RESUMO
Leishmaniasis represents a group of parasitic diseases caused by a protozoan of the genus Leishmania and is widely distributed in tropical and subtropical regions. Leishmaniasis is one of the major tropical neglected diseases, with 1.5 to 2 million new cases occurring annually. Diagnosis remains a challenge despite advances in parasitological, serological, and molecular methods. Dogs are an important host for the parasite and develop both visceral and cutaneous lesions. Our goal was to contribute to the diagnosis of canine cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) using the recombinant cysteine proteinase B (F-CPB) from Leishmania braziliensis and its N- and C-terminal domains (N-CPB and C-CPB) as antigens in an enzyme-linked immunosorbent assay (ELISA). Sera from dogs from Northwest Argentina diagnosed with CL were tested by ELISA against a supernatant of L. braziliensis lysate, the F-CPB protein, and its domains. We found values of sensitivity (Se) of 90.7%, 94.4%, and 94.3% and specificity (Sp) of 95.5%, 90.9%, and 91.3% for F-CPB and its N- and C-terminal domains, respectively. In sera from dogs diagnosed with VL from Northeast Argentina, we found Se of 93.3%, 73.3%, and 66.7% and Sp of 92.3%, 76.9%, and 88.5% for F-CPB and its N- and C-terminal domains, respectively. These results support CPB as a relevant antigen for canine leishmaniasis diagnosis in its different clinical presentations. More interestingly, the amino acid sequence of CPB showed high percentages of identity in several Leishmania species, suggesting that the CPB from L. braziliensis qualifies as a good antigen for the diagnosis of leishmaniasis caused by different species.
Assuntos
Antígenos de Protozoários/imunologia , Cisteína Proteases/genética , Doenças do Cão/diagnóstico , Leishmania braziliensis/enzimologia , Leishmaniose Cutânea/veterinária , Leishmaniose Visceral/veterinária , Animais , Antígenos de Protozoários/genética , Doenças do Cão/parasitologia , Cães , Ensaio de Imunoadsorção Enzimática , Leishmania braziliensis/genética , Leishmaniose Cutânea/sangue , Leishmaniose Cutânea/diagnóstico , Leishmaniose Visceral/sangue , Leishmaniose Visceral/diagnóstico , Proteínas de Protozoários/genética , Proteínas Recombinantes/genética , Sensibilidade e Especificidade , Testes SorológicosRESUMO
In order to find novel plant-derived biologically active compounds against Trypanosoma cruzi, we isolated, from the organic extract of Smallanthus sonchifolius, the sesquiterpene lactones enhydrin (1), uvedalin (2), and polymatin B (3) by bioassay-guided fractionation technique. These compounds showed a significant trypanocidal activity against the epimastigote forms of the parasite with IC50 values of 0.84 µ M (1), 1.09 µ M (2), and 4.90 µ M (3). After a 24 h treatment with 10 µ g/mL of enhydrin or uvedalin, parasites were not able to recover their replication rate. Compounds 1 and 2 showed IC50 values of 33.4 µ M and 25.0 µ M against T. cruzi trypomastigotes, while polymatin B was not active. When the three compounds were tested against the intracellular forms of T. cruzi, they were able to inhibit the amastigote replication with IC50 of 5.17 µ M, 3.34 µ M, and 9.02 µ M for 1, 2, and 3, respectively. The cytotoxicity of the compounds was evaluated in Vero cells obtaining CC50 values of 46.5 µ M (1), 46.8 µ M (2), and 147.3 µ M (3) and the selectivity index calculated. According to these results, enhydrin and uvedalin might have potentials as agents against Chagas disease and could serve as lead molecules to develop new drugs.
