Functional infrared thermography imaging can be used to assess the effectiveness of Maxicam Gel® in pre-emptively treating transient synovitis and lameness in horses.

Introduction: Diagnosing and treating lameness in horses is essential to improving their welfare. In equine orthopedic practice, infrared thermography (IRT) can indirectly detect soreness. Non-steroidal anti-inflammatory drugs can treat painful and inflammatory processes in horses. Using IRT, the efficacy of meloxicam (Maxicam Gel®) was evaluated in pre-treating transient synovitis in horses induced by a middle carpal joint injection of lipopolysaccharides (LPS) from E. coli 055:B5 at a dose of 10 endotoxin units. Methods: In a cross-over design, six healthy horses were randomly assigned to receive either 0.6 mg/kg of oral Maxicam Gel® (MAXVO) or a mock administration (control group, C) following a two-week washout period. IRT of the middle carpal joint, visual lameness assessment and joint circumference were recorded over time. Clinical and hematological evaluations were performed. Synovial fluid aspirates were analyzed for total nucleated cell count, total protein, and prostaglandin E2. A mixed effects analysis of variance was performed for repeated measures over time, followed by Tukey's test. A multinomial logistic regression was conducted to determine whether there is a relationship between a thermography temperature change and the lameness score. Results: There were no changes in joint circumference. The MAXVO group showed a lower rectal temperature 4 h after synovitis induction. The C group presented an increase in neutrophils and a decrease in total hemoglobin and hematocrit 8 h after induction. No changes were observed in the synovial fluid between groups. The horses that received meloxicam did not show clinically significant lameness at any time, while the C group showed an increase in lameness 2, 4, and 8 h after synovitis induction. Discussion: IRT indicated that the skin surface temperature of the middle carpal joint was lower in horses who received meloxicam, suggesting a reduction in the inflammatory process induced by LPS. It was observed that the maximum temperature peaks in the dorsopalmar and lateropalmar positions can be utilized to predict the severity of lameness, particularly when the temperature rises above 34°C. Horses pre-treated with meloxicam showed either reduced or no indication of mild to moderate pain and presented a lowehr thermographic temperature, which indicates the effectiveness of Maxicam Gel® as an anti-inflammatory.

Carbon stock in aboveground biomass and necromass in the Atlantic Forest: an analysis of data published between 2000 and 2021.

Synthesising knowledge on carbon stocks is an essential tool for understanding the potential of forests to store carbon and its drivers. However, such a synthesis needs to be constructed for the Atlantic Forest due to various methodological approaches and biogeographic heterogeneity. Thus, here we conducted a bibliographic search (2000 to 2021) on carbon stocks in the biomass and necromass of Atlantic Forest ecosystems to understand the variation in stocks and their explanatory variables. Drivers included spatial (altitude, forest size) and climatic (precipitation and temperature) variables, and successional stages. Based on the information in 46 articles, biomass exhibited the highest carbon stock (96%), in Mature Forests (MF), with an average of 125.34±40.3 MgC.ha-1, whereas Secondary Forests (SF) stored 82.7±38.2 MgC.ha-1. The carbon in the necromass varied from 1.63 to 11.47 MgC.ha-1, with SF exhibiting 3.90±2.73 MgC.ha-1 and MF 4.31±2.82 MgC.ha-1. Only average annual precipitation and successional stage positively explained the carbon in Atlantic Forest. This research clarifies the function and potential of Atlantic Forest fragments for storing carbon and reinforces need for conserving mature forest patches throughout the biome since one hectare of mature forest can store almost twice as much carbon as one hectare of secondary young patches.

Changes in Astroglial Water Flow in the Pre-amyloid Phase of the STZ Model of AD Dementia.

Alzheimer's disease (AD) is an age-dependent neurodegenerative disease that is typically sporadic and has a high social and economic cost. We utilized the intracerebroventricular administration of streptozotocin (STZ), an established preclinical model for sporadic AD, to investigate hippocampal astroglial changes during the first 4 weeks post-STZ, a period during which amyloid deposition has yet to occur. Astroglial proteins aquaporin 4 (AQP-4) and connexin-43 (Cx-43) were evaluated, as well as claudins, which are tight junction (TJ) proteins in brain barriers, to try to identify changes in the glymphatic system and brain barrier during the pre-amyloid phase. Glial commitment, glucose hypometabolism and cognitive impairment were characterized during this phase. Astroglial involvement was confirmed by an increase in glial fibrillary acidic protein (GFAP); concurrent proteolysis was also observed, possibly mediated by calpain. Levels of AQP-4 and Cx-43 were elevated in the fourth week post-STZ, possibly accelerating the clearance of extracellular proteins, since these proteins actively participate in the glymphatic system. Moreover, although we did not see a functional disruption of the blood-brain barrier (BBB) at this time, claudin 5 (present in the TJ of the BBB) and claudin 2 (present in the TJ of the blood-cerebrospinal fluid barrier) were reduced. Taken together, data support a role for astrocytes in STZ brain damage, and suggest that astroglial dysfunction accompanies or precedes neuronal damage in AD.

