19 results on '"Silveira JAG"'
Search Results
2. Calf immunization protocols with low-virulence isolates of Anaplasma marginale: Analysis of post-inoculation effects and protection against natural challenge.
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Mendonça FLM, Coelho MF, Bastos CV, da Silveira JAG, Nicolino RR, Uribe JAZ, Ribeiro MFB, Silvestre BT, Meneses RM, de Carvalho AÚ, Moreira TF, and Facury-Filho EJ
- Abstract
Bovine anaplasmosis is endemic and is of fundamental importance worldwide. Therefore, measures for controlling and preventing clinical diseases are warranted to ensure the reduction of associated economic losses. The objective of the present study was to assess the post-inoculation effects and protection conferred by three different protocols of inoculation of low-virulence live strains of Anaplasma marginale (UFMG1 and UFMG3) in field-challenged cattle. Sixty-eight Holstein calves with an average age of 17 days were randomly divided into four groups. The groups received two subcutaneous administrations spaced 40 days apart, at a dosage of 2 × 10
6 infected erythrocytes of the following A. marginale strains: G1 (UFMG1 + UFMG1); G2 (UFMG3 + UFMG3); G3 (UFMG1 + UFMG3); and G4 (control). Every two days, the animals were evaluated for rectal temperature, Packed Cell Volume (PCV), and blood smears. Blood samples were collected prior to inoculation, before the field challenge, and after the challenge period, nPCR and IFAT techniques were performed. There were no significant differences in rickettsemia levels, reduction in PCV, or antibody detection among the different inoculation strategies. Forty days after the second inoculation, 90 %, 84.6 %, and 90.9 % of the animals in G1, G2, and G3, respectively, tested positive using nPCR. After inoculation, the group G2, which received the UFMG3 inoculum, had a higher frequency of treatment (odds ratio of 6.7; 1.198-38.018 CI; p = 0.03), while groups G1 and G3 demonstrated similar treatment frequencies compared to the control. During the natural challenge phase, 13.3 % of animals in group G1 required treatment (odds ratio of 0.108; 0.018-0.635 CI; p = 0.014) compared to 58.8 % of the control group. Considering the results collectively, the protocol using the UFMG1 strain (G1) stands out for its potential to be safe and induce some degree of immunization against A. marginale, reducing the incidence of clinical disease and the need for treatment during natural challenge., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier GmbH.)- Published
- 2024
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3. Hemopathogens in naturally infected bovine fetuses in Brazil.
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Andrade LS, de Souza RS, Carvalho de Araujo A, Silva SO, Melo MN, Melo FG, Ribeiro GHS, de Sousa FG, Bastos CV, Moreira TF, Meneses RM, Carvalho AU, Facury-Filho EJ, and Silveira JAG
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- Animals, Brazil epidemiology, Cattle, Female, Pregnancy, Prevalence, Babesia isolation & purification, Fetus microbiology, Fetus parasitology, Mycoplasma Infections epidemiology, Mycoplasma Infections veterinary, Mycoplasma Infections microbiology, Theileria isolation & purification, Trypanosoma vivax isolation & purification, Infectious Disease Transmission, Vertical veterinary, Anaplasma isolation & purification, Babesiosis epidemiology, Babesiosis parasitology, Anaplasmosis epidemiology, Anaplasmosis microbiology, Ehrlichia isolation & purification, Cattle Diseases epidemiology, Cattle Diseases microbiology, Cattle Diseases parasitology, Mycoplasma isolation & purification
- Abstract
The transplacental transmission of parasites and hemoparasites is crucial for understanding the epidemiology of diseases. This study aimed to assess the prevalence of hemopathogens in bovine fetuses at various gestational periods. Samples were obtained from a slaughterhouse in the state of Minas Gerais, Brazil, and a total of 236 fetuses were collected. DNA extracted from blood samples (145) and organ samples (a pool of brain and spleen) (236) underwent a nested PCR (nPCR) assay to detect Babesia spp., Theileria spp., Trypanosoma vivax, Anaplasma marginale, Anaplasma bovis, Anaplasma phagocytophilum, Ehrlichia minasensis, and hemotropic Mycoplasma spp. Additionally, serological analysis of 145 plasma samples was conducted using the indirect fluorescent antibody test-IFAT to detect IgG against Babesia bovis, Babesia bigemina, A. marginale, and Trypanosoma vivax. The observed prevalence of transplacental transmission was 19.3 %, 6.2 %, 42.7 % and 2.7 %, for A. marginale, B. bigemina, 'Candidatus M. haemobos', and Mycoplasma wenyonii, respectively. The prevalence of A. marginale by gestational trimester was 16 % (13/81) in the second trimester and 23 % (14/60) in the third trimester, with no positive samples in the first trimester. Regarding the species B. bovis and B. bigemina, all evaluated animals tested negative by nPCR, and no serological evidence for B. bovis was found by the IFAT. Babesia bigemina demonstrated an overall seroprevalence of 6.2 % (9/145), with 4.8 % (7/145) in the last trimester and 1.3 % (2/145) in the second trimester of pregnancy. In total, 42.7 % (62/145) of blood samples were positive for 'Candidatus M. haemobos', with 42 % (34/81) in the middle trimester, and 43 % (26/60) in the final trimester of pregnancy. Mycoplasma wenyonni was detected in 2.7 % (4/145) blood samples, all in coinfection with 'C. M. haemobos'. The prevalence by pregnancy trimester was 25 % (1/4) in the first trimester; 1.2 % (1/81) in the second trimester and 3.3 % (2/60) in the third trimester of pregnancy. Hemopathogen DNA was detected in fetus blood samples but not the brain or spleen samples. All the samples were negative for T. vivax, Theileria spp., Anaplasma spp. and Ehrlichia spp. Overall, in this study, approximately 70 % of fetuses were positive for one or more of the studied parasites. No significant associations were observed between pairs of pathogens, except 'C. M. haemobos' and A. marginale., (Copyright © 2024. Published by Elsevier GmbH.)
