Peripheral and intestinal T lymphocyte subsets in dogs with chronic inflammatory enteropathy.

BACKGROUND: Dysregulated T lymphocyte response is thought to play a key role in chronic intestinal inflammation (CIE). OBJECTIVES: To evaluate the presence of changes in peripheral and intestinal T lymphocyte subsets and to describe potential immune and inflammatory biomarkers in dogs with CIE. ANIMALS: Sixteen healthy dogs and 26 dogs were diagnosed with CIE. METHODS: Prospective case-control study evaluating peripheral and intestinal T lymphocytes using flow cytometry and inflammatory markers obtained from complete blood cell counts. RESULTS: Dogs with CIE had higher peripheral activated T helper (Th) lymphocytes (87/µL [18-273] CIE, 44/µL [16-162] healthy control (HC, P = .013) and regulatory T cells (Treg; 108/µL [2-257] CIE, 34/µL [1-114] HC, P = .004). In the intestinal epithelium, CIE dogs presented lower percentages of Th (4.55% [1.75-18.67] CIE, 8.77% [3.79-25.03] HC, P = .002), activated Th cells (0.16% [0.02-0.83] CIE, 0.33% [0.05-0.57] HC, P = .03) and CD4/CD8 ratio (0.08 [0.02-0.39] CIE, 0.21 [0.07-0.85] HC, P = .003). Conversely, higher percentage of activated T cytotoxic cells (20.24% [3.12-77.12] CIE, 12.32% [1.21-39.22] HC, P = .04) and interferon-gamma (IFN-γ) producing T lymphocytes (7.36% [0.63-55.83] CIE, 1.44% [0.00-10.56] HC, P = .01) within the epithelium was observed. In the lamina propria the percentage of Treg lymphocytes was higher (6.02% [1.00-21.48] CIE, 3.52% [0.18-10.52] HC, P = .02). CONCLUSIONS AND CLINICAL IMPORTANCE: Systemic and intestinal immune alterations occur in dogs with CIE suggesting that blood IFN-γ producing T lymphocytes and the systemic immune-inflamation index (SII) could potentially serve as biomarkers for the disease.

First detection of Anaplasma phagocytophilum and Babesia divergens and high infection rates of Anaplasma marginale and Babesia bigemina in cattle in extensive grazing systems of Central Spain.

Bovine vector-borne diseases have a considerable economic impact worldwide and affect health of humans and animals. However, different aspects of their epidemiology and their pathogenesis remain unclear. Despite the frequent description of clinical cases reported by practitioners attending cattle from Madrid, Central Spain, molecular prevalence of Anaplasma spp. and Babesia spp. has not been described. The aim of this study was to assess the positivity rate of A. phagocytophilum, A. marginale, A. centrale, B. bigemina and B. divergens in livestock of this area and to evaluate the existence of associations between these pathogens and haematological, biochemical and epidemiological data. Babesia divergens and A. phagocytophilum were detected for the first time in cattle from Madrid. Their positivity percentages were low (2.2% ± 1.4% and 1.8% ± 1.2%, respectively), but this description is of special interest, as these agents are potentially zoonotic. Both agents were found in areas of higher altitude and relative humidity and lower temperature. The detection of ticks in livestock during the moment of sampling was confirmed as a risk factor for these infections. Anaplasma marginale showed the highest molecular infection rate (30% ± 4.1%) in this study, followed by B. bigemina (21.9% ± 3.7%). Higher positivity rates of A. marginale and B. bigemina were found in the areas of mountain climate and warm-summer continental Mediterranean climate. The use of ectoparasiticide treatment was found as a risk factor for infection by A. marginale and B. bigemina. This finding could lead to reconsider the ectoparasiticide protocols that are used nowadays. Grazing on pastures with domestic or wild ruminants and the presence of wild carnivores were associated with higher rates of infection by these four agents and coinfections were frequently found.

Effect of parasite dose and host age on the infection with Besnoitia besnoiti tachyzoites in cattle.