RESUMO
We examined the ability of IgG anti-crotalic PLA2 to cross-react with Bothrops spp. venoms, from snakes found in the northeast of Argentina. Immunoblotting and ELISA tests showed that IgG anti-crotalic PLA2 recognize antigens of bothropic venoms. Indirect hemolytic activity tests showed that the quantity of antibodies that neutralized 50% of Crotalus durissus terrificus venom (ED50: 2.1 mg IgG anti-crotalic PLA2/100 µg of venom) were also able to neutralize venom from other snakes in the following proportion: 34% of B. alternatus, 18% of B. diporus and 12% of B. jararacussu. Likewise, direct PLA2 activity neutralization tests showed a similar cross-neutralization pattern including 56% of B. alternatus, 29% of B. diporus and 30% of B. jararacussu. In addition, in a myotoxic activity neutralization test, measured by plasma activity of creatine kinase, 35% of B. alternatus venom and 26% of B. diporus venom were neutralized, while no neutralization was detected with B. jararacussu venom. This study presents original data concerning cross-reactions between bothropic venoms from Argentina and IgG anti-crotalic PLA2. Our results suggest that anti-crotalic PLA2 antibodies should not be used to neutralize PLA2 activity of B. alternatus, B. diporus and especially B. jararacussu venoms; nor to enrich commercial antivenoms against these Bothrops species.(AU)
Assuntos
Animais , Imunoglobulina G , Testes de Neutralização , Fosfolipases A2 , AnticorposRESUMO
AIMS: To assess the inhibitory activity on Gram-positive and Gram-negative bacteria of several species of enterococci recovered from a natural corn silage. METHODS AND RESULTS: The inhibitory activity of strains of Enterococcus faecalis (58), Enterococcus faecium (35), Enterococcus gallinarum (3) and Enterococcus casseliflavus (4) were studied employing indicator strains from various sources (clinical, food and ATCC). Enterococcus faecalis MR99, the only strain with inhibitory activity, inhibited other enterococci, Listeria spp., Staphylococcus aureus, Clostridium spp., Bacillus spp., Escherichia coli, Shigella sonnei and Shigella flexneri. The bacterium contained only one conjugative pheromone-responsive plasmid. The partially chromatography-purified MR99 enterocin (PPE) had a molecular weight of approx. 5000 Da and a pI of 6.2, was sensitive to proteolytic enzymes and could be extracted in benzene and butanol. It appeared stable to adjustment of pH 4.0, 5.0, 6.0, 7.0 and 8.0 and was resistant to heat. Inactivation was at 15 min at 121 degrees C. Enterocin MR99 was bactericidal on strains of Listeria monocytogenes, Staph. aureus, and bovine mastitis agents, it was bacteriostatic on E. coli. Although enterocins MR99 and AS48 have inhibitory activity on Gram-negative bacilli, PCR studies demonstrated a lack of relationship between them. CONCLUSIONS: The active component had a protein nature, was resistant to heat and presented a wide inhibitory spectrum. SIGNIFICANCE AND IMPACT OF THE STUDY: The biological properties of Ent. faecalis MR99 suggest that this strain merits further investigations so it can be applied in human and veterinary health programmes.
Assuntos
Bacteriocinas/farmacologia , Enterococcus/fisiologia , Microbiologia de Alimentos , Silagem/microbiologia , Zea mays/microbiologia , Bacillus/efeitos dos fármacos , Hidrocarbonetos Aromáticos com Pontes/análise , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Clostridium/efeitos dos fármacos , Meios de Cultura , Eletroforese em Gel de Poliacrilamida/métodos , Enterococcus faecalis/fisiologia , Enterococcus faecium/fisiologia , Escherichia coli/efeitos dos fármacos , Focalização Isoelétrica/métodos , Listeria/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/ultraestrutura , Microscopia Eletrônica/métodos , Plasmídeos/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Shigella/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestruturaRESUMO
The aims of this study were to characterize human American tegumentary leishmaniasis, which includes cutaneous, mucocutaneous and mucosal leishmaniasis, in Northwest Argentina, to determine the prevalence of double infection with Trypanosoma cruzi and to identify the species of Leishmania in this area. Most of the 330 leishmaniasis patients presented cutaneous ulcers (96.1%), 2.4% mucocutaneous and 1.5% the mucosal form ('espundia'). The aetiological agents, determined by isoenzyme electrophoresis, were identified as Leishmania (Viannia) braziliensis in 16 out of 20 isolates and in the remaining 4 as Leishmania (Leishimania) amazonensis, the first ever-documented in Argentina. Sera analysed by ELISA and IFA using complex antigen from both T. cruzi and L. braziliensis showed a very high percentage of positives (66.3-78.2%). When antigens for specific diagnosis of Chagas' disease were used, 40.9% of the leishmaniasis patients were also found to be infected by T. cruzi. These results indicate that the strong immune response against T. cruzi gave no protection to Leishmania, in spite of the serological cross-reaction between these parasites. In addition, we showed that more than 40% of the patients would be misdiagnosed as chagasic if complex antigens, as epimastigotes or soluble fraction from epimastigotes, were used in IFA or ELISA. This is of paramount importance not only because patients' treatment would be associated to misdiagnosis but the fact that in many countries in Central and South America, a positive test for Chagas' disease means a rejection for those seeking employment.
