ABSTRACT
An unknown Trypanosoma species was isolated from an axenic culture of intact skin from a domestic dog captured in Rio de Janeiro, Brazil, which was co-infected with Leishmania (Viannia) braziliensis. Giemsa-stained smears of cultures grown in different media revealed the presence of epimastigotes, trypomastigotes, spheromastigotes, transitional stages, and dividing forms (epimastigotes or spheromastigotes). The highest frequency of trypomastigotes was observed in RPMI (15.2%) and DMEM (9.2%) media containing 5% FCS, with a mean length of these forms of 43.0 and 36.0 mum, respectively. Molecular analysis by sequential application of PCR assays indicated that this trypanosome differs from Trypanosoma cruzi and T. rangeli when specific primers were applied. On the other hand, a PCR strategy targeted to the D7 domain of 24salpha rDNA, using primers D75/D76, amplified products of about 250 bp in that isolate (stock A-27), different from the amplification products obtained with T. cruzi and T. rangeli. This organism differs from T. cruzi mainly by the size of its trypomastigote forms and kinetoplasts and the absence of infectivity for macrophages and triatomine bugs. It is also morphologically distinct from salivarian trypanosomes reported in Brazil. Isoenzyme analysis at 8 loci demonstrated a very peculiar banding pattern clearly distinct from those of T. rangeli and T. cruzi. We conclude that this isolate is a new Trypanosoma species. The name T. caninum is suggested.
Subject(s)
Dog Diseases/parasitology , Skin Diseases, Parasitic/parasitology , Skin/parasitology , Trypanosoma/classification , Trypanosoma/isolation & purification , Trypanosomiasis/veterinary , Animals , Base Sequence , Brazil , Culture Media , DNA, Ribosomal/analysis , Dogs , Isoenzymes/analysis , Macrophages, Peritoneal/parasitology , Mice , Molecular Sequence Data , Polymerase Chain Reaction , RNA , Sequence Analysis, DNA , Species Specificity , Trypanosoma/enzymology , Trypanosoma/growth & development , Trypanosomiasis/parasitologyABSTRACT
We compared the accuracy of ELISA and indirect immunofluorescence (IIF) using Leishmania braziliensis and L. major-like antigens and antigens from the Bio-Manguinhos kit for serological diagnosis of American tegumentary leishmaniasis (ATL). Cut-off values were defined by the area under the receiver-operating characteristic curve. For ELISA, statistical analyses revealed better accuracy [95.7% sensitivity, 100% specificity, 100% positive predictive value (PPV), 97.5% negative predictive value (NPV)] and reliability [intraclass correlation coefficient (ICC): 0.940] for L. braziliensis antigen compared with L. major-like antigen (78.7% sensitivity, 82.8% specificity, 73.3% PPV, 86.6% NPV, ICC: 0.833). ELISA optical density values obtained for both antigens were higher in mucosal forms of ATL. For IIF, sensitivity and specificity were 81.5 and 86.2%, respectively, for the L. braziliensis antigen, compared with 95.4 and 77.7% for the L. major-like antigen and 75.4 and 89.2% for the Bio-Manguinhos kit. No difference in the specificity of the IIF test was observed between antigens, whereas sensitivity differed between the L. braziliensis and L. major-like antigens and the Bio-Manguinhos kit. Parallel ELISA and IIF testing increased sensitivity, irrespective of the antigen employed, and serial testing increased overall specificity. These results support the recommendation that ELISA employing L. braziliensis antigen be used as a diagnostic tool for suspected cases of ATL in L. braziliensis-endemic areas.
