RESUMO
Human contact with wild animals in synanthropic habits is often mediated by arthropod vectors such as ticks. This is an important method of spreading infectious agents that pose a risk to human health. Thus, this study aimed to molecularly detect Ehrlichia spp., Anaplasma spp., Borrelia spp., and protozoa of the order Piroplasmida in ticks collected from coatis of Iguaçu National Park (PNI), Paraná, Brazil. This study involved 553 ticks DNA, including Amblyomma spp. larvae, Haemaphysalis juxtakochi nymphs, Amblyomma brasiliense, Amblyomma coelebs, and adults of Amblyomma ovale. The DNA extracted from each sample was subjected to polymerase chain reaction (PCR) targeting the genes 23S rRNA for the Anaplasmataceae family, 16S rRNA for Anaplasma spp., dsb for Ehrlichia spp., flaB, 16S rRNA, hpt, and glpQ for Borrelia spp., and 18S rRNA for Piroplasmid protozoans. DNA from Anaplasma sp. was detected in ticks of the species A. coelebs (4/553); Borrelia sp. DNA was detected in A. coelebs (3/553), A. ovale (1/553), and Amblyomma larvae (1/553); and Theileria sp. was detected in A. coelebs (2/553). All tested samples were negative for Ehrlichia spp. Our study constitutes the newest report in South America of these microorganisms, which remain poorly studied.
Assuntos
Borrelia , Procyonidae , Carrapatos , Adulto , Animais , Humanos , RNA Ribossômico 16S/genética , Brasil , Parques Recreativos , Ecossistema , Florestas , Amblyomma , Anaplasma/genética , Borrelia/genética , Ehrlichia/genética , LarvaRESUMO
The present study aimed to describe the occurrence of Borrelia spp. in cattle in the states of Minas Gerais and Pará in southeastern and northern Brazil, respectively. Bovine whole blood samples were examined by blood smear and polymerase chain reaction (PCR) to detect the flagellin B (flaB) gene of Borrelia spp. Frequencies of positive animals for Borrelia spp. were 1.52% (2/132) in the municipality of Unaí, Minas Gerais, and 14.2% (2/7) in the municipality of Marabá, Pará. Subsequent genetic sequencing confirmed that the detected spirochetes close to the species B. theileri. In both locations, the animals positive for B. theileri were also highly infested by Rhipicephalus microplus ticks. Despite the low frequency of Borrelia spp., the occurrence of this spirochete indicates that further studies are needed to determine the consequences in cattle herds.
Assuntos
Borrelia , Rhipicephalus , Bovinos , Animais , Brasil/epidemiologia , Borrelia/genética , Reação em Cadeia da Polimerase/veterináriaRESUMO
Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either Theileria equi or Babesia caballi. This disease represents a serious problem for the horse industry and its control is critical for the international trade of horses. The objective of the present study was to detect B. caballi and T. equi infections in horses reared in western Cuba. Blood samples from 100 horses were tested for the presence of piroplasms by using Giemsa-stained blood smears and nested PCR (nPCR) assays targeting merozoite antigen genes of B. caballi (bc48) and T. equi (ema-1). All animals were inspected for the detection of tick infestation and tick specimens were collected for species identification. Erythrocyte inclusions were observed in 13 (13%) of the analyzed samples. nPCR analysis showed that 25 (25%) samples were positive for B. caballi, 73 (73%) for T. equi, and 20 (20%) showed dual infections. Only one tick species was found infesting horses, Dermacentor nitens. In addition, three nearly full-length sequences of T. equi 18S rRNA gene were obtained and subjected to phylogenetic analyses. This study reports a high prevalence of T. equi and B. caballi single and coinfections in horses in western Cuba. Molecular analysis of the 18S rRNA gene of T. equi suggested that different genotypes of this hemoparasite circulate in Cuba. To the best of our knowledge, this is the first report describing the molecular detection of B. caballi and T. equi in horses in Cuba.