Assuntos
Doença de Chagas/complicações , Doença de Chagas/imunologia , Leishmania/classificação , Leishmania/isolamento & purificação , Leishmaniose Cutânea/complicações , Leishmaniose Cutânea/imunologia , Trypanosoma cruzi/isolamento & purificação , Animais , Argentina/epidemiologia , Doença de Chagas/diagnóstico , Doença de Chagas/parasitologia , Reações Cruzadas , Feminino , Genes de Protozoários/genética , Humanos , Leishmania/enzimologia , Leishmania/genética , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/parasitologia , Masculino , FilogeniaRESUMO
In a study, carried out in 2000, of the clinical and parasitological status of a Wichi Aboriginal community living in the suburbs of Tartagal, northern Salta, Argentina, 154 individuals were screened for parasitic infections. Ninety-five faecal samples were also obtained from the same population. Ninety-three percent of the subjects were positive for 1 or more of the parasites investigated by direct test and 70.5% of them had parasitic superinfection. The most frequent helminths were Strongyloides stercoralis (50.5%) and hookworm (47.4%). We found low reinfection rates and a long reinfection period after treatment and provision of safe water and sanitation. Serum reactivity of these patients was analysed by enzyme-linked immunosorbent assay and indirect immunofluorescent assay and 22.1% of them had anti-Toxocara antibodies, 16.2% were positive for a complex antigen of Leishmania braziliensis, 29.9% were positive for a complex Trypanosoma cruzi antigen, and 17.5% were positive for a specific Trypanosoma cruzi antigen, Ag 163B6/cruzipain.
Assuntos
Indígenas Sul-Americanos/etnologia , Doenças Parasitárias/etnologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/etnologia , Anemia/parasitologia , Argentina/epidemiologia , Criança , Pré-Escolar , Eosinofilia/etnologia , Eosinofilia/parasitologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Doenças Parasitárias/diagnósticoRESUMO
Some Leishmania species affect humans in two principal forms: visceral and cutaneous leishmaniosis (CL). Several studies have identified dogs as the main reservoirs of the visceral leishmaniosis (VL) caused by Leishmania infantum. The purpose of this work was to carry out a survey of the canine population associated with human cases of American tegumentary leishmaniosis (ATL), in order to establish the clinical, parasitological, serological and immunological characteristics of the canine disease, in an endemic region for both ATL and Chagas' disease in the province of Salta, in northwestern Argentina. Two hundred and eight dogs from the endemic area were examined and 41 (19.7%) of them presented lesions compatible with leishmaniosis. In order to investigate the presence of antibodies against Leishmania spp. and Trypanosoma cruzi, sera were screened by ELISA using two complex antigens from these parasites and, because of cross-reactions between them, a specific antigen for diagnosis of T. cruzi infection. Sixty-two (29.8%) of 208 dogs were positive for the complex antigen F45 from Leishmania and 50 (24%) were positive for the complex antigen F105 from T. cruzi. Nine dogs (4.3%) were positive for the specific Ag163B6-cruzipain suggesting that these dogs were truly infected with T. cruzi. Furthermore, three of these nine dogs presented Leishmania sp. in their skin lesions and therefore were considered as infected by both, T. cruzi and Leishmania parasites. The prevalence of Leishmania infection detected by lesions and/or positive serology was 27.4% (57/208). On the basis of previous observations regarding the clustered appearance of human ATL, the dog population was divided into two groups: zone A, dogs living within a 100 m radius from houses with human cases, and zone B, dogs living beyond this limit. The prevalence of ATL in dogs was significantly higher in zone A (34.6%) than in zone B (7.3%), suggesting a strong correlation between canine and human cases. The average time required for a parasitological diagnosis by microscopy was six times longer for dog samples than human ones, and the average number of parasites per 100 microscopic fields was 14-fold lower in canine samples. The high prevalence of Leishmania infection and the close association with human cases, demonstrated that dogs are a very susceptible host for Leishmania infection, but the scarcity of parasites in their lesions suggests that they may not be the main reservoir of the parasite in this endemic area.