Bovine besnoitiosis is continuing to spread in Europe. Therefore, the development of ruminant animal models of infection is urgently needed to evaluate therapeutic and prophylactic tools. Herein, we studied the effect of parasite dose and host age on the infection dynamics with Besnoitia besnoiti tachyzoites in cattle in two independent experimental infections. In experiment A, twelve 3-month-old male calves were inoculated intravenously with either three different doses of tachyzoites (G1: 108 ; G2: 107 ; G3: 106 ) or with PBS (G4). In experiment B, six 14-month-old bulls were inoculated with 106 tachyzoites based on results obtained in experiment A. In both trials, clinical signs compatible with acute and chronic besnoitiosis were monitored daily; blood and skin samples were collected regularly for 70-115 days post-infection (pi). Finally, animals were killed, and tissues were collected for lesion and parasite detections. Infected animals developed mild-moderate signs compatible with acute besnoitiosis. Lymphadenopathy and fever were observed in both calves (from 12 hr until 7 days pi) and bulls (from 6 days until 9 days pi). Seroconversion was detected at 16-19 days pi, and antibody levels remained high. Infected animals did not developed characteristic clinical signs and macroscopic lesions of chronic besnoitiosis. However, successfully, parasite-DNA was detected in a reduced number of target tissues: conjunctiva, ocular sclera, epididymis, skin of the scrotum and carpus in calves (n = 10, 6 of which belonged to G3), and pampiniform plexus and testicular parenchyma in bulls. Remarkably, one tissue cyst and mild microscopic lesions were also detected. In summary, inoculated animals developed the acute besnoitiosis and chronic infection was evidenced by microscopic findings. However, our results suggest that tachyzoite dose and host age are not key variables for inducing clinical signs and macroscopic lesions characteristic of chronic besnoitiosis. Thus, a further refinement of this model should evaluate other parasite- and host-dependent variables.

Molecular, epidemiological, haematological and biochemical evaluation in asymptomatic Theileria annulata infected cattle from an endemic region in Spain.

Mediterranean theileriosis is one of the most fatal theilerioses, with considerable economic impact on livestock production. The potential consequences of asymptomatic infection on the animal's health and on the epidemiology in endemic regions are still unclear. The objectives of this study were to determine the molecular prevalence of T. annulata in a representative population of asymptomatic cattle in extensive management in Madrid, Central Spain, an area where practitioners frequently report cases of clinical theileriosis, and to evaluate the existence of associations between infection by this pathogen and haematological, biochemical and epidemiological data. T. annulata DNA was detected in 22.4% of the study population. The age was statistically associated with T. annulata prevalence rates, with a higher prevalence in cows older than 8 years (26.1%). Introduction of new cattle to the farm, grazing on pastures with other herds of cattle and previous history of clinical cases were statistically related to a higher prevalence of T. annulata infection. Herds with more than one ectoparasiticide treatment per year and that used more than one drug had significantly lower prevalences of infection with T. annulata. The location of farms in areas with a mean temperature higher than 17.1°C and mean altitude lower than 962m was statistically associated with the presence of T. annulata. In our study, the mean values of haematological parameters were within the normal adult range, but it is noteworthy that some T. annulata-infected animals presented low values for red blood cell parameters.

Molecular detection of Hepatozoon spp. and Cytauxzoon sp. in domestic and stray cats from Madrid, Spain.

BACKGROUND: Different species of apicomplexan protozoans of the genera Hepatozoon and Cytauxzoon can infect domestic cats, but their epidemiology and clinical relevance are not fully understood. The aim of this study was to assess the molecular prevalence of Hepatozoon spp. and Cytauxzoon spp. and to identify associated risk factors and clinical and laboratory abnormalities in a population of cats from Madrid, Spain. METHODS: Six hundred and forty-four client-owned and stray cats from Madrid, Spain, were included in this study. DNA samples were analyzed by two polymerase chain reaction (PCR) tests to detect a partial sequence of the 18S rRNA gene of Hepatozoon spp. and Cytauxzoon spp. In order to evaluate possible associations between infection by these protozoans and epidemiological or clinical parameters, data were collected related to: the season of sample collection, age, gender, spayed/neutered status, breed, living area, lifestyle, outdoor access, contact with other animals, prey on wild animals, history of tick or flea infestation, travel history, ectoparasiticide treatment, previous blood transfusion, previous tetracycline administration in the last 60 days, Feline Leukemia virus (FeLV) and Feline Immunodeficiency virus (FIV) status, positivity to other vector-borne diseases, the presence or absence of clinical signs and hematological or biochemical alterations. RESULTS: DNA of Hepatozoon spp. and Cytauxzoon sp. was amplified from the blood of 10 (1.6%) and 8 (1.2%) cats, respectively. Previous treatment with tetracyclines in the last 60 days, previous administration of blood transfusion, a decrease in haematocrit and an increase in creatinine were associated with Hepatozoon spp. infection. Cytauxzoon sp. infection was more frequent in samples collected during the winter months and in cats living in rural areas. This infection was associated with a FIV-positive status. Some of the cats that were positive for Hepatozoon spp. or Cytauxzoon sp. had been exposed to other vector-borne pathogens, such as Ehrlichia canis and Bartonella henselae. CONCLUSIONS: Our results indicate that cats from Madrid, central Spain, are infected with Hepatozoon spp. and Cytauxzoon sp., although with a low prevalence. Further studies are needed to determine the virulence of these agents in Spanish cats.