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Background: Dogs are considered the main domestic animals that may be a reservoir for Leishmania infantum, the agent of zoonotic visceral leishmaniasis (ZVL) in several countries of the world. The dog may host other Leishmania species, but its epidemiological role in the maintenance and spreading of these parasites is not completely elucidated. Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, affects thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries, few reports of L. major-positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL., Methods: Our research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. A total of 51 dogs with no or mild clinical signs of vector borne diseases were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat quantitative polymerase chain reaction (qPCR), popliteal fine needle aspiration, and cutaneous biopsy punch for lymph node and skin qPCR., Results: The results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test; the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted as infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, which can suggest a possible visceral spread of a cutaneous Leishmania species in the dog. Interestingly, one of the two L. major-positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to as ZCL., Conclusions: To our knowledge, this is the first report of L. major-positive dogs in Tunisia, the  epidemiological role of which remains under investigation., (© 2024. The Author(s).)

Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania (L.) infantum and L. major, respectively, are endemic in Tunisia. The aim of the study was to assess canine Leishmania spp. infection prevalence as well as to identify the Leishmania species involved in two well-documented and geographically distinct VL and ZCL foci. One hundred seventy-six dogs were randomly recruited in the VL focus of Sbikha-Zaghouan (n = 100) and the ZCL focus of Echrarda-Nasrallah (n = 76). Physical examination and blood collection were systemically performed. Needle aspiration was done in case of lymph node (LN) enlargement. All sera were tested by ELISA. kDNA RT-PCR was performed on DNA extracts from (i) buffy coats of seropositive dogs and (ii) LN aspirates. Leishmania species identification was done by ITS1 PCR-sequencing. Thirty-three dogs (18.8%) were infected by Leishmania; 30 having anti-Leishmania antibodies and 3 were seronegative dogs with Leishmania DNA in LN aspirates. Prevalence of infection was significantly higher in VL foci than in ZCL foci (27% versus 7.9%, p = 0.002). Leishmania species was identified in 11 dogs and corresponded to L. infantum. Combination of serology and qPCR on LN aspirates seems to be the best option for canine leishmaniasis diagnosis. Infection is more frequent in VL foci and L. infantum is the only identified species., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ZRIBI LILIA reports financial support was provided by Ministry of Higher Education and Scientific Research. ZRIBI LILIA reports financial support was provided by Bilateral Turkish & Tunisian Project 119 O 735 TUBITAK&MHESR. ZRIBI LILIA reports financial support was provided by LeiSHield-MATI H2020 RISE project., (Copyright © 2023. Published by Elsevier B.V.)

Background: Ocular manifestations in dogs with leishmaniasis are frequent and complications in affected tissues can lead to blindness. Immune processes play a very important role in the pathogenesis of ocular inflammation. Therefore, the immunology of ocular manifestations in dogs with leishmaniasis remains complex and poorly understood., Objectives: Estimation and characterisation of ocular and periocular manifestations in dogs naturally infected with Leishmania infantum and investigation of the production site of specific anti-Leishmania infantum IgG., Methods: The present investigation used 53 confirmed dogs infected with Leishmania infantum, presenting ocular and periocular lesions, and 10 control non-infected dogs. Complete macroscopic ophthalmic examination of eyelids and globes was performed. Both total and anti-Leishmania infantum IgG antibodies were studied in sera and aqueous humour (AH) of all dogs by ELISA technique. A Goldmann-Witmer coefficient (C value) was calculated., Results: The main ophthalmological findings were keratoconjunctivitis (71.7%; 38/53), hyperplasia of conjunctival lymphoid follicles (54.7%; 29/53), blepharitis (50.9%; 27/53) and uveitis (20.7%; 11/53). Ocular production of anti-Leishmania infantum IgG was detected in 73.6% (39/53) of infected dogs. There was no correlation between the antibody levels in AH and sera of the same dog. The mean anti-Leishmania infantum IgG in AH was higher in uveitis, followed by lesions affecting only the adnexa (p < 0.0001). The highest mean C values were observed for uveitis, conjunctivitis and keratitis., Conclusions: Our findings suggest that production of anti-Leishmania IgG in dogs infected with Leishmania infantum with ocular manifestations begin in situ and follows by a transfer of antibodies from the bloodstream to the AH., (© 2022 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Alzheimer's disease (AD) is multifactorial disease characterized by the accumulation of abnormal extracellular deposits of amyloid-beta (Aβ) peptide, and intracellular neurofibrillary tangles (NFTs), along with dramatic neuronal death and decreased levels of choline acetyltransferase. Given the limited therapeutic success of available drugs, it is urgent to explore all the opportunities available to combat this illness. Among them, the discovery of new heterocyclic scaffolds binding different receptors involved in AD should offer structural diversity and new therapeutic solutions. In this context, this work describes new triazolopyridopyrimidine easily prepared in good yields showing anticholinesterase inhibition and strong antioxidant power, particularly the most balanced: 6-amino-5-(4-methoxyphenyl)-2-phenyl-[1,2,4]triazolo[1',5':1,6] pyrido[2,3-d]pyrimidine-4-carbonitrile( 3c ) with IC 50 equal to 1.32 μM against AChE and oxygen radical absorbance capacity (ORAC) value equal to 4.01 Trolox equivalents (TE); thus representing a new and very promising hit-triazolopyridopyrimidine for AD therapy.

