34 results about "Toxigenic strain" patented technology

The ability of two Aspergillus flavus Link isolates (CT3 and K49) to reduce aflatoxin contamination of corn was assessed in a four-year field study (2001 to 2004). Soil was treated with six wheat inoculant treatments: toxigenic isolate F3W4; the non-toxigenic isolate K49; the non-aflatoxigenic isolate CT3, two mixtures of CT3 or K49 with F3W4; and an autoclaved wheat control, applied at 20 kg / ha. In 2001, inoculation with the toxigenic isolate increased corn grain aflatoxin levels by 167% compared to the non-inoculated control, while CT3 and K49 inoculation reduced aflatoxin levels in corn grain by 86% & 60%, respectively. In 2002, inoculation of CT3 and K49 reduced aflatoxin levels by 61% and 76% compared to non-inoculated controls, respectively. In 2001 mixtures of toxigenic and non-toxigenic isolates had little effect on aflatoxin levels, but in 2002 inoculation with mixtures of K49 and CT3 reduced aflatoxin levels 68 and 37% compared to non-inoculated controls, respectively. In 2003 and 2004, a low level of natural aflatoxin contamination was observed (8 ng / g). However, inoculation with mixtures of K49+F3W4 and CT3+F3W4, reduced levels of aflatoxin 65 to 94% compared to the toxigenic strain alone. Compared to the non-sclerotia producing CT3, strain K49 produces large sclerotia, has more rapid in vitro radial growth, and a greater ability to colonize corn when artificially inoculated, perhaps indicating greater ecological competence. Results indicate that non-toxigenic, indigenous A. flavus isolates, such as strain K49, have potential use for biocontrol of aflatoxin contamination in southern U.S. corn.

The invention provides a p porcine pseudorabies virus and vaccine composition and applications thereof, belonging to the field of biotechnology. The microbial preservation number of the porcine pseudorabies virus PRV-JS strain is CGMCCNO.6604. The invention further provides a vaccine composition which comprises an inactivated porcine pseudorabies virus PRV-JS strain and adjuvant acceptable on veteriary pharmacy. The vaccine composition further comprises a carrier acceptable on the veterinary pharmacy. The porcine pseudorabies virus PRV-JS strain is screened from porcine pseudorabies prevalent strains separated from all pig farms and has good immunogenicity, and can be used as inactivated vaccine production virus seeds or virus seeds for testing. After being immunized by the vaccine composition, pigs have higher produced antibody level and the lasting period is long. The vaccine composition prepared by adopting the porcine pseudorabies virus PRV-JS strain can be used for preventing the sow abortionbreeding difficulty and mortality syndromeboar infertility caused by the porcine pseudorabies virus, boar infertility and pseudorabies of other pigs.

The invention discloses an LAMP detection method for clostridium difficile AB toxins and a special primer and a kit thereof. The LAMP detection method disclosed by the invention comprises the following steps: designing a primer according to the specific conserved genes tcdA and tcdB of clostridium difficile; then, by taking a genomic DNA of an object to be detected as a template, carrying out LAMP amplification under the guide of the obtained primer; and synchronously and qualitatively detecting toxigenic strains of clostridium difficile in a sample to be detected through the color changes and turbidity changes of a reaction liquid. According to the invention, toxigenic strains of clostridium difficile can be detected in a fast, convenient, synchronous, high efficiency, high specificity and high sensitivity mode under isothermal conditions without using complex instruments, so that a new technical platform is provided for the detection and toxin classification of clostridium difficile, therefore, the LAMP detection method disclosed by the invention can be used for screening and detecting clostridium difficile by grassroots medical health units and various disease prevention and control centers, has a broad market prospect and great economic and social benefits, and is suitable for large-scale popularization and application.

The invention relates to a composite PCR detection method for fumonisin toxicogenic strains in corn and corn products, wherein a plurality of pairs of primers are designed by application of DNAman sequence analysis software respectively on the basis of polyketide synthetase genes FUM1, serine-hexadecanoyl transferase genes FUM8 and longevity guarantee factor genes FUM17 required for biosynthesis of fumonisin, and primer matched groups with optimized specificity are obtained through experimental comparison of the primers and fusarium specific primers IstF / IstR; the fumonisin toxicogenic strains are simultaneously detected in the same reaction system; and the plurality of pairs of primers are subjected to amplification simultaneously in the same reaction system by the composite PCR technology. The composite PCR detection method comprises the following detection steps: template DNA is directly extracted from a sample to be detected by the improved SDS method; and the template DNA is subjected to composite PCR reaction, electrophoresis, dyeing and rinsing, a gel imaging device is used for observing the result and taking a picture, and finally the detection result is obtained after spectrogram analysis. The composite PCR detection method improves the detection accuracy, saves the detection time and can be massively promoted by means of a reagent kit.

The invention relates to a method for detecting fumonisin toxicogenic strains in asparaguses by the composite PCR technology, which uses primer pairs rp32 / rp33 and primer pairs rp679 / rp680 which are designed according to polyketide synthetase genes FUM1 and serine-hexadecanoyl transferase genes FUM8 required for biosynthesis of fumonisin, and fusarium specific primers IstF / IstR respectively. The method simultaneously detects the fumonisin toxicogenic strains in the same reaction system, and not only can detect unknown fumonisin toxicogenic strains but also can identify whether the detected strains belong to fusarium. Moreover, a plurality of pairs of primers are subjected to amplification in the same reaction system simultaneously by the composite PCR technology, so that the method improves the detection accuracy, saves the detection time, is a simple, quick and effective composite PCR detection method for the fumonisin toxicogenic strains in the asparaguses, and can be massively promoted by means of a kit.

The invention provides a preparation method of a contagious pustular dermatitis virus attenuated strain, which is characterized in that virulence genes of contagious pustular dermatitis virus are mutated and inactivated, and the virulence genes are mutated into ORFs 120 / 121 double-gene mutation. After the ORFs 120 / 121 gene is deleted, the pathogenicity of the ORFV is obviously reduced. According to the present invention, the ORFs 120 / 121 gene of the ORFV-SY17 strain is knocked out to obtain the double-gene-deleted contagious pustular dermatitis virus attenuated strain, and the double-gene-deleted contagious pustular dermatitis virus attenuated strain has potential application value in preparation of the contagious pustular dermatitis gene-deleted attenuated live vaccine production strain. The deleted ORFs 120 / 121 gene can also be used as a marker gene to establish a differential diagnosis method for ORFV vaccine virus and wild virus detection.

The present invention relates to an aflatoxin contamination risk warning molecule and use thereof. The steps are as follows: weighing a quantitative sample, extracting the aflatoxin contamination risk warning molecule to obtain a sample extract, and detecting and analyzing the sample extract to obtain a quantitative result of the aflatoxin contamination risk warning molecule; performing modeling with a chemometrics method using the content of one or more of the aflatoxin contamination risk warning molecules as a variable to obtain a classification prediction model, and performing risk assessment on aflatoxin contamination risk of the sample based on the classification prediction model, wherein a warning molecule of an aflatoxin toxigenic strain is one or a combination of more than one of versiconol (VOH), versicolorin B (Ver B), and 5-methoxysterigmatocystin (5-MST).