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Gondim CN, Ferreira SDA, Vasconcelos BKS, Wouters F, Fujiwara RT, de Castro JC, Barçante JMDP. Visceral leishmaniasis in a recent transmission region: 27.4% infectivity rate among seronegative dogs. Parasitology 2022:1-6. [PMID: 35249570 DOI: 10.1017/s0031182022000063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
American visceral leishmaniasis (VL) is a parasitic disease whose main domestic reservoir in the urban environment is dog and is considered one of the most important zoonoses in the context of public health. Serological tests are typically used for the diagnostic screening of the disease. This study aimed to analyse the performance of different methodologies used in the diagnosis of VL in dogs sampled from a recent transmission area. The sample consisted of 52 dogs separated into groups based on the absence and presence of clinical signs of VL. The following serological techniques were carried out: the DPP® rapid test (RT), the ALERE® RT and an RT and immunoenzymatic assay with a recently developed protein (rKDDR-plus). In addition, molecular techniques were carried out with conjunctival swabs, and bone marrow aspirate samples and parasitological samples were obtained directly from bone marrow aspirates. It was concluded that 27.4% of seronegative dogs were infected, but the serological tests, used as screening tests, showed unsatisfactory sensitivity results (average: 51.2%) for dogs without clinical signs. It was suggested that polymerase chain reaction with conjunctival swabbing be used as a screening test for dogs without clinical signs, as this is a non-invasive collection technique with high-sensitivity values.
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Affiliation(s)
- Carolina Novato Gondim
- Department of Health Sciences, Faculty of Health Sciences, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Sidney de Almeida Ferreira
- Department of Health Sciences, Faculty of Health Sciences, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Beatriz Ketelin Sousa Vasconcelos
- Department of Veterinary Medicine, Faculty of Zootechnics and Veterinary Medicine, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Flademir Wouters
- Department of Veterinary Medicine, Faculty of Zootechnics and Veterinary Medicine, Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Ricardo Toshio Fujiwara
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Joseane Camilla de Castro
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Resende LA, Aguiar-Soares RDDO, Moreira NDD, Ferreira SDA, Lanna MF, Cardoso JMDO, Mathias FAS, Coura-Vital W, Mariano RMDS, Leite JC, Silveira P, de Carvalho TF, Santos RL, da Silveira-Lemos D, Martins-Filho OA, Dutra WO, Reis AB, Giunchetti RC. In vitro Infectivity of Strains Isolated From Dogs Naturally Infected With Leishmania infantum Present a Distinct Pathogenic Profile in Hamsters. Front Med (Lausanne) 2020; 7:496. [PMID: 32984376 PMCID: PMC7483547 DOI: 10.3389/fmed.2020.00496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/20/2020] [Indexed: 11/20/2022] Open
Abstract
Visceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum. Dogs are the parasite's main reservoir, favoring its transmission in the urban environment. The analysis of L. infantum from infected dogs contributes to the identification of more virulent parasites, thereby supporting basic and applied studies such as vaccinal and therapeutic strategies. We proposed the in vitro and in vivo characterization of L. infantum strains from naturally infected dogs from a VL endemic area based on an infectivity and pathogenicity analysis. DH82 canine macrophages were infected in vitro with different strains for infectivity analysis, showing distinct infectivity profiles. The strains that showed greater and lesser infectivity using in vitro analyses (616 and 614, respectively) were used to infect hamsters for pathogenicity analysis. The group infected with strain 616 showed 100% survival while the group infected with strain 614 showed 50% after seven months of follow up. Furthermore, the 614 strain induced more noticeable clinicopathological changes and biochemical abnormalities in liver function, along with high inflammation and parasite load in the liver and spleen. We confirmed high variability of infectivity and pathogenicity in L. infantum strains from infected dogs. The results support the belief that screening for L. infantum infectivity using in vitro experiments is inadequate when it comes to selecting the most pathogenic strain.