Assuntos
Babesia/genética , Babesiose/epidemiologia , Doenças dos Cavalos/parasitologia , Cavalos/parasitologia , Theileria/genética , Theileriose/epidemiologia , Infestações por Carrapato/veterinária , Animais , Babesia/isolamento & purificação , Bovinos , Coinfecção , Cuba/epidemiologia , Equidae/parasitologia , Feminino , Masculino , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Theileria/isolamento & purificação , Carrapatos/parasitologiaRESUMO
Borrelia burgdorferi sensu stricto is the main etiological agent of Lyme disease (LD) in the USA. In Brazil, it is believed that a similar spirochete is the causal agent of the Baggio-Yoshinari syndrome (BYS), a zoonosis also transmitted by ticks, whose clinical manifestations are similar to those of LD. Despite the epidemiological importance, there are no studies reporting the presence and the prevalence of B. burgdorferi among horses in Mato Grosso State. The aim of this study was to detect and measure the frequency of IgG antibodies anti-B. burgdorferi American strain G39/40 in horses in the municipality of Sinop, MT-Brazil, using the indirect enzyme-linked immunosorbent assay (ELISA) for serological diagnosis. Blood samples from 367 horses were collected in 81 farms. An epidemiological questionnaire was applied during the visits to obtain information related to the animals and the farms. From the 367 horses, 214 were positive for B. burgdorferi sensu stricto according to the results of the ELISA test, representing an apparent prevalence of 54.04% [CI = 0.4548051-0.6237234]. Concomitantly, 89 blood samples were taken for molecular analysis by nested polymerase chain reaction (PCR). According to the PCR test results, none of the samples were reactive, although 53 of these samples were reactive according to ELISA. Seventy five farms (92.59%) had at least one reactive horse for B. burgdorferi. Our results support the hypothesis of the presence of anti-Borrelia spp. antibodies in horses in Mato Grosso, reaching a high animal prevalence. Besides that, leisure/sport purposes proved to be a risk factor, with an odds ratio of 3.16. These findings clearly indicate the need of borreliosis control in Sinop and make a significant contribution to the knowledge of the disease in Mato Grosso.
Assuntos
Infecções por Borrelia/veterinária , Borrelia burgdorferi/isolamento & purificação , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/microbiologia , Animais , Infecções por Borrelia/epidemiologia , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Cavalos , Humanos , Doença de Lyme , Reação em Cadeia da Polimerase , Prevalência , ZoonosesRESUMO
This study aimed to evaluate season, breed, number of lactations and milk production as risk factors relating to Rhipicephalus microplus infestation in dairy cows during the peripartum. Eighty-four animals were randomly selected through proportional stratified sampling. All engorged and partially engorged female R. microplus specimens measuring 4.5-8.0 mm were counted during the 5 weeks before calving, calving week and 5 weeks after calving. The peripartum had a significant effect [calving (p < 0.05; prevalence ratio (PR)= 3.12) and post calving (p < 0.05; PR = 2.02)] on R. microplus infestation. Although the average tick count was higher during the rainy season than during the dry season, there was no significant difference (p = 0.055; PR = 0.63). The average R. microplus count was significantly higher (p < 0.05; PR = 2.10) in Bos taurus animals, followed by F1 (p < 0.05; PR = 1.64) and Girolando (p < 0.05; PR = 1.39). The average R. microplus count was significantly higher (p < 0.05; PR = 0.97) in first-lactation animals, followed by those at the second, third and, fourth or subsequent lactation. Milk production showed a negative correlation with R. microplus count, such that high-production animals were significantly (p = 0.003; PR = 2.04) more vulnerable to infestation than were low-production animals. First-lactation and high-production B. taurus animals had greatest vulnerability to R. microplus infestation over the peripartum period, and constituted the at-risk group in the dairy herd.
Assuntos
Doenças dos Bovinos/parasitologia , Rhipicephalus/crescimento & desenvolvimento , Infestações por Carrapato/veterinária , Animais , Brasil , Bovinos , Doenças dos Bovinos/imunologia , Feminino , Lactação/imunologia , Leite/metabolismo , Período Periparto , Gravidez , Fatores de Risco , Estações do Ano , Estatísticas não ParamétricasRESUMO
Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America.
