Anti-histone antibodies in dogs with leishmaniasis and glomerulonephritis

The association between serum anti-histone antibodies and glomerulonephritis was studied in 43 dogs with leishmaniasis (Leishmania infantum). Dogs with increased serum creatinine levels and urine protein-creatinine ratio >1 were considered to have glomerulonephritis. Moderately elevated anti-histone antibodies were found in 38.89% (7/18) of infected dogs without glomerulonephritis, whereas 88% of dogs with glomerulonephritis (22/25) showed moderate or strongly elevated anti-histone antibodies. Prevalence of positive anti-histone antibodies reactions and mean serum concentration was significantly higher (P < 0.001; P < 0.0001) in infected dogs with glomerulonephritis. Correlation between anti-histone antibodies and urine protein-creatinine ratio was significant when groups were analysed together (P < 0.046). Positive predictive value for glomerulonephritis of positive anti-histone antibodies was 88%. In conclusion, high anti-histone antibodies are significantly associated with glomerulonephritis. Although other factors must be involved, dogs with moderate or strong positive anti-histone antibodies reactions may have a higher probability to develop glomerular lesions in canine leishmaniasis.     

Local and systemic immune response in pigs during subclinical and clinical swine influenza infection

Local and systemic immune responses in pigs intranasally (IN) and intratracheally (IT) inoculated with swine influenza virus (SIV) were studied. No clinical signs were observed in IN-inoculated pigs, while IT-inoculated pigs developed typical signs of influenza. Significantly higher titres of specific antibodies and changes of haematological parameters were found only in IT-inoculated pigs. Because positive correlations between viral titre, local cytokine concentration, and lung pathology have been observed, we hypothesise that both viral load and the local secretion of cytokines play a role in the induction of lung lesions. It could be that a higher replication of SIV stimulates immune cells to secrete higher amounts of cytokines. The results of the present study indicate that pathogenesis of SIV is dependent on both, the damage caused to the lung parenchyma directly by virus, and the effects on the cells of the host's immune system.     

A survey on canine leishmaniasis and phlebotomine sand flies in central Italy

Zoonotic visceral leishmaniasis (ZVL) is a vector-transmitted zoonosis caused by the parasitic protozoan Leishmania infantum. Bloodsucking sand flies of the subfamily Phlebotominae are the obligatory insect hosts, and the dog is the only domestic reservoir.This study reports data from a survey of canine infection and sand fly phlebotomine monitoring in the province of Perugia in central Italy. The overall seroprevalence in a total of 100 dogs tested was 8% (95% confidence interval: 3.8-15.6%). Data analysis revealed that serological positivity was statistically associated with age (p-value = 0.03) and the area where dogs lived. Standard blacklight traps employed for sampling Culicoides midges in bluetongue disease surveillance were used in phlebotomine monitoring. A total of 5698 sand flies were collected and the two species, Leishmania competent vectors, were identified, Phlebotomus perfiliewi (50%) and Phlebotomus perniciosus (30%).     

Crossbreeding parameters of general immune response traits in White Leghorn chickens

Crossbreeding parameters of immune response traits were estimated from a set of well characterized crossbred populations derived from three chicken lines selected over 12 generations for three different general immune response traits and their F1, F2 and backcrosses. The three traits investigated were the selection criteria from each of the lines, i.e. antibody response to the Newcastle disease virus vaccine 3 weeks after vaccination (ND3), cell-mediated immune response (response to phytohemagglutinin, PHA) and phagocytic activity measured as carbon clearance (CC). Crossbreeding parameters included direct and maternal additive line effects, direct and maternal heterosis as well as direct epistatic recombination loss. They were estimated as linear combinations of genetic group effects estimated using animal model methodology. Significant line differences were obtained for ND3 and, to a lesser extent, CC. They were mainly due to direct effects, maternal effects being significant for none of the 3 traits. Significantly negative direct heterosis effects were also observed for ND3 and CC, but not for PHA. Maternal heterosis effects were not estimated for CC. They were non significant for PHA, and negative and significant (− 0.78 ± 0.24) for ND3. The significant favourable recombination gain estimated for ND3 (3.21 ± 0.88) indicates that epistatic interactions could be important for this trait.The present work shows that it was worthwhile to complete second generation crosses to be able to assess to what extent immunity gained by selection is maintained in advanced crossbred generations, and to compare the transmission of immune traits implicated in different aspects of immunity.     

