Invited review: Improved control of Johne's disease in dairy cattle through advancements in diagnostics, testing, and management of young stock.

Johne's disease (JD; paratuberculosis) control programs have been regionally implemented across the globe, but few have successfully eradicated the pathogen (Mycobacterium avium ssp. paratuberculosis; MAP) causing this disease. The limited success may partly be attributed to excluding young stock (calves and replacement heifers or bulls) from testing strategies aimed at identifying MAP-infected cattle.

Progress and persistence of diseases of high consequence to livestock in the United States.

The USDA/ARS-National Disease Center (NADC) will celebrate its 65th anniversary of existence in November 2026. NADC continues as one of the world's premier animal health research centers conducting basic and applied research on endemic diseases with economic impact on U.S.

Vaccination of cattle with a virus vector vaccine against a major membrane protein of Mycobacterium avium subsp. paratuberculosis elicits CD8 cytotoxic T cells that kill intracellular bacteria.

Analysis of the recall response ex vivo in cattle vaccinated with a Mycobacterium avium subsp. paratuberculosis (Map) rel deletion mutant revealed the immune response was directed toward a 35 kD major membrane protein (MMP) of Map. Antigen presenting cells (APC) primed with MMP elicited expansion of CD8 cytotoxic memory T cells (CTL) with ability to kill intracellular bacteria.

The Fur-like regulatory protein MAP3773c modulates key metabolic pathways in Mycobacterium avium subsp. paratuberculosis under in-vitro iron starvation.

Johne's disease (JD) is a chronic enteric infection of dairy cattle worldwide. Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of JD, is fastidious often requiring eight to sixteen weeks to produce colonies in culture-a major hurdle in the diagnosis and therefore in implementation of optimal JD control measures.

Genetic and chemical control of tuberculostearic acid production in subspecies .

Tuberculostearic acid (TBSA) is a fatty acid unique to mycobacteria and some corynebacteria and has been studied due to its diagnostic value, biofuel properties, and role in membrane dynamics. In this study, we demonstrate that TBSA production can be abrogated either by addition of pivalic acid to mycobacterial growth cultures or by a gene knockout encoding a flavin adenine dinucleotide (FAD)-binding oxidoreductase. subspecies () growth and TBSA production were inhibited in 0.

Complete genome sequence of an ovine ancestral strain of subspecies 6756.

The complete genome sequence of the most ancestral type SI strain of subspecies 6756, isolated from a sheep, was determined. The genome was sequenced using PacBio technology, yielding a genome size of 4,830,294 nucleotides with no identified plasmids.

Precursor-Directed Biosynthesis and Biological Testing of -Alicyclic- and -Branched Tunicamycin -Acyl Variants.

Tunicamycins (TUNs) are -derived natural products, widely used to block protein -glycosylation in eukaryotes or cell wall biosynthesis in bacteria. Modified or synthetic TUN analogues that uncouple these activities have considerable potential as novel mode-of-action antibacterial agents. Chemically modified TUNs reported previously with attenuated activity on yeast have pinpointed eukaryotic-specific chemophores in the uridyl group and the -acyl chain length and terminal branching pattern.

subsp. Candidate Vaccine Strains Are Pro-apoptotic in RAW 264.7 Murine Macrophages.

subsp. (MAP) is the etiological agent of Johne's disease, a severe gastroenteritis of ruminants. This study developed a model cell culture system to rapidly screen MAP mutants with vaccine potential for apoptosis.

Improved DNA Amplification of the Hallmark IS Element in subsp. : a Reexamination Based on Whole-Genome Sequence Analysis.

Amplification of the IS multicopy element is a hallmark nucleic acid-based diagnostic test for Mycobacterium avium subsp. , which causes Johne's disease in ruminants. This assay is frequently used to determine the presence of the bacterium in feces of infected cattle and sheep.

B cell phenotypes and maturation states in cows naturally infected with Mycobacterium avium subsp. Paratuberculosis.

Little is known about the role that B cells play in immune responses to infection with the intracellular pathogen, Mycobacterium avium subsp. paratuberculosis (MAP). Traditionally, the role of B cells has been constrained to their function as antibody-producing cells, however, antibodies are not thought to play a protective role in mycobacterial infections.

Vitamin D alters macrophage phenotype and endosomal trafficking markers in dairy cattle naturally infected with subsp. .

Macrophages are important host defense cells in ruminant paratuberculosis (Johne's Disease; JD), a chronic enteritis caused by subsp. (MAP). Classical macrophage functions of pathogen trafficking, degradation, and antigen presentation are interrupted in mycobacterial infection.

