Fuidi herd management and risk stratification methods

摘要

The invention concerns the detection of pathogenic mycobacterium comprising Mycobacterium avium subsp. paratuberculosis (Map) and genomic variants in a bulk milk sample, and more particularly a method for herd management that stratifies the risk of bulk tank milk lots derived from diagnostic-tested subgroups potentially containing DNA from pathogenic mycobacterium including Map. The method involves creating defined risk groups (categories) of milk-producing animals, such as dairy cows, for the presence of Map or related genomic variants in their milk. Another aspect of the invention concerns a method to strengthen the ability of milk-producing animals to resist environmental challenges by Map based on identifying those animals that have and maintain a low antibody level to Map using their female progeny as replacement animals.

主权项

1. A method for herd management that stratifies the risk of bulk tank milk lots derived from diagnostic-tested subgroups potentially containing DNA from pathogenic mycobacterium comprising Mycobacterium avium subspecies paratuberculosis (Map), said method comprising:
(a) determining the level of a Map-specific antibodies in blood samples from individual milk-producing animals, wherein said determining comprises:
(i) conducting a first test that identifies if the animals have had antigenic exposure to Map, wherein the first test is an immunoassay comprising contacting a plasma or a serum from an animal with FUIDI antigen deposited as ATCC PTA-11837 and detecting the binding of antibodies to said FUIDI antigen; and(ii) conducting a second test that assesses active Map replication in the animals, wherein the second is an immunoassay comprising contacting a plasma or serum from said animals with Map lipoarabinomannan polysaccharides (LAM) and/or membrane lipoproteins and detecting the binding of antibodies to said Map LAM and/or membrane lipoproteins, and wherein the presence of antibodies against Map LAM and/or membrane lipoproteins indicates active Map replication; (b) categorizing the animals into a plurality of risk categories based on the results of the first and second tests; the risk categories comprising:
(i) a first category of animals having no detectable Map-specific antibodies in the first and second tests;(ii) a second category of animals having a low level of Map-specific antibodies in the first test and no detectable Map-specific antibodies in the second test;(iii) a third category of animals having an intermediate level of Map-specific antibodies in the first test and no detectable Map-specific antibodies in the second test;(iv) a fourth category of animals having a high level of Map-specific antibodies in the first test and no detectable Map-specific antibodies in the second test; and(v) a fifth category of animals having a low, intermediate. or high level of Map-specific antibodies in the first test, and low or intermediate level of Map-specific antibodies in the second test; and (c) detecting the presence of Map in a bulk milk sample obtained from a volume of milk from a plurality of animals in each category by determining the presence of a nucleic acid encoding SEQ ID NO: 6 in the bulk milk sample.