Estimation of the sensitivity and specificity of four serum ELISA and one fecal PCR for diagnosis of paratuberculosis in adult dairy cattle in New Zealand using Bayesian latent class analysis.

In New Zealand, a new diagnostic approach for the control of paratuberculosis in mixed aged milking cows has been developed using a combination of ELISA and quantitative fecal PCR (f-qPCR). Our analysis was designed to evaluate performance of these individual tests in infected or infectious mixed aged cows across the prevalence of infection typically encountered on NZ dairy farms and calculate test accuracy when used as a screening test of serological ELISAs for four separate antigens read in parallel followed by a confirmatory quantitative f-qPCR test. Data from a cross-sectional study of 20 moderate prevalence herds was combined with existing data from 2 low and 20 high prevalence herds forming a dataset of 3845 paired serum and fecal samples.

Control of Mycobacterium avium subsp. paratuberculosis infection on a New Zealand pastoral dairy farm.

Background: Johne's disease is a major production limiting disease of dairy cows caused by infection with Mycobacterium avium subsp. paratuberculosis in calf-hood. The disease is chronic, progressive, contagious and widespread with no treatment and no cure.

Control of paratuberculosis: who, why and how. A review of 48 countries.

Paratuberculosis, a chronic disease affecting ruminant livestock, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). It has direct and indirect economic costs, impacts animal welfare and arouses public health concerns.

The effect of sub-clinical infection with Mycobacterium avium subsp. paratuberculosis on milk production in a New Zealand dairy herd.

Background: Johne's disease is a major production limiting disease of dairy cows. The disease is chronic, progressive, contagious and widespread; there is no treatment and there is no cure. Economic losses arise from decreased productivity through reduced growth, milk yield and fertility and capital losses due to premature culling or death.

Bovine milk RNases modulate pro-inflammatory responses induced by nucleic acids in cultured immune and epithelial cells.

Activation of innate immune receptors by exogenous substances is crucial for the detection of microbial pathogens and a subsequent inflammatory response. The inflammatory response to microbial lipopolysaccharide via Toll-like receptor 4 (TLR4) is facilitated by soluble accessory proteins, but the role of such proteins in the activation of other pathogen recognition receptors for microbial nucleic acid is not well understood. Here we demonstrate that RNase4 and RNase5 purified from bovine milk bind to Salmonella typhimurium DNA and stimulate pro-inflammatory responses induced by nucleic acid mimetics and S.

Farmed deer: A veterinary model for chronic mycobacterial diseases that is accessible, appropriate and cost-effective.

Although most studies in immunology have used inbred mice as the experimental model to study fundamental immune mechanisms they have been proven to be limited in their ability to chart complex functional immune pathways, such as are seen in outbred populations of humans or animals. Translation of the findings from inbred mouse studies into practical solutions in therapeutics or the clinic has been remarkably unproductive compared with many other areas of clinical practice in human and veterinary medicine. Access to an unlimited array of mouse strains and an increasing number of genetically modified strains continues to sustain their paramount position in immunology research.

Use of ethanol extract of Mycobacterium bovis for detection of specific antibodies in sera of farmed red deer (Cervus elaphus) with bovine tuberculosis.

Background: Bovine tuberculosis (bTB) in wildlife species poses a threat to domestic livestock in many situations. Control programs for bTB in livestock depend on testing and slaughtering the positive animals; however, the currently available diagnostic tests often have poor specificity. In our previous study, we developed a specific and sensitive enzyme linked immunosorbent assay (ELISA) for another mycobacterial disease - Johne's disease, using surface antigens of Mycobacterium avium ssp.

Composite testing for ante-mortem diagnosis of Johne's disease in farmed New Zealand deer: correlations between bacteriological culture, histopathology, serological reactivity and faecal shedding as determined by quantitative PCR.

Background: In the absence of overt clinical signs of Johne's Disease (JD), laboratory based tests have largely been limited to organism detection via faecal culture or PCR and serological tests for antibody reactivity. In this study we describe the application of quantitative faecal PCR for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in New Zealand farmed deer to quantify the bacterial load in cervine faecal samples as an adjunct to an existing serodiagnostic test (Paralisa™) tailored for JD diagnosis in deer.