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- 2024
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4. Evidence of SARS-CoV-2 infection and co-infections in stray cats in Brazil.
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Castillo AP, Miranda JVO, Fonseca PLC, Silva SO, Lopes REN, Spanhol VC, Moreira RG, Nicolino RR, Queiroz DC, de Araújo E Santos LCG, Dos Santos APS, Rivetti HAA, Martins-Duarte ES, de Almeida Vitor RW, Dos Reis JKP, Aguiar RS, and da Silveira JAG
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- Cats, Animals, Humans, Brazil epidemiology, Seroepidemiologic Studies, Pandemics, Phylogeny, SARS-CoV-2 genetics, Leukemia Virus, Feline, Coinfection epidemiology, Coinfection veterinary, COVID-19 epidemiology, COVID-19 veterinary, Immunodeficiency Virus, Feline, Cat Diseases epidemiology
- Abstract
The zoonotic virus SARS-CoV-2, which causes severe acute respiratory syndrome in humans (COVID-19), has been identified in cats. Notably, most positive cases were in cats that had close contact with infected humans, suggesting a role for humans in animal transmission routes. Previous studies have suggested that animals with immune depletion are more susceptible to SARS-CoV-2 infection. To date, there is limited evidence of SARS-CoV-2 infections in stray and free-range cats affected by other pathogens. In this study, we investigated infections caused by SARS-CoV-2, Leishmania spp., Toxoplasma gondii, Mycoplasma spp., Bartonella spp., Feline leukemia virus (FeLV), and Feline immunodeficiency virus (FIV) in stray cats from an urban park in Brazil during the COVID-19 pandemic. From February to September 2021, 78 mixed-breed cats were tested for SARS-CoV-2 and hemopathogens using molecular analysis at Américo Renné Giannetti Municipal Park, Belo Horizonte, Minas Gerais, Brazil. An enzyme-linked immunosorbent assay (ELISA) was used to detect IgG in T. gondii. None of the animals in this study showed any clinical signs of infections. The SARS-CoV-2 virus RNA was detected in 7.7 % of cats, and a whole virus genome sequence analysis revealed the SARS-CoV-2 Delta lineage (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from cats was grouped into the sublineage AY.99.2, which matches the epidemiological scenario of COVID-19 in the urban area of our study. Leishmania infantum was detected and sequenced in 9 % of cats. The seroprevalence of T. gondii was 23.1 %. Hemotropic Mycoplasma spp. was detected in 7.7 % of the cats, with Mycoplasma haemofelis and Candidatus Mycoplasma haemominutum being the most common. Bartonella henselae and Bartonella clarridgeiae were detected in 38.5 % of the cats, FeLV was detected in 17,9 %, and none of the cats studied tested positive for FIV. This study reports, for the first time, the SARS-CoV-2 infection with whole-genome sequencing in stray cats in southeastern Brazil and co-infection with other pathogens, including Bartonella spp. and Feline leukemia virus. Our study observed no correlation between SARS-CoV-2 and the other detected pathogens. Our results emphasize the importance of monitoring SARS-CoV-2 in stray cats to characterize their epidemiological role in SARS-CoV-2 infection and reinforce the importance of zoonotic disease surveillance., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2024
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5. Dogs (Canis familiaris) as sentinels for determining the risk of occurrence of Rickettsia spp. and Anaplasma phagocytophilum in previously undiagnosed areas.
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Mesquita CAM, Guimarães AM, Guedes E, Silveira JAG, Rocha GC, Nogueira CI, Varaschin MS, de Souza Santos MA, and da Rocha CMBM
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- Dogs, Animals, Humans, Seroepidemiologic Studies, Rickettsia Infections diagnosis, Rickettsia Infections epidemiology, Rickettsia Infections veterinary, Anaplasma phagocytophilum, Dog Diseases diagnosis, Dog Diseases epidemiology, Dog Diseases microbiology, Rickettsia
- Abstract
Determining the occurrence of Rickettsia spp. and Anaplasma phagocytophilum in municipalities with no case records is important to define surveillance strategies and is essential to reduce lethality in different regions. Therefore, an approach aimed at enhancing surveillance in municipalities with an unknown epidemiological situation was tested, according to the classification suggested by Resolution SMA/SES 07/01/16. Canine sera collected in the annual anti-rabies campaign were submitted to the indirect fluorescent antibody test for Rickettsia amblyommatis, R. belli, R. parkeri, R. rickettsii and A. phagocytophilum. Titers ≥1:64 and ≥1:320 were considered positive for Rickettsia spp. and A. phagocytophilum, respectively. For Rickettsia spp., 61.8% of dogs were seropositive, with 26% positive for more than one species, and 42.3% were seropositive for R. rickettsii. Dogs from the urban area presented 5.16 (CI 1.18; 7.69) times greater odds of seropositivity for R. parkeri (p = 0.037) and 3.39 (CI 1.04; 3.70) times greater odds for R. belli (p = 0.017). Considering the 1:40 cutoff point, 19.1% of dogs were reactive for A. phagocytophilum. Two (1%) dogs in rural areas were positive (titer 1:640). The results indicate all species ever tested in Lavras/MG, since the present study is the city's first report on the subject. According to classifications of the aforementioned Resolution, the results determine that the municipality of Lavras should be considered a "risk area" for Brazilian spotted fever(BSF). The methodology presented is efficient, straight forward to perform and inexpensive for diagnosing a risk situation for BSF and human granulocytic anaplasmosis. Moreover, its use can be applied throughout Brazil and other countries as a public health alert guideline., Competing Interests: Declaration of Competing Interest I declare that there are no conflicts of interest between the authors of the article entitled: “DOGS (Canis familiaris) AS SENTINELS FOR DETERMINING THE RISK OF OCCURRENCE OF Rickettsia spp. AND Anaplasma phagocytophilum IN PREVIOUSLY UNDIAGNOSED AREAS” submitted for consideration at VETERINARY PARASITOLOGY: REGIONAL STUDIES AND REPORTS., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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6. Molecular detection of vector-borne pathogens in semen from dogs in southeastern Brazil.
