Suppression of immune response to sheep red blood cells in rats experimentally infected with Trypanosoma brucei gambiense

A direct haemagglutination assay for antibodies to sheep red blood cells (SRBC) was used to assess the response of rats infected with Trypanosoma brucei gambiense. Whereas uninfected rats showed an efficient primary and secondary immune response to SRBC, trypanosome-infected rats displayed depressed antibody response starting about six days after infection. Infected rats failed to respond to a challenge dose of SRBC given 14 days after infection while uninfected control animals responded with an increased level of antibody production. These observations showed that T. b. gambiense infection inhibited both primary and secondary immune response to SRBC in rats. The result of this experiment is very important with regard to serological methods used to detect increasing levels of antibody production for diagnosis of diseases caused by bacterial and viral pathogens. In a concurrent trypanosome infection such increasing antibody levels would not be observed, leading to inaccurate diagnosis. Thus trypanosomiasis infection should be excluded under field conditions before the value of a serological diagnosis can be fully utilized.     

Immunoprotection of recombinant <Emphasis Type="Italic">Eg</Emphasis>.P29 against <Emphasis Type="Italic">Echinococcus granulosus</Emphasis> in sheep

Objective

This study aims to investigate the immunoprotection of recombinant Eg.P29 (rEg.P29) vaccine and analyze the underlying mechanism in sheep.

Methods

Three groups of male sheep were immunized subcutaneously with rEg.P29 and PBS, Freund’s complete adjuvant as controls, respectively. After prime-boost vaccination, the sheep were challenged with encapsulated Echinococcus granulosus eggs. The percentage of protection in sheep was determined 36 weeks after the infection. Humoral immune response was analyzed for specific IgG, IgG1, IgG2, IgM and IgE levels. Moreover, cytokines including interferon (IFN)-γ, interleukin (IL)-2, IL-4,and IL-10 were also evaluated.

Results

Immunization with rEg.P29 induced protective immune responses up to 94.5 %, compared with immunoadjuvant group. The levels of specific IgG, IgG1, IgG2, and IgE as well as IFN-γ, IL-2, and IL-4 significantly increased after two immunizations (P < 0.05); however, the levels of IgM and IL-10 did not show difference.

Conclusion

rEg.P29 showed Immunoprotection and induced Th1 and Th2 immune responses; hence, rEg.P29 is a potential vaccine for E. granulosus infection.

     

A case report of <Emphasis Type="Italic">Mycoplasma wenyonii</Emphasis> associated immune-mediated haemolytic anaemia in a dairy cow

Background and case presentation

A three year old, second lactation Holstein dairy cow presented to the Scottish Centre for Production Animal Health and Food Safety, Glasgow University Veterinary School in November 2014 with a history of post-calving vulval/vaginal bleeding nine days prior to presentation, followed by a sudden reduction in milk yield. Subsequent investigations resulted in a diagnosis of immune-mediated haemolytic anaemia secondary to infection with Mycoplasma wenyonii.

Conclusion

This report of a novel presentation of Mycoplasma wenyonii in a dairy cow illustrates the need to consider M.wenyonii as a potential differential diagnosis when a cow presents with anaemia and will discuss the potential implications of the condition at herd-level.

     

Gastric inflammatory pseudotumour secondary to <Emphasis Type="Italic">Actinomyces hordeovulneris</Emphasis> infection in a cat

Background

The authors report the first case of feline gastric actinomycosis associated with infection by Actinomyces hordeovulneris.

Case presentation

A 4-year-old, neutered male, semi-feral European cat, with a 1 year history of chronic vomiting, was referred to the clinic. Abdominal ultrasound examination identified a hypoechoic focal transmural thickening with loss of normal wall layering and hyperechoic speckles at the gastric body. Initial gastroscopic examination showed a tumour-like gastric mass with an ulcerated depression at the level of the greater curvature. Histologic examination of endoscopic biopsy specimens was consistent with a severe lymphoplasmacytic gastritis. After 2 months, due to persistence of abdominal discomfort, surgical exploration and intraoperative sampling of gross abnormalities was recommended. Full thickness gastric wall biopsies, and fine needle aspiration of the gastric thickening and gastric lymph node, were performed. Histopathological examination identified a transmural pyogranulomatous gastritis. Aspirate samples of the gastric wall cultured positive, with colony morphology, biochemical testing and PCR of the 16 s rRNA gene compatible with Actinomyces hordeovulneris. After 4 months of treatment with cefovecin (8 mg/kg subcutaneously every 14 days), the vomiting completely resolved, as well as the ultrasonographic gastric alteration.