Assuntos
Didelphis/parasitologia , Eucoccidiida/fisiologia , Distribuição Animal , Animais , Brasil , Eucoccidiida/citologia , Interações Hospedeiro-Parasita , Urina/parasitologiaRESUMO
Anaplasma marginale is endemic in tropical and subtropical areas around the world. Some studies have suggested that cows during peripartum may present a transient immunosuppression state and development of clinical signs of anaplasmosis. The aim of this study was to investigate the relationship between some risk factors and the seroprevalence of A. marginale in dairy cows during peripartum in Rio de Janeiro, Brazil. The risk factors analyzed in association with the prevalence of antibodies against A. marginale in dairy cows were calving season, reproductive experience, breed standard, tick infestations, stocking density, and milk yield. The antibodies against A. marginale were tested in indirect enzyme-linked immunosorbent assays. A primary screening using a 2 × k contingency table of the exposed variables with the outcomes was performed. All variables for which p < 0.20 were included in a fixed effects log regression. The risk factors investigated to anaplasmosis were calving (OR 2.61, IC 1.08-7.63), breed standard (OR 3.83, IC 0.08-0.28), reproductive experience (OR 33.7, IC 2.14-5.16), milk yield (OR 3.9, IC 2.24-7.03), Rhipicephalus microplus infestations (OR 10.3, IC 0.05-0.17), and stocking density (OR 22.3, IC 0.05-0.17). Low titers of antibodies against A. marginale during peripartum had been characterized as a period previous to development of clinical anaplasmosis. Thus, studies on anaplasmosis should consider each farm as an epidemiological unit, where environmental and immunological factors may influence the endemic status of the pathogen.
Assuntos
Anaplasmose/patologia , Doenças dos Bovinos/patologia , Período Periparto , Anaplasma marginale , Animais , Anticorpos Antibacterianos , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Indústria de Laticínios , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Lactação , Razão de Chances , Gravidez , Rhipicephalus , Fatores de Risco , Estudos Soroepidemiológicos , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterináriaRESUMO
To evaluate the prevalence and possible risk factors for brucellosis caused by Brucella abortus in water buffaloes in the state of Pará, Brazil, 3,917 female buffalo serum samples from pregnant and non-pregnant animals were examined: 2,809 from Marajó Island and 1,108 from the mainland. The buffered acidified plate antigen (BAPA) screening test positively diagnosed 4.8% (188/3,917) of the animals with brucellosis, and the 2-mercaptoethanol (2-ME) confirmatory test affirmed 95.7% (180/188) of the results. The brucellosis prevalence was 4.17 times greater in mainland animals than on Marajó Island, with the highest prevalence in Tailândia (11.30%) and Paragominas (12.38%). Brucellosis seroprevalence was significantly influenced (p < 0.05) by reproductive status, with pregnant females being most vulnerable. These results demonstrate that brucellosis infection is active in the Brazilian region containing the largest buffalo population and that this disease poses a threat to public health and buffalo production in Pará.