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Valle GR, Ribeiro VM, Teles PPA, Ottino J, Salome DM, Melo MN, Silva SO, da Silveira JAG, Dias AHF, and Dantas-Torres F
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- Dogs, Animals, Brazil epidemiology, Arthropod Vectors, Ehrlichia canis genetics, Semen, Disease Vectors
- Abstract
Vector-borne pathogens (VBPs) are primarily transmitted by arthropod vectors, but secondary ways of transmission have been described, including via venereal route. Nonetheless, there is still limited research on possible sexual transmission of VBPs in dogs. We molecularly investigated the presence of vector-borne pathogens in semen from dogs living in an area where these agents are endemic. Upon PCR testing, seven out of 22 (31.8%) semen samples tested positive for at least one VBP, whereas simultaneous positivity to two or more pathogens was detected in three (13.6%) dogs. Among pathogens detected in semen, Trypanosoma cruzi (n = 1) and Leishmania infantum (n = 3) were identified to species level by restriction fragment length polymorphism analysis. Attempts to sequence PCR products from other pathogens were unsuccessful, but coupled epidemiological and molecular data suggest the presence of Anaplasma platys (n = 5), Babesia vogeli (n = 1) and Ehrlichia canis (n = 1) in semen from dogs. Further experimental studies would be needed to confirm the sexual transmission hypothesis for these VBPs and also the possible implications of these findings for canine reproduction., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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7. Potential of recombinant LiHyQ, a novel Leishmania infantum protein, for the diagnosis of canine visceral leishmaniasis and as a diagnostic and prognostic marker for human leishmaniasis and human immunodeficiency virus co-infection: A preliminary study.
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Santos TTO, Ramos FF, Gonçalves IAP, Tavares GSV, Ludolf F, Bandeira RS, Silva AM, Oliveira-da-Silva JA, Reis TAR, Machado AS, Lage DP, Freitas CS, Vale DL, Martins VT, Alves LA, Guimarães NS, Chaves AT, Chávez-Fumagalli MA, Cota GF, Silveira JAG, Tupinambás U, Gonçalves DU, Christodoulides M, and Coelho EAF
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- Animals, Antibodies, Protozoan, Antigens, Protozoan, Dogs, HIV, Humans, Prognosis, Sensitivity and Specificity, Serologic Tests, Coinfection diagnosis, Coinfection veterinary, Dog Diseases diagnosis, HIV Infections, Leishmania infantum, Leishmaniasis, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral veterinary
- Abstract
Laboratory diagnosis of leishmaniasis shows variable efficacy in detecting infected mammalian hosts and there is a need to identify suitable antigens to improve the accuracy of diagnostic tests. In the present study, a L. infantum hypothetical protein called LiHyQ was evaluated for the diagnosis of tegumentary (TL) and visceral (VL) leishmaniasis using canine and human samples. A collection of dog sera (n=155) were tested and contained samples from asymptomatic (n=20) and symptomatic (n=25) VL animals, from healthy dogs living in endemic (n=25) or non-endemic (n=25) areas of disease, from Leish-Tec® vaccinated dogs (n=20) or from dogs infected with Ehrlichia canis (n=15), Babesia canis (n=10) and Trypanosoma cruzi (n=15). Sensitivity (Se), Specificity (Sp), Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of 100% were observed for rLiHyQ with these samples, whereas the Se, Sp, PPV and NPV values with L. infantum Soluble Leishmania Antigen (SLA) preparation were 60.0%, 99.0%, 96.0% and 86.0%, respectively. A collection of human sera (n=305) were tested and contained samples from TL (n=50) and VL (n=40) patients, from VL/HIV co-infected patients (n=35), from patients infected with HIV alone (n=30), Chagas Disease (n=30), malaria (n=10), tuberculosis (n=10), paracoccidioidomycosis (n=15), leprosy (n=30) or aspergillosis (n=15); and from healthy subjects (n=40). Se, Sp, PPV and NPV values of 100% were observed for rLiHyQ with these samples, whereas the Se, Sp, PPV and NPV values with SLA were 58.0%, 76.0%, 50.0% and 82.0%, respectively. The antibody reactivity against the protein was compared with commercial kits, and the kappa index varied from 0.95 to 1.00 for rLiHyQ, and of 0.55 to 0.82 for the kits. In addition, the serological follow-up of treated patients showed a significant reduction in rLiHyQ-specific IgG antibody levels. All canine and human samples were tested at the same time using the same reagents, in order to reduce experimental variation and interference in data interpretation. In conclusion, our preliminary data suggest a diagnostic and prognostic role for rLiHyQ against leishmaniasis., (Copyright © 2021. Published by Elsevier B.V.)
- Published
- 2021
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8. Serodiagnosis of canine leishmaniasis using a novel recombinant chimeric protein constructed with distinct B-cell epitopes from antigenic Leishmania infantum proteins.