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Affiliation(s)
- Lucilene Aparecida Resende
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | | | - Nádia das Dores Moreira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Programa de Pós Graduação em Ciências Farmacêuticas (Cipharma), Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Sidney de Almeida Ferreira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Laboratório de Biologia Parasitária, Faculdade de Ciências da Saúde, Universidade Federal de Lavras, Lavras, Brazil
| | - Mariana Ferreira Lanna
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | | | | | - Wendel Coura-Vital
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Programa de Pós Graduação em Ciências Farmacêuticas (Cipharma), Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Laboratório de Pesquisa em Epidemiologia e Citologia, Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Reysla Maria da Silveira Mariano
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jaqueline Costa Leite
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Patricia Silveira
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Tatiane Furtado de Carvalho
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Renato Lima Santos
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Denise da Silveira-Lemos
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Grupo Integrado de Pesquisas em Biomarcadores, Instituto René Rachou, FIOCRUZ, Belo Horizonte, Brazil.,Departamento de Medicina, Universidade José Do Rosário Vellano, UNIFENAS, Belo Horizonte, Brazil
| | | | - Walderez Ornelas Dutra
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Alexandre Barbosa Reis
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.,Programa de Pós Graduação em Ciências Farmacêuticas (Cipharma), Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Rodolfo Cordeiro Giunchetti
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Roatt BM, Aguiar-Soares RDDO, Reis LES, Cardoso JMDO, Mathias FAS, de Brito RCF, da Silva SM, Gontijo NDF, Ferreira SDA, Valenzuela JG, Corrêa-Oliveira R, Giunchetti RC, Reis AB. A Vaccine Therapy for Canine Visceral Leishmaniasis Promoted Significant Improvement of Clinical and Immune Status with Reduction in Parasite Burden. Front Immunol 2017; 8:217. [PMID: 28321217 PMCID: PMC5338076 DOI: 10.3389/fimmu.2017.00217] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 02/15/2017] [Indexed: 12/18/2022] Open
Abstract
Herein, we evaluated the treatment strategy employing a therapeutic heterologous vaccine composed of antigens of Leishmania braziliensis associated with MPL adjuvant (LBMPL vaccine) for visceral leishmaniasis (VL) in symptomatic dogs naturally infected by Leishmania infantum. Sixteen dogs received immunotherapy with MPL adjuvant (n = 6) or with a vaccine composed of antigens of L. braziliensis associated with MPL (LBMPL vaccine therapy, n = 10). Dogs were submitted to an immunotherapeutic scheme consisting of 3 series composed of 10 subcutaneous doses with 10-day interval between each series. The animals were evaluated before (T0) and 90 days after treatment (T90) for their biochemical/hematological, immunological, clinical, and parasitological variables. Our major results showed that the vaccine therapy with LBMPL was able to restore and normalize main biochemical (urea, AST, ALP, and bilirubin) and hematological (erythrocytes, hemoglobin, hematocrit, and platelets) parameters. In addition, in an ex vivo analysis using flow cytometry, dogs treated with LBMPL vaccine showed increased CD3+ T lymphocytes and their subpopulations (TCD4+ and TCD8+), reduction of CD21+ B lymphocytes, increased NK cells (CD5-CD16+) and CD14+ monocytes. Under in vitro conditions, the animals developed a strong antigen-specific lymphoproliferation mainly by TCD4+ and TCD8+ cells; increasing in both TCD4+IFN-γ+ and TCD8+IFN-γ+ as well as reduction of TCD4+IL-4+ and TCD8+IL-4+ lymphocytes with an increased production of TNF-α and reduced levels of IL-10. Concerning the clinical signs of canine visceral leishmaniasis, the animals showed an important reduction in the number and intensity of the disease signs; increase body weight as well as reduction of splenomegaly. In addition, the LBMPL immunotherapy also promoted a reduction in parasite burden assessed by real-time PCR. In the bone marrow, we observed seven times less parasites in LBMPL animals compared with MPL group. The skin tissue showed a reduction in parasite burden in LBMPL dogs 127.5 times higher than MPL. As expected, with skin parasite reduction promoted by immunotherapy, we observed a blocking transmission to sand flies in LBMPL dogs with only three positive dogs after xenodiagnosis. The results obtained in this study highlighted the strong potential for the use of this heterologous vaccine therapy as an important strategy for VL treatment.