Assuntos
Reservatórios de Doenças/veterinária , Doenças do Cão/parasitologia , Doenças Endêmicas , Leishmania infantum/isolamento & purificação , Leishmaniose Cutânea/veterinária , Animais , Anticorpos Antiprotozoários/sangue , Argentina/epidemiologia , Biópsia/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/transmissão , Cães , Ensaio de Imunoadsorção Enzimática , Humanos , Hipersensibilidade Tardia/parasitologia , Hipersensibilidade Tardia/veterinária , Leishmaniose Cutânea/sangue , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Estudos Soroepidemiológicos , Pele/parasitologia , Trypanosoma cruzi/parasitologiaRESUMO
Congenital Chagas disease, due to the intracellular parasite Trypanosoma cruzi, is associated with premature labor, miscarriage, and placentitis. Human enzyme placental alkaline phosphatase (PLAP) (EC 3.1.3.1.) is membrane-anchored through glycosylphosphatidylinositol (GPI). PLAP is present in plasma in late pregnancy, 36 to 40 weeks; there are lower levels in maternal Chagas disease. Infants born to such mothers may have congenital Chagas disease. Human placental villi (PV) were treated with phospholipase-C (PL-C) and then cultured with T. cruzi to determine the effect of the parasites on PLAP activity as an in vitro model. There is less PLAP activity after treatment by PL-C and during culture with T. cruzi. Pretreatment of PV with PL-C before culture with T. cruzi yielded essentially normal specific activity of PLAP and prevented or greatly reduced infective penetration of villi by parasites. The results are consistent with a pathogenetic role for placental alkaline phosphatase in congenital Chagas disease. Receptor activation of membrane attachment to PLAP may be a device used by T. cruzi to enable parasite invasion of human trophoblast.
Assuntos
Fosfatase Alcalina/metabolismo , Doença de Chagas/congênito , Isoenzimas/metabolismo , Placenta/enzimologia , Placenta/parasitologia , Trofoblastos/parasitologia , Trypanosoma cruzi/fisiologia , Fosfatase Alcalina/sangue , Animais , Células Cultivadas , Doença de Chagas/enzimologia , Doença de Chagas/fisiopatologia , Técnicas de Cultura , Feminino , Humanos , Imuno-Histoquímica , Isoenzimas/sangue , Camundongos , Camundongos Endogâmicos BALB C , Placenta/citologia , Placenta/efeitos dos fármacos , Gravidez , Fosfolipases Tipo C/metabolismoRESUMO
A clinical-serological follow-up was carried out in a canine population in endemic foci of Leishmania braziliensis spread in northwestern Argentina. Each dog was studied in at least two visits, 309+/-15 days (X+/-SE) apart. Some initially healthy dogs (n=52) developed seroconversion or lesions. The clinical evolution of the disease in dogs resembles in many aspects the human disease. Similarities include the long duration of most ulcers with occasional healing or appearance of new ones and the late appearance of erosive snout lesions in some animals. Yearly incidence rates of 22.7% for seroconversion and of 13.5% for disease were calculated as indicators of the force of infection by this parasite upon the canine population.
Assuntos
Doenças do Cão/parasitologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/veterinária , Animais , Argentina , Reservatórios de Doenças/veterinária , Doenças do Cão/patologia , Cães , Seguimentos , Leishmaniose Cutânea/patologia , Estudos LongitudinaisRESUMO
The objective of the present study is to describe two cases of dogs with mucocutaneous lesions caused by Leishmania spp. Both dogs presented destruction of the nasal septum, hyperemia with soft palate edema and barking alteration due to laryngeal compromise. Biopsies were taken from the lesion border and Leishmania spp. amastigotes were seen in the imprints. The dogs presented positive serology when complex soluble antigen from Leishmania mexicana was used. One of the dogs was also suspected to be infected by Trypanosoma cruzi as suggested by its positive reaction with a purified specific antigen, Ag163B6-cruzipain. Most of the studies concerning leishmaniosis in dogs have described the cutaneous form of this disease in close association with human cases of Leishmania infection instead of the mucocutaneous form described herein. The presence of dogs with mucocutaneous leishmaniosis alerts on an increase of the prevalence of this form in humans, which can cause deforming lesions, alterations of the speech and even an inadequate nutrition due to difficulties in deglutition.
Assuntos
Doenças do Cão/epidemiologia , Leishmaniose Mucocutânea/veterinária , Animais , Anticorpos Antiprotozoários/sangue , Argentina/epidemiologia , Biópsia , Doença de Chagas/complicações , Doença de Chagas/parasitologia , Doença de Chagas/veterinária , Clima , Surtos de Doenças , Reservatórios de Doenças , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Doenças do Cão/patologia , Cães , Humanos , Leishmania mexicana/imunologia , Leishmania mexicana/isolamento & purificação , Leishmaniose Mucocutânea/complicações , Leishmaniose Mucocutânea/epidemiologia , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Mucocutânea/patologia , Masculino , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
The objective of the present study is to describe two cases of dogs with mucocutaneous lesions caused by Leishmania spp. Both dogs presented destruction of the nasal septum, hyperemia with soft palate edema and barking alteration due to laryngeal compromise. Biopsies were taken from the lesion border and Leishmania spp. amastigotes were seen in the imprints. The dogs presented positive serology when complex soluble antigen from Leishmania mexicana was used. One of the dogs was also suspected to be infected by Trypanosoma cruzi as suggested by its positive reaction with a purified specific antigen, Ag163B6-cruzipain. Most of the studies concerning leishmaniosis in dogs have described the cutaneous form of this disease in close association with human cases of Leishmania infection instead of the mucocutaneous form described herein. The presence of dogs with mucocutaneous leishmaniosis alerts on an increase of the prevalence of this form in humans, which can cause deforming lesions, alterations of the speech and even an inadequate nutrition due to difficulties in deglutition.
