The use of conjunctival swab samples for PCR screening for visceral leishmaniasis in vaccinated dogs

The polymerase chain reaction (PCR) has been shown to provide a rapid and sensitive technique for Leishmania detection. The aim of this study was to evaluate the technique of noninvasive conjunctival swabs (CS) as a sampling method for molecular screening for visceral leishmaniasis (VL) in a group of 42 police dogs, all of them vaccinated against VL, and to compare the results with those obtained by serological tests. The serological assays were performed independently by three laboratories. Laboratories 1 and 2 were private laboratories and laboratory 3 was the National Reference Laboratory. The first serological screening performed by laboratory 1 showed 15 reactive dogs and 4 indeterminate. Laboratory 2 confirmed only 3 reactive dogs and 2 indeterminate. Laboratory 3 confirmed 7 reactive dogs and 3 indeterminate. The PCR diagnosis using the CS procedure was performed on all 42 animals and was able to detect Leishmania DNA in 17 dogs. The PCR assay confirmed all the cases that were simultaneously reactive in the serological tests by two laboratories. The results showed that the CS technique was a sensitive and practical method for sample collection, thus allowing reliable diagnostic tests through PCR

Revista Brasileira de Parasitologia Veterinária The use of conjunctival swab samples for PCR screening for visceral leishmaniasis in vaccinated dogs The use of conjunctival swab samples for PCR screening for visceral leishmaniasis in vaccinated dogs

Abstract The polymerase chain reaction (PCR) has been shown to provide a rapid and sensitive technique for Leishmania detection. The aim of this study was to evaluate the technique of noninvasive conjunctival swabs (CS) as a sampling method for molecular screening for visceral leishmaniasis (VL) in a group of 42 police dogs, all of them vaccinated against VL, and to compare the results with those obtained by serological tests. The serological assays were performed independently by three laboratories. Laboratories 1 and 2 were private laboratories and laboratory 3 was the National Reference Laboratory. The first serological screening performed by laboratory 1 showed 15 reactive dogs and 4 indeterminate. Laboratory 2 confirmed only 3 reactive dogs and 2 indeterminate. Laboratory 3 confirmed 7 reactive dogs and 3 indeterminate. The PCR diagnosis using the CS procedure was performed on all 42 animals and was able to detect Leishmania DNA in 17 dogs. The PCR assay confirmed all the cases that were simultaneously reactive in the serological tests by two laboratories. The results showed that the CS technique was a sensitive and practical method for sample collection, thus allowing reliable diagnostic tests through PCR. Keywords: Visceral leishmaniasis, dog, diagnosis, PCR, conjunctival swab. Resumo A PCR (do inglês Polymerase Chain Reaction) tem demonstrado ser uma técnica rápida e sensível para detecção de Leishmania. O objetivo deste estudo foi avaliar a técnica não invasiva do swab conjuntival na identificação por PCR de animais infectados em um grupo de 42 cães policiais, todos vacinados contra a Leishmaniose Visceral (VL), e comparar os resultados com aqueles obtidos pelos testes sorológicos. Os ensaios sorológicos foram realizados independentemente por três laboratórios. Os laboratórios 1 e 2 eram privados. O laboratório 3 era o Laboratório de Referência Nacional. A primeira triagem sorológica realizada pelo laboratório 1 apresentou 15 cães reativos e 4 indeterminados. O laboratório 2 confirmou apenas 3 cães reativos e 2 animais indeterminados. O laboratório 3 confirmou 7 cães reativos e 3 cães foram classificados como indeterminados. O diagnóstico pela PCR, utilizando o procedimento do swab conjuntival, foi realizado em todos os 42 animais e foi capaz de detectar DNA de Leishmania em 17 cães. A PCR confirmou todos os casos simultaneamente reativos nos testes sorológicos de dois laboratórios. Os resultados demonstraram que o swab conjuntival é um método sensível e prático para coleta de amostra, permitindo um diagnóstico consistente através da PCR

Combination oral therapy against Leishmania amazonensis infection in BALB/c mice using nanoassemblies made from amphiphilic antimony(V) complex incorporating miltefosine

8p.-3 fig.-1 tab.Clinically available drugs for mucocutaneous and cutaneous leishmaniases (CL) include mainly pentavalent antimony (Sb(V)) complexes, liposomal amphotericin B, and miltefosine (HePC). However, they present at least one of the following limitations: long-term parenteral administration through repeated doses, severe side effects, drug resistance, and high cost. HePC is the only oral drug available, but the appearance of resistance has resulted in changes of its use from monotherapy to combination therapy. Amphiphilic Sb(V) complexes, such as SbL8 obtained from reaction of Sb(V) with N-octanoyl-N-methylglucamide, were recently found to be orally active against experimental CL. The property of SbL8 to self-assemble in aqueous solution, forming nanostructures, led us to investigate the incorporation of HePC into SbL8 nanoassemblies and the therapeutic efficacy of SbL8/HePC nanoformulation by oral route in a murine model of CL. HePC incorporation into the SbL8 nanosystem was evidenced by using a fluorescent analog of HePC. The antileishmanial activity of SbL8/HePC nanoassemblies was evaluated after daily oral administration for 30 days in Leishmania amazonensis-infected BALB/c mice, in comparison with monotherapies (SbL8 or HePC) and saline control. All the treatments resulted in significant reduction in the lesion size growth, when compared with control. Strikingly, only SbL8/HePC nanoassemblies promoted a significant decrease of the parasite burden in the lesion. This work establishes the therapeutic benefit of SbL8/HePC association by oral route in a CL model and constitutes an important step towards the development of new orally active drug combination.This work was supported by the Brazilian agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant number: 425332/2018–7), Coordenação de Aperfeicoamento de Pessoal de Nível Superior (CAPES, grant number: PNPD20131163), and Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG, grant number: APQ-03129-16) for financial support. F.F. was recipient of fellowship from CNPq (grant number: 305659/2017-0) and Chaire Jean d’Alembert, Université Paris-Saclay, France (ANR-11-IDEX-0003-02). L.R was supported by Program of Redes Temáticas de Investigación Cooperativa RETICS-FEDER (grant number: RD16/0027/0010).Peer reviewe