Evaluation of safety and probiotic properties of a strain of Enterococcus faecium isolated from chicken bile.

Probiotics are important bacteria due to their benefit on human health. In this study, four strains of lactic acid bacteria from chicken bile were isolated and the strain with the best antimicrobial activity was selected for further identification and evaluation on its probiotic traits and safety. The strain was identified as Enterococcus faecium by biochemical characterization and 16S rDNA gene sequencing. The strain, named E. faecium MK-SQ-1, was tolerant to acid (pH 3.0), bile salts (up to 0.3%) or trypsin (up to 0.4%) for 3 h and it was able to survive from high temperature (up to 60 °C) for 15 min. This strain inhibited the growth of Salmonella enteritidis and Staphylococcus aureus intermediately. The genes responsible for virulence including asa1, cylA, efaA, esp, gelE and hyl were absent and the mice administrated orally with a very high dose (2 × 109 CFU) of the strain daily for 35 days were not found abnormal. The strain enhanced the serum IgG level and phagocytic index of mice significantly by daily oral administration at a high dose (2 × 108 CFU) for 21 days (p < 0.05). The strain did not have multi-antibiotic resistance and vancomycin resistance. Comprehensive evaluation showed E. faecium MK-SQ-1 could be a candidate as a probiotic strain used in human or animals.

The effects of taurochenodeoxycholic acid in preventing pulmonary fibrosis in mice.

The present study prepared the pulmonary fibrosis model in mice by using Bleomycin and carry out the investigations on the effects of taurochenodeoxycholic acid (TCDCA) in preventing pulmonary fibrosis in mice. Expression profiles of the bile acid receptors in the lung of mice FXRα and TGR5 were examined, and pulmonary coefficient, pathohistology as well as expression of TNF-α, MMP-2, MMP-9 and TIMP-2 in pulmonary fibrosis mice. The results showed that FXRα and TGR5 simultaneously expressed in the lung of the mice; TCDCA in dosages of 0.05 and 0.1g/kg can extremely significantly decrease the pulmonary coefficient in the model mice (P>0.01), TCDCA in a dosage of 0.2g/kg significantly decreased the pulmonary coefficient in the model mice (P<0.05); TCDCA in dosages of 0.05 and 0.1g/kg significantly reduce the pathological damages on their lungs; TCDCA can extremely significantly decrease the expression levels of TNF-α and TIMP-2 in pulmonary tissues in the pulmonary fibrosis mice (P>0.01), the expression level of MMP-9 extremely significantly increased (P>0.01), while it has no significant effects on MMP2. The results as mentioned above indicated that TCDCA had antagonistic actions on pulmonary fibrosis in mice.

An Attempt of a New Strategy in PRV Prevention: Co-Injection with Inactivated Enterococcus faecium and Inactivated Pseudorabies Virus Intravenously.

Pseudorabies virus (PRV) is one of the causative agents of common infectious diseases in swine herds. Enterococcus faecium is a probiotic belonging to the group of lactic acid bacteria and has excellent immunomodulatory effects. Vaccine immunization is an important approach to prevent animal diseases in the modern farming industry, and good immunization outcomes can substantially reduce the damage caused by pathogens to animals, improve the quality of animals' lives, and reduce economic losses. In the present study, we showed that inactivated E. faecium and inactivated PRV when co-injected intravenously significantly reduced the mortality of mice after inoculation with PRV. The inactivated E. faecium + inactivated PRV intravenous injection group induced more production of Th cells and Tc cells. Additionally, the inactivated E. faecium + inactivated PRV intravenous injection group showed higher concentrations of cytokines (IFN-γ and IL-10) and induced higher antibody production. Thus, the co-injection of inactivated E. faecium and inactivated PRV could remarkably prevent and control the lethality of PRV infection in mice, which is a critical finding for vaccination and clinical development.

Evaluation of the antiviral effect of four plant polysaccharides against duck circovirus.