Immunological Evaluation of Goats Immunized with a Commercial Vaccine against Johne's Disease.

Johne's disease affects ruminants causing an economic burden to dairy, meat and wool industries. Vaccination against subspecies (), which causes Johne's disease, is a primary intervention for disease control in livestock. Previously, a comprehensive, multi-institutional vaccine trial for Johne's disease was conducted to test the efficacy of live attenuated strains.

Corrigendum: Exogenous Vitamin D Modulates Response of Bovine Macrophages to subsp. Infection and Is Dependent Upon Stage of Johne's Disease.

[This corrects the article DOI: 10.3389/fcimb.2021.

Exogenous Vitamin D Modulates Response of Bovine Macrophages to subsp. Infection and Is Dependent Upon Stage of Johne's Disease.

subspecies (MAP), the causative agent of ruminant enteritis, targets intestinal macrophages. During infection, macrophages contribute to mucosal inflammation and development of granulomas in the small intestine which worsens as disease progression occurs. Vitamin D is an immunomodulatory steroid hormone with beneficial roles in host-pathogen interactions.

Use of a Ferret Model to Test Efficacy and Immunogenicity of Live Attenuated Mycobacterium avium Subspecies paratuberculosis Vaccines.

Native hosts for the bacterial agent that causes Johne's disease are ruminants, which include cattle, sheep and goats among others. These large animals are often too costly to be used in testing experimental vaccines. In this chapter, we provide detailed methods to use an inexpensive and more manageable animal host, the ferret, to test efficacy and immunogenicity of live-attenuated Mycobacterium avium subspecies paratuberculosis (MAP) mutant strains prior to consideration as vaccine candidates.

Challenges in Veterinary Vaccine Development.

Animals provide food and clothing in addition to other value-added products. Changes in diet and lifestyle have increased the consumption and the use of animal products. Infectious diseases in animals are a major threat to global animal health and its welfare; their effective control is crucial for agronomic health, for safeguarding food security and also alleviating rural poverty.

A Comparative Study on the Efficiency of Two subsp. (MAP)-Derived Lipopeptides of L3P and L5P as Capture Antigens in an In-House Milk ELISA Test.

subsp. (MAP) surface-exposed lipopeptides could be specific capture-antigen molecules targeting antibodies against MAP, in milk, through ELISA. Previous studies have revealed that MAP strains, isolated from sheep (S) or cow (C), could produce specific lipopeptides, L3P or L5P, respectively.

Draft Genome Sequences of Two Bison-Type and Two Sheep-Type Strains of Mycobacterium avium subsp. .

Genome sequences of two type B and two type S strains of Mycobacterium avium subsp. are presented. These strains were isolated in the United States from sheep, bison, and cattle suffering from Johne's disease.

Whole-Genome Analysis of subsp. IS -.

subsp. () is the etiological agent of Johne's disease in ruminants. The IS insertion sequence (IS) has been used widely as an epidemiological marker and target for PCR diagnosis.

Comparative cellular immune responses in calves after infection with Mycobacterium avium subsp. paratuberculosis, M. avium subsp. avium, M. kansasii and M. bovis.

In the present study, calves were infected with Mycobacterium avium subsp. paratuberculosis (MAP), Mycobacterium avium subsp. avium (M.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of subsp. Infection.

Unlike other MAC members, subsp. (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18-C20).

Reduced tissue colonization of Mycobacterium avium subsp. paratuberculosis in neonatal calves vaccinated with a cocktail of recombinant proteins.

An increasing prevalence of paratuberculosis supports the need for new efficacious vaccines as an essential management tool. Two separate studies were performed in neonatal calves to evaluate the effectiveness of pooled recombinant Mycobacterium avium subsp. paratuberculosis (MAP) proteins (MAP1087, MAP1204, MAP1272c, MAP2077c) as a potential vaccine.

Complete Genome Sequence of a Type III Ovine Strain of Mycobacterium avium subsp. .

The complete genome sequence of a type III strain of subsp. was determined. The genome size for this pathogen of sheep is 4,895,755 bp with no plasmid DNA.

Diagnostic Sequences That Distinguish Subspecies Strains.

Over a decade ago subspecies () specific genes were initially identified in a whole genome context by comparing draft genome sequences of strain K-10 with subspecies () strain 104. This resulted in identification of 32 specific genes, not including repetitive elements, based on the two-genome comparison. The goal of this study was to define a more complete catalog of subspecies-specific genes.