Conclusion

This case report of feline gastric actinomycosis, caused by Actinomyces hordeovulneris, suggests that gastric bacterial infection should be considered in cases of focal gastric wall thickening associated with chronic vomiting in the cat, which may otherwise closely resemble neoplastic disease. Once a diagnosis of actinomycosis was obtained, a correct treatment with antibiotic therapy can resolve it.

     

Control of <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in sheep using basidiocarps of <Emphasis Type="Italic">Agaricus blazei</Emphasis> Murril

Objective

This study evaluated the effects in vitro and in vivo of Agaricus blazei against Haemonchus contortus in sheep.

Methods

The in vitro efficacy of aqueous extract on egg hatching inhibition (EHI) was investigated and after 72 h incubation with varying concentrations the effects on, blastomeres, embryonated eggs, and first stage larvae (L1) were evaluated. Larval development inhibition (LDI) for dry powder and the aqueous extract were evaluated in fecal cultures of sheep infected with H. contortus. In vivo efficacy was determined by reduction in fecal egg count (FEC). Lambs were treated with powder A. blazei (11.4 g/kg pc) or trichlorfon, or were untreated and the possible toxicity of this fungus was monitored by plasmatic enzyme analysis.

Results

Concentrations equal to and higher than 3.62 mg/mL and of aqueous extract were 100% effective in the EHI test. In the LDI test, LC90 was estimated for 5.66 and 106.0 mg/g fecal culture for aqueous extract and powder, respectively. The mean FEC in lambs 14 days post-treatment with A. blazei powder was significantly lower than observed for the negative control, and the serum levels of aspartate transaminase and alanine transaminase were normal.

Conclusion

The fungi supplementation promotes, respectively, high and moderate anthelmintic efficacy with in vitro and in vivo tests, respectively, suggesting it as an alternative or complementary treatment for haemonchosis in sheep.

     

Isolation of <Emphasis Type="Italic">Chlamydia abortus</Emphasis> from a laboratory worker diagnosed with atypical pneumonia

Background

Identifying the aetiological agent of atypical pneumonia in human can sometimes be a tedious process, especially in cases where Mycoplasma pneumoniae, Legionella species and Chlamydia pneumoniae are ruled out. In such cases, a correct anamnesis of the patient is basic to clarify which pathogens might have produced the infection. For this reason, health professionals including veterinarians and laboratory personnel working with zoonotic pathogens should keep their doctors informed.

Case presentation

A human case of atypical pneumonia linked to Chlamydia abortus is reported. A 47-year-old male, a veterinarian researcher into chlamydiae, developed respiratory symptoms, breathing problems and high fever. Serological analyses ruled out the involvement of several respiratory pathogens, such as M. pneumoniae, Legionella pneumophila, Rickettsia conorii and C. pneumoniae, and Chlamydia abortus was identified as the possible aetiological agent of the infection. The isolation of C. abortus from the patient’s sputum and subsequent molecular analysis confirmed the presence of this microorganism.

Conclusion

As far as we know, although C. abortus has not been previously described as capable of causing pneumonia in humans, this is the first reported case of atypical pneumonia in which C. abortus is thought to have played an aetiological role.

     

The activation of the IFNβ induction/signaling pathway in porcine alveolar macrophages by porcine reproductive and respiratory syndrome virus is variable

Background

It has been recognized that the expression of type I interferon (IFNα/β) may be suppressed during infection with porcine reproductive, respiratory syndrome virus (PRRSV). This causes profound negative effects on both the innate and adaptive immunity of the host resulting in persistence of infection.