Recently, outbreaks of duck circovirus (DuCV) are frequently occurring worldwide due to secondary infections caused by post infection-induced immunosuppression. Due to a lack of preventive drugs and vaccines, the waterfowl industry losses are ever increasing. In this study, we extracted Astragalus polysaccharides (APS), pine pollen polysaccharides (PPPS), Aloe vera polysaccharides (AVE), and Ficus carica polysaccharides (FCPS) from Astragalus, pine pollen, aloe, and F. carica leaves, respectively. We randomly divided 150 one-day-old Cherry Valley ducks into five groups, which were inoculated with the DuCV solution and orally administered APS, PPPS, AVE, FCPS, and phosphate buffer saline (PBS), respectively. We collected the duck immune organs and serum samples at 8, 16, 24, 32, 40, and 48 days post-infection (dpi). Using clinical symptom analysis, molecular biology experiments, and serological experiments, we proved that plant polysaccharides could (a) improve the duck immunity, (b) reduce the viral load, and (c) mitigate DuCV-induced damage to immune organs, with both APS and PPPS having significant effects. Moreover, we detected viral load and cytokines within the first 8 dpi. Since the body's innate immunity could inhibit viral replication within five days of virus infection, 1-5 dpi was the best treatment time. Among the four polysaccharides showing in vitro anti-apoptotic activity, APS and PPPS significantly inhibited the DuCV infection-induced apoptosis of peripheral blood lymphocytes. Overall, since our findings show APS and PPPS having significant anti-DuCV effects both in vivo and in vitro, they can be promising candidates for preventing DuCV infection in ducks.

Generation of internal image monoclonal anti-idiotypic antibodies against idiotypic antibodies to GP5 antigen of porcine reproductive and respiratory syndrome virus.

Syngeneic monoclonal anti-idiotypic antibodies (Mab2s) were generated against idiotypic antibodies to membrane glycoprotein GP5 of porcine reproductive and respiratory syndrome virus (PRRSV) using the sequential immunization method. Six of 12 Mab2s possessed potential internal image characteristics by recognizing a common idiotype on murine and swine anti-GP5 antibodies. Further serological characterization demonstrated that one of the Mab2 (Mab2-5G2) represents internal image anti-idiotope which mimicked the GP5 antigen that inhibited the interaction between idiotypic anti-GP5 antibodies and GP5 antigen, its reaction with the idiotypic anti-GP5 antibody was inhibited by GP5 antigen and detected the common Id on anti-PRRSV antibodies from pigs that were experimentally infected with PRRSV. In addition, Mab2-5G2 identified a soluble protein on MA-104 and porcine alveolar macrophages. These results indicate that Mab2-5G2 may be a useful candidate as an alternative PRRSV serodiagnostic reagent and a useful probe to study PRRSV-cell interaction.

Occurrence of reticuloendotheliosis in Chinese partridge.

Two commercial flocks of Chinese partridge experienced increased mortality associated with a wasting disease at 120-day old in June 2006. Postmortem examination of dead chickens consistently showed visceral tissues mainly proventriculus, liver and spleen were diffuse enlargement. Microscopic examination revealed masses of immature lymphocytes with frequent mitotic figures were seen in various tissues including proventriculus, liver, spleen, kidney, heart, lung, thymus and intestine. Reticuloendotheliosis virus (REV) was isolated from each of four blood samples. Viral antigens were observed in cultured CEF (SPF embryos came from the Ji-nan poultry institute) inoculated blood samples via on indirect immunofluorescent assay. Three hundred bp fragments of LTR of REV obtained from liver samples of six chickens by PCR. This disease has not previously been reported in Chinese partridge. Chinese partridge may represent a potential reservoir of infection for other Chinese local chickens.

[PCR-RFLP analysis of the mtDNA Cytb gene in three different horse breeds].

Restriction endonucleases, namely BamH I, Taq I, Hae III, Rsa I and Hinc II, were used to analyze the polymorphism of partial mtDNA Cytb gene sequences from 256 horses 6 types (Thoroughbred, Sanhe, Wuzhumuqin, Xinihe, Wushen and Pony) including the imported breed, cultivated breed and local breed. The products of endonuclease digestion were run on 8% non-denaturing polyacrylamide gel electrophoresis and detected by silver staining. Results indicated BamH I and Taq I polymorphism. In all 7 restriction patterns were defected that could be sorted into 3 haplotypes, of which haplotypes I and III were the basic haplotypes. We infer that these horses came from one female ancestor through the analysis thorough one pattern, namely BamH I-B.

[Sequence comparing of mtDNA D-Loop varied region in Chinese Mongolian horse and External Thoroughbred horse].

Mitochondrial DNA D-Loop varied region 400 bp sequence variations in 4 Chinese Mongolian horses and 4 External Thoroughbred horses were analyzed in this experiment. The results showed that the average nucleotide mutational rate of mtDNA D-Loop varied region in 4 Chinese Mongolian horses was 3.69%, while External Thoroughbred horses were 4.00%. Three types of mutations including transition, transversion and deletion were all found in the investigated mtDNA D-Loop regions, of which transition was the most frequent. Nucleotide mutational loci were abundant, length mutations were found and great differences were all observed among the 8 horses. It showed there existed much polymorphism in the mitochondrial DNA D-Loop varied region of Chinese Mongolian horses and External Thoroughbred horses.