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Vale DL, Lage DP, Machado AS, Freitas CS, de Oliveira D, Galvani NC, Fernandes BB, Luiz GP, Oliveira JS, Oliveira-da-Silva JA, Ramos FF, Santos TTO, Siqueira WF, Alves LA, Chávez-Fumagalli MA, de Magalhães-Soares DF, Silveira JAG, Bueno LL, Fujiwara RT, Machado-de-Ávila RA, Martins VT, and Coelho EAF
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- Animals, Antigens, Protozoan genetics, Antigens, Protozoan immunology, Dogs, Enzyme-Linked Immunosorbent Assay veterinary, Epitopes, B-Lymphocyte genetics, Epitopes, B-Lymphocyte immunology, Recombinant Fusion Proteins genetics, Recombinant Proteins genetics, Recombinant Proteins immunology, Sensitivity and Specificity, Serologic Tests veterinary, Dog Diseases diagnosis, Leishmania infantum genetics, Leishmania infantum immunology, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral veterinary
- Abstract
Visceral leishmaniasis (VL) is an important public health problem in the world, and control measures are insufficient to avoid the spread of this neglected disease. Dogs are important domestic reservoirs of Leishmania parasites in countries where VL is a zoonosis, representing a major source of infection between sand fly vectors and humans. In this context, a precise diagnosis of canine leishmaniasis (CanL) could help to reduce the number of human cases. Distinct approaches for the diagnosis of CanL have used recombinant proteins in serological assays. However, variable results of the antigens have been found, mainly to diagnosis asymptomatic cases. The present study used bioinformatics to select specific B-cell epitopes of four Leishmania infantum proteins, which had previously been proven to be antigenic in VL, aiming to produce a novel chimeric protein and to evaluate it for the diagnosis of CanL. Seven B-cell epitopes were identified and used to construct the chimera, which was analyzed in a recombinant format through an ELISA assay against a canine serological panel. A soluble Leishmania antigenic extract (SLA) was used as an antigen control. Results showed 100 % sensitivity and specificity for chimera, while when using SLA the values were 26.0 % and 96.4 %, respectively. The performance of chimera was compared with a commercial kit using asymptomatic and symptomatic dog sera, and the data showed that no false-negative result was found when the recombinant protein was used. However, when using the commercial kit, 40.0 % and 16.0 % of the false-negative results were found, respectively. In conclusion, the recombinant chimera showed an antigenic potential to be evaluated in new studies against a larger serological panel for the diagnosis of CanL., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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9. Seven years of evaluation of ectoparasites and vector-borne pathogens among ring-tailed coatis in an urban park in southeastern Brazil.
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Estevam LGTM, Fonseca Junior AA, Silvestre BT, Hemetrio NS, Almeida LR, Oliveira MM, Silva SM, Ribeiro MFB, and Silveira JAG
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- Animals, Brazil epidemiology, Cities, Ectoparasitic Infestations epidemiology, Ectoparasitic Infestations parasitology, Parks, Recreational, Prevalence, Vector Borne Diseases epidemiology, Vector Borne Diseases microbiology, Vector Borne Diseases parasitology, Ectoparasitic Infestations veterinary, Procyonidae, Vector Borne Diseases veterinary
- Abstract
Wild animals have been recognized as potential reservoirs of vector-borne pathogens. Proximity between these animals and urban areas increases the need to know which pathogens these are and whether they can infect domestic animals and humans. In Mangabeiras Municipal Park in Belo Horizonte, Brazil, coatis live near the urban area, which is mainly occupied by human residents and their domestic animals. Therefore, the objective of this study was to detect, through molecular and direct methods, the presence of ectoparasites and hemoparasites in coatis. A total of 216 samples were collected, of which 209 samples were from first-captures and seven were from recaptures. The following parasites were found: ticks of the genus Amblyomma, lice of the species Neotrichodectes pallidus and fleas of the species Rhopalopsyllus lutzi lutzi and Ctenocephalides felis felis. All the samples were negative for the family Anaplasmataceae and the species Leishmania sp. and Trypanosoma cruzi. The hemoparasites Trypanosoma evansi, Hepatozoon procyonis, Babesia sp. and Sarcocystis neurona were found. The area of the present study is not endemic for T. evansi, which therefore suggests that these coatis may be acting as reservoirs or sentinels of this parasite. This finding is of great epidemiological importance and should be investigated more closely. Thus, this study showed that there is a great variety of pathogens in the park that transit among coatis and, probably, among other animals that inhabit or live close to the park., Competing Interests: Declaration of Competing Interest The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2020. Published by Elsevier B.V.)
- Published
- 2020
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10. A Leishmania infantum hypothetical protein evaluated as a recombinant protein and specific B-cell epitope for the serodiagnosis and prognosis of visceral leishmaniasis.
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Machado AS, Ramos FF, Oliveira-da-Silva JA, Santos TTO, Ludolf F, Tavares GSV, Costa LE, Lage DP, Steiner BT, Chaves AT, Chávez-Fumagalli MA, de Magalhães-Soares DF, Silveira JAG, Napoles KMN, Tupinambás U, Duarte MC, Machado-de-Ávila RA, Bueno LL, Fujiwara RT, Moreira RLF, Rocha MOC, Caligiorne RB, and Coelho EAF
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- Adult, Animals, Antigens, Protozoan immunology, Dogs, Enzyme-Linked Immunosorbent Assay methods, Female, Humans, Male, Middle Aged, Prognosis, Protozoan Proteins immunology, Recombinant Proteins immunology, Serologic Tests methods, Epitopes, B-Lymphocyte immunology, Leishmania infantum immunology, Leishmaniasis, Visceral diagnosis
- Abstract
The serodiagnosis of visceral leishmaniasis (VL) presents problems related to the sensitivity and/or specificity of the tests. In this context, more refined antigens should be identified and applied for the improvement of disease diagnosis. In the present study, DNA with an encoding of a Leishmania infantum hypothetical protein, LiHyC, was cloned, and the recombinant protein was expressed, purified, and evaluated for the serodiagnosis of canine and human VL. In addition, a specific B-cell epitope present in the LiHyC sequence was predicted; the peptide was both synthetized and evaluated in the ELISA experiments. For comparison, commercial diagnostic kits were used against positive (VL hosts) and negative (healthy hosts) samples. Results showed that the recombinant protein (rLiHyC) and synthetic peptide (PeptC) were highly sensitive and specific to diagnose canine and human VL, with 100% sensitivity and specificity, while no false-positive or false-negative result was detected. When the DPP® CVL kit was used to identify canine samples, 44 and 52 of the 60 L. infantum-infected animals, without or with clinical signals of disease, respectively, were identified, while eight and four samples were considered as false-negatives, respectively. For human VL, an IT LEISH® kit was used, and 33 of the 40 VL patients were identified, while seven samples were considered to be false-negatives. Post-therapeutic serological follow-up testing sera samples from treated and untreated VL patients showed a significant drop in the anti-PeptC and anti-rLiHyC antibody levels, thus suggesting the feasibility to use the recombinant protein and/or synthetic peptide in future studies as diagnostic and/or prognostic markers for VL., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
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11. A resistant cowpea (Vigna unguiculata [L.] Walp.) genotype became susceptible to cowpea severe mosaic virus (CPSMV) after exposure to salt stress.