Background: Visceral leishmaniasis is a zoonotic disease of major public health concern in several countries in the world. The local population awareness would improve prevention, early detection and treatment of both human and animal leishmaniasis., Methods: The aim of this survey was to assess the knowledge about visceral leishmaniasis in a sample of dog owners visiting the National School of Veterinary Medicine of Sidi Thabet, Tunisia, through a structured questionnaire., Findings: Two hundred dog owners were interviewed, 87% were men and 47% had higher education level. Ninety four per cent were from neighbouring districts to Ariana, where the National School of Sidi Thabet is located. Out of 200 respondents, 79 confirmed knowing leishmaniasis. The correct answers concerning canine visceral leishmaniasis (CVL) (77%) were significantly higher than those concerning human visceral leishmaniasis (HVL) (23%). Correct answers concerning CVL were given in part by previously diseased dogs' owners. The respondent could not explain what is exactly leishmaniasis, but the majority of questioned persons know that human and dogs are the most important hosts. Forty-four out 79 (56%) of the persons think that mosquitoes or insects are the vectors of leishmaniasis and 63% (53/79) knows that it is a zoonotic disease but 72% (38/53) were not able to define how., Conclusion: Despite the frequent visits to veterinarians for vaccination or other medical issues and their long experience in dog breeding, the sample of dog owners had not enough knowledge and several misconceptions regarding leishmaniasis. Large education programmes should be implemented in Tunisia to improve the knowledge of the Tunisian population, especially dog owners, concerning leishmaniasis.

Interferon-Gamma (IFN-γ) Release Assays (IGRAs) are easy tests that allow rapid screening of primed memory T-cells immunity in response to antigen. The aim of this study was to use IGRA to assess IFN-γ release in response to Soluble Leishmania infantum antigen (SLA) in whole blood of dogs living in endemic area of visceral leishmaniasis and to interpret IGRA results according to clinical examination, specific anti-Leishmania humoral response and presence of L. infantum DNA in blood. The study was carried out on 56 dogs living in greater Tunis area. Physical examination, quantitative serology and PCR on blood were used to characterize dogs' status in relation to Leishmania infection and disease. IGRA consisted on testing by ELISA for IFN-γ-secretion in whole blood after a 20-h challenge with SLA. PBS and Phytohemagglutinin (PHA) stimulations were used as controls. Four groups of dogs were characterized: 31 were negative by both serology and PCR, two had doubtful serology, 10 presented no to mild clinical signs but low antibodies levels and 13 were affected by Canine Leishmaniasis (CanL). In seronegative dogs, IGRA was little contributory in 4 puppies (age <6months) and 5 old dogs (median age=72months, IQR: 45-84 months) that didn't respond to PHA stimulation, IGRA was negative in 19 and positive in three animals with lymph node enlargement. In dogs with doubtful serology, IGRA was positive in one dog and negative in the other. In infected dogs with no to mild clinical signs, one dog exhibited high level of IFN-γ in absence of antigenic stimulation and all the other were positive by IGRA. CanL dogs showed variable IGRA results. Negative IGRAs (n=4) were shown in animals with the highest parasitic burden whereas positive IGRAs (n=5) were shown in dogs with negative PCR or low parasitic load. The 4 remaining dogs either didn't respond to PHA (n=2) or showed non-specific secretion in PBS tube (n=2). The results of this study showed that IGRA is a useful new tool that can assess exposure to Leishmania in dogs with no to mild clinical signs in endemic area. Further comparative investigations using assays exploring cellular immunity are needed to determine its accuracy., (Copyright © 2017 Elsevier B.V. All rights reserved.)