Objective

Test the effects of PRRSV infection of porcine alveolar macrophages (PAMs), the main target cell, on the expression of interferon beta (IFNβ) and downstream signaling events.

Methods

In order to examine those effects, PAMs harvested from lungs of healthy PRRSV-free animals were infected with virulent, attenuated, infectious clone-derived chimeric viruses, or field PRRS virus strains. Culture supernatants from the infected PAMs were tested for IFNβ protein expression by means of indirect ELISA and for bioactivity by a vesicular stomatitis virus plaque reduction assay. The expression of the Mx protein was assayed to ascertain signaling events.

Results

These experiments demonstrated that PRRSV does induce variably, the expression of bioactive IFNβ protein in the natural host cell. To further elucidate the effects of PRRSV infection on IFNβ signaling, Mx-1 an interferon stimulated gene (ISG), was also tested for expression. Interestingly, Mx-1 expression by infected PAMs generally correlated with IFNβ production.

Conclusion

The results of this study demonstrate that the induction of IFNβ and signaling in PAMs after PRRSV infection is variable.

     

Assessment of an ELISA method to support surveillance of bovine tuberculosis in Albania

Background

Bovine tuberculosis (bTB) is an important bacterial infectious disease in Albania of concern to animal and human health; its prevalence is poorly documented.

Methods

In this longitudinal study, we tested by ELISA 2661 serum samples, from 154 herds, with the aim of establishing the suitability of this approach to screen the bovine population for bTB. In a follow-on survey of 87 animals in three villages, we assessed the usefulness of the Mycobacterium bovis IDEXX ELISA (IDEXX M. bovis Antibody (Ab) Test. IDEXX Europe B.V P.O. Box 1334, 2130 EK Hoofddorp, The Netherlands) assay by comparing IDEXX results with the results of the single intradermal cervical skin test. Skin tests were performed either after or at the time of collection of blood samples, and therefore cattle were not sensitized by tuberculin before serological testing.

Results

The proportion of herds in which serologically positive cattle were found was 18.2 % (95 % CI, 1.9–25.8 %) and the prevalence of seropositive cattle was 1.4 % (95 % CI, 0.8–2.1 %). In the follow-up study, two of the 87 animals reacted positively to the skin test and two produced inconclusive reactions. No overlap was found between the four animals with positive IDEXX ELISA results and the four animals with non-negative skin test results.

Conclusion

The lack of agreement between the results of the two tests may reflect different elements of the immune response (humoral and cell-mediated immunity). In future, cattle should be sensitized by the intradermal injection of tuberculin 14 days prior to the collection of blood samples, which would then be tested by the Mycobacterium bovis IDEXX ELISA Test in order to determine more accurately the prevalence of infection.

     

Immunological and pathological investigations in equine experimental uveitis

Background

The pathogenic mechanism of equine recurrent uveitis (ERU) is still poorly defined and many variations between experimental animal models and spontaneous disease exist.

Objectives

The aim of our study was to investigate if Th17 cell-mediated response plays role in the pathogenesis of the used experimental model in horses and to reveal its pathological findings.

Methods

Experimental uveitis was induced in 6 healthy horses. The concentrations of retinal autoantigen CRALBP and IL-17 were measured using ELISA in aqueous humor and vitreous body of the 12 inflamed eyes as well as in 12 control non-inflamed eyes taken from 6 horses in slaughter house. After centrifugation of the two eye media, smears were prepared and cytological investigation was performed. Tissue specimens were taken from all eye globes and were submitted to histopathological investigation.

Results

CRALBP and IL-17 concentrations were significantly elevated in eye media of horses with experimental uveitis in comparison with controls. Cytological and histopathological findings corresponded to the changes characteristic of chronic immune-mediated inflammation with mononuclear cell infiltration of uvea, choroid, retina, and eye media as well as severe retinal destruction.

Conclusions

Our study demonstrated the involvement of the retinal autoantigen CRALBP as well as IL-17 in the pathogenesis of experimental uveitis in horses. These findings suggests that this experimental uveitis in horses may serve as a suitable animal model for investigation of IL-17- mediated immune response during spontaneous autoimmune uveitis in horses as well as in humans.