Assuntos
Animais , Cães , Humanos , Masculino , Doenças do Cão/epidemiologia , Leishmaniose Mucocutânea/veterinária , Anticorpos Antiprotozoários/sangue , Argentina , Biópsia , Clima , Surtos de Doenças , Reservatórios de Doenças , Doença de Chagas/complicações , Doença de Chagas/parasitologia , Doença de Chagas/veterinária , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Doenças do Cão/patologia , Leishmania mexicana , Leishmaniose Mucocutânea/complicações , Leishmaniose Mucocutânea/epidemiologia , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Mucocutânea/patologia , Trypanosoma cruziRESUMO
The objective of the present study is to describe two cases of dogs with mucocutaneous lesions caused by Leishmania spp. Both dogs presented destruction of the nasal septum, hyperemia with soft palate edema and barking alteration due to laryngeal compromise. Biopsies were taken from the lesion border and Leishmania spp. amastigotes were seen in the imprints. The dogs presented positive serology when complex soluble antigen from Leishmania mexicana was used. One of the dogs was also suspected to be infected by Trypanosoma cruzi as suggested by its positive reaction with a purified specific antigen, Ag163B6-cruzipain. Most of the studies concerning leishmaniosis in dogs have described the cutaneous form of this disease in close association with human cases of Leishmania infection instead of the mucocutaneous form described herein. The presence of dogs with mucocutaneous leishmaniosis alerts on an increase of the prevalence of this form in humans, which can cause deforming lesions, alterations of the speech and even an inadequate nutrition due to difficulties in deglutition.(AU)
Assuntos
Animais , Cães , Humanos , Masculino , RESEARCH SUPPORT, NON-U.S. GOVT , Doenças do Cão/epidemiologia , Leishmaniose Mucocutânea/veterinária , Anticorpos Antiprotozoários/sangue , Argentina/epidemiologia , Biópsia , Doença de Chagas/complicações , Doença de Chagas/parasitologia , Doença de Chagas/veterinária , Clima , Surtos de Doenças , Reservatórios de Doenças , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Doenças do Cão/patologia , Leishmania mexicana/imunologia , Leishmania mexicana/isolamento & purificação , Leishmaniose Mucocutânea/complicações , Leishmaniose Mucocutânea/epidemiologia , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Mucocutânea/patologia , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
Toxocara canis and Ancylostoma spp. are geohelmints that parasites dogs and can eventually affect humans, mainly children, causing visceral and cutaneous larva migrans respectively, constituting a serious public health problem. This study was carried out in two towns located in the xerophilous forest Chaco salteño where humans live closely with many animals, including dogs. Hematological values and anti-Toxocara canis antibodies, determined by ELISA in serum, were evaluated in 98 children from this area. Thirty-six children presented with eosinophilia of 10% or higher in peripheral blood. Twenty out of 98 (20.4%) children had antibodies against antigen from L2 larvae of Toxocara canis. A high percentage (55.6%) of the children with eosinophilia presented anti-Toxocara canis antibodies. Nine children had multiple serpiginous lesions typical of cutaneous larva migrans. Feces from dogs were collected in the area where children lived, in order to search for parasite contamination. Three different techniques of stool examination were employed and eggs were counted. Out of the 106 feces examined, parasites were found in 82 samples (77.4%). Ancylostoma spp eggs were found in 74 (69.8%) samples and eggs from Toxocara canis were found in 19 (17.2%). The average number of T. canis and Ancylostoma spp eggs/gr of feces, were 200 and 3,871 respectively. Giardia spp (14.5%), Trichuris vulpis (7.6%), Genus Endamoeba (2.8%) and Taenia spp (1.9%) were also identified in the stools. Sanitary control and health education in order to control these parasitoses are emphasized.
