Infection of dogs by Leishmania infantum elicits a general response of IgG subclasses.
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SUBMITTER: Olias-Molero AI
PROVIDER: S-EPMC7606601 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThree species of Leishmania cause disease in humans in Israel and are endemic in the Middle East: Leishmania infantum, Leishmania tropica and Leishmania major. These species infect dogs and cats, but little is known about their prevalence in pet populations and their clinical manifestations. A study on dog and cat Leishmania infection was conducted in a focus of human L. tropica infection in central Israel with the aim of getting insight on leishmaniosis in pets in an area where human infection is highly prevalent.MethodsBlood, demographic and clinical data were collected from dogs and cats brought for veterinary care in a focus of human L. tropica infection during 2018-2020. kDNA PCR and internal transcribed spacer1 high-resolution melt analysis PCR (ITS1 HRM PCR) with DNA sequencing were performed for the detection of Leishmania and species determination.ResultsForty-three of 189 dogs (22.8%) and 44 of 152 cats (28.9%) were positive for Leishmania spp. infection by kDNA PCR. The ITS1 HRM PCR detected six dogs (3.3%) infected with L. infantum and one (0.5%) with L. tropica, whereas six cats (3.9%) were found infected by L. infantum and five (3.3%) by L. tropica. Four of the five L. tropica-positive cats suffered from weight loss, four had azotemia, two with mild and two with severe azotemia and progressive renal disease. Three cats had gingivostomatitis; three had skin lesions with abscess and ulcers in two and scales and hair loss in another cat, which was also FIV +. This is the first report of feline L. tropica infection in Israel. Clinical information on cats with this infection from previous studies elsewhere is scarce.ConclusionsA high rate of Leishmania spp. infection, mostly estimated as sub-clinical, was found in dogs and cats admitted for veterinary care in an L. tropica focus. Among the animals in which infection could be characterized to the species level, more dogs were infected with L. infantum than with L. tropica while 5 of 11 cats were infected with L. tropica and had signs of systemic and skin disease not described before in feline L. tropica infection.
| S-EPMC9087926 | biostudies-literature
Project description:Canine visceral leishmaniasis (CVL) is endemic in São Luís Maranhão/Brazil and it leads a varied clinical picture, including neurological signs.Histopathological evaluation showed that 14 dogs exhibited pathological alterations in at least one of the analyzed areas. Of these, mononuclear inflammatory reaction was the most frequent, although other lesions, such as hemorrhage, chromatolysis and gliosis were also observed. The presence of L. infantum amastigotes was confirmed in eight dogs, identified in four regions: telencephalon, hippocampus, thalamus and caudal colliculus, but only one presented neurological signs. Polymerase chain reaction results detected the DNA of the parasite in 11 samples from seven dogs. The positive areas were the telencephalon, thalamus, hippocampus, cerebellum, caudal and rostral colliculus.These results reveal that during canine visceral leishmaniasis, the central nervous system may display some alterations, without necessarily exhibiting clinical neurological manifestations. In addition, the L. infantum parasite has the ability to cross the blood brain barrier and penetrate the central nervous system.
| S-EPMC5563018 | biostudies-other
Project description:Leishmaniases are neglected tropical diseases of humans and animals. We detected Leishmania infantum in 3 mixed-breed dogs in Zambia that had no travel history outside the country. Our findings suggest presence of and probable emergence of leishmaniasis in Zambia, indicating the need for physicians and veterinarians to consider the disease during diagnosis.
| S-EPMC8962896 | biostudies-literature
Project description:Genetic polymorphisms in natural Leishmania populations have been reported in endemic areas. Microsatellite typing is a useful tool to elucidate the genetic variability of parasite strains, due to its capability for high-resolution mapping of genomic targets. The present study employed multilocus microsatellite typing (MLMT) to explore the genotypic composition of Leishmania infantum in naturally infected dogs by genotyping parasites infecting different tissues with or without in vitro expansion. Eighty-six samples were collected from 46 animals in an endemic region of visceral leishmaniasis (VL). MLMT was performed for 38 spleen samples and 48 L. infantum cultures isolated from different tissues. Of the 86 samples, 23 were effectively genotyped by MLMT, identifying nine multilocus genotypes (MLG; referred to as MLG A-I). MLGs A, B and C were detected in more than one type of tissue and in more than one sample. Conversely, MLG D-I were uniquely detected in one sample each. The results showed that multiple genotype infections occur within a single host and tissue. Paired sample analysis revealed the presence of different MLMT alleles in 14 dogs, while the same MLG allele was present in 15 animals. STRUCTURE analysis demonstrated the presence of two populations; 13 samples displayed a similar admixture of both ancestral populations, and these were not assigned to any population. Only samples for which Q ≥ 0.70 after CLUMPP alignment were considered to be part of Population 1 (POP1) or Population 2 (POP2). POP2 comprised the majority of samples (n = 54) compared to POP1 (n = 19). This study presents evidence of multiple genotype infections (caused by L. infantum) in dogs in an area with high VL transmission. Further investigations must be undertaken to determine the effects of multiple infection on the host immune response and disease dynamics and treatment.