Global gene expression profiling of monocyte-derived macrophages from red deer (Cervus elaphus) genotypically resistant or susceptible to Mycobacterium avium subspecies paratuberculosis infection.

Mycobacterium avium subspecies paratuberculosis (MAP) can cause a chronic inflammatory bowel disease, Johne's disease (JD), in ruminant animals. This study has explored the molecular basis of resistance and susceptibility to this disease in red deer breeds previously confirmed to express polarised phenotypes by experimental infection trials and following natural infection. Monocyte-derived macrophage cultures were obtained from uninfected red deer selected for either a resistant or susceptible phenotype.

Innate immune markers that distinguish red deer (Cervus elaphus) selected for resistant or susceptible genotypes for Johne's disease.

While many factors contribute to resistance and susceptibility to infectious disease, a major component is the genotype of the host and the way in which it is expressed. Johne's disease is a chronic inflammatory bowel disease affecting ruminants and is caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP). We have previously identified red deer breeds (Cervus elaphus) that are resistant; have a low rate of MAP infection and do not progress to develop Johne's disease.

Longitudinal Pathogenesis Study of Young Red Deer (Cervus elaphus) after Experimental Challenge with Mycobacterium avium subsp. paratuberculosis (MAP).

Paratuberculosis progresses more quickly in young red deer than in sheep or cattle. This study describes the clinical, immunological and pathological changes over a 50-week period in fourteen 4-month-old red deer that received heavy oral challenge with Mycobacterium avium subsp. paratuberculosis (MAP).

The mammalian secreted RNases: mechanisms of action in host defence.

The mammalian ribonucleaseA family comprises a large group of structurally similar proteins which are secreted by a range of tissues and immune cells. Their physiological role is unclear. It has been suggested that some of these RNases contribute to host defence, notably eosinophil-derived neurotoxin, eosinophil cationic protein, eosinophil-associated RNases, RNase4, angiogenin (RNase5), RNase7, RNase8 and bovine seminal RNase.

Ovine immune parameters following immunisation against Mycobacterium avium ssp. paratuberculosis using a lipid-based live-cell vaccine.

Current commercial sheep vaccines against Mycobacterium avium subspecies paratuberculosis (MAP) are based on the use of live or killed cells from avirulent MAP strains. These stimulate a mixed immune response, featuring both antibody-based and cell-mediated immunity, and can only confer partial protection against Johne's disease but do not prevent infection. This study aimed to identify immune responses in sheep following immunisation with a novel lipid-based live-cell vaccine, drawing comparisons against responses observed to a commercial killed-cell vaccine (Gudair).

Development of the thymus and Peyer's patches in the first year of life in red deer (Cervus elaphus).

In young ruminants, as in most animals, the thymus and Peyer's patches (PP) play a key role in immune function. In sheep and cattle it has been shown that they follow a recognisable pattern of development throughout early life but a study of these tissues in red deer (Cervus elaphus) had not been previously conducted. Red deer are undergoing increasing domestication thus it was important to determine whether there were any significant differences between species.

Peripheral blood mononuclear cell population changes associated with age and Mycobacterium avium subspecies paratuberculosis infection in red deer (Cervus elaphus).

In this study we aimed to document the maturation of the immune system in red deer and investigate the hypothesis that an immature immune system may predispose young red deer (Cervus elaphus) to an increased susceptibility to Johne's disease. Peripheral blood mononuclear cell populations were analysed using flow cytometry techniques to monitor changes associated with age and severity of infection with Mycobacterium avium subspecies paratuberculosis in red deer. The percentage of cells expressing cell population markers CD4, CD8, WC1, gammadelta TCR, CD14 and B-B4 as well as the cell activation markers CD25, CD44, ACT1 and ACT31 were analysed in relation to age and M.

Identification of immune parameters to differentiate disease states among sheep infected with Mycobacterium avium subsp. paratuberculosis.

Johne's disease, a chronic enteritis of ruminants, is caused by infection with Mycobacterium avium subsp. paratuberculosis. Three distinct forms have been observed in sheep: paucibacillary disease (PB), multibacillary disease (MB), and asymptomatic infection (AS).