Evaluation of Leishmania (Leishmania) infantum excreted-secreted antigens for detection of canine leishmaniasis

Abstract Background Leishmania tarentolae is a protozoan isolated from geckoes (Tarentola annularis, Tarentola mauritanica), which is considered non-pathogenic and is transmitted by herpetophilic Sergentomyia spp. sand flies. This species occurs in sympatry with Leishmania infantum in areas where canine leishmaniasis is endemic. In the present study, we investigated the circulation of L. tarentolae and L. infantum in sand flies, dogs and lizards in a dog shelter in southern Italy, where canine leishmaniasis by L. infantum is endemic. Methods Sheltered dogs (n = 100) negative for Leishmania spp. (March 2020) were screened by immunofluorescence antibody test (IFAT) using promastigotes of both species at two time points (June 2020 and March 2021). Whole blood from dogs, tissues of Podarcis siculus lizards (n = 28) and sand flies (n = 2306) were also sampled and tested by a duplex real-time PCR (dqPCR). Host blood meal was assessed in sand flies by PCR. Results Overall, 16 dogs became positive for L. infantum and/or L. tarentolae by IFAT at one or both sampling periods. One canine blood sample was positive for L. infantum, whilst two for L. tarentolae by dqPCR. At the cytology of lizard blood, Leishmania spp. amastigote-like forms were detected in erythrocytes. Twenty-two tissue samples, mostly lung (21.4%), scored molecularly positive for L. tarentolae, corresponding to 10 lizards (i.e., 35.7%). Of the female Sergentomyia minuta sampled (n = 1252), 158 scored positive for L. tarentolae, four for L. infantum, and one co-infected. Two Phlebotomus perniciosus (out of 29 females) were positive for L. tarentolae. Engorged S. minuta (n = 10) fed on humans, and one P. perniciosus, positive for L. tarentolae, on lagomorphs. Conclusions Dogs and lacertid lizards (Podarcis siculus) were herein found for the first time infected by L. tarentolae. The detection of both L. tarentolae and L. infantum in S. minuta and P. perniciosus suggests their sympatric circulation, with a potential overlap in vertebrate hosts. The interactions between L. tarentolae and L. infantum should be further investigated in both vectors and vertebrate hosts to understand the potential implications for the diagnosis and control of canine leishmaniasis in endemic areas. Graphical abstract

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Evaluation of the performance of three serological tests for diagnosis of Leishmania infantum infection in dogs using latent class analysis

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612020105 ◽

2020 ◽

Vol 29 (4) ◽

Author(s):

Asier Basurco ◽

Alda Natale ◽

Katia Capello ◽

Antonio Fernández ◽

María Teresa Verde ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Leishmania Infantum ◽

Latent Class ◽

Rapid Test ◽

Antibody Test ◽

Latent Class Models ◽

Canine Leishmaniasis ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Serological Tests

Abstract Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum. Serological methods are the most common diagnostic techniques used for the diagnosis of the CanL. The objective of our study was to estimate the sensitivity and specificity of one in-house ELISA kit (ELISA UNIZAR) and three commercially available serological tests (MEGACOR Diagnostik GmbH) including an immunochromatographic rapid test (FASTest LEISH®), an immunofluorescent antibody test (MegaFLUO LEISH®) and an enzyme-linked immunosorbent assay (MegaELISA LEISH®), using latent class models in a Bayesian analysis. Two hundred fifteen serum samples were included. The highest sensitivity was achieved for FASTest LEISH® (99.38%), ELISA UNIZAR (99.37%), MegaFLUO LEISH® (99.36%) followed by MegaELISA LEISH® (98.49%). The best specificity was obtained by FASTest LEISH® (98.43%), followed by ELISA UNIZAR (97.50%), whilst MegaFLUO LEISH® and MegaELISA LEISH® obtained the lower specificity (91.94% and 91.93%, respectively). The results of present study indicate that the immunochromatographic rapid test evaluated FASTest LEISH® show similar levels of sensitivity and specificity to the quantitative commercial tests. Among quantitative serological tests, sensitivity and specificity were similar considering ELISA or IFAT techniques.

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CD45+, CD68+ and E-cadherin+ Expressions in Skin Dogs Naturally Infected by Leishmania infantum

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.79402 ◽

2017 ◽

Vol 45 (1) ◽

pp. 7

Author(s):

Társsila Mara Vieira Ferreira ◽

Tiago Cunha Ferreira ◽

Fernanda Maria Aragão Ximenes Porto ◽

Conceição Da Silva Martins ◽

Berlamino Eugênio Lopes Neto ◽

...

