathogenesis is the susceptibility of the viral hemagglutinin (HA) to proteolytic cleavage/activation. Here, we identified that an amino acid substitution, Ser to Tyr found at the P2 position of the MS96 HA cleavage site optimizes cleavage by the protease plasmin (Pm). Importantly, we identified that certain Staphylococcus sp. are able to cleave and activate MS96 HA by activating plasminogen (Plg) to plasmin by use of a virulence factor, staphylokinase. Overall, these studies provide an in-vitro mechanism for bacterially mediated enhancement of influenza activation, and allow insight into the microbiological mechanisms underlying the avian influenza H9N2 outbreak in Korea in1996.
Project description:Abstract Obesity is the lipid deposition caused by the imbalance between energy intake and consumption caused by a variety of factors. Obesity can lead to multiple systemic complications. At present, the treatment of obesity is mainly lifestyle intervention, drug weight loss, and weight loss surgery, but the curative effect is limited or the side effects are serious. Traditional Chinese medicine plays a unique role in the treatment of obesity. Existing studies have found that traditional Chinese medicine can treat obesity in a variety of ways, such as regulating intestinal microflora, enhancing hormone level, regulating fat metabolism, and so on. In this review, we will introduce and summarize the mechanism of traditional Chinese medicine in the treatment of obesity.
Project description:BACKGROUND: The traditional Japanese medicine juzentaihoto (JTX) is a pharmaceutical grade multi-herbal medicine widely used for the prevention of cancer metastasis and infection in immuno-compromized patients in Japan. The effect of JTX has been supposed to be intimately affected by the immunological properties of host and enteric microflora. The influence of JTX on the gene expression profile in the large and small intestines was investigated by microarray analyses using mice of different strains with or without enteric microflora. RESULTS: In all types of mice, including germfree (GF) animals, the genes most affected by two-week oral JTX treatment were the type 1 interferon (IFN)-related genes including Stat1, Isgf3g and Irf7, which play a critical role in the feedback loop of IFN-? production cascade. In IQI specific pathogen free (SPF) mice JTX increased the steady state level of the expression of IFN-related genes, but had the opposite effect in IQI GF and BALB/c SPF mice. Promoter analysis suggests that tandem repeated $IRFF (the promoter sequences for interferon regulatory factors) may be a primary target for JTX action. Pre-treatment of JTX accelerated the effects of an oral IFN "inducer" 2-amino-5-bromo-6-methyl-4-pyrimidinol (ABMP) (up-regulation of IFN-? production in IQI strain and down-regulation in BALB/c mice), which is in good accordance with the effect of JTX on gene expression of type 1 IFN-related genes. CONCLUSIONS: Microarray analysis revealed that the target of JTX might be the transcription machinery regulating the steady-state level of genes involved in the ISGF3-IRF7 cascade, whose effect is bi-directional in a strain- and microbiota-dependent manner.