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Varela ALN, Oliveira JTA, Komatsu S, Silva RGG, Martins TF, Souza PFN, Lobo AKM, Vasconcelos IM, Carvalho FEL, and Silveira JAG
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- Proteomics, Comovirus metabolism, Genotype, Plant Diseases virology, Plant Proteins metabolism, Salt Stress, Vigna genetics, Vigna metabolism, Vigna virology
- Abstract
In nature, plants are simultaneously challenged by biotic and abiotic stresses. However, little is known about the effects of these combined stresses for most crops. This work aimed to evaluate the responsed of the virus-resistant cowpea genotype BRS-Marataoã to the exposure of salt stress combined with CPSMV infection. Cowpea plants were exposed to 200 mM NaCl either simultaneously (SV plant group) or 24 h prior to the CPSMV infection [S(24 h)V plant group]. Physiological, biochemical, and proteomic analyses at 2 and 6 days post salt stress (DPS) revealed that cowpea significantly reprogrammed its cellular metabolism. Indeed, plant size, photosynthetic parameters (net photosynthesis, transpiration rate, stomatal conductance, and internal CO
2 partial pressure) and chlorophyll and carotenoid contents were reduced in S(24 h)V compared to SV. Moreover, accumulation of viral particles at 6 DPS in S(24 h)V was observed indicating that the salt stress imposed prior to virus infection favors viral particle proliferation. Proteomic analysis showed differential contents of 403 and 330 proteins at 2 DPS and 6 DPS, respectively, out of 733 differentially abundant proteins between the two plant groups. The altered leaf proteins are involved in energy and metabolism, photosynthesis, stress response, and oxidative burst. BIOLOGICAL SIGNIFICANCE: This is an original study in which a virus-resistant cowpea genotype (BRS-Marataoã) was (i) exposed simultaneously to 200 mM NaCl and inoculation with CPSMV (SV plant group) or (ii) exposed to 200 mM NaCl stress 24 h prior to inoculation with CPSMV [S(24 h)V plant group]. The purpose was to shed light on how this CPSMV resistant cowpea responded to the combined stresses. Numerous key proteins and associated pathways were altered in the cowpea plants challenged with both stresses, but unexpectedly, the salt stress imposed 24 h prior to CPSMV inoculation allowed viral proliferation, turning the cowpea genotype from resistant to susceptible., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2019
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12. Proteomic and physiological approaches reveal new insights for uncover the role of rice thylakoidal APX in response to drought stress.
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Cunha JR, Carvalho FEL, Lima-Neto MC, Jardim-Messeder D, Cerqueira JVA, Martins MO, Fontenele AV, Márgis-Pinheiro M, Komatsu S, and Silveira JAG
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- Dehydration, Hydrogen Peroxide metabolism, Photosynthesis, Ascorbate Peroxidases metabolism, Oryza enzymology, Oxidative Stress, Plant Proteins metabolism, Thylakoids enzymology
- Abstract
Chloroplast APX isoforms display controversial roles as H
2 O2 scavengers and signaling players in response to abiotic stress and conclusive results are lacking. We tested the hypothesis that thylakoidal APX displays an important role for drought tolerance, especially by regulating abundance of essential protein species. For this, OsApx8 RNAi-silenced rice (apx8) and non-transformed plants (NT) were exposed to mild water deficit. The drought-sensitivity in apx8 plants was revealed by decreases in shoot growth, relative water content and photosynthesis, which was accompanied by increased membrane damage, all compared to NT plants. This higher sensitivity of apx8 plants to mild drought stress was also related to a lower accumulation of important protein species involved in several metabolic processes, especially photosynthesis, photorespiration and redox metabolism. Despite apx8 plants have displayed an effective induction of compensatory antioxidant mechanisms in well-watered conditions, it was not enough to maintain H2 O2 homeostasis and avoid oxidative and physiological disturbances under mild drought conditions. Thus, thylakoidal APX is involved in several phenotypic modifications at proteomic profile level, possibly via a H2 O2 -induced signaling mechanism. Consequently, this APX isoform is crucial for rice plants effectively cope with a mild drought condition. BIOLOGICAL SIGNIFICANCE: This work provides for the first time an integrative study involving proteomic, physiological and biochemical analyses directed to elucidation of thylakoidal APX roles for drought tolerance in rice plants. Our data reveal that this enzyme is crucial for maintaining of growth and photosynthesis under mild water deficit conditions. This essential role is related to maintaining of H2 O2 homeostasis and accumulation of essential proteins involved in several important metabolic pathways. Remarkably, for drought resistance was essential the accumulation of proteins involved with metabolism of photosynthesis, signaling, carbohydrates, protein synthesis/degradation and stress. These results can contribute to understand the role of chloroplast ascorbate peroxidases in drought tolerance, highlighting the physiological importance of key proteins in this process., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2019
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13. Potential application of small myristoylated protein-3 evaluated as recombinant antigen and a synthetic peptide containing its linear B-cell epitope for the serodiagnosis of canine visceral and human tegumentary leishmaniasis.