| S-EPMC7410330 | biostudies-literature
Project description:Visceral leishmaniasis is a systemic and chronic disease and dogs are the main reservoir of the etiologic agent, Leishmania infantum (syn L. chagasi). A serological and molecular investigation of canine visceral leishmaniasis (CVL) was performed in the municipality of Alfenas, located in the southern region of Minas Gerais, where the disease is not endemic. Samples from 87 dogs were submitted to serological tests including the Dual Path Platform (DPP (r) ) CVL Bio-Manguinhos rapid test, an in-house enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence antibody test (IFAT), as well as molecular techniques such as a conventional polymerase chain reaction (PCR) with the RV1/RV2 primers and a quantitative PCR (qPCR) with the LinJ31, Ldon and DNApol primers. Of the 87 serum samples, eight (9.2%) were positive for Leishmania using the DPP rapid test, but only four (4.6%) were confirmed by ELISA and two (2.3%) by IFAT. In these two serologically confirmed cases, spleen and liver samples were positive by all the employed molecular and parasitological procedures performed on spleen samples. When whole blood samples were used in the molecular assays, two samples (2.3%) were positive only by qPCR. DNA extracted and amplified from the spleens of seropositive dogs was sequenced, showing 100% of similarity with the Leishmania infantum (syn L. chagasi) sequence. Thus, the first cases of CVL have been confirmed in the Alfenas region, suggesting the importance of canine surveys in non-endemic municipalities for CVL to monitor disease progression and to prevent outbreaks.
| S-EPMC5096629 | biostudies-literature
Project description:BackgroundThe relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential.MethodsParasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection.ResultsParasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs.ConclusionsSkin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs.
| S-EPMC3886905 | biostudies-literature
Project description:INTRODUCTION:In southern European countries, multicentric lymphoma and leishmaniosis are the main differential diagnoses in dogs presented with generalized lymphadenomegaly. The cytological examination is in some cases inconclusive and polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) has become a common method to confirm or rule out a lymphoproliferative neoplasia. According to the literature, leishmaniosis may lead to clonal arrangements and therefore to a false diagnosis of lymphoma, but this assumption is made from a single leishmania infected dog. Therefore, the objective of this study was to prospectively evaluate results from PARR in dogs with lymphadenomegaly due to clinical leishmaniosis at the moment of diagnosis. MATERIALS AND METHODS:31 dogs with a diagnosis of leishmaniosis based on the LeishVet guidelines were included in the study. Samples from enlarged lymph nodes were taken for cytological examination, clonality testing and Leishmania infantum PCR. RESULTS:All 31 dogs had medium to high positive antibody titers against Leishmania spp. and 30/31 had a positive Leishmania PCR from the lymph node. A polyclonal arrangement for B cells (immunoglobulin heavy chain gene) and T cells (T-cell receptor gamma chain gene) antigen receptors was found in 28/31 dogs. Two out of 31 dogs showed a monoclonal arrangement for Ig with high (1:2) and low (1:7) polyclonal background respectively; and one of the 31 dogs showed a monoclonal arrangement for T cell receptor with low (1:3) polyclonal background. CONCLUSION:Infections with Leishmania infantum resulted in clonal rearrangement, and therefore in a possible false diagnosis of lymphoma, in 3 out of 31 dogs (9.7%). Although, PARR is a useful method to differentiate lymphoma from reactive lymphoid hyperplasia in dogs with leishmaniosis, mono-/biclonal results should be interpreted carefully, especially in the presence of any degree of polyclonal background, and together with other clinicopathological findings.