     

A survey of rift valley fever and associated risk factors among the one-humped camel (<Emphasis Type="Italic">Camelus dromedaries</Emphasis>) in Sudan

Background

Rift valley fever (RVF) is a mosquito-borne viral disease of domestic livestock and wild ruminants. In camels RVF may cause abortion among pregnant camels, but is most often asymptomatic among other camels. In this study, a seroepidemiological survey was conducted to determine the prevalence of RVFV antibodies and to identify the potential risk factors associated with RVFV seropositivity among the Sudanese one-humped camel (Camelus dromedaries) in Khartoum State, Sudan. A cross sectional study was conducted in Khartoum State, Sudan, in a total of 240 camels selected randomly from four localities. Sera sampled were tested for the presence of RVFV-specific immunoglobulin G (IgG) antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA).

Results

RVFV seropositivity was recorded in 23 out of 240 animals, prevalence rate of 9.6 % among camels in Khartoum State. Age (OR?=?8.29, p-value?=?0.04) and heavy rainfall (OR?=?5.36, p value?=?0.01) were recorded as potential risk factors for contracting RVF.

Conclusions

Older age and heavy rainfall were considered as potential risk factors for seropositivity to RVF. Surveillance for RVF among camels and distribution of mosquito vectors should continue to better understand the clinical signs associated with RVFV infection in camels and provide public health authorities an opportunity to anticipate and prepare for a possible RVF outbreak in Khartoum State, Sudan.

     

Survival time with pacemaker implantation for dogs diagnosed with persistent atrial standstill

Objectives

To evaluate survival time in dogs with persistent atrial standstill after pacemaker implantation and to compare the survival times for cardiac-related vs. non-cardiac deaths. Secondary objectives were to evaluate the effects of breed and the presence of congestive heart failure (CHF) at the time of diagnosis on survival time.

Typhlocolitis associated with <Emphasis Type="Italic">Clostridium difficile</Emphasis> ribotypes 078 and 110 in neonatal piglets from a commercial Irish pig herd

Background

Clostridium difficile is a recognised cause of typhlocolitis and diarrhoea in neonatal pigs but has never been confirmed in association with pathology and disease in Irish pigs.

Case Presentation

Four neonatal piglets, with a history of diarrhoea were referred to the Central Veterinary Research Laboratory, Backweston for necropsy. They were from a fully integrated, commercial pig farm with approximately 1000 sows. Three piglets had acute, superficial, erosive and suppurative typhlocolitis and the other had mild suppurative mesocolitis. Clostridium difficile (C. difficile) toxins A/B were detected using ELISA in the colonic contents from each piglet. C. difficile isolates from two of the piglets were PCR-ribotyped as 078 and an isolate from a third pig was ribotyped as 110.

Conclusions

This is the first report confirming C. difficile in association with typhlocolitis in Irish pigs.

     

Insights into antimicrobial resistance among long distance migratory East Canadian High Arctic light-bellied Brent geese (<Emphasis Type="Italic">Branta bernicla hrota</Emphasis>)

Background

Antimicrobial resistance (AMR) is the most significant threat to global public health and ascertaining the role wild birds play in the epidemiology of resistance is critically important. This study investigated the prevalence of AMR Gram-negative bacteria among long-distance migratory East Canadian High Arctic (ECHA) light-bellied Brent geese found wintering on the east coast of Ireland.

Findings

In this study a number of bacterial species were isolated from cloacal swabs taken from ECHA light-bellied Brent geese. Nucleotide sequence analysis identified five species of Gram-negative bacteria; the dominant isolated species were Pantoea spp. (n?=?5) followed by Buttiauxella agrestis (n?=?2). Antimicrobial susceptibility disk diffusion results identified four of the Pantoea spp. strains, and one of the Buttiauxella agrestis strains resistant to amoxicillin-clavulanic acid.

Conclusion

To our knowledge this is the first record of AMR bacteria isolated from long distance migratory ECHA light-bellied Brent geese. This indicates that this species may act as reservoirs and potential disseminators of resistance genes into remote natural ecosystems across their migratory range. This population of geese frequently forage (and defecate) on public amenity areas during the winter months presenting a potential human health risk.