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Affiliation(s)
- Bruno Mendes Roatt
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Departamento de Patologia Clínica, COLTEC, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT), Salvador, Brazil
| | | | - Levi Eduardo Soares Reis
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto , Ouro Preto, Minas Gerais , Brazil
| | - Jamille Mirelle de Oliveira Cardoso
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto , Ouro Preto, Minas Gerais , Brazil
| | - Fernando Augusto Siqueira Mathias
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto , Ouro Preto, Minas Gerais , Brazil
| | - Rory Cristiane Fortes de Brito
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto , Ouro Preto, Minas Gerais , Brazil
| | - Sydnei Magno da Silva
- Laboratório de Bioensaios em Leishmania, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia , Uberlândia, Minas Gerais , Brazil
| | - Nelder De Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais , Brazil
| | - Sidney de Almeida Ferreira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto , Ouro Preto, Minas Gerais , Brazil
| | - Jesus G Valenzuela
- Vector Molecular Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Rockville, MD , USA
| | - Rodrigo Corrêa-Oliveira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT), Salvador, Brazil
| | - Rodolfo Cordeiro Giunchetti
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais , Brazil
| | - Alexandre Barbosa Reis
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT), Salvador, Brazil
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Ferreira SDA, Almeida GG, Silva SDO, Vogas GP, Fujiwara RT, de Andrade ASR, Melo MN. Nasal, oral and ear swabs for canine visceral leishmaniasis diagnosis: new practical approaches for detection of Leishmania infantum DNA. PLoS Negl Trop Dis 2013; 7:e2150. [PMID: 23593518 PMCID: PMC3617150 DOI: 10.1371/journal.pntd.0002150] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/20/2013] [Indexed: 11/27/2022] Open
Abstract
Background The aim of this study was to evaluate the potential use of nasal, oral, and ear swabs for molecular diagnosis of canine visceral leishmaniasis (CVL) in an endemic urban area in Brazil. Methodology/Principal Findings Sixty-two naturally infected and ten healthy dogs were enrolled in this study. Bone marrow aspirates, peripheral blood, skin biopsy, and conjunctival, nasal, oral, and ear swabs were collected. All samples, except blood, were submitted to conventional PCR (cPCR) and quantitative real time PCR (qPCR) to detect and quantify Leishmania infantum DNA, respectively. All dogs were submitted to thorough clinical analysis and were included based on a combination of serological (ELISA immunoassay and immunofluorescent antibody test) and parasitological methods. The cPCR positivity obtained from nasal swab samples was 87% (54/62), equivalent to those from other samples (P>0.05). Positive results were obtained for 79% (22/28) in oral swabs and 43% (12/28) in ear swab samples. A significant difference was observed between these data (P = 0.013), and the frequency of positive results from oral swab was equivalent to those from other samples (P>0.05). The use of ear swab samples for cPCR assays is promising because its result was equivalent to skin biopsy data (P>0.05). The qPCR data revealed that parasite loads in mucosal tissues were similar (P>0.05), but significantly lower than the parasite burden observed in bone marrow and skin samples (P<0.05). Conclusions Nasal and oral swab samples showed a high potential for the qualitative molecular diagnosis of CVL because their results were equivalent to those observed in samples collected invasively. Considering that mucosae swab collections are painless, noninvasive, fast and practical, the combination of these samples would be useful in massive screening of dogs. This work highlights the potential of practical approaches for molecular diagnosis of CVL and human leishmaniasis infections. Visceral leishmaniasis (VL) is an important public health problem in different regions of the world. It presents high lethality in human cases without suitable treatment and is considered one of the most important disorders in dogs, the main domestic reservoir of the etiological agent of VL (Leishmania infantum). Most cases of VL in Latin America occur in Brazil, and control campaigns have not shown satisfactory results. The diagnosis of human and canine infection is critical for making decisions regarding surveillance and control policies. In this work, we propose a non-invasive collection method of mucosal and epithelial cells for the molecular diagnosis of canine VL by conventional polymerase chain reaction (cPCR) and for the estimation of parasite load by quantitative real time PCR (qPCR). We used nasal, oral, and ear swabs as practical, simple, painless and fast alternatives for collecting samples. These procedures are according to the need of more simplified methods for detecting L. infantum infection by using robust diagnostic techniques such as cPCR and qPCR. Additionally, potential applications for diagnosing human VL are highlighted.