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Salles BCS, Dias DS, Steiner BT, Lage DP, Ramos FF, Ribeiro PAF, Santos TTO, Lima MP, Costa LE, Chaves AT, Chávez-Fumagalli MA, Fujiwaraa RT, Buenoa LL, Caligiorne RB, de Magalhães-Soares DF, Silveira JAG, Machado-de-Ávila RA, Gonçalves DU, and Coelho EAF
- Subjects
- Adult, Aged, Animals, Antibodies, Protozoan blood, Antigens, Protozoan genetics, Cross Reactions, Dogs, Epitopes, B-Lymphocyte genetics, Female, Humans, Male, Middle Aged, Recombinant Proteins genetics, Sensitivity and Specificity, Serologic Tests, Young Adult, Antigens, Protozoan immunology, Dog Diseases diagnosis, Epitopes, B-Lymphocyte immunology, Leishmania physiology, Leishmaniasis, Visceral diagnosis, Recombinant Proteins immunology, Zoonoses diagnosis
- Abstract
Serological tests are important tools for the diagnosis of Leishmania infection. However, they are not effective markers to diagnose asymptomatic cases of visceral leishmaniasis (VL) and patients developing tegumentary leishmaniasis (TL), since antileishmanial antibodies can be encountered in low levels resulting in false-negative results in the serological trials. In this context, antigens able to be recognized by antibodies in sera from both VL and TL patients will be desirable to be employed in a more sensitivity and specific diagnosis of disease. In the present study, a conserved Leishmania protein, small myristoylated protein-3 (SMP-3), which was showed to be conserved in different Leishmania species and an effective vaccine candidate against Leishmania infantum infection in a murine model, was cloned and the recombinant protein was evaluated as a serological marker for the diagnosis of human TL and canine VL. In addition, a linear B cell-specific epitope (MQKDEESGEFKCEL) was identified, synthetized and also investigated as a serological marker. As antigen controls, rA2 protein and antigenic Leishmania extracts (SLA) were used. Results showed that ELISA-rSMP-3 and ELISA-Peptide presented sensitivity and specificity values higher than 90% in both diseases in humans and canids, having identified all asymptomatic cases and did not present cross-reaction with cross-reactivity diseases in both mammalian hosts. On the other hand, sensitivity and specificity values were worst when rA2 or SLA were used as antigens in humans and dogs. In conclusion, results showed the efficacy and Leishmania SMP-3 protein, employed as a recombinant antigen or a B cell epitope, for the improvement of the serodiagnosis of human TL and canine VL. This candidate can be tested in other diagnostic platforms, such as rapid immunochromatographic dipstick tests, aiming its use in epidemiological studies in remote areas where laboratories are not readily accessible for conventional assays., (Copyright © 2018 Elsevier GmbH. All rights reserved.)
- Published
- 2019
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14. Recombinant prohibitin protein of Leishmania infantum acts as a vaccine candidate and diagnostic marker against visceral leishmaniasis.
- Author
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Dias DS, Ribeiro PAF, Martins VT, Lage DP, Ramos FF, Dias ALT, Rodrigues MR, Portela ÁSB, Costa LE, Caligiorne RB, Steiner BT, Chávez-Fumagalli MA, Salles BCS, Santos TTO, Silveira JAG, Magalhães-Soares DF, Roatt BM, Machado-de-Ávila RA, Duarte MC, Menezes-Souza D, Silva ES, Galdino AS, and Coelho EAF
- Subjects
- Animals, Antigens, Protozoan immunology, Dogs, Humans, Leishmania infantum immunology, Leishmania infantum metabolism, Leishmaniasis, Visceral metabolism, Mice, Mice, Inbred BALB C, Prohibitins, Recombinant Proteins metabolism, Repressor Proteins metabolism, Th1 Cells immunology, Vaccines metabolism, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral immunology, Repressor Proteins immunology
- Abstract
Visceral leishmaniasis (VL) represents a serious public health problem, as Leishmania infantum is one of main disease causative agents in the Americas. In a previous immunoproteomic study, the prohibitin (PHB) protein was identified in L. infantum promastigote and amastigote extracts by antibodies in asymptomatic and symptomatic VL dog sera. This protein was found to be highly conserved between different Leishmania spp., but it presented a low identity with amino acid sequences of other organisms. The aim of the present study was to evaluate the cellular response induced by the recombinant PHB (rPHB) protein in BALB/c mice, as well as in PBMCs purified from untreated and treated VL patients, as well as to evaluate its protective efficacy against an infection by L. infantum promastigotes. Our data showed that there was a Th1 cellular response to rPHB, based on high levels of IFN-γ, IL-12, and GM-CSF in the immunized animals, as well as a proliferative response specific to the protein and higher IFN-γ levels induced in PBMCs from individuals who had recovered from the disease. The protection was represented by significant reductions in the parasite load in the animals' spleen, liver, bone marrow, and draining lymph nodes, as compared to results found in the control groups. In addition, an anti-rPHB serology, using a canine and human serological panel, showed a high performance of this protein when diagnosing VL based on high sensitivity and specificity values, as compared to results found for the rA2 antigen and the soluble Leishmania antigenic extract. Our data suggest that PHB has a potential application for the diagnosis of canine and human VL through antibody detection, as well as an application as a vaccine candidate to protect against disease., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2018
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15. An ELISA immunoassay employing a conserved Leishmania hypothetical protein for the serodiagnosis of visceral and tegumentary leishmaniasis in dogs and humans.
