Pathological findings in genital organs of bulls naturally infected with Besnoitia besnoiti.

Bulls chronically affected by bovine besnoitiosis can suffer from sterility. There is limited information about the distribution of Besnoitia cysts and their associated lesions within the male genital organs. This work describes the gross and histological abnormalities in the genital organs of 6 bulls chronically infected with Besnoitia besnoiti, including both clinically (n = 4) and subclinically (n = 2) affected cases. Parasitic cysts were observed in the genital organs of all the clinically affected bulls. The tissue cysts were most commonly found within the pampiniform plexus (4/4), where they were often seen within venous vascular walls and associated with vasculitis, followed by epididymis (3/4), tunica albuginea (2/4), and penis (1/4). In decreasing order of their frequency, observed abnormalities included seminiferous tubule degeneration, testicular fibrosis, testicular necrosis, lack of/or diminished numbers of spermatozoa, testicular atrophy, and Leydig cell hyperplasia. Only one of the subclinically infected bulls had few Besnoitia cysts within the pampinoform plexus, which was associated to small areas of necrosis and mineralization in the ipsilateral testicle. Results indicate that Besnoitia cysts and genital abnormalities are frequent in bulls chronically affected by bovine besnoitiosis, while they are mild and scarce in subclinically affected ones. Moreover, present data show that Besnotia-associated testicular lesions can occur without the presence of cysts within the testicular parenchyma. B. besnoiti cysts seem to have a tropism for the vascular structures of the spermatic chord, which may cause testicular abnormalities via vascular damage, reduced blood flow, and/or impaired thermoregulation and subsequently lead to the observed testicular lesions.

Characterization of lesions in the temporal muscle and the male reproductive system (epididymis and testicle) of dogs experimentally infected with Leishmania infantum with different clinical stages.

Leishmaniosis is a zoonotic disease with a very complex pathogenesis modulated by the interaction between the parasite, the vector and the host. Although the pathological characteristics have been extensively studied in the typically affected organs, some locations such as muscles and reproductive organs have been less studied. The objective of this study was to evaluate the presence of lesions in the temporal muscle and the male reproductive organs (testicle and epididymis) and correlate their characteristics with the presence of the parasite and with the clinical status of the dogs. The temporal muscle was studied in 25 infected beagle dogs (nine females and 16 males) and five uninfected control dogs (two females and three males) and the testicle and epididymis in the 19 males. Dogs were euthanized one year after infection and clinical signs, anti-Leishmania serum antibodies, and lymph node parasite load were assessed. Muscular and reproductive lesions were characterized by H&E and immunohistochemistry (IHC). The presence of the parasite in the lesions was evaluated using IHC and molecular techniques. Myositis was observed in 72% (18/25) of the dogs and was characterized by lymphoplasmacytic or histiocytic lesions. Mild and severe lesions were detected, the latter being statistically associated with the presence of the parasite and with the clinical status of the dogs. Orchitis was observed in 50% (8/16) of the dogs and was mainly mild and lymphoplasmacytic. No statistical relationship was found between testicular lesions and the presence of the parasite or the clinical status. Epididymitis was observed in 87.5% (14/16) of the dogs, and the lesions were often infiltrated by numerous histiocytes and neutrophils. Epididymal lesions were statistically associated with the clinical status of the dogs and with the presence of the parasite in the lesions. IgG and IgM immunoglobulins were found in all lesions, suggesting a local immune response with reactivation of the infection. Leishmania was more frequently detected in severe and histiocytic lesions, although some lesions had no detectable parasites. These results have shown that lesions in the temporal muscle, epididymis, and testicles are common in dogs infected by Leishmania infantum and that dogs may show a different response to infection. This response is characterized by varying degrees of cellular and immune responses associated with a variable presence of the parasite.

Comparative Study of Real-Time PCR (TaqMan Probe and Sybr Green), Serological Techniques (ELISA, IFA and DAT) and Clinical Signs Evaluation, for the Diagnosis of Canine Leishmaniasis in Experimentally Infected Dogs.

Canine leishmaniasis (CanL) diagnosis is not fully resolved. Currently, two specific methodologies are in continuous development, the detection of the parasite DNA or RNA in target organs and the detection of specific antibodies against Leishmania sp. For a correct diagnosis, it has been shown that the joint use of this type of test is necessary. In this work, a Sybr Green and a TaqMan Probe based on real time PCRs (qPCR) was performed for the detection of Leishmania sp. in order to correlate the results with clinicopathological and serological evaluations (IFA, ELISA and DAT) to propose an optimal biological sample to be used to detect the parasite in both early and late stages of the infection. A total of four samples were processed: conjunctival swabs, popliteal lymph node aspirates, bone marrow aspirates, and peripheral blood from experimentally infected dogs belonging to a larger study. Our results indicated that a single non-invasive sample (conjunctival swab) and the application of both types of qPCR would be reliable for determining Leishmania infection as well as the disease stage in dogs, thus avoiding bone marrow, lymph node aspirate or blood samples collection.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) Is Related with the Proteinuria Degree and the Microscopic Kidney Findings in Leishmania-Infected Dogs.

Early diagnosis of renal damage in Leishmania infected dogs may allow appropriate treatments and prevent some deaths. This study investigates neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker of kidney disease in dogs experimentally infected with Leishmania infantum. Serum, urine, and kidney samples were collected from 30 infected beagle dogs and six uninfected control dogs. Based on proteinuria and azotemia values, dogs were initially classified. NGAL was measured in urine and serum samples. Then, the urinary NGAL to creatinine ratio (uNGAL/C) was calculated. Kidney samples were taken for histopathological studies, and the dogs were classified according to the severity of glomerular and tubulointerstitial lesions. In Leishmania-infected dogs, the uNGAL/C was significantly higher in proteinuric non-azotemic dogs compared with non-proteinuric non-azotemic dogs (p = 0.038). Serum NGAL (sNGAL) concentration did not differ between groups. Microscopic studies revealed several degrees of glomerulonephritis and slight focal lymphoplasmacytic interstitial nephritis in 89% and 55% of infected dogs, respectively. Urinary protein to creatinine ratio (UPC) and uNGAL/C were significantly higher in dogs with affected glomeruli compared to infected dogs without renal lesions (p = 0.045 and p = 0.043, respectively). The results show that uNGAL/C correlates with proteinuria and the presence of moderate glomerular lesions in non-azotemic dogs experimentally infected with L. infantum.

Prevalence of Besnoitia besnoiti infection in beef cattle from the Spanish Pyrenees.

Reports of recent outbreaks of bovine besnoitiosis in Europe have emphasized the need for prevalence studies to determine the importance of the disease. A previous cross-sectional study carried out in a northern province of Spain showed that seropositive cattle were beef breeds primarily located in regions where the disease is endemic (such as in the Pyrenees). The present study focused on this population. Sixty-three beef herds were selected and at least 50% of the animals in each herd were sampled (n = 3318). The herd, intra-herd and animal prevalence rates were calculated. All breeding bulls located in the same region were also sampled (n = 587), and the animal prevalence calculated. Sera were tested by ELISA. The herd prevalence rate of bovine besnoitiosis was 87.3%, and both sexes were similarly affected (approximately 50%). The results indicate that the disease is highly widespread in the Pyrenees, and that serological examination of cattle should be recommended when trading beef cattle.