Subject(s)
Antibodies, Protozoan/analysis , Leishmania braziliensis/immunology , Leishmania major/immunology , Leishmaniasis, Cutaneous/diagnosis , Animals , Antigens, Protozoan/immunology , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Humans , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
We report here the first case of co-infection with Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi in a naturally infected dog from Rio de Janeiro, Brazil. Isoenzyme characterisation identified the parasites isolated in culture from the cutaneous lesion as L. (V.) braziliensis and the isolates from blood and lymph node as L. (L.) chagasi. PCR analysis using specific primers followed by molecular hybridisation for direct Leishmania species identification in tissue fragments confirmed the presence of L. (V.) braziliensis DNA in the cutaneous lesion and of L. (L.) chagasi DNA in spleen and popliteal lymph node fragments. This report emphasises the importance of identification of Leishmania species infecting seropositive dogs in endemic areas, and the consequent re-assessment of control and epidemiological surveillance measures for the control of leishmaniasis, as is the case in Brazil.
Subject(s)
Dog Diseases/parasitology , Leishmania/isolation & purification , Leishmaniasis, Cutaneous/veterinary , Leishmaniasis, Visceral/veterinary , Animals , Brazil , DNA, Protozoan/analysis , Disease Reservoirs , Dogs , Electrophoresis/veterinary , Leishmania/enzymology , Leishmania/genetics , Leishmania braziliensis/enzymology , Leishmania braziliensis/genetics , Leishmania braziliensis/isolation & purification , Leishmaniasis, Cutaneous/complications , Leishmaniasis, Visceral/complications , Male , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , ZoonosesABSTRACT
A study was carried out using macrophages cultured from the peritoneal exudate of dogs infected in vitro with three species of Leishmania: L. (L.) chagasi, L. (Viannia) braziliensis and L. (L.) amazonensis with the aim of investigating the growth kinetics and infectivity of these species in the host cell. Results were expressed as the percentage of macrophages infected measured at 24 hr intervals over six days in RPMI - 1640 culture medium at a temperature of 34-35oC. The findings open the possibility of using canine peritoneal cells as a model for the screenning of leishmanicide drugs and to study the pathogenesis of these species.
Subject(s)
Animals , Dogs , Male , Female , In Vitro Techniques , Leishmania/pathogenicity , Macrophages, Peritoneal/parasitology , Leishmania braziliensis/pathogenicity , Leishmania infantum/pathogenicity , Leishmania mexicana/pathogenicity , Leishmaniasis, Cutaneous , Leishmaniasis, Mucocutaneous , Leishmaniasis, VisceralABSTRACT
Cutaneous disseminated lesions caused by Leishmania sp. were found in a pregnant mare (Equus cabalus) from a rural city in the State of rio de Janeiro, Brazil. Before delivering, treatment was undertaken by immunotherapy followed by chemotherapy. Histopatology and serology were performed during treatment, as well as the biochemical characterization of the parasite (L. braziliensis) that was isolated from one of the lesions
Subject(s)
Animals , Female , Pregnancy , Pregnancy Complications, Parasitic/veterinary , Horse Diseases/parasitology , Leishmania braziliensis , Leishmaniasis, Diffuse Cutaneous/veterinary , Pregnancy Complications, Parasitic/therapy , Horse Diseases/therapy , Horses , Immunotherapy , Leishmaniasis, Diffuse Cutaneous/therapyABSTRACT
In order to characterize the epidemiology of American Cutaneous Leishmaniasis (ACL) in a periurban area of the municipality of Sabará in the metropolitan region of Belo Horizonte (MRBH), an area until then considered free of the disease, a cross sectional survey was undertaken in 1990. The survey of the population consisted of 1119 interviews and 881 clinical examinations using Montenegro's skin test (MST). A low prevalence (3.7%) of positive MST was encountered. The disease had been occuring in the area for about 20 years in the form of sporadic cases. The predominant species of sandfly both in domestic areas and nearby areas of secondary vegetation was Lutzomyia whitmani. A canine survey of delayed hypersensitivity to the antigen P10,000 identified only one dog with a positive reaction out of 113 examined. The transmission of ACL in MRBH was confirmed. The occurrence of the disease in women, children and individuals with no contact with forest areas as well as the presence of potential vector species in the domiciliar environment, suggests the transmission of the disease in this environmewnt