- Author
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Carvalho AMRS, Costa LE, Salles BCS, Santos TTO, Ramos FF, Lima MP, Chávez-Fumagalli MA, Silvestre BT, Portela ÁSB, Roatt BM, Silveira JAG, Gonçalves DU, Magalhães-Soares DF, Duarte MC, Menezes-Souza D, and Coelho EAF
- Subjects
- Animals, Antigens, Protozoan genetics, Antigens, Protozoan immunology, Chagas Disease immunology, Conserved Sequence genetics, Cross Reactions, Dogs, Humans, Leishmaniasis, Cutaneous immunology, Leishmaniasis, Visceral immunology, Predictive Value of Tests, Recombinant Proteins genetics, Recombinant Proteins immunology, Reproducibility of Results, Sensitivity and Specificity, Antigens, Protozoan metabolism, Chagas Disease diagnosis, Enzyme-Linked Immunosorbent Assay methods, Leishmania immunology, Leishmaniasis, Cutaneous diagnosis, Leishmaniasis, Visceral diagnosis, Recombinant Proteins metabolism
- Abstract
In the present study, a conserved Leishmania hypothetical protein, namely LiHypA, was evaluated for the serodiagnosis of visceral and tegumentary leishmaniasis in dogs and humans. This protein showed a high amino acid sequence homology between viscerotropic and cutaneotropic Leishmania species. An enzyme-linked immunosorbent assay (ELISA) was developed using the recombinant antigen (rLiHypA), in addition to the A2 protein and two parasite antigenic preparations, which were used as controls. Regarding human diagnosis, results showed that rLiHypA was more sensitive and specific than ELISA-L. braziliensis SLA in detecting both cutaneous or mucosal leishmaniasis patients, but not those from Chagas disease patients or healthy subjects. Regarding canine diagnosis, this recombinant antigen showed higher sensitivity and specificity values, as well as a perfect accuracy to identify asymptomatic and symptomatic visceral leishmaniasis (VL) in dogs, but not those from vaccinated animals or those developing babesiosis, ehrlichiosis, or Chagas disease. However, using the rA2 protein or L. braziliensis SLA as controls, significant cross-reactivity was found when these samples were used, hampering their sensitivity and specificity values for the diagnosis. In this context, LiHypA could be considered a candidate to be evaluated for the serodiagnosis of visceral and tegumentary leishmaniasis in dogs and humans., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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16. Gel-free/label-free proteomic, photosynthetic, and biochemical analysis of cowpea (Vigna unguiculata [L.] Walp.) resistance against Cowpea severe mosaic virus (CPSMV).
- Author
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Varela ALN, Komatsu S, Wang X, Silva RGG, Souza PFN, Lobo AKM, Vasconcelos IM, Silveira JAG, and Oliveira JTA
- Subjects
- Gene Expression Regulation, Plant immunology, Host-Pathogen Interactions immunology, Photosynthesis, Plant Proteins analysis, Comovirus immunology, Disease Resistance, Proteomics methods, Vigna immunology
- Abstract
Cowpea severe mosaic virus (CPSMV) causes significant losses in cowpea (Vigna unguiculata) production. In this present study biochemical, physiological, and proteomic analysis were done to identify pathways and defense proteins that are altered during the incompatible interaction between the cowpea genotype BRS-Marataoã and CPSMV. The leaf protein extracts from mock- (MI) and CPSMV-inoculated plantlets (V) were evaluated at 2 and 6days post-inoculation (DPI). Data support the assumptions that increases in biochemical (high hydrogen peroxide, antioxidant enzymes, and secondary compounds) and physiological responses (high photosynthesis index and chlorophyll content), confirmed by label-free comparative proteomic approach, in which quantitative changes in proteasome proteins, proteins related to photosynthesis, redox homeostasis, regulation factors/RNA processing proteins were observed may be implicated in the resistance of BRS-Marataoã to CPSMV. This pioneering study provides information for the selection of specific pathways and proteins, altered in this incompatible relationship, which could be chosen as targets for detailed studies to advance our understanding of the molecular, physiological, and biochemistry basis of the resistance mechanism of cowpea and design approachs to engineer plants that are more productive., Biological Significance: This is a pioneering study in which an incompatible relationship between a resistant cowpea and Cowpea severe mosaic virus (CPSMV) was conducted to comparatively evaluate proteomic profiles by Gel-free/label-free methodology and some physiological and biochemical parameters to shed light on how a resistant cowpea cultivar deals with the virus attack. Specific proteins and associated pathways were altered in the cowpea plants challenged with CPSMV and will contribute to our knowledge on the biological process tailored by cowpea in response to CPSMV., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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17. Molecular assays reveal the presence of Theileria spp. and Babesia spp. in Asian water buffaloes (Bubalus bubalis, Linnaeus, 1758) in the Amazon region of Brazil.
