42 results about "Low pathogenic" patented technology

Bacteria which co-express protease inhibitors and protease sensitive therapeutic agents, which are surface displayed, secreted and/or released and result in their localized production and maintenance within a target tissue and inactivation outside of the target tissue, thereby increasing therapeutic activity and reducing the systemic toxicity. The bacteria may be attenuated, non-pathogenic, low pathogenic or a probiotic. Protease sensitivity may be further accomplished by engineering protease degradation sites within the therapeutic agents, further enhancing the inactivation outside of the target tissue while retaining activity within the target tissue through co-expression of a protease inhibitor. Novel chimeric proteins secreted by bacteria, including chimeric toxins targeted to neoplastic cells, tumor matrix cells and cells of the immune system, and combination therapies of these protease inhibitor:chimeric toxin-expressing bacteria together with small-molecule and biologic agents are also described. Non-conjugative bacteria limiting exchange of genetic material, and antibody resistant bacteria are also provided.

Chimeric proteins are expressed, secreted or released by a bacterium to immunize against or treat a parasite, infectious disease or malignancy. The delivery vector may also be attenuated, non-pathogenic, low pathogenic, or a probiotic bacterium. The chimeric proteins include chimeras of, e.g., phage coat and/or colicin proteins, bacterial toxins and/or enzymes, autotransporter peptides, lytic peptides, multimerization domains, and/or membrane transducing (ferry) peptides. The active portion of the immunogenic chimeric proteins can include antigens against a wide range of parasites and infectious agents, cancers, Alzheimer's and Huntington's diseases, and have enhanced activity when secreted or released by the bacteria, and/or have direct anti-parasite or infectious agent activity. The activity of the secreted proteins is further increased by co-expression of a protease inhibitor that prevents degradation of the effector peptides. Addition of an antibody binding or antibody-degrading protein further prevents the premature elimination of the vector and enhances the immune response.

The invention discloses an H9N2 subtype avian influenza virus strain as well as an inactivated vaccine and application thereof, and belongs to the field of separation and application of avian influenza virus strains. The H9N2 subtype avian influenza virus strain J/ZY strain is separated from a suspected H9N2 avian influenza pathogenetic chicken flock, and the microbial collection number of the strain is CGMCC No. 8853. The invention further discloses a preparation method for the H9N2 subtype avian influenza inactivated vaccine, and the preparation method comprises the following steps: culturing viruses to obtain a virus supernate; adding an inactivating agent to inactivate the virus supernate; mixing adjuvants and the virus supernate uniformly, and emulsifying to obtain the inactivated vaccine. Immune protection experiments prove that the separated H9N2 subtype avian influenza virus strain J/ZY strain serving as a vaccine strain has good immunogenicity and a relatively high antibody level can be produced after an animal is immunized by the strain.

The invention discloses a triple RT-PCR primer composition for rapid simultaneous identification of H4 subtype and/or H6 subtype and/or H9 subtype AIV. The triple RT-PCR primer composition comprises 3 pairs of specific amplification primers. The specific amplification primers comprise a primer pair of H4-F and H4-R, a primer pair of H6-F and H6-R and a primer pair of H9-F and H9-R. The invention also discloses a kit comprising the triple RT-PCR primer composition, a use of the triple RT-PCR primer composition in rapid simultaneous identification of H4 subtype and/or H6 subtype and/or H9 subtype AIV and a method for rapid simultaneous identification of H4 subtype and/or H6 subtype and/or H9 subtype AIV through the triple RT-PCR primer composition. The triple RT-PCR primer composition has the characteristics of simple operation, short detection time, strong specificity and high accuracy, provides an effective diagnostic detection scheme for low pathogenic AIV inspection and quarantine and disease monitoring and control and has an important meaning for prevention, control and monitoring of low pathogenic AIV.

