ABSTRACT
BACKGROUND: Transmission of canine leishmaniasis (CanL), a severe infection caused by L. infantum, usually occurs through the sand fly bite to the vertebrate host. A venereal route of transmission has also been suggested, but this issue is still controversial. FINDINGS: Here, we report a case of a dog affected by orchitis showing a clinical profile of L. infantum infection. By exploiting a real-time PCR assay, we detected a significantly higher DNA load of the parasite in the lymph node and testis than in blood and urine samples collected from the dog. CONCLUSIONS: Our results suggest that: 1) L. infantum infection can be associated with testicular lesions in naturally infected dogs; 2) genital involvement could result in shedding of the parasites in the semen, favoring venereal transmission of the disease.
Subject(s)
Dog Diseases/diagnosis , Dog Diseases/parasitology , Leishmania infantum/isolation & purification , Leishmaniasis, Visceral/veterinary , Orchitis/veterinary , Animals , Dogs , Leishmania infantum/genetics , Leishmaniasis, Visceral/parasitology , Lymph Nodes/parasitology , Male , Orchitis/parasitology , Parasite Load , Polymerase Chain Reaction , Testis/parasitologyABSTRACT
Choroid plexuses (CPs) play pivotal roles in a wide range of processes that establish, survey, and maintain the biochemical and cellular status of the central nervous system. Mammalian CPs contain a very high density of serotonin receptors, and serotonin has been shown to affect CP functions. The serotonin transporter (SERT) regulates the entire serotonergic system, including serotonin receptors by means of modulation of serotonin concentration in the extracellular fluid. In this study, the expression of SERT in the CPs from the brain of a mammalian species, Bubalis bubalis, was established. By immunogold labeling in scanning electron microscopy, SERT immunoreactivity was found to be localized on the apical surface of the choroid epithelium. In particular, SERT positivity was detected on the apical portion of villi, and both on the membrane and in the cytoplasm of grouped cells on the surface of the choroid epithelium. Significantly, no SERT was detected in blood vessels irrigating the CPs. The expression of SERT mRNA transcripts of 440 bp in the CPs was detected by reverse-transcription polymerase chain reaction, and Western blotting analysis revealed the presence of three isoforms of the protein with molecular masses of approximately 70, 80, and 140 kDa, respectively, probably corresponding to differently glycosylated SERT. Our findings provide the first report of SERT detection in the CPs of buffalo brain and indicate that this protein is locally synthesized from the choroid epithelial cells. We suggest that SERT might have an important role in mammalian CPs, possibly regulating the serotonin flow between brain and rest of the body.
Subject(s)
Buffaloes/metabolism , Choroid Plexus/metabolism , Serotonin Plasma Membrane Transport Proteins/metabolism , Animals , Buffaloes/anatomy & histology , Choroid Plexus/anatomy & histology , Immunohistochemistry/methods , Microscopy, Electron, Scanning/methods , RNA, Messenger/genetics , RNA, Messenger/metabolism , Serotonin Plasma Membrane Transport Proteins/geneticsABSTRACT
In this study, different types of tissue sampling for PCR-based diagnosis and follow-up of canine visceral leishmaniosis were compared. Skin, whole blood and lymph node samples were collected from 95 naturally infected dogs living in South Italy, where the disease is endemic. Twenty-nine of these 95 dogs, treated with meglumine administered concurrently with allopurinol for 30 days, and then with allopurinol alone, were monitored during a period of 2 years. The DNA extracted from the clinical specimens was amplified by PCR using as target DNA a 116-bp fragment in the constant region of the kinetoplast DNA minicircle. PCR analysis was more sensitive than indirect immunofluorescence antibody test in detecting Leishmania infection in symptomatic dogs: 99% of lymph node samples resulted positive, whereas 94% of blood samples and 95% of skin samples gave a positive result. PCR analysis of samples from dogs followed up 2 years showed that: (1) all subjects resulted positive in at least one of the three types of samples; (2) all time the dogs had a relapse, PCR resulted positive in all three types of samples; (3) when dogs were apparently healthy, PCR analysis was positive on skin and lymph node samples, but not always on blood samples. Since lymph node sampling is invasive and sometimes difficult in healthy asymptomatic dogs, our results suggest that, independently from the presence or not of cutaneous lesions, skin biopsy represents a good substratum for PCR-based diagnosis and follow-up of canine visceral leishmaniosis.