Assuntos
Doenças do Cão/transmissão , Toxocara canis , Toxocaríase/transmissão , Zoonoses/transmissão , Animais , Anticorpos Anti-Helmínticos/sangue , Argentina/epidemiologia , Criança , Pré-Escolar , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Doenças Endêmicas , Fezes/parasitologia , Humanos , Lactente , Recém-Nascido , Prevalência , Toxocaríase/epidemiologia , Toxocaríase/parasitologiaRESUMO
Toxocara canis and Ancylostoma spp. are geohelmints that parasites dogs and can eventually affect humans, mainly children, causing visceral and cutaneous larva migrans respectively, constituting a serious public health problem. This study was carried out in two towns located in the xerophilous forest Chaco salteño where humans live closely with many animals, including dogs. Hematological values and anti-Toxocara canis antibodies, determined by ELISA in serum, were evaluated in 98 children from this area. Thirty-six children presented with eosinophilia of 10
or higher in peripheral blood. Twenty out of 98 (20.4
) children had antibodies against antigen from L2 larvae of Toxocara canis. A high percentage (55.6
) of the children with eosinophilia presented anti-Toxocara canis antibodies. Nine children had multiple serpiginous lesions typical of cutaneous larva migrans. Feces from dogs were collected in the area where children lived, in order to search for parasite contamination. Three different techniques of stool examination were employed and eggs were counted. Out of the 106 feces examined, parasites were found in 82 samples (77.4
). Ancylostoma spp eggs were found in 74 (69.8
) samples and eggs from Toxocara canis were found in 19 (17.2
). The average number of T. canis and Ancylostoma spp eggs/gr of feces, were 200 and 3,871 respectively. Giardia spp (14.5
), Trichuris vulpis (7.6
), Genus Endamoeba (2.8
) and Taenia spp (1.9
) were also identified in the stools. Sanitary control and health education in order to control these parasitoses are emphasized.
RESUMO
The objective of the present study is to describe two cases of dogs with mucocutaneous lesions caused by Leishmania spp. Both dogs presented destruction of the nasal septum, hyperemia with soft palate edema and barking alteration due to laryngeal compromise. Biopsies were taken from the lesion border and Leishmania spp. amastigotes were seen in the imprints. The dogs presented positive serology when complex soluble antigen from Leishmania mexicana was used. One of the dogs was also suspected to be infected by Trypanosoma cruzi as suggested by its positive reaction with a purified specific antigen, Ag163B6-cruzipain. Most of the studies concerning leishmaniosis in dogs have described the cutaneous form of this disease in close association with human cases of Leishmania infection instead of the mucocutaneous form described herein. The presence of dogs with mucocutaneous leishmaniosis alerts on an increase of the prevalence of this form in humans, which can cause deforming lesions, alterations of the speech and even an inadequate nutrition due to difficulties in deglutition.
RESUMO
The existence of patients suffering a double infection caused by Trypanosoma cruzi and Leishmania spp. has been suggested by several authors. Since the conventional serological tests now available for the diagnosis of Chagas' disease lack specificity due to the cross-reactivity between these two parasites, a serological confirmation of a T. cruzi infection cannot be made unless specific antigens are used. An enzyme linked immunosorbent assay (ELISA) to detect antibodies against a specific T. cruzi antigen, named Ag163B6, and immunoblotting using T. cruzi epimastigotes, are non-conventional serological techniques that could be employed for specific diagnosis of Chagas' disease. Using these two methods 34 cutaneous or mucocutaneous leishmaniasis patients were classified into two groups: (A) patients with serological evidence of T. cruzi infection, i.e. those who tested positive in at least one assay (18/34); and (B) patients with no serological evidence of T. cruzi infection, i.e. those who were negative for both assays (16/34). Taking into account the difficulties of xenodiagnosis and its low sensitivity (less than 50%) for a direct diagnosis in the chronic period of the disease, we used polymerase chain reaction (PCR) to confirm a T. cruzi infection in those leishmaniasis patients who presented positive results with the non-conventional serological techniques. Of the 18 patients with serological evidence of T. cruzi infection, 17 gave positive results when genomic DNA primers were used. Using minicircle primers, 15/18 of that group were positive. Nevertheless, all the patients suspected of being double infected were positive in at least one PCR test. Just one patient with no serological evidence of T. cruzi infection gave a positive PCR result when amplifying the minicircle sequence. The proof of the existence of a T. cruzi infection by PCR in leishmaniasis patients suspected to be chagasic when non-conventional serology was used, strongly supports the use of the specific Ag163B6 and immunoblotting with epimastigotes as specific serological diagnostic tools to determine a T. cruzi infection.