| S-EPMC6913964 | biostudies-literature
Project description:A genome-wide association study (GWAS) could unravel the complexity of the cell-mediated immunity (CMI) to canine leishmaniasis (CanL). Therefore, we scanned 110,165 single-nucleotide polymorphisms (SNPs), aiming to identify chromosomal regions associated with the leishmanin skin test (LST), lymphocyte proliferation assay (LPA), and cytokine responses to further understand the role played by CMI in the outcome of natural Leishmania infantum infection in 189 dogs. Based on LST and LPA, four CMI profiles were identified (LST-/LPA-, LST+/LPA-, LST-/LPA+, and LST+/LPA+), which were not associated with subclinically infected or diseased dogs. LST+/LPA+ dogs showed increased interferon gamma (IFN-?) and tumor necrosis factor alpha (TNF-?) levels and mild parasitism in the lymph nodes, whereas LST-/LPA+ dogs, in spite of increased IFN-?, also showed increased interleukin-10 (IL-10) and transforming growth factor ? (TGF-?) levels and the highest parasite load in lymph nodes. Low T cell proliferation under low parasite load suggested that L. infantum was not able to induce effective CMI in the early stage of infection. Altogether, genetic markers explained 87%, 16%, 15%, 11%, 0%, and 0% of phenotypic variance in TNF-?, TGF-?, LST, IL-10, IFN-?, and LPA, respectively. GWAS showed that regions associated with TNF-? include the following genes: IL12RB1, JAK3, CCRL2, CCR2, CCR3, and CXCR6, involved in cytokine and chemokine signaling; regions associated with LST, including COMMD5 and SHARPIN, involved in regulation of NF-?B signaling; and regions associated with IL-10, including LTBP1 and RASGRP3, involved in T regulatory lymphocytes differentiation. These findings pinpoint chromosomic regions related to the cell-mediated response that potentially affect the clinical complexity and the parasite replication in canine L. infantum infection.
| S-EPMC5116739 | biostudies-literature
Project description:BackgroundCanine leishmaniasis caused by Leishmania infantum is a parasitic disease of great veterinary significance. Some dogs infected by L. infantum may mount a strong cellular immune response and clear the infection, while others may respond with exaggerated antibody production against the parasite and develop an overt disease, which may be fatal, if left untreated. The initial factors triggering the polarization of the immune response towards a predominantly T-helper 1 or T-helper 2 cytokines, as well as the markers of resistance and susceptibility to L. infantum infection and disease development in dogs, are not fully understood. Herein, we assessed the association between single nucleotide polymorphisms (SNPs) in the canine β-defensin-1 (CBD1) gene and the infection by L. infantum in two dog populations from Brazil (Sobral in Ceará State and São Raimundo Nonato in Piauí State) and one dog population from Italy.ResultsA total of 387 dogs were assessed for L. infantum by real time PCR and 34.6% of them were positive. In CBD1 gene sequences from these positive dogs, nine polymorphic sites were detected, but only SNPs 3, 4, 7 and 8 were associated with L. infantum, in dogs from southern Italy. No association was found with dogs from Brazil.ConclusionThis study sets the basis for further studies on the usefulness of CBD1 as a marker of L. infantum infection susceptibility in dogs.
| S-EPMC5399410 | biostudies-literature
Project description:BackgroundThere are several screening tools for detecting Leishmania infantum infection in dogs and various preventive measures to protect against it. Some studies have investigated them, but not many have described their current use. The aim of this study was to investigate which preventive measures and serological screening tools for L. infantum infection were employed from 2012 to 2018 in dogs from different endemic European countries.MethodsA set of electronic datasheets was completed for each dog from several veterinary centres. Classification of preventive measures included: (1) repellents, (2) vaccines and (3) immunomodulators. Classification of serological tests included the: (1) direct agglutination test (DAT), (2) enzyme-linked immunosorbent assay (ELISA), (3) indirect immunofluorescence (IFI), (4) rapid tests and (5) other assays. Dogs were also classified depending on their risk of exposure and living area.ResultsInformation from 3762 dogs was gathered. Preventive measures were applied in 91.5% of dogs and the most frequently used were repellents (86.2%) followed by vaccines (39.8%) and Leisguard® (15.3%). The different types of repellents (collar and spot-on) were used similarly. A combination of a vaccine and repellents was preferred in the high-risk group while the low-risk preferred a combination of Leisguard® and a repellent (Chi-square test: X2 = 88.41, df = 10, P < 0.001). Furthermore, all preventive measures were similarly used through the years except for repellents, which were predicted to have a small increase of use each year. Regarding serological screening tools, the most used were rapid and ELISA tests. Rapid tests, ELISA tests and DAT were used similarly through the years, but a significant change was found in the use of IFI and other assays whose use decreased a little each year.ConclusionsRepellents were the preferred measure, while vaccines and Leisguard® were second-line options. Some dogs were not treated by any measures, which highlights the need for dog owner education. Moreover, there seems to be a preference for rapid tests in the clinical setting to detect specific L. infantum antibodies while ELISA or IFI are less often employed. This underlines an increasing problem, as qualitative rapid tests have a variable diagnostic performance limiting the adequate diagnosis of seropositive dogs in endemic areas.
| S-EPMC9088038 | biostudies-literature