     

Interference with the humoral immune response in diverse genetic lines of chickens. II. The effect of colloidal carbon

Two experiments were conducted to study the difference in humoral immune responses between lines of chickens selected for high (H) or low (L) antibody production to sheep red blood cells (SRBC). Prior to i.v. immunization with SRBC or Brucella abortus (BA), chicks of both lines were injected with either 2, 3 or 4 ml carbon suspension (59 mg carbon/ml) per kg body weight; controls were not injected. In both the H and L line, a higher dose of carbon showed a more progressive depression of the total antibody titer to SRBC during the initial stage of the primary response. The 2ME-resistant antibody titers to SRBC showed the same tendency during the latter phase of the primary response. However, chicks treated with 3 ml carbon had lower 2ME-resistant antibody titers than any other group. Following i.m. reimmunization with SRBC, the previous treatment with carbon doses enhanced total antibody titers throughout the secondary response, when compared to the controls. The 3 ml carbon-treated chicks had the highest total anti-SRBC titers in the secondary response. The secondary 2ME-resistant anti-SRBC titers were not affected by the carbon doses. Carbon treatment did not affect the antibody titers to BA. No differences between the H and L line were found in the effects of carbon on the humoral immune responses to SRBC or BA.     

Influence of the Th2 immune response established by Nippostrongylus brasiliensis infection on the protection offered by different vaccines against Chlamydophila abortus infection

Chlamydophila abortus is the aetiological agent of enzootic abortion in small ruminants in which it infects the placenta to cause abortion during the last trimester of gestation. In a mouse model, a Th1 immune response involving IFN-γ production and CD8⁺ T cells is necessary for the infection to be resolved. The authors previously demonstrated that infection with Nippostrongylus brasiliensis, a rodent gastrointestinal nematode extensively used in experimental models to induce Th2 responses, alters the specific immune response against C. abortus infection, increasing bacterial multiplication in liver and reducing specific IFN-γ production. The aim of the present work was to clarify whether a Th2 immune response has any influence on the success of vaccination using both inactivated and attenuated vaccines. The results showed that the Th2 response established prior to vaccination did not influence the induction of protection offered by the vaccines. However, the effectiveness of this protective response can be altered, depending on the adjuvant employed in the inactivated vaccines, when the Th2 response is established after vaccination, just before challenge with C. abortus.     

Partial neuromuscular block impairs arytenoid abduction during hypercarbic challenge in anesthetized dogs

Objective

To evaluate the effect of two levels of partial neuromuscular block (NMB) on arytenoid abduction, tidal volume (V_T) and peak inspiratory flow (PIF) in response to a hypercarbic challenge in anesthetized dogs.

Dystrophic mineralization of the arterial fibrovascular tissue associated with a vitamin D hypervitaminosis in an 8-year-old female Alpaca (<Emphasis Type="Italic">Vicugna pacos</Emphasis>)

Background

Prophylactic Vitamin D supplementation is a common practice in Alpaca breeding in many regions around the world. An overdosage can lead to dystrophic mineralization of soft tissues. In this paper we illustrate a suspected case of hypervitaminosis D in an 8-year-old female Alpaca.

Case presentation

In June 2015, the carcass of an 8-year-old female Alpaca (Vicugna pacos) was submitted to the diagnostic laboratory of the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) for necropsy. The animal had undergone a spontaneous abortion with uterine prolapse and delivery of the placenta, and had died shortly thereafter. Death occurred due to internal haemorrhage related to dystrophic mineralization of the left renal artery with subsequent rupture and damage of the renal hilum. During the necropsy, histopathological and serum biochemical analyses were performed. After laboratory analyses and the history of mineral and vitamin supplementation reported by the breeder, a hypervitaminosis D was suspected to be the most probable cause of the dystrophic mineralization observed in the left renal artery.

Conclusions

Most of the information regarding Llamas and Alpacas comes from the South American and Australian regions. It is therefore important to provide scientific information about these animals in other regions of the world in order to have a better and wider understanding of the nutritional and environmental conditions necessary for optimal breeding.