Assuntos
Doença de Chagas/complicações , Doença de Chagas/diagnóstico , Leishmaniose Cutânea/complicações , Leishmaniose Mucocutânea/complicações , Reação em Cadeia da Polimerase/métodos , Trypanosoma cruzi/isolamento & purificação , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Doença de Chagas/parasitologia , Cisteína Endopeptidases/imunologia , DNA de Protozoário/análise , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Immunoblotting , Recém-Nascido , Leishmania/imunologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Mucocutânea/parasitologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologiaRESUMO
The distribution of the dopaminergic D4 receptor in rat brain was studied employing site directed polyclonal antibodies. Antisera were raised in rabbits to two oligopeptides corresponding to amino acids 160-172 of the second extracellular loop (P1) and amino acids 260-273 of the third intracellular loop (P2) of the D4 receptor sequence. Affinity-purified antibodies (anti-P1 and anti-P2) specifically recognized two major bands of 42-45 and 95 kDa in Western blots of denatured preparations of various rat brain areas. Immunocyto-chemistry studies showed that D4 receptor is widely distributed in rat central nervous system (CNS) showing higher labelling in the hippocampus (CA1, CA2, CA3 and dentate gyrus) frontal cortex, entorhinal cortex, caudate putamen, nucleus accumbens, olfactory tubercle, cerebellum, supraoptic nucleus and sustancia nigra pars compacta. In addition, anti-P1 decreased the binding of the antagonist [3H]YM-09151-2 selective for D2, D3 and D4 receptors but did not modify the binding of [3H]raclopride an antagonist selective for D2 and D3, in striatal synaptosomes. Anti-P2 did not modify the binding of these ligands. These results confirm the selectivity of the antibodies towards the D4 receptor and suggest that the binding site for the antagonists might be located at or close to the second extracellular loop of the protein sequence. D4 receptor protein is mainly expressed in plasma membranes and in the peripheral cytoplasm of neurons and is more widely distributed than was originally proposed based on mRNA localization, since it is present both in limbic, diencephalic and motor areas of rat brain.
Assuntos
Encéfalo/citologia , Neurônios/citologia , Receptores de Dopamina D2/análise , Sequência de Aminoácidos , Animais , Anticorpos , Especificidade de Anticorpos , Encéfalo/metabolismo , Química Encefálica , Membrana Celular/metabolismo , Antagonistas de Dopamina/metabolismo , Ensaio de Imunoadsorção Enzimática , Imuno-Histoquímica , Masculino , Neurônios/metabolismo , Especificidade de Órgãos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Coelhos , Racloprida , Ratos , Ratos Wistar , Receptores de Dopamina D2/química , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D4 , Salicilamidas/metabolismo , Sinaptossomos/metabolismoRESUMO
The proliferative response of CD4 and CD8 T lymphocytes obtained from C3H/HeN mice chronically infected with Trypanosoma cruzi strains that differ in virulence, tropism and immunogenicity, was assayed against skeletal muscle, sciatic nerve and spinal cord homogenates. Although both CD4 and CD8 T lymphocytes from mice infected with the RA strain strongly proliferated against the nervous system, no response against skeletal muscle antigens was detected. CD4 and CD8 T lymphocytes from mice infected with the K-98 clone (from CA-I strain) showed low proliferative response against all the antigens assayed. To determine whether the proliferation patterns showed correlation with T cell-mediated neuromuscular damage, passive cell transfer studies were performed. Fifteen days after transfer of CD4 T cells from RA-infected donors (CD4-RA), normal syngeneic recipients displayed exclusively nervous tissue damage, such as perineural, endoneural and/or meningeal inflammatory infiltrates, with predominance of CD4 T cells. Fifteen days after transfer of CD4 T lymphocytes from mice infected with K-98 (CD4-K98), recipients showed inflammatory infiltrates only in skeletal muscle, where CD4 T lymphocytes and macrophages were predominant cells. Recipients of CD8 T cells from RA-infected mice (CD8-RA) showed lesions in both spinal cord and sciatic nerves. Higher percentages of CD8 T cells were observed in comparison with the recipients of CD4-RA or CD4-K98. In contrast, CD8 T cells from K-98-infected donors (CD8-K98) did not induce tissue damage. These results provide evidence that mice infected with T. cruzi populations that differ in their biological characteristics show diverse immune mechanisms that may be involved in the pathogenesis of peripheral nervous system damage.