Defining the immune response to Ehrlichia species using murine models

Pathogenic bacteria belonging to the family Anaplasmataceae include species of the genera Ehrlichia and Anaplasma. Ehrlichia chaffeensis, first known as the causative agent of human monocytic ehrlichiosis, also infects several vertebrate hosts including white-tailed deer, dogs, coyotes and goats. E. chaffeensis is transmitted from the bite of an infected hard tick, such as Amblyomma americanum. E. chaffeensis and other tick-transmitted pathogens have adapted to both the tick and vertebrate host cell environments. Although E. chaffeensis persists in both vertebrate and tick hosts for long periods of time, little is known about that process. Immunological studies will be valuable in assessing how the pathogen persists in nature in both vertebrate and invertebrate hosts. Understanding the host immune response to the pathogen originating from dual host backgrounds is also important to develop effective methods of diagnosis, control and treatment. In this paper, we provide our perspective of the current understanding of the immune response against E. chaffeensis in relation to other related Anaplasmataceae pathogens.     

Cutaneous immune mechanisms in canine leishmaniosis due to Leishmania infantum

Canine leishmaniosis (CanL) caused by the parasite Leishmania infantum is a systemic disease with variable clinical signs. The disease is endemic in the Mediterranean countries and dogs are the main domestic reservoir of the parasite. The quite complicated immune response against the parasite is crucial for the evolution of CanL infection with the skin playing a major role in its immunopathogenesis.After the inoculation of Leishmania promastigotes into the dermis by sand fly bites, complement factors, Langerhan's cells, neutrophils, fibroblasts and keratinocytes are involved in the activation of the innate arm of the skin immune system, with the macrophages and dendritic cells to play a major key role.The effective activation of cellular immunity is the cornerstone of dog's resistance against the parasite. Promastigotes reaching the dermis are engulfed, processed and transferred by APCs to draining lymph nodes to stimulate naïve T-cells for proliferation and differentiation into armed effector T-cells. Th1 cells activate the infected macrophages to kill Leishmania, whereas Th2 cells divert the immune response to humoral immunity and down regulation of cellular immunity with Th1 cell anergy. Inhibition of co-stimulatory molecules expression by infected macrophages contributes to T-cell anergy. In canine subclinical infections cutaneous lymphocytic infiltrate and parasites are absent, as opposed to dogs with clinical leishmaniosis. CD8+ cells constitute a significant population of cellular immunity in CanL since they outnumber CD4+ cells in the dermis, producing IFN-γ in sub clinically infected dogs and high levels of IL-4 in dogs with clinical leishmaniosis.Numerous B-lymphocytes have been shown to heavily infiltrate the dermis at least in exfoliative dermatitis in CanL. A mixed Th1/Th2 cytokine profile has been found in the dermis of naturally infected with L. infantum dogs. In the skin of dogs with clinical leishmaniosis, where plasma cells outnumber T lymphocytes in the dermal infiltrate, there is an overproduction of IL-4, IL-13 and TNF-α leading to Th2-biased humoral immune response. The issue of humoral immunity polarization in CanL remains controversial. Much still needs to be learned about other mechanisms underlying the complex interaction between the skin immune system and the parasite.     

The immune response and PBMC subsets in canine visceral leishmaniasis before, and after, chemotherapy

Peripheral blood mononuclear cell subsets, in vitro lymphoproliferative response to leishmanial antigen, and Leishmania-specific serum antibody levels were examined in 11 dogs, naturally infected with L. infantum, and 9 healthy control dogs. A decrease in the percentage of CD4+ T-cells and an increase in the proportion of gammadelta T-cells and sIgG+ B-cells were observed during canine visceral leishmaniasis (CVL). These changes may be responsible for the marked humoral response and the absence of in vitro lymphoproliferation to mitogen and specific parasite antigens. This possibility was supported by the analysis of these subsets after treatment with amphotericin B. One month after therapy, a significant increase in the percentage of CD4+ T-cells and a decrease of gammadelta T-cells and sIgG+ B-cells were observed. At the same time, the lymphocyte blastogenesis assay with leishmanial antigen was positive and the levels of specific antibodies to Leishmania were significantly lower than before the treatment. Five months after therapy, lymphocyte proliferative response to LSA disappeared, antibody and lymphocyte subsets levels returned to those observed during CVL. Therapeutic failure in CVL is associated with the inability of antileishmanial drugs to completely revert the profound immunodepression induced by the infection and prevent relapse.     