The invention discloses application of corynebacterium diphtheroid as an immune adjuvant in a poultry oil emulsion inactivated vaccine. The corynebacterium diphtheroid refers to the corynebacterium similar to corynebacterium diphtheriae in respect of morphological and biological characteristics, namely the low-pathogenic or non-pathogenic corynebacterium except the high-pathogenic corynebacteriumdiphtheriae. The corynebacterium diphtheroid active adjuvant disclosed by the invention has high immunity stimulation activity and can be used for non-specifically stimulating the immune functions ofT and B lymphocytes so as to promote secretion of a plurality of cytokines; by adding the immune adjuvant into the poultry oil emulsion inactivated vaccine, the vaccine induced generation of animal antibody can be obviously promoted.

A biochip for detecting avain fluenza virus of both human and fowls is prepared as providing activated chip substrate, providing various fluenza virus subset sections to be sample-set, providing quality control protein, carrying out arrangement pattern design of point measurement, making sample-sets of quality control protein and various avain fluenza virus subset sections according to prepared pattern for detecting out antibodies generated by various subsets simultaneously.

The invention discloses a swine-origin miR-c89 capable of resisting PRRSV (Porcine reproductive and respiratory syndrome virus) infection. Through RT-qPCR (Real Time-quantitative Polymerase Chain Reaction), TCID50 (Tissue Culture Infectious Dose 50) and western blot methods, miR-c89 derived from swine coding is proved to obviously inhibit the replication and the proliferation of high pathogenicityand low pathogenicity PRRSV for the first time, the micoRNA is hopefully developed into a novel medicine capable of preventing and curing porcine reproductive and respiratory syndrome and used for researching the gene-modified pig capable of resisting the porcine reproductive and respiratory syndrome, and a foundation is laid for the prevention and control of the PRRSV.

A method for determining the pathogenic affection of concurrent bacterial infection to avian influenza virus includes such steps as inoculating the bacterium able to secrete subtilisinoid and/or the bacterium able to secrete tryptase and the low-pathogenicity avian influenza virus in culture medium of CEF in a particular mode, culturing, and observing if CPE presents. Its cell culture equipment is composed of cell culture bottle and bacteria culture chamber. Its advantages are simple method, short time, high correctness and low cost.

The invention provides lactobacillus plantarum and a microecological preparation, a preparation method and application thereof. The lactobacillus plantarum is named as Lactobacillus Plantarum BLCC2-0125, and is preserved in the China Center for Type Culture Collection in Wuhan City on April 24th, 2020, and the preservation number is CCTCC NO: M 2020078. The lactobacillus plantarum can improve thebody immunity, has a prevention effect on low-pathogenicity avian influenza, and can prevent and treat mycoplasma gallisepticum disease.

The invention discloses a reagent and method for highly pathogenic H7 avian influenza virus detection and application of the reagent. The reagent for highly pathogenic H7 avian influenza virus detection in the present application comprises a primer pair and/or a probe. The primer pair and/or the probe is designed for a specific recognition sequence of highly pathogenic H7 avian influenza virus. The specific recognition sequence is a sequence shown in Seq ID No. 1, or a reverse complementary sequence of the sequence shown in Seq ID No. 1, or a synonymous mutation sequence of the sequence shown in Seq ID No. 1 or the reverse complementary sequence of the sequence shown in Seq ID No. 1, or a sequence substituted with 1-4 bases. The reagent in the present application can effectively distinguish the highly pathogenic H7 avian influenza virus from low pathogenic H7 avian influenza virus, thereby providing technical support and guidance for timely taking effective prevention and control measures, and reducing economic losses in livestock and poultry industry due to a failure in distinguishing between high pathogenicity and low pathogenicity of the H7 avian influenza virus.

The invention discloses an artificial recombinant H5N8 influenza virus and a preparation method and application thereof. The artificial recombinant H5N8 influenza virus has a highly pathogenic avian influenza virus A/swan/Shanxi/4-1/2020 (H5N8) surface antigen Hemagglutinin (HA) gene and a Neuraminidase (NA) gene, but an HA cleavage site has a typical low pathogenic avian influenza virus molecular characteristic (-RETR-), and has six internal genes of PB2, PB1, PA, NP, M and NS of an influenza virus chick embryo high-titer adaptive strain A/PR/8/34(H1N1), the strain number is H5-Re14, and the preservation number is CCTCC NO: V202160. The artificial recombinant H5N8 influenza virus has good chick embryo adaptability, and the virus growth titer can be increased by 9 times or above compared with that of a wild virus; and the artificial recombinant H5N8 influenza virus is used as a vaccine strain for producing a vaccine, the production cost of the vaccine can be greatly reduced, and the quality of the vaccine is improved.