Assuntos
Doença de Chagas/complicações , Doença de Chagas/imunologia , Doenças Neuromusculares/etiologia , Subpopulações de Linfócitos T/fisiologia , Transferência Adotiva , Animais , Antígenos de Protozoários/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Divisão Celular , Doença de Chagas/sangue , Epitopos , Imunização Passiva , Masculino , Camundongos , Camundongos Endogâmicos C3H , Trypanosoma cruzi/imunologiaRESUMO
The occurrence of leishmaniasis patients carrying a double infection with Trypanosoma cruzi has been suspected but not proved. In this study, we analyzed sera of leishmaniasis patients from a region endemic for both parasites by using immunoblotting with epimastigotes and a purified antigen specific for T. cruzi (Ag 163B6). Seven of 12 patients showed a pattern of bands characteristic of chagasic patients reacting with antigens with molecular weights of 131, 125, 116, 111, 51-45, and 43 kD, and positive reactivity with Ag 163B6. Xenodiagnosis for T. cruzi was carried out in all patients; this technique has a positivity rate of 50% in chronic chagasic patients. The presence of T. cruzi trypomastigotes was shown in the blood of three, thus confirming the existence of a double infection in humans. Since the two parasites possess cross-reacting antigens, it may be assumed that previous infection with one of the parasites may affect the course of subsequent infection with the other. Nevertheless, T. cruzi infection did not prevent the appearance of typical leishmaniasis lesions. Therefore, antigenic cross-reactivity is unable to induce a sterilizing immune response against Leishmania.
Assuntos
Anticorpos Antiprotozoários/sangue , Doença de Chagas/complicações , Leishmania/imunologia , Leishmaniose/complicações , Trypanosoma cruzi/imunologia , Adolescente , Adulto , Idoso , Animais , Antígenos de Protozoários/imunologia , Doença de Chagas/diagnóstico , Doença de Chagas/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Immunoblotting , Leishmaniose/diagnóstico , Leishmaniose/imunologia , Masculino , Pessoa de Meia-Idade , Triatoma/parasitologia , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
In many regions of South America there are overlapping endemic areas for American Trypanosomiasis (Chagas' disease) and Leishmaniasis. T. cruzi and Leishmania spp, the causative agents of these parasitoses belong to the Trypanosomatidae family and share various antigens that cause cross-reactivity in serological diagnosis when complex antigenic mixtures are used. We studied patients who sought medical attention because of cutaneous or mucocutaneous lesions typical of leishmaniasis infection. These patients were from the province of Salta where Trypanosomiasis and Leishmaniasis are endemic diseases. Sixty-two patients gave a positive Montenegro skin test and, of these, 53 (85, 48%) showed the presence of amastigotes in Giemsa stained smears of dermal scrapings. Seven patients were not included because they were negative for both assays. We analyzed the leishmaniasic sera against homologous antigens to study the immune response and against complex heterologous antigens from T. cruzi to evaluate cross-reactivity phenomena. We also tested these sera against specific antigens for diagnosis of Chagas' disease in order to search for mixed infections. When complex antigens from leishmania were used, the sera showed an unusually strong antibody response 100% positive by IFA, 88.7% by ELISA and 80.6% by immunoblotting. Furthermore, significant cross-reactivity was found when conventional antigens for the serodiagnosis of Chagas' disease were used: 74.19% by IHA, 91.93% by IFA, and 76.80% by ELISA. We have previously purified by immunoaffinity, using a monoclonal antibody, an antigen termed Ag163B6 which is not present in L. mexicana. This antigen has shown the ability to specifically differentiate sera of chronic chagasic patients from those of leishmaniasic patients in ELISA. Furthermore, recent studies from our laboratory by immunoblotting, have demonstrated that chronic chagasic patients exhibit a specific reactivity pattern against T. cruzi epimastigotes that can be distinguished from those presented by leishmaniasic patients in spite of cross-reactive antigens. According to the results obtained in these assays, we classified the patients in two groups: 1) Patients with evidence of T. cruzi infection, those who tested positive in at least one assay: 2) Patients with no evidence of T. cruzi infection who were negative for both assays. More than 50% (32/62) of the patients showed strong evidence of mixed infection with T. cruzi. On the other hand, high cross-reactivity between these two parasitoses was shown in the second group without any evidence of T. cruzi infection since 18 out of 30 were positive in at least two conventional serological reactions. This implies that they would be misdiagnosed as chagasics if conventional reactions were used. These results emphasize the importance of the use of defined antigens and appropriate techniques for the differential diagnosis of these parasitoses, which is more important in areas endemic for both of them.