Assessment of serological tests for the diagnosis of canine visceral leishmaniasis

An immunoenzymatic assay (ELISA), an indirect immunofluorescence antibody test (IFAT) with different antigens (ELISA-Leishmania chagasi, ELISA-L. major-like, IFAT-L. chagasi and IFAT-L. major-like), and an immunochromatographic test were assessed for the diagnosis of canine visceral leishmaniasis (CVL). Serum samples from 144 dogs from an endemic area for visceral leishmaniasis in the municipality of Rio de Janeiro were tested. The sensitivities of the serological tests were 93%, 100%, 73%, 60% and 93%, with specificities of 87%, 92%, 77%, 96% and 92% for the ELISA-L. major-like, ELISA-L. chagasi, IFAT-L. major-like, IFAT-L. chagasi and the immuno chromatographic test, respectively. ELISA-L. chagasi was the best test for the diagnosis of CVL, but the immunochromatographic test could be a useful alternative as it offers simple and rapid diagnosis without the need for a specialized laboratory.     

Application of a recombinant protein for the serological diagnosis of canine leishmaniasis

This work reports the results obtained by a new enzyme-linked immunosorbent assay (ELISA) test developed for the serological diagnosis of canine leishmaniasis.The new ELISA is based on a recombinant protein obtained by joining different antigens of Leishmania infantum.Test performances have been evaluated through the screening 227 sera of dogs, infected and uninfected by L. infantum. The new ELISA test has been compared to the indirect immunofluorescent-antibody test (IFAT) as a reference assay of canine leishmaniasis, and to a commercial ELISA.Excluding from the total number of IFAT positive sera the 27 sera with IFAT titre 1:40 (considered doubtful), the recombinant ELISA showed 97.0% specificity, 93.9% sensitivity and 95.5% agreement with IFAT. The commercial ELISA showed 78.2% specificity, 94.9% sensitivity and 86.5% agreement with IFAT.The results demonstrate a higher performance of the new recombinant ELISA test for the detection of negative samples, with a greater agreement with the reference test (IFAT).     

Factors affecting the occurrence, duration of hospitalization and final outcome in canine parvovirus infection

The objectives of this matched case-control study in a veterinary teaching hospital were to investigate the influence of signalment and historical data on the odds of occurrence of canine parvovirus (CPV) enteritis and the potential usefulness of the clinical signs and clinicopathologic abnormalities recorded on admission as prognostic indicators of mean duration of hospitalization (DOH) and outcome of the disease. Ninety-four puppies with natural CPV enteritis and 188 age-matched controls were studied. The odds to develop CPV enteritis were higher in purebreds compared to mixed-breed puppies. Vomiting and depression at the time of admission were associated with a prolongation of DOH by 2 and 1.75 days, respectively. The lymphopenic and hypoalbuminemic dogs were hospitalized for 1.9 and 2.5 more days, respectively, compared to those without these abnormalities. The odds of non-survival were higher in those puppies with evidence of systemic inflammatory response syndrome (SIRS) at the time of admission.     

Ghrelin-stimulation test in the diagnosis of canine pituitary dwarfism

This study investigated whether ghrelin, a potent releaser of growth hormone (GH) secretion, is a valuable tool in the diagnosis of canine pituitary dwarfism. The effect of intravenous administration of ghrelin on the release of GH and other adenohypophyseal hormones was investigated in German shepherd dogs with congenital combined pituitary hormone deficiency and in healthy Beagles. Analysis of the maximal increment (i.e. difference between pre- and maximal post-ghrelin plasma hormone concentration) indicated that the GH response was significantly lower in the dwarf dogs compared with the healthy dogs. In none of the pituitary dwarfs, the ghrelin-induced plasma GH concentration exceeded 5 microg/l at any time. However, this was also true for 3 healthy dogs. In all dogs, ghrelin administration did not affect the plasma concentrations of ACTH, cortisol, TSH, LH and PRL . Thus, while a ghrelin-induced plasma GH concentration above 5 microg/l excludes GH deficiency, false-negative results may occur.     