- Author
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Silveira JAG, de Oliveira CHS, Silvestre BT, Albernaz TT, Leite RC, Barbosa JD, Oliveira CMC, and Ribeiro MFB
- Subjects
- Animals, Babesia classification, Babesia genetics, Babesiosis epidemiology, Babesiosis transmission, Brazil epidemiology, Cattle, Cattle Diseases epidemiology, Cattle Diseases transmission, DNA, Protozoan genetics, Genetic Variation, Lymphoproliferative Disorders etiology, Lymphoproliferative Disorders parasitology, Lymphoproliferative Disorders veterinary, Phylogeny, Polymerase Chain Reaction, Theileria classification, Theileria genetics, Theileriasis epidemiology, Theileriasis transmission, Babesia isolation & purification, Babesiosis parasitology, Buffaloes parasitology, Cattle Diseases parasitology, Theileria isolation & purification, Theileriasis parasitology
- Abstract
Approximately 50% of buffalo herds in Brazil are located in Pará state in northern Brazil. There are several properties where cattle and buffalo live and graze together, and thus, buffalo pathogens may threaten the health of cattle and vice versa. Therefore, knowledge of infectious agents of buffalo is essential for maintaining healthy livestock. Clinical disease caused by Theileria and Babesia parasites in the Asian water buffalo is not common, although these animals may act as reservoir hosts, and the detection of these hemoparasites in buffaloes is as important as it is in cattle. Studies of the infection of buffaloes by hemoparasites in Brazil are scarce. The objective of the present study was to investigate the occurrence of Piroplasmida parasites in Asian water buffaloes in the state of Pará in the Amazon region of Brazil using nested PCR assays and phylogenetic analysis. The 18S rRNA gene and ITS complete region were amplified from DNA extracted from blood samples collected from 308 apparently healthy buffaloes bred on six properties in the state of Pará, Brazil. The prevalence of positive buffalo samples was 4.2% (13/308) for Theileria spp., 3.6% (11/308) for Babesia bovis and 1% (3/308) for Babesia bigemina. Animals infected with Theileria were detected in 50% (3/6) of the assessed properties. Phylogenetic analyses indicated that the Theileria species detected in this study were closely related to Theileria buffeli, Theileria orientalis and Theileria sinensis. To our knowledge, this is the first report of Theileria in Asian water buffaloes in the Americas. The majority of Theileria-positive buffaloes (11/13) belong to a property that has a history of animals presenting lymphoproliferative disease of unknown etiology. Therefore, the present research suggests that this disorder can be associated with Theileria infection in this property. Our results provide new insights on the distribution and biological aspects of hemoparasites transmissible from buffaloes to cattle., (Copyright © 2016 Elsevier GmbH. All rights reserved.)
- Published
- 2016
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18. Proteomics, photosynthesis and salt resistance in crops: An integrative view.
- Author
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Silveira JAG and Carvalho FEL
- Subjects
- Plant Proteins analysis, Plant Proteins physiology, Salinity, Stress, Physiological, Crops, Agricultural physiology, Photosynthesis physiology, Proteomics methods, Salt-Tolerant Plants chemistry
- Abstract
Salinity is a stressful condition that causes a significant decrease in crop production worldwide. Salt stress affects several photosynthetic reactions, including the modulation of several important proteins. Despite these effects, few molecular-biochemical markers have been identified and evaluated for their importance in improving plant salt resistance. Proteomics is a powerful tool that allows the analysis of multigenic events at the post-translational level that has been widely used to evaluate protein modulation changes in plants exposed to salt stress. However, these studies are frequently fragmented and the results regarding photosynthesis proteins in response to salinity are limited. These constraints could be related to the low number of important photosynthetic proteins differently modulated in response to salinity, as has been commonly revealed by conventional proteomics. In this review, we present an evaluation and perspective on the integrated application of proteomics for the identification of photosynthesis proteins to improve salt resistance. We propose the use of phospho-, thiol- and redox-proteomics, associated with the utilization of isolated chloroplasts or photosynthetic sub-organellar components. This strategy may allow the characterization of essential proteins, providing a better understanding of photosynthesis regulation. Furthermore, this may contribute to the selection of molecular markers to improve salt resistance in crops., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
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19. Identification of a vertically transmitted strain from Anaplasma marginale (UFMG3): Molecular and phylogenetic characterization, and evaluation of virulence.
- Author
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Silvestre BT, Silveira JAG, Meneses RM, Facury-Filho EJ, Carvalho AU, and Ribeiro MFB
- Subjects
- Anaplasma marginale pathogenicity, Animals, Cattle, Cattle Diseases epidemiology, Female, Genetic Variation, Infectious Disease Transmission, Vertical, Male, Phylogeny, Pregnancy, Splenectomy, Virulence, Anaplasma marginale genetics, Anaplasmosis parasitology, Cattle Diseases microbiology
- Abstract
Bovine anaplasmosis is a disease caused by the intraerythrocytic rickettsia species Anaplasma marginale and results in great economic losses in tropical and subtropical regions. Vertical transmission is an important phenomenon that contributes to the persistence of different strains of the agent within the same herd. The identification of new strains and genetic characterization studies are essential to understanding their epidemiology and virulence and for vaccine development. The aim of this study was to perform molecular and phylogenetic characterizations of a new vertically transmitted strain from A. marginale and to evaluate its virulence by experimental inoculation of rickettsia-free calves. Thirty newborn Holstein calves were subjected to molecular tests for the detection of A. marginale, Babesia bovis and Babesia bigemina. Calves positive for A. marginale (n=3) were splenectomized and monitored for the clinical manifestations of anaplasmosis. Blood samples from one of the calves that presented rickettsemia of 42.8% and spontaneous recovery of clinical parameters were used for molecular and phylogenetic characterization (msp1a gene), and inoculum production was used for the evaluation of virulence. This strain was identified as UFMG3. Three tandem repeat forms (13 and MGI19) were identified from the analysis of the msp1a gene, in which the form MGI19 appeared twice. Analysis of these repeats revealed the presence of the sequences QASTSS and SSASGQQQESS and of aspartic acid (D) at position 20 of both repeats. Phylogenetic analysis showed a close relationship among the UFMG3, MGI19 and UFMG2 strains. For virulence evaluation, six Holstein calves were inoculated intravenously with 2×10(7)A. marginale UFMG3-infected erythrocytes. The calves showed maximum rickettsemia of 5.1%, a moderate decrease in packed cell volume and spontaneous recovery of clinical parameters without the need for treatment. The results of experimental inoculation suggest that the strain A. marginale UFMG3 has low virulence and potential application for use as a live vaccine against A. marginale., (Copyright © 2015 Elsevier GmbH. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
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