The invention relates to a low-pathogenicity porcine reproductive and respiratory syndrome virus (PRRSV), and a vaccine and an application thereof. The PRRSV is separated from porcine lung tissues by using Marc-145 cells, the above separated strain can proliferate on the Marc-145 cells and make the Marc-145 cells have typical cytopathy, the Marc-145 is detected to obtain the tilter of the separated strain of 10<7.0> TCID50/mL, and the strain is preserved in China General Microbiological Culture Collection Center on Oct. 22, 2015 with the preservation number of CGMCC No.9819; and leaned piglets artificially inoculated with the new virus strain only have weak thermal response, have no obvious clinic symptoms, and normally grow without untoward effects. The new strain artificially inoculated to pigs can induce the pigs to have good immune response I order to generate high level PRRSV antibodies.

The invention discloses a carrier pigeon Newcastle disease virus genetic engineering modified attenuated strain as well as a preparation method and application of the carrier pigeon Newcastle disease virus genetic engineering modified attenuated strain. The method specifically comprises the following steps: carrying out site-directed mutagenesis on amino acids of three cleavage sites of F protein of a carrier pigeon Newcastle disease virus strain (PNDV-YQ strain) by using a reverse genetic manipulation technology, constructing and obtaining a full-length cDNA plasmid pOK-YQ of a low-toxicity gene in a segmented cloning manner, respectively cloning ORF genes of NP, P and L of the PNDV-YQ strain to an eukaryotic expression vector pCIneo, and carrying out expression by using a recombinant vector pCIneo, according to the invention, helper plasmids pCI-NP, pCI-P and pCI-L are constructed and obtained. After a BSR-T7 cell is co-transfected by the full-length plasmid and a helper plasmid, a recombinant attenuated virus, namely the pigeon Newcastle disease virus (PNDV-aYQ strain), is rescued. The strain of virus is a low-pathogenicity or non-pathogenicity strain, and has good proliferation characteristics and stable hereditary characteristics. Compared with the existing newcastle disease vaccine, the inactivated vaccine prepared from the virus strain has the advantages of low side reaction, early immune production period and high protection rate.

The invention discloses a fluorescent RT-PCR primer, probe and method for detecting a highly pathogenic H7N9 avian influenza virus (HP-H7N9). The established HP-H7N9 fluorescent RT-PCR detection method can specifically detect the HP-H7N9, and no cross reactions appear with a low pathogenicity H7N9 influenza virus (LP-H7N9), H7N3 influenza virus, H3N2 influenza virus, H5N1 avian influenza virus, H5subtype avian influenza virus (Re-6 vaccine strain), H5 subtype avian influenza virus (Re-8 vaccine strain), H9 subtype avian influenza virus, influenza A (H1N1) virus (H1N1), infectious bursal disease virus (IBDV), chicken infectious bronchitis virus (IBV), newcastle disease virus (NDV) and the like; positive plasmids with the lowest concentration of 7.09 copies/[mu]L can be detected; the variable coefficient (CV) value of a repeatability test is between 1.97% and 4.89%, the method is indicated to have good repeatability. The established HP-H7N9 fluorescent RT-PCR method has the advantages of specificity, sensitivity, rapidness and good repeatability, and is a good method for rapidly detecting HP-H7N9.

A method for determining the affection of concurrent bacterial infection to virus infection pathogenicity includes such steps as inoculating the bacteria and low-pathogenicity virus in cell culturingmedium, culturing, and observing in cell lesion (CPE) presents. Its culture equipment is composed of cell culture bottle and bacteria culture chamber. Its advantages are simple process, short time, high currectness and low cost.