新城疫病毒感染绵羊诱导免疫应答反应的实验研究

为探索新城疫病毒(NDV)作为羊病毒病疫苗载体的可行性,验证NDV感染绵羊的可能性,本研究采用NDV Clone-30株分别通过滴鼻和气管灌注两种途径接种绵羊,接种后观察临床症状,检测接种动物排毒情况,通过血凝抑制试验检测接种绵羊特异性血凝抑制抗体,ELISA试验检测接种绵羊血清特异性IgG抗体,微量中和试验检测接种绵羊血清中和抗体.研究结果表明,NDV在绵羊体内是非致病性的,并且通过两种接种途径在绵羊体内均可以产生血凝抑制抗体、NDV特异性IgG抗体和中和抗体反应.本研究结果表明NDV有可能作为宿主限制性疫苗载体用于预防无特效疫苗的羊类疾病,且与气管灌注接种途径比,滴鼻接种途径相对安全.     

Urine sampling for real-time polymerase chain reaction based diagnosis of canine leishmaniasis.

A real-time polymerase chain reaction (PCR) assay was used for quantifying Leishmania infantum DNA in urine samples from naturally infected dogs. Forty-one infected dogs were divided into 3 groups: 22 dogs showing only cutaneous signs (group 1), 12 dogs showing hematuria (group 2), and 7 dogs affected by severe nephropathy (group 3). Groups 2 and 3 dogs showed altered laboratory parameters related to an impairment of renal function. The real-time PCR analysis showed higher levels of Leishmania DNA in the lymph node aspirates from all groups of infected dogs versus those measured in their blood or urine. Interestingly, urine samples from dogs belonging to groups 2 and 3 contained a higher Leishmania DNA load than that detected in their blood. This finding suggests that a real-time PCR analysis of urine from infected dogs could be a useful and noninvasive tool for monitoring the severity of leishmaniasis.     

Stimulation and analysis of the immune response in calves from vaccinated pregnant cows

The effect of vaccinating pregnant cows with an inactivated vaccine against Mannheimia haemolytica, BRSV and PI3V infections on selected immune responses in their offspring was examined. Blood samples were collected weekly for 12 weeks from six newborn calves from each of vaccinated (experimental) and unvaccinated (control) dams. Specific antibodies to M. haemolytica, BRSV and PI3V and mean values of IgA, IgG concentrations were significantly higher in the experimental calves compared with the controls. However, specific antibody titres to adenovirus type 3, BHV1 and BVDV in the experimental calves had constant levels while the control group levels changed. The IgM, Hp and SAA concentrations generally increased until week 8 in the experimental group, but the control group titres became higher after week 9. This study demonstrates that specific immunisation of cows pre-partum significantly stimulated parameters associated with immunity and it also controlled the acute phase response intensity in their offspring. Therefore the vaccination of dams may provide additional antibody protection against infection to their offspring.     

Comparison of PCR methods for diagnosis of canine visceral leishmaniasis in conjunctival swab samples

Four PCR assays for detection of Leishmania DNA in conjunctival swab samples were compared. All methods had two steps: a first amplification followed by hybridization or by a new amplification (nested or seminested). Two methods (kDNA PCR-hybridization and kDNA snPCR) used primers targeted to the minicircles of kinetoplast DNA (kDNA) and the other two methods to the coding (LnPCR) and intergenic noncoding regions (ITS-1 nPCR) of ribosomal rRNA genes. kDNA PCR-hybridization was positive for 22/23 dogs (95.6%) and for 40/46 samples (86.9%), considering the right and the left conjunctivas. kDNA snPCR was positive for 21/23 dogs (91.3%) and for 40/46 samples (86.9%). The ITS-1 nPCR and LnPCR were both able to detect the parasites in 17/23 dogs (73.9%) and 29/46 (63%) and 30/46 (65.2%) samples, respectively. The positivities of the kDNA based methods were significantly higher; however the choice of the best method will depend on the kind of information required with the diagnosis.     

