BACKGROUND Trypanosoma cruzi, which causes Chagas disease (CD), is a versatile haemoparasite that uses several strategies to evade the host’s immune response, including adipose tissue (AT), used as a reservoir of infection. As it is an effective barrier to parasite evasion, the effectiveness of the drug recommended for treating CD, Benznidazole (BZ), may be questionable. OBJECTIVE To this end, we evaluated the parasite load and immunomodulation caused by BZ treatment in the culture of adipocytes differentiated from human adipose tissue-derived stem cells (ADSC) infected with T. cruzi. METHODS The ADSC were subjected to adipogenic differentiation. We then carried out four cultures in which we infected the differentiated AT with trypomastigote forms of the Y strain of T. cruzi and treated them with BZ. After the incubation, the infected AT was subjected to quantitative polymerase chain reaction (qPCR) to quantify the parasite load and transmission electron microscopy (TEM) to verify the infection. The supernatant was collected to measure cytokines, chemokines, and adipokines. FINDINGS We found elevated secretion of IL-6, CXCL-10/IP-10, CCL2/MCP-1, CCL5/RANTES, and leptin in infected fat cells. However, treatment with BZ promoted a decrease in IL-6. MAIN CONCLUSION Therefore, we believe that BZ has a beneficial role as it reduces inflammation in infected fat cells. CD , (CD) hosts host s response AT, (AT) infection evasion BZ, (BZ) questionable end tissuederived derived (ADSC T differentiation incubation qPCR (qPCR TEM (TEM cytokines chemokines adipokines IL6, IL6 IL 6, 6 IL-6 CXCL10/IP10, CXCL10IP10 CXCLIP CXCL 10/IP 10, 10 IP CXCL-10/IP-10 CCL2/MCP1, CCL2MCP1 CCLMCP CCL2/MCP 1, CCL2 MCP 1 CCL CCL2/MCP-1 CCL5RANTES CCLRANTES CCL5 RANTES CCL5/RANTES However IL6. 6. Therefore (CD (AT (BZ IL- CXCL10 IP10 CXCL10/IP10 CXCL10IP1 10IP CXCL-10/IP-1 MCP1 CCL2/MCP1 CCL2MCP CCL2/MCP- CXCL1 IP1 CXCL10/IP1 CXCL10IP CXCL-10/IP- CXCL10/IP CXCL-10/IP

Abstract INTRODUCTION: Molecular techniques have been shown to be alternative methods for the accurate detection of infectious and parasitic diseases, such as the leishmaniases. The present study describes the optimization and evaluation of a duplex real-time quantitative PCR (qPCR) protocol developed for the simultaneous detection of Leishmania infantum DNA and sample quality control. METHODS: After preliminary tests with the newly designed TaqMan® probes for the two targets ( L. infantum and glyceraldehyde 3-phosphate dehydrogenase (G3PD) gene), the duplex qPCR protocol was optimized. For the evaluation of the standardized protocol, human blood samples were tested (n=68) and the results were compared to those obtained by reference diagnostic techniques. Statistical analyses included percentage agreement and the Kappa ( k ) coefficient. RESULTS: The detection limit of L. infantum DNA reached 2x10 2 fg (corresponding to ~1 parasite) per µL of blood (ε: 93.9%). The percentage agreement obtained between the duplex VL qPCR and the reference techniques was individually obtained as follows: molecular: 88.3% ( k =0.666; 95% CI 0.437-0.894, good), and serological: 81.7% ( k =0.411; 95% CI 0.125-0.697, moderate). Between the reference techniques, the percentage agreement was 86.7% ( k =0.586; 95% CI 0.332-0.840, moderate). CONCLUSIONS: The new duplex VL qPCR protocol indicated good potential for the accurate, fast, and reliable detection of L. infantum DNA, when applied as a complement to the classical diagnostic tools already available, especially in health or research reference centers.

Background : Molecular biological methods have become increasingly relevant to the diagnosis and control of infectious diseases, such as leishmaniasis. Since various factors may affect the sensitivity of PCR assays, including DNA yield and purity, an optimal extraction method is pivotal. Losses of a parasite’s DNA during extraction may significantly impair its detection by PCR and lead to false-negative results. This study proposes a triplex PCR assay targeting the parasite’s DNA, an external control (pUC18) and an internal control (G3PD) for accurate diagnosis of leishmaniasis.Results : Two primer pairs were designed to detect the plasmid pUC18 and a triplex PCR assay targeting theLeishmania braziliensiskinetoplast DNA, the external control and the internal control was standardized. The triplex PCR assay was assessed for its ability to detect the three target DNA fragments simultaneously. PCR products from pUC18 DNA resulted in bands of 368 (P1) and 316 (P2) base pairs (bp). The triplex PCR optimized with the chosen external control system (P1) allowed the simultaneous detection of the internal control (G3PD – 567 bp) as well as of small quantities (10 pg) of the target parasite’s DNA, detected by amplification of a 138 bp product.Conclusions : The new tool standardized herein enables a more reliable interpretation of PCR results, mainly by contributing to quality assurance of leishmaniasis diagnosis. Furthermore, after simple standardization steps, this protocol could be applied to the diagnosis of other infectious diseases in reference laboratories. This triplex PCR enables the assessment of small losses during the DNA extraction process, problems concerning DNA degradation (sample quality) and the detection ofL. braziliensiskDNA.

A leishmaniose cutânea canina causada por Leishmania braziliensis é uma doença negligenciada, mas disseminada entre cães na America do Sul. Este artigo descreve alterações clínicas e hematológicas em 17 cães infectados por L. braziliensis do Brasil. As alterações hematológicas mais comuns foram trombocitopenia (82,4%), anemia (70,6%), baixo valor de hematócrito (52,9%) e eosinofilia (41,2%). Doze (70,6%) cães apresentaram pelo menos uma alteração física; 11 (64,7%) apresentaram lesões cutâneas, quatro (23,5%) perda de peso e dois (11,8%) onicogrifose. Cães infectados por L. braziliensis apresentaram alterações clínicas e hematológicas inespecíficas que são comumente observadas em cães infectados por outros patógenos. Isso indica que veterinários e profissionais de saúde pública não deveriam considerar a presença de tais sinais clínicos como critério de diagnóstico para leishmaniose visceral em cães, em áreas endêmicas, no intuito de evitar um diagnóstico equivocado e a subsequente eliminação de cães infectados por L. braziliensis.

Canine cutaneous leishmaniasis by Leishmania braziliensis is a neglected, but widespread disease of dogs in South America. This paper describes clinical and hematological alterations in 17 L. braziliensis-infected dogs from Brazil. The most common hematological findings were thrombocytopenia (82.4%), anemia (70.6%), low packed cell volume (52.9%) and eosinophilia (41.2%). Twelve (70.6%) dogs displayed at least one evident physical alteration; 11 dogs (64.7%) presented skin lesions, four (23.5%) had weight loss and two (11.8%) onychogryphosis. L. braziliensis-infected dogs present clinical and hematological signs often observed in dogs infected by other pathogens. This indicates that veterinarians and public health workers should not consider the presence of non-specific clinical signs as diagnostic criteria for visceral leishmaniasis in dogs living endemic areas to avoid misdiagnosis and subsequent elimination of dogs infected by L. braziliensis.