Assuntos
Anticorpos Antibacterianos/sangue , Brucella abortus/isolamento & purificação , Brucelose/veterinária , Búfalos , Animais , Brasil/epidemiologia , Brucelose/sangue , Brucelose/epidemiologia , Estudos Transversais , Feminino , Ilhas , Gravidez , Prevalência , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Dogs are important in the epidemiology of tick-borne diseases, playing a significant role mainly in endemic areas of rickettsiosis and borreliosis, and serving as sentinels in epidemiological surveys. We analyzed the distribution of Rickettsia and Borrelia spp. in dogs and their ticks in the municipalities of Guaxupé, Minas Gerais, and Tapiratiba, São Paulo, Brazil, two areas non-endemic for Baggio-Yoshinari Syndrome (BYS) and rickettsiosis. Serum from 242 dogs of different ages (>12 months) and breeds were tested by the Indirect Immunofluorescence Assay (IFA) using specific antigens for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Rickettsia rhipicephali, and Rickettsia bellii, and by an indirect Enzyme Linked Immunosorbent Assay (ELISA) for the detection of homologous IgG antibodies against Borrelia burgdorferi American strain G39/40. Ticks were collected from the animals and subjected to PCR and nested PCR for detection of Rickettsia spp. (synthase citrate gene) and Borrelia spp. (flagellin gene). Serological data showed that 7.85% (19/242) of the analyzed dogs were seropositive for at least one of the five Rickettsia antigens tested; one (0.41%) was considered seropositive for R. parkeri (1:64) and one (0.41%) for R. rickettsii (1:256). Nine (3.72%) were considered seropositive for R. bellii and one (0.41%) for R. amblyommatis; a seroprevalence of 13.64% (33/242) for IgG class immunoreactive antibodies against B. burgdorferi was observed. A total of 148 ticks were collected from the dogs; among these 3.40% were identified as larvae of the genus Rhipicephalus and 0.70% of the genus Amblyomma; 89.8% were identified as Rhipicephalus sanguineus, 4.70% Amblyomma sculptum and 1.40% Amblyomma ovale; all negative for PCR of Rickettsia spp. and nested PCR for Borrelia spp.. The serological findings of this study suggest the circulation of Rickettsiae associated with the spotted fever group and vector ticks, just like Borrelia spp. in a non-endemic Brazilian area, drawing attention to the possibility of a zoonotic cycle in the region.
Assuntos
Borrelia , Doenças do Cão , Rhipicephalus sanguineus , Infecções por Rickettsia , Rickettsia , Amblyomma , Animais , Brasil/epidemiologia , Doenças do Cão/microbiologia , Cães , Imunoglobulina G , Rickettsia/genética , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Infecções por Rickettsia/veterinária , Estudos SoroepidemiológicosRESUMO
This study evaluates the presence of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil. These ectoparasites were collected on mammal species Hydrochoerus hydrochaeris, Tapirus terrestris, Dicotyles tajacu, Didelphis aurita, Cuniculus paca, Cerdocyon thous, and Coendou prehensilis, and on the terrestrial bird Dromaius novaehollandiae. Ticks and fleas were identified morphologically using specific taxonomic keys. A total of 396 ticks and 54 fleas were tested via polymerase chain reaction (PCR) for the presence of Rickettsia spp., Borrelia spp., microorganisms of the order Piroplasmida and Anaplasmataceae family. This total is distributed among nine tick species of the genus Amblyomma and one flea species. Rickettsia bellii was detected in Amblyomma dubitatum and Amblyomma pacae; Rickettsia sp. strain AL was found in Amblyomma longirostre; Rickettsia parkeri strain Atlantic rainforest was found in Amblyomma ovale; and "Candidatus Rickettsia senegalensis" and Rickettsia felis were detected in Ctenocephalides felis felis. Wolbachia sp. was detected in C. f. felis, and Borrelia sp. was detected in Amblyomma calcaratum (here named Borrelia sp. strain Acalc110). All tested samples were negative for Ehrlichia spp. and microorganisms of the Piroplasmida order. This study detected a new bacterial strain, Borrelia sp. strain Acalc 110 (which is genetically close to B. miyamotoi and B. venezuelensis) and the Rickettsia sp. strain 19P, which is 100% similar to "Ca. R. senegalensis", a bacterium recently discovered and now being reported for the first time in Brazil.