Dairy herd health, impedance on six acupuncture points and immune response factors in milk: A pilot study

This study aimed to evaluate whether immunological parameters in milk and the impedance at 6 acupuncture points (APs) were related to herd health: good versus poor. The study used a purposively selected sample of 10 herds and in each herd 15 to 18 animals were observed. Statistical models at animal level included a random herd effect, with age and days in milk as covariates. The capacity for immune response was estimated through in vitro proliferation counts in medium, LPS, and ConA. At the right and left bladder meridians we measured impedance at 3 APs related to disease resistance. The energy balance at the onset of lactation and other parameters confirmed the classification in good and poor health herds. The immunological parameters in milk were not significantly related to health status, but LPS values of two herds with the apparent poorest health were consistently lower. The good health herds showed significantly lower impedance at all APs. Impedance values at APs correlated negatively with counts of LPS, indicating that good health animals had consistently higher counts of macrophages, i.e. better innate disease resistance. To confirm prospects of the parameters, we recommend repeating the study with a larger randomly selected sample.     

犬细小病毒病的诊断与治疗

犬细小病毒病在临床上常表现为剧烈呕吐,腹泻,血痢等症状,和犬的其它传染病难以区分,易造成临床误诊,延误病情而导致患病犬严重脱水,中毒,全身衰竭而死亡。通过临床症状,病理剖检和实验室检查对其进行了诊断并运用特异性疗法加“一消二止三补”的综合治疗方法治疗,取得了较好的治疗效果。科学的饲养管理和严格的预防措施是防制该病的根本。     

A serological study of canine herpesvirus-1 infection in a population of breeding bitches in Norway

Background

Canine herpesvirus-1 (CHV1) causes a fatal hemorrhagic disease in neonatal puppies and is associated with infertility in female dogs. This study was conducted to assess the status of CHV1 infection in bitches in proestrus or estrus and to investigate possible risk factors by a detailed questionnaire. Blood samples were collected from healthy bitches (n = 193) not vaccinated against CHV1, aged one year or older and admitted for estrus control to the Canine Reproductive Clinical Unit, Norwegian School of Veterinary Science. The serum samples were analysed by immunoperoxidase monolayer assay and serum titers were recorded as the reciprocal value of the highest dilution producing specific cell staining.

Results

Altogether, 85.5% of the dogs had CHV1 titers ≥ 80 and were classified as positive. Mean age for dogs included in the study was 4.2 years (95% CI 4.0-4.5), and there was no difference in age between seronegative dogs vs seropositive dogs. When grouping the seropositive dogs into three categories according to the magnitude of the titer, a total of 38.8% of the bitches displayed a weakly positive titer of 80, 44.8% had moderately positive titers of 160 or 320 and 16.4% of the dogs fell into the strongly positive category with titer of ≥640. No association was demonstrated when comparing CHV1 antibody titers to fertility parameters such as previous matings, pregnancies, whelpings, puppies born or condition of puppies. Further, there was no difference in seroprevalence between bitches that had been abroad for a period of time and dogs only living within a Norwegian environment. Samples from dogs collected in summer and fall displayed moderate to high antibody titers indicating recent infection with CHV1. Season, previous birth, and participation in competitions/shows explained 67-78% of the variation in antibody titer.

Conclusions

This study demonstrates that CHV1 infection is common in breeding bitches in the eastern part of Norway. Associations with putative risk factors were not identified. However, season, previous whelping, and participation in competitions/shows explained 67-78% of the variation in antibody titer.     

Synergetic effects of oral administration of levamisole and Echinacea purpurea on immune response in Wistar rat

This research investigated the effects of levamisole and Echinacea purpurea (EP), separately and together on the immune response of the rat as a laboratory model. In this experiment, 40 male Wistar rats were obtained and divided into four groups (n = 10). These groups received normal saline (10 mg/kg), EP (500 mg/kg), levamisole (2 mg/kg) and EP (500 mg/kg) with levamisole (2 mg/kg) as oral gavages every day for a period of 4 weeks, respectively. After obtaining blood samples (at the end of each week), haematocrit (HCT), differential and total white blood cell (WBC) counts, phagocyte activity (number), total protein, albumin and globulins levels of samples were obtained. The results of the study showed that the gamma globulin level, WBC, neutrophil and monocyte counts and phagocyte activity increased significantly in comparison with normal saline group during the study. According to the results, each of the mentioned agents had a stimulant effect on the immune system separately and together on rats. In the group that received EP and levamisole simultaneously, these effects were synergistically increased. These compounds, by increasing the mentioned factors, will probably affect the immune system.