Genealogy of an passaged isolate of western Canadian bovine respiratory syncytial virus.

Bovine respiratory syncytial virus (BRSV) is a primary respiratory pathogen in calves. Clinical infection with this pathogen has been experimentally modelled to assess vaccine efficacy using a field isolate (Asquith) of BRSV that has been sequentially passaged in neonatal calves to maintain virulence. The objective of this retrospective cumulative analysis of passages over approximately 20 years was to determine if there have been any changes in the viral genome of this isolate because of this process.

Antibody recognition of cathepsin L1-derived peptides in Fasciola hepatica-infected and/or vaccinated cattle and identification of protective linear B-cell epitopes.

Fasciola hepatica infection causes important economic losses in livestock and food industries around the world. In the Republic of Ireland F. hepatica infection has an 76% prevalence in cattle.

Frequency and phenotype of natural killer cells and natural killer cell subsets in bovine lymphoid compartments and blood.

Natural killer (NK) cells are widely distributed in lymphoid and non-lymphoid tissues, but little is known about the recirculation of NK cells between blood and tissues. This is relevant to understanding recirculation in the steady-state and also for determining the roles for NK cells in vaccine-induced immunity and responses to infection. Therefore, the percentage of NK cells and their phenotype across peripheral blood, afferent lymph and lymph nodes in steady-state conditions was investigated in cattle using the pseudo-afferent lymphatic cannulation model.

Interactions between natural killer cells and dendritic cells favour T helper1-type responses to BCG in calves.

Vaccination of neonatal calves with BCG induces a significant level of protection from infection with Mycobacterium bovis, the causative agent of bovine tuberculosis. Since neonatal vaccination of humans with BCG induces activation of NK cells, and young calves have high circulating numbers of these cells, we hypothesised that NK cells are important in the protective response to BCG. Furthermore, since NK cells play a role in shaping adaptive immune responses through interactions with DCs, we investigated the interactions between NK cells and DCs in the context of BCG.

Efficacy of intranasal vaccination with a multivalent vaccine containing temperature-sensitive modified-live bovine herpesvirus type 1 for protection of seronegative and seropositive calves against respiratory disease.

OBJECTIVE To evaluate efficacy and duration of immunity of the bovine herpesvirus type 1 (BHV-1) fraction of a trivalent vaccine also containing parainfluenza virus-3 and bovine respiratory syncytial virus fractions administered intranasally (IN) for protection of calves against infectious bovine rhinotracheitis (IBR). DESIGN Controlled challenge study. ANIMALS 120 dairy calves (3 to 8 days old) seronegative for antibody against BHV-1 (experiments 1 and 2) or seropositive for maternally derived antibody against BHV-1 (experiment 3).

Mevalonate Biosynthesis Intermediates Are Key Regulators of Innate Immunity in Bovine Endometritis.

Metabolic changes can influence inflammatory responses to bacteria. To examine whether localized manipulation of the mevalonate pathway impacts innate immunity, we exploited a unique mucosal disease model, endometritis, where inflammation is a consequence of innate immunity. IL responses to pathogenic bacteria and LPS were modulated in bovine endometrial cell and organ cultures by small molecules that target the mevalonate pathway.

Differential endometrial cell sensitivity to a cholesterol-dependent cytolysin links Trueperella pyogenes to uterine disease in cattle.

Purulent disease of the uterus develops in 40% of dairy cows after parturition, when the epithelium of the endometrium is disrupted to expose the underlying stroma to bacteria. The severity of endometrial pathology is associated with isolation of Trueperella pyogenes. In the present study, T.

Duration of immunity to experimental infection with bovine respiratory syncytial virus following intranasal vaccination of young passively immune calves.

Objective: To determine whether a combination modified-live bovine respiratory syncytial virus (BRSV) vaccine could stimulate protective immunity in young BRSV-seropositive calves following intranasal administration and determine the duration of clinical immunity.

Design: Controlled challenge study. Animals-84 dairy calves (3 to 11 days old).

Structure of the type IV secretion system in different strains of Anaplasma phagocytophilum.

Background: Anaplasma phagocytophilum is an intracellular organism in the Order Rickettsiales that infects diverse animal species and is causing an emerging disease in humans, dogs and horses. Different strains have very different cell tropisms and virulence. For example, in the U.

Rickettsia africae in Amblyomma variegatum and domestic ruminants on eight Caribbean islands.

We used PCRs with omp A primers to determine if spotted fever group rickettsiae occurred in Amblyomma variegatum from 6 Caribbean islands. Positive amplicons were obtained from ticks from the U.S.

Diversity of Ehrlichia ruminantium major antigenic protein 1-2 in field isolates and infected sheep.