RESUMO
BACKGROUND: Canine monocytic ehrlichiosis (CME) is caused by the tick-borne pathogen Ehrlichia canis, an obligate intracellular Gram-negative bacterium of the family Anaplasmataceae with tropism for canine monocytes and macrophages. The trp36 gene, which encodes for the major immunoreactive protein TRP36 in E. canis, has been successfully used to characterize the genetic diversity of this pathogen in different regions of the world. Based on trp36 sequence analysis, four E. canis genogroups, United States (US), Taiwan (TWN), Brazil (BR) and Costa Rica (CR), have been identified. The aim of this study was to characterize the genetic diversity of E. canis in Cuba based on the trp36 gene. METHODS: Whole blood samples (n = 8) were collected from dogs found to be infested with the tick vector Rhipicephalus sanguineus sensu lato (s.l.) and/or presenting clinical signs and symptoms of CME. Total DNA was extracted from the blood samples and trp36 fragments were amplified by PCR. Nucleotide and protein sequences were compared using alignments and phylogenetic analysis. RESULTS: Four of the trp36 sequences obtained (n = 8) fall within the phylogenetic cluster grouping the US genogroup E. canis strains. The other E. canis trp36 sequences formed a separate and well-supported clade (94% bootstrap value) that is phylogenetically distant from the other major groups and thus represents a new genogroup, herein designated as the 'Cuba (CUB) genogroup'. Notably, dogs infected with the CUB genogroup presented frequent hemorrhagic lesions. CONCLUSIONS: The results of this study suggest that genetic diversification of E. canis in Cuba is associated with the emergence of E. canis strains with increased virulence.
Assuntos
Doenças do Cão , Ehrlichiose , Animais , Cuba , Doenças do Cão/microbiologia , Cães , Ehrlichia , Ehrlichia canis/genética , Ehrlichiose/microbiologia , Ehrlichiose/veterinária , Genótipo , FilogeniaRESUMO
BACKGROUND: Currently, various zoonotic diseases are classified as emerging or reemerging. Because equids have a direct relationship with various vectors, they are possibly more frequently exposed to zoonotic agents than are humans. The undeniable importance of diseases such as human granulocytic anaplasmosis, spotted fever, and leishmaniasis for both public and animal health, as well as the possibility of equids acting as sources, reservoirs, or even sentinels for these pathogens, justifies the detection of their frequency and factors associated with infection in equids from northeastern Brazil. METHODS: Blood samples were collected from 569 equids (528 horses, 33 donkeys, and 8 mules), 516 from a rural area and 53 from an urban area. Pathogen detection was carried out as follows: Borrelia spp. and Rickettsia spp., serological analysis; Leishmania spp., serological analysis and polymerase chain reaction (PCR); Anaplasma phagocytophilum, PCR. Determination of associated factors was carried out through generalized linear models. RESULTS: The frequencies of positivity for the pathogens observed in equids were as follows: Borrelia spp., 13.9% (79/569); Leishmania spp., 3.5% (20/569); Rickettsia spp. 33.4% (190/569). Regarding factors associated with infection, male sex was associated with protection against Borrelia spp.; donkeys and mules were associated with protection against Rickettsia spp., while a younger age was a risk factor. The infection of A. phagocytophilum was not detected in the sampled population. Co-infection was detected in 5.1% (29/569) of the animals. CONCLUSIONS: Most of the studied pathogenic agents are present in the prospected area, indicating a possible risk for both human and animal health. This demonstrates that equids can be considered important sentinels in the assessment of pathogens with zoonotic potential in the region.
Assuntos
Equidae/parasitologia , Leishmaniose/veterinária , Doença de Lyme/veterinária , Infecções por Rickettsia/veterinária , Zoonoses/epidemiologia , Zoonoses/parasitologia , Anaplasma/isolamento & purificação , Anaplasma/patogenicidade , Anaplasmose/epidemiologia , Animais , Borrelia/isolamento & purificação , Borrelia/patogenicidade , Brasil/epidemiologia , Feminino , Leishmania/isolamento & purificação , Leishmania/patogenicidade , Leishmaniose/epidemiologia , Doença de Lyme/epidemiologia , Masculino , Rickettsia/isolamento & purificação , Rickettsia/patogenicidade , Infecções por Rickettsia/epidemiologiaRESUMO
This study aimed to evaluate the infection of the marsupial Monodelphis domestica (the gray short-tailed opossum) by Rickettsia parkeri and its role as an amplifier of the bacterium for Amblyomma ticks. Ten M. domestica males were inoculated with phosphate-buffered saline (PBS) and 106 Vero cells infected with R. parkeri. In seven animals, inoculation was intramuscular, and in three intraperitoneal. One male (control) received 1 ml of the same vehicle used for inoculation intraperitoneally. The three animals inoculated intraperitoneally were infested with uninfected A. sculptum larvae and nymphs between the 2nd and 9th day post-infection (DPI). Parasitemia was monitored from the 3rd to 9th DPI by polymerase chain reaction, using primers for 17 kDa and ompA. The animals were also clinically evaluated. Of the animals infected intramuscularly, only one was blood-positive by the 5th DPI. The three animals infected intraperitoneally were blood-positive on the 2nd, 5th, 7th, and 9th DPI. Of the ten pools of recovered engorged ticks, six had positive bands. The kidney, liver, heart, and spleen of an intramuscularly infected animal were also positive. The rectal temperature of the animals tested increased only in the first three DPI. The animals inoculated intraperitoneally showed prostration, bristled hair, and weight loss. The study found that R. parkeri was capable of infecting M. domestica, which developed rickettsemia and caused infection in xenodiagnostic ticks.