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Affiliation(s)
- Sidney de Almeida Ferreira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
| | - Gregório Guilherme Almeida
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
| | - Soraia de Oliveira Silva
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
| | - Gabriela Peixoto Vogas
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
| | - Ricardo Toshio Fujiwara
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
| | - Antero Silva Ribeiro de Andrade
- Centro de Desenvolvimento da Tecnologia Nuclear, Comissão Nacional de Energia Nuclear, Campus da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Maria Norma Melo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brasil
- * E-mail:
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de Almeida Ferreira S, Leite RS, Ituassu LT, Almeida GG, Souza DM, Fujiwara RT, de Andrade ASR, Melo MN. Canine skin and conjunctival swab samples for the detection and quantification of Leishmania infantum DNA in an endemic urban area in Brazil. PLoS Negl Trop Dis 2012; 6:e1596. [PMID: 22506084 PMCID: PMC3323509 DOI: 10.1371/journal.pntd.0001596] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We evaluated kDNA PCR/hybridization and quantitative real-time PCR (qPCR) targeting the gene of DNA polymerase of Leishmania infantum for CVL diagnosis and assessment of parasite load in clinical samples obtained invasively and non-invasively. METHODOLOGY/PRINCIPAL FINDINGS Eighty naturally infected dogs from an endemic urban area in Brazil were used. Animals were divided into two groups based on the presence or absence of CVL clinical sings. Skin biopsies, bone marrow, blood and conjunctival swabs samples were collected and submitted to L. infantum DNA detection. In addition, anti-Leishmania antibody titers were measured by Immunofluorescence antibody test. The symptomatic dogs had increased titers compared to asymptomatic dogs (P = 0.025). The frequencies of positive results obtained by kDNA PCR/hybridization for asymptomatic and symptomatic dogs, respectively, were as follows: right conjunctiva, 77.5% and 95.0%; left conjunctiva, 75.0% and 87.5%; skin, 45.0% and 75.0%; bone marrow, 50.0% and 77.5%; and blood, 27.5% and 22.5%. In both groups, the parasite load in the skin samples was the highest (P<0.0001). The parasite loads in the conjunctival swab and bone marrow samples were statistically equivalent within each group. The parasite burden in conjunctival swabs was higher in the dogs with clinical signs than in asymptomatic dogs (P = 0.028). This same relationship was also observed in the bone marrow samples (P = 0.002). No differences in amastigotes load in the skin were detected between the groups. CONCLUSIONS The conjunctival swab is a suitable clinical sample for qualitative molecular diagnosis of CVL. The highest parasite burdens were detected in skin regardless of the presence of VL-associated clinical signs. The qPCR results emphasized the role of dogs, particularly asymptomatic dogs, as reservoirs for CVL because of the high cutaneous parasite loads. These results may help to explain the maintenance of high transmission rates and numbers of CVL cases in endemic urban regions.
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Affiliation(s)
- Sidney de Almeida Ferreira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Rodrigo Souza Leite
- Centro de Desenvolvimento da Tecnologia Nuclear, Comissão Nacional de Energia Nuclear, Campus da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Leonardo Trindade Ituassu
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Gregório Guilherme Almeida
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Daniel Menezes Souza
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Ricardo Toshio Fujiwara
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Antero Silva Ribeiro de Andrade
- Centro de Desenvolvimento da Tecnologia Nuclear, Comissão Nacional de Energia Nuclear, Campus da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Maria Norma Melo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
- * E-mail:
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Leite RS, Ferreira SDA, Ituassu LT, de Melo MN, de Andrade ASR. PCR diagnosis of visceral leishmaniasis in asymptomatic dogs using conjunctival swab samples. Vet Parasitol 2010; 170:201-6. [PMID: 20227834 DOI: 10.1016/j.vetpar.2010.02.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 01/14/2010] [Accepted: 02/13/2010] [Indexed: 11/30/2022]
Abstract
The efficacy of conjunctival swab (CS) as a sampling method for visceral leishmaniasis (VL) diagnosis by PCR of asymptomatic dogs was evaluated. The CS was compared to blood samples (B) and skin biopsies (SB), two less invasive samples potentially useful for massive screening of dogs. Thirty asymptomatic dogs, with serological and parasitological positive tests, were used. The samples were analyzed by two PCR methods: kDNA PCR-hybridization and ITS-1 nPCR. The DNA sample volume used was of 1.0 microL and 10.0 microL respectively. Using CS samples the kDNA PCR-hybridization was able to detected parasite DNA in 24/30 dogs (80%) using the right conjunctiva (RC) and 23/30 dogs (76.6%) with the left conjunctiva (LC), 17/30 dogs (56.7%) by means of SB and 4/30 dogs (13.3%) with B. The CS positivity obtained combining RC and LC results was of 90% (27/30 dogs). The assay of CS samples by ITS-1 nPCR revealed that 25/30 dogs (83.3%) were positive when using RC and 20/30 dogs (66.6%) were positive when using LC. Via the same method 15/30 dogs (50.0%) were positive by SB and 17/30 dogs (56.7%) with B. The CS positivity obtained by ITS-1 nPCR combining RC and LC was of 83.3%. The CS positivities for RC and LC were significantly higher (p<0.05) than SB and B for kDNA PCR-hybridization method. Statistical difference in relation to SB and B was verified by ITS-1 nPCR only for RC. The kDNA PCR-hybridization and ITS-1 nPCR methods showed similar sensitivities for CS and SB samples. On the other hand, for blood samples, the positivity of ITS-1 nPCR was significantly higher than the one obtained by the kDNA PCR-hybridization, indicating that sensitivity of PCR methods can vary according to the biological sample examined. Our results showed that CS was suitable to detect Leishmania DNA in asymptomatic animals when comparing to other low-invasive samples. The CS sensitivities obtained in this study were similar to the ones observed in other studies for VL diagnosis in symptomatic dogs. We concluded that the use of CS for regular screenings of dogs by PCR should be considered.