Keyword(s):

Leishmania Infantum ◽

Mononuclear Cells ◽

Plasma Cells ◽

Clinical Signs ◽

Clinical Manifestations ◽

Canine Leishmaniasis ◽

Control Group ◽

Asymptomatic Group ◽

G Ratio ◽

E Cadherin

Background: In canine leishmaniasis (CanL), infection occurs through phlebotomine vectors that inoculate the protozoan Leishmania infantum into the skin that infected macrophages and activated dendritic cells (CD). Dogs with CanL present variable clinical manifestations, being common the presence of cutaneous lesions. The aim of this study was to evaluate the expression of CD45+, CD68+ and E-cadherin+ associating the skin sentinels cells and to compare the clinical-dermatological manifestations in the skin of dogs naturally infected by L. infantum.Materials, Methods & Results: Dogs infected (n = 22) by L. infantum were divided into asymptomatic group (AD, n = 9), and symptomatic group (SD, n = 13), according criteria based on the presence or absence of skin changes. Dogs non-infected (CD, n = 5) were included as control group. Samples of skin biopsies collected from scapular region were processed by routine histology and labeled by immunohistochemistry with monoclonal antibodies against CD45+, CD68+ and E-cadherin+, and were described as none, mild, moderate and intense. SD presented keratoconjunctivitis, onychogryphose, lichenification, depigmentation, alopecia, hypotrichosis, erythematous dermatitis, exfoliative dermatitis, ulcerative dermatitis and crusted dermatitis, and the frequency these alterations was expressed as percentage. The results of hematological and biochemical parameters were analyzed by Kruskal-Wallis test followed by the Dunn’s test and expressed as mean ± standard deviation, with values P < 0.05. Leukocytosis (not significant), red blood cells, hematocrit and hemoglobin (P < 0.05), total protein serum (P < 0.05), globulins (P < 0.05), albumin and A/G ratio (P < 0.01) were altered in SD in relation to CD. Cutaneous cellular infiltration, composed by macrophages, plasma cells, lymphocytes and neutrophils, was observed in CD. There was an increase of expression of the markers in SD when compared to the other groups, as moderate CD68+ expression and L. infantum, and intense CD45+ and E-cadherin+ expressions.Discussion: Cutaneous involvement is very important in CanL, as it corresponds to where is the first interaction between the parasite and the immune system. Dermatological clinical signs, leukocytosis, anemia, globulins levels have been reported for dogs naturally infected by L. infantum. Inflammatory infiltrate was distributed at superficial and deep dermis, which was composed by mononuclear cells as macrophages, plasma cells, lymphocytes and neutrophils. To characterize the immune sentinels cells in the skin it was evaluated CD45+, CD68+ and E-cadherin+ expressions. In syntomatic dogs, our results revelead an increase of expression of these markers. CD45+ is one of the most abundant molecules expressed on the white blood cell surface in various mammals, while CD68+ is a myelomonocytic marker that seems to be retained during monocyte differentiation. In the skin, increased numbers of CD68+ are related to dendritic epidermal cells, which can be expressed as CD45+/CD1a-/HLA-DR+. DCs of the skin, particularly epidermal Langerhans cells (LCs), form networks anchored to neighboring keratinocytes via E-cadherin. Thus, CD45+, CD68+ and E-cadherin+ expressions may be related to activation of skin sentinels cells in dogs naturally infected by L. infantum. Our results indicated that CanL modify the CD45+, CD68+ and E-cadherin+ expressions, which characterize the immune sentinels cells activation that promove the recruitment the cellular infiltrate, which was composed by macrophages, plasma cells, lymphocytes and neutrophils. Thus, these informations may contribute to the follow-up of CanL progression in skin.

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Seroepidemiology of Leishmania infantum in dogs in the city of Porto Alegre, Rio Grande do Sul, Brazil

Semina Ciências Agrárias ◽

10.5433/1679-0359.2016v37n6p4077 ◽

2016 ◽

Vol 37 (6) ◽

pp. 4077 ◽

Cited By ~ 1

Author(s):

Mariana Caetano Teixeira ◽

Neusa Saltiel Stobbe ◽

Verônica Schmidt ◽

Valéria Marçal Felix de Lima ◽

Ana Luisa Tartarotti ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Leishmania Infantum ◽