Assuntos
Amblyomma/microbiologia , Monodelphis , Infecções por Rickettsia/veterinária , Rickettsia/fisiologia , Infestações por Carrapato/transmissão , Amblyomma/crescimento & desenvolvimento , Animais , Larva/crescimento & desenvolvimento , Larva/microbiologia , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Infecções por Rickettsia/microbiologia , Infecções por Rickettsia/transmissão , Infestações por Carrapato/microbiologiaRESUMO
This study aims to evaluate the infection's clinical parameters and genetic diversity of msp1α of the AmRio1 strain in acute and chronic infections in cattle and ticks. A calf experimentally infected with the A. marginale AmRio1 strain was monitored during acute infection, and the presence of the msp1α gene was verified in the semi-nested polymerase chain reaction (PCR) during the acute and persistent phases of infection. From day seven after inoculation of the pathogen, the calf showed an increase in body temperature, decrease in hematocrit and increase in the percentage of cells infected by the agent, as well as clinical signs. Blood samples from the experimentally infected calf were positive during the acute infection and the persistent PCR infection for the msp1α gene. During the acute phase, infestation with Rhipicephalus microplus was performed. To evaluate the chronic phase, a blood sample was collected at 90â¯days post-infection. There was no variation of the MSP1a protein in this study. The AmRio1 strain was pathogenic as it caused severe changes in the clinical parameters of the monitored cattle. The positivity of this strain in organs and saliva of the analyzed ticks indicates a probable biological transmission.
Assuntos
Anaplasma marginale/genética , Anaplasmose/microbiologia , Vetores Aracnídeos/microbiologia , Proteínas da Membrana Bacteriana Externa/genética , Doenças dos Bovinos/microbiologia , Rhipicephalus/microbiologia , Sequência de Aminoácidos , Anaplasma marginale/classificação , Anaplasmose/transmissão , Animais , Proteínas da Membrana Bacteriana Externa/química , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/transmissão , Reação em Cadeia da Polimerase , Saliva/microbiologiaRESUMO
AIM: The aim of this study was to evaluate the action of homeopathic treatment on mice experimentally infected with Trypanosoma cruzi. METHODS: Eighty adult male C57BL/6 inbred mice were randomly allocated to five groups treated with biotherapy (nosode) of T. cruzi 12dH (12x) pre- and post-infection; Phosphorus 12dH post-infection; infected control treated with control solution and uninfected control. The biotherapy was prepared by the Costa method from the blood of mice experimentally infected with the Y strain of T. cruzi. Phosphorus was used because of its clinical and reportorial similarity to Chagas disease. T. cruzi (10(4)) sanguineous forms were inoculated intraperitoneally per animal. Parasitaemia was monitored, leukocyte and serological responses were evaluated at 0, 7, 14 and 42 days after infection. The prepatent and patent periods of parasitaemia, maximum of parasitaemia, day of maximum parasitaemia and mortality rates were compared between groups. RESULTS: A significantly shorter period of patent parasitaemia was observed in the group treated with the biotherapy before infection (p<0.05) than in the other groups. This group also had the lowest parasitaemias values at 9, 13, 15 (p<0.05), 17 (p<0.05), 22, 24 and 28 days, a lower rate of mortality and a significant increase of lymphocytes compared to the infected control group. The Phosphorus group had the longest period of patent parasitaemia, higher maximum parasitaemia, and a significant reduction of lymphocyte numbers, but no mortality. The infected control group had the highest mortality rate (not statistically significant), and the highest IgG titres at 42 days post-infection (p<0.05). CONCLUSIONS: The results suggest that pre-treatment with biotherapy modulates host immune response to T. cruzi, mainly during the acute phase of the infection. Phosphorus shows an action on the pathogenicity by T. cruzi infection. Homeopathic treatment of T. cruzi infection should be further investigated.