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Affiliation(s)
- Rodrigo Souza Leite
- Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Cidade Universitária-Campus da UFMG, 31120-970, Belo Horizonte, MG, Brazil.
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Pilatti MM, Ferreira SDA, de Melo MN, de Andrade ASR. Comparison of PCR methods for diagnosis of canine visceral leishmaniasis in conjunctival swab samples. Res Vet Sci 2009; 87:255-7. [PMID: 19298988 DOI: 10.1016/j.rvsc.2009.02.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/30/2008] [Accepted: 02/06/2009] [Indexed: 11/16/2022]
Abstract
Four PCR assays for detection of Leishmania DNA in conjunctival swab samples were compared. All methods had two steps: a first amplification followed by hybridization or by a new amplification (nested or seminested). Two methods (kDNA PCR-hybridization and kDNA snPCR) used primers targeted to the minicircles of kinetoplast DNA (kDNA) and the other two methods to the coding (LnPCR) and intergenic noncoding regions (ITS-1 nPCR) of ribosomal rRNA genes. kDNA PCR-hybridization was positive for 22/23 dogs (95.6%) and for 40/46 samples (86.9%), considering the right and the left conjunctivas. kDNA snPCR was positive for 21/23 dogs (91.3%) and for 40/46 samples (86.9%). The ITS-1 nPCR and LnPCR were both able to detect the parasites in 17/23 dogs (73.9%) and 29/46 (63%) and 30/46 (65.2%) samples, respectively. The positivities of the kDNA based methods were significantly higher; however the choice of the best method will depend on the kind of information required with the diagnosis.
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Affiliation(s)
- Marcia Maria Pilatti
- Centro de Desenvolvimento da Tecnologia Nuclear, Cidade Universitária-Campus da UFMG, 31120-970 Belo Horizonte, MG, Brazil.
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Ferreira SDA, Ituassu LT, de Melo MN, de Andrade ASR. Evaluation of the conjunctival swab for canine visceral leishmaniasis diagnosis by PCR-hybridization in Minas Gerais State, Brazil. Vet Parasitol 2008; 152:257-63. [PMID: 18242866 DOI: 10.1016/j.vetpar.2007.12.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 11/29/2007] [Accepted: 12/10/2007] [Indexed: 11/19/2022]
Abstract
The visceral leishmaniasis (VL) in Brazil is caused by Leishmania chagasi (L. infantum) and dogs are considered to be the main domestic reservoir. The epidemiological control involves the elimination of infected dogs. Therefore, the correct diagnosis is very important in order to avoid the disease transmission or unnecessary culling of dogs. Recently, an antileishmanial vaccine for dogs was licensed and commercialized in Brazil. Vaccinated dogs test positive in the conventional serological tests, rendering these assays useless for control programs involving vaccinated animals. The Polymerase Chain Reaction (PCR) is an attractive alternative to the diagnosis in this context; but non-invasive samplings have great importance because they are simpler, painless and less resisted by dog-owners. This study aimed at evaluating the conjunctival swab (CS) for canine VL diagnosis by the PCR-hybridization procedure. Two groups of 23 seropositive dogs were used. CS samples were obtained from both eyes of each animal. The DNA extraction from CS was performed by the phenol chloroform method in group 1 and by boiling in group 2. In addition, blood was collected from each animal so that 30 microl was spotted onto filter paper (FP) and 1.0 ml was treated to obtain the buffy coat (BC). The DNA extraction from the BC and FP was accomplished by identical procedures in both groups using commercial kits. The PCR positivities for both groups 1 and 2 were, respectively: 73.9% and 52.2% (CS), 13% and 30.4% (BC), 8.7% and 17.4% (FP). The hybridization step increased the positivities for: 91.3% and 65.2% (CS), 21.7% and 34.8% (BC), 30.4% and 43.5% (FP), respectively. The highest frequency of positivity was obtained by the association between CS and DNA extraction by phenol chloroform. This approach can be very useful for diagnosis of canine leishmaniasis and could be applied to the follow-up and regular screening of vaccinated dogs.
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Affiliation(s)
- Sidney de Almeida Ferreira
- Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Rua Professor Mário Werneck S/No., Cidade Universitária - Campus da UFMG, 31120-970 Belo Horizonte, MG, Brazil.
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