Clinical Manifestations ◽

Rio Grande ◽

The State ◽

Canine Leishmaniasis ◽

Insect Vector ◽

Rio Grande Do Sul ◽

Porto Alegre ◽

The City

Leishmaniosis are zoonoses that present several clinical manifestations in humans and have dogs as their main reservoir in the urban environment. Visceral leishmaniasis (VL) is the most severe form of the parasitosis and has been increasing in Brazil, despite the actions of public health agencies. Until 2002, the State of Rio Grande do Sul (RS) was considered free of human and canine leishmaniasis. The first human case of cutaneous leishmaniasis in RS was recorded in 2003. In 2009, the first autochthonous cases of human VL and canine visceral leishmaniasis (CVL) were confirmed in São Borja, RS, and the occurrence of the insect vector was recorded for the first time in the state. In 2010, the first confirmed case of CVL was reported and seropositive dogs were identified in the city of Porto Alegre, RS. Given the importance of this zoonosis and the difficulties of a reliable diagnosis in dogs, this study aimed to identify epidemiological aspects of CVL in dogs in an area of Porto Alegre where cases of the disease have been reported. A total of 300 blood samples were collected from dogs in this area, which were then tested by the methods of RT-DPP® and ELISA for diagnosis of Leishmania infantum. An epidemiological questionnaire was completed by dog owners, containing aspects related to care of the animals, characteristics of their environment, and their living conditions. We observed that 83% (250/300) of the studied dogs were of mixed breed, 58% (175/300) were female, 78% (238/300) slept outdoors, and 61% (183/300) shared their living quarters with other species. Clinically, we observed that 90% (270/300) of the animals were infested by ectoparasites, 70% (210/300) had dermatopathies, 24% (72/300) presented weight loss and anorexia, and 22% (65/300) had ocular disorders. The results of the two serological tests were 100% concordant for the three seropositive samples (1%), and the remaining 297 (99%) were negative for both tests. We conclude that despite the low prevalence of L. infantum seropositive dogs, conditions in the region are favorable for CVL transmission, creating a risk of VL for the human population in the city of Porto Alegre.

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Toward Diagnosing Leishmania infantum Infection in Asymptomatic Dogs in an Area Where Leishmaniasis Is Endemic

Clinical and Vaccine Immunology ◽

10.1128/cvi.00268-08 ◽

2009 ◽

Vol 16 (3) ◽

pp. 337-343 ◽

Cited By ~ 45

Author(s):

D. Otranto ◽

P. Paradies ◽

D. de Caprariis ◽

D. Stanneck ◽

G. Testini ◽

...

Keyword(s):

Leishmania Infantum ◽

Clinical Signs ◽

Antibody Test ◽

Diagnostic Methods ◽

Canine Leishmaniasis ◽

Enzyme Linked Immunosorbent Assay ◽

Canine Monocytic Ehrlichiosis ◽

Immunofluorescence Antibody Test ◽

Immunofluorescence Antibody

ABSTRACT The most frequently used diagnostic methods were compared in a longitudinal survey with Leishmania infantum-infected asymptomatic dogs from an area of Italy where leishmaniasis is endemic. In February and March 2005, 845 asymptomatic dogs were tested by an immunofluorescence antibody test (IFAT), a dipstick assay (DS), and an enzyme-linked immunosorbent assay (ELISA) for L. infantum and by IFAT for Ehrlichia canis. Dogs seronegative for L. infantum were further parasitologically evaluated by microscopic examination of lymph node tissues and PCR of skin samples. A total of 204 animals both serologically and parasitologically negative for L. infantum at the first sampling were enrolled in the trial and were further examined for canine leishmaniasis (CanL) and canine monocytic ehrlichiosis in November 2005 (i.e., the end of the first sandfly season) and March 2006 and 2007 (1- and 2-year follow-ups, respectively). At the initial screening, the overall rates of L. infantum seroprevalence were 9.5% by IFAT, 17.1% by ELISA, and 9.8% by DS and the overall rate of E. canis seroprevalence was 15%. The rates of concordance between the results of IFAT and DS were almost equal, whereas the rate of concordance between the results of IFAT and DS and those of the ELISA was lower. The results of the annual incidence of Leishmania infection were variable, depending on the test employed, with the highest values registered for PCR (i.e., 5.7% and 11.4% at the 1- and 2-year follow-ups, respectively), followed by ELISA, IFAT, and DS. Over the 2 years of observation, 55 animals (i.e., 26.9%) became positive for L. infantum by one or more diagnostic tests at different follow-up times, with 12.7% showing clinical signs related to CanL, while the remaining 87.3% were asymptomatic. A diagnostic scheme for assessment of the L. infantum infection status in asymptomatic dogs is suggested.

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