Proteins expressed from the map1 multigene family of Ehrlichia ruminantium are strongly recognized by immune T and B cells from infected animals or from animals that were infected and have recovered from heartwater disease (although still remaining infected carriers). Analogous multigene clusters also encode the immunodominant outer membrane proteins (OMPs) in other ehrlichial species. Recombinant protein analogs of the expressed genes and DNA vaccines based on the multigene clusters have been shown to induce protective immunity, although this was less effective in heterologous challenge situations, where the challenge strain major antigenic protein 1 (MAP1) sequence differed from the vaccine strain MAP1.

Infection of a goat with a tick-transmitted Ehrlichia from Georgia, U.S.A., that is closely related to Ehrlichia ruminantium.

We detected a novel tick-transmitted Ehrlichia in a goat following exposure to lone star ticks (Amblyomma americanum) from a park in the metropolitan area of Atlanta, GA, U.S.A.

Evaluation of E. ruminantium genes in DBA/2 mice as potential DNA vaccine candidates for control of heartwater.

Heartwater caused by the rickettsia Ehrlichia ruminantium (E. ruminantium) is an acute and fatal tick-borne disease of domestic and some wild ruminants. A user-friendly vaccine does not exist.

Ticks and tick-borne disease in Guatemalan cattle and horses.

Blood samples and ticks were collected from 48 cattle and 74 horses from seven sites in the Peten region of Guatemala. Data on body condition, mucous membrane capillary refill time and tick infestation levels were recorded for each animal in the study. Horses had significantly higher levels of tick infestation than cattle, as well as poorer body condition scores.

Control and eradication of chelonian tick infestations, with particular reference to vectors of heartwater.

Studies using the African tortoise tick (Amblyomma marmoreum) and leopard tortoises (Geochelone pardalis) demonstrated that cyfluthrin and permethrin were safe and efficacious acaricides for control of Amblyomma ticks on tortoises. A protocol was developed that successfully eradicated an A. sparsum infestation from a tortoise breeding facility in Florida.

Increasing risks of introduction of heartwater onto the American mainland associated with animal movements.

Opportunities to introduce heartwater onto the American mainland through animal movements include importation from Africa of tick-infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the Caribbean infested with Amblyomma variegatum ticks. Measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the American mainland. Measures to control importation of infected wildlife must focus on improved methods, such as the PCR assay, of screening animals to prevent the entry of carriers of Cowdria ruminantium.

Evaluation of safety and efficacy of acaricides for control of the African tortoise tick (Amblyomma marmoreum) on leopard tortoises (Geochelone pardalis).

Nine acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, fipronil, lindane, permethrin, phenothrin, and pyrethrins) were studied for their efficacy in killing the African tortoise tick (Amblyomma marmoreum). Only four of the acaricides (chlorpyrifos, cyfluthrin, lindane, and permethrin) produced 100% mortality within 24 hr of application, and only two (cyfluthrin and permethrin) continued to cause 100% mortality when diluted to as low as 1:10,000. Five of the acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, and permethrin) were studied for toxicity to the leopard tortoise (Geochelone pardalis), the most common host of A.

Ehrlichia ruminantium infection (heartwater) in wild animals.

Several wild animal species have been implicated as hosts of Ehrlichia ruminantium (formerly Cowdria ruminantium), the rickettsial agent causing heartwater, a fatal disease of domestic ruminants in sub-Saharan Africa and eastern Caribbean. However, evidence for infection in most wild species is inconclusive because of inadequate diagnostic techniques. Infection has been proven only in 12 African ruminants, three non-African ruminants and two African rodents.

Comparison of three enzyme-linked immunosorbant assays with the indirect immunofluorescent antibody test for the diagnosis of canine infection with Ehrlichia canis.

The aim of this study was to compare three different enzyme-linked immunosorbant assays (recombinant major antigenic protein 2 (rMAP2)-ELISA, the Immunocomb (Biogal, Israel) and the Snap 3Dx assay (IDEXX Laboratories Inc., USA)) with the indirect immunofluorescent antibody test in detecting anti-Ehrlichia canis immunoglobulin-G (IgG) antibodies. Samples tested were collected from dogs suspected to be naturally infected with E.

Immunisation of cattle against heartwater by infection with Cowdria ruminantium elicits T lymphocytes that recognise major antigenic proteins 1 and 2 of the agent.

There is growing evidence that immunity of cattle to Cowdria ruminantium infection is mediated by T lymphocytes. C. ruminantium antigens that stimulate these responses are therefore of considerable importance to the development of a sub-unit vaccine against the disease.

DNA vaccination with map1 gene followed by protein boost augments protection against challenge with Cowdria ruminantium, the agent of heartwater.

A DNA vaccine encoding the immunodominant MAP1 protein of Cowdria ruminantium (Crystal Springs (CS) strain) was shown to partially protect DBA/2 mice against homologous lethal challenge. To enhance the protective capacity of this DNA vaccine, the effects of length of interval between vaccinations and of prime-boost regimes were investigated. Increasing the interval between vaccinations from 2 to 12 weeks did not result in better protection (P=0.