Assuntos
Doença de Chagas/tratamento farmacológico , Homeopatia/métodos , Parasitemia/tratamento farmacológico , Fósforo/farmacologia , Fitoterapia/métodos , Extratos Vegetais/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Camundongos , Camundongos Endogâmicos C57BL , Parasitemia/virologia , Extratos Vegetais/farmacologia , Distribuição AleatóriaRESUMO
This study aimed to evaluate, by means of artificial feeding, the interaction between a pathogenic rickettsia and the hard tick R. microplus. We used partially engorged females fed on calves free of Rickettsia spp. Group 1 (G1), containing 20 ticks, was fed bovine blood only. Group 2 (G2), containing 20 ticks, was fed blood containing uninfected VERO cells, and group 3 (G3), containing 40 ticks, was fed blood containing VERO cells infected with Rickettsia parkeri. Biological parameters of the non-parasitic phase and a possible bacterial transmission to the tick eggs and to guinea pigs were evaluated. At the end of oviposition, all G3 females were PCR-positive for genes specific for the genus Rickettsia. Although no guinea pigs were infected, the experimental infection of R. microplus by R. parkeri caused a deleterious effect on the oviposition and provided the first report of transovarian transmission of rickettsia in this tick.
Assuntos
Oviposição , Rhipicephalus/microbiologia , Rhipicephalus/fisiologia , Rickettsia/fisiologia , Animais , Chlorocebus aethiops , Feminino , Cobaias , Reação em Cadeia da Polimerase , Rickettsia/genética , Infecções por Rickettsia/transmissão , Células Vero/microbiologiaRESUMO
The objective of this study was to assess the effect of the exposure to fluazuron on the activity of common pesticide detoxification enzyme groups in the cattle tick (Rhipicephalus microplus). Engorged females of a susceptible strain (POA) and a resistant strain (Jaguar) were exposed in vitro to fluazuron and their eggs and larvae were used to compare the activities of the general esterases, mixed-function oxidases (MFO) and glutathione-S-transferase (GST). The results showed significant elevation in MFO contents and esterases activity in the resistant strain when compared with the susceptible strain, in eggs and larvae respectively. In the POA strain, the MFO activity in eggs was down-regulated by fluazuron exposure. Based on these results, it can be concluded that different detoxification enzymes can act in distinct pathways depending on the tick's development stage, and may be related to fluazuron detoxification in resistant strains.
Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Glutationa Transferase/metabolismo , Oxigenases de Função Mista/metabolismo , Compostos de Fenilureia/farmacologia , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Larva/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Rhipicephalus/enzimologia , Infestações por Carrapato/tratamento farmacológicoRESUMO
The objective of this study was to determine the prevalence of antibodies to Neospora caninum and Toxoplasma gondii among 500 cattle (Bos indicus) and 500 buffaloes (Bubalus bubalis) using the indirect fluorescent antibody test (IFAT) technique. Blood samples from were collected from water buffalo and cattle in 10 municipalities in the northern region of Brazil. The frequency of cattle and water buffaloes seropositive for Neospora caninum in Pará state, Brazil, was 55% and 44%, respectively, and the frequency of cattle and water buffaloes seropositive for Toxoplasma gondii was 52% and 39%, respectively. Seropositivity for both N. caninum and T. gondii was detected in 10.6% of the cattle samples and 14.8% of the buffalo samples. The frequency of cattle positive for N. caninum and T. gondii was significantly (p<0.05) higher than that of buffalo in two and three provinces, respectively. Buffaloes had a lower seroprevalence for N. caninum or T. gondii in all of the provinces studied. These results suggest that both species, when exposed to the same risks for N. caninum and T. gondii infection, have a high serological prevalence. Cattle showed a higher probability of being seropositive when exposed to the same risks for N. caninum and T. gondii. Our study, which included an extensive number of blood samples, provides important epidemiological information pertinent to buffalo production in tropical countries that can be used as a basis for disease-management practices in Latin America.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Bovinos/epidemiologia , Coccidiose/veterinária , Neospora/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Brasil/epidemiologia , Búfalos/parasitologia , Bovinos/parasitologia , Doenças dos Bovinos/parasitologia , Coccidiose/sangue , Coccidiose/epidemiologia , Coccidiose/imunologia , Técnica Indireta de Fluorescência para Anticorpo , Neospora/isolamento & purificação , Prevalência , Estudos Soroepidemiológicos , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/sangue , Toxoplasmose Animal/imunologiaRESUMO
Anaplasma marginale is the most prevalent pathogen transmitted by ticks in cattle in tropical and subtropical regions of the world. However, the tick species involved in the transmission of A. marginale in buffaloes in Brazil have not been identified. The objective of the present study was to determine the presence of A. marginale in ticks parasitizing water buffaloes. A total of 200 samples of Rhipicephalus microplus, Dermacentor nitens, Amblyomma cajennense, and Amblyomma maculatum were collected and tested by conventional and quantitative PCR for the presence of the msp1a and msp5 genes. In the present study, 35 ticks (17.5%) were positive for A. marginale DNA by qPCR analysis. The positive ticks belonged to four different species: R. microplus (22.2%), A. cajennense (13.8%), A. maculatum (16.0%), and D. nitens (10.0%). Individuals of the three developmental stages (larvae, nymphs, and adults) of R. microplus and A. cajennense were found to be positive for A. marginale, only nymphs and adults of A. maculatum were found to be positive, and finally, only adults of D. nitens were positive for A. marginale. Our results suggest that R. microplus, A. cajennense, A. maculatum, and D. nitens ticks may be involved in the transmission of A. marginale in buffaloes. However, while A. marginale PCR positive ticks were recorded, this does not indicate vector competence; only that the ticks may contain a blood meal from an infected host. Additionally, the results show that the strains of A. marginale from buffaloes and cattle are phylogenetically related.
Assuntos
Anaplasma marginale/genética , Búfalos/parasitologia , Ixodidae/classificação , Infestações por Carrapato/veterinária , Anaplasma marginale/isolamento & purificação , Anaplasmose/transmissão , Animais , Brasil , Bovinos , Ixodidae/genética , Ixodidae/crescimento & desenvolvimento , Ixodidae/microbiologia , Filogenia , Infestações por Carrapato/parasitologiaRESUMO
Bovine anaplasmosis, caused by Anaplasma marginale, occurs in tropical and subtropical regions throughout the world and is a major constraint on cattle production in many countries. Approximately 60% of the buffalo herds in South America are located in northern Brazil. However, compared with the research on cattle, research on buffaloes has been neglected. Therefore, the present study was conducted to investigate the distribution of A. marginale in water buffaloes in northern Brazil. A total of 500 buffalo blood samples was randomly collected from 16 provinces and was analyzed using both nPCR assay and ELISA techniques. The percentage of animals that were seropositive for A. marginale according to ELISA was 49% (245/500). The main risk factors associated with seroprevalence were the region (p=0.021; OR=1.2) and the reproductive status (p=0.0001; OR=1.6). Anaplasma marginale DNA was detected in 5.4% (27/500) of the sampled buffaloes. Our data provide information about the incidence of A. marginale infection in water buffaloes and may guide future programs aimed at controlling the disease in the northern region of Brazil. Although these water buffaloes are exposed to A. marginale, a low rate of A. marginale PCR-positive animals was found, which could be explained by the habitat in which the sampled animals live because they exhibited a low rate of attached ticks on their skin.