Leishmania (Sauroleishmania) tarentolae versus pathogenic species: comparative evaluation of protease activity, glycoconjugates, resistance to complement and metabolome composition.

BACKGROUND: Leishmania tarentolae is a non-pathogenic species found in lizards representing an important model for Leishmania biology. However, several aspects of this Sauroleishmania remain unknown to explain its low level of virulence. OBJECTIVES: We reported several aspects of L. tarentolae biology including glycoconjugates, proteolytic activities and metabolome composition in comparison to pathogenic species (Leishmania amazonensis, Leishmania braziliensis, Leishmania infantum and Leishmania major). METHODS: Parasites were cultured for extraction and purification of lipophosphoglycan (LPG), immunofluorescence probing with anti-gp63 and resistance against complement. Parasite extracts were also tested for proteases activity and metabolome composition. FINDINGS: Leishmania tarentolae does not express LPG on its surface. It expresses gp63 at lower levels compared to pathogenic species and, is highly sensitive to complement-mediated lysis. This species also lacks intracellular/extracellular activities of proteolytic enzymes. It has metabolic differences with pathogenic species, exhibiting a lower abundance of metabolites including ABC transporters, biosynthesis of unsaturated fatty acids and steroids, TCA cycle, glycine/serine/threonine metabolism, glyoxylate/dicarboxylate metabolism and pentose-phosphate pathways. MAIN CONCLUSIONS: The non-pathogenic phenotype of L. tarentolae is associated with alterations in several biochemical and molecular features. This reinforces the need of comparative studies between pathogenic and non-pathogenic species to elucidate the molecular mechanisms of virulence during host-parasite interactions.

Diagnosis of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM).

Hyperprolactinemia is a frequent cause of menstrual irregularity, galactorrhea, hypogonadism, and infertility. The most common etiologies of hyperprolactinemia can be classified as physiological, pharmacological, and pathological. Among pathological conditions, it is essential to distinguish prolactinomas from other tumors and pituitary lesions presenting with hyperprolactinemia due to pituitary stalk disconnection. Proper investigation considering clinical data, laboratory tests, and, if necessary, imaging evaluation, is important to identify the correctcause of hyperprolactinemia and manage the patient properly. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Societyof Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and medication-induced hyperprolactinemia in women.

Treatment of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM).

Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia. Treatment with these agents is effective in 80%-90% of the cases. Infertility treatment of patients with hyperprolactinemia is also carried out with dopamine agonists, aiming for the normalization of prolactin levels. The risk of symptomatic growth of prolactinomas during pregnancy is dependent on the tumor's size, duration of previous treatments, and prolactin levels. Notably, the corresponding risk is relatively low in cases of microprolactinomas (<5%). Remission of hyperprolactinemia occurs in about 30% of the patients after drug treatment and may also occur after pregnancy and menopause. The use of some drugs, such as antidepressants and antipsychotics, is a frequent cause of hyperprolactinemia, and managing this occurrence involves unique considerations. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and drug-induced hyperprolactinemia in women.

Maternal Vitamin D Deficiency Impairs the Development of ß Cells in Offspring Rats in a Sex-Dependent Manner.

Recent studies have shown that maternal vitamin D deficiency (VDD) causes long-term metabolic changes in offspring. However, little is known about the impact of maternal VDD on offspring endocrine pancreas development and insulin secretion in the adult life of male and female animals. Female rats (Wistar Hannover) were fed either control (1000 IU Vitamin D3/kg), VDD (0 IU Vitamin D3/kg), or a Ca2+-enriched VDD diet (0 IU Vitamin D3/kg + Ca2+ and P/kg) for 6 weeks and during gestation and lactation. At weaning, VDD status was confirmed based on low serum calcidiol levels in dams and pups. Next, male and female offspring were randomly separated and fed a standard diet for up to 90 days. At this age, serum calcidiol levels were restored to normal levels in all groups, but serum insulin levels were decreased in VDD males without affecting glucagon levels, glycemia, or glucose tolerance. Islets isolated from VDD males showed lower insulin secretion in response to different glucose concentrations, but this effect was not observed in VDD females. Furthermore, VDD males, but not females, showed a smaller total pancreatic islet area and lower ß cell mass, an effect that was accompanied by reduced gene expression of Ins1, Ins2, Pdx1, and SLC2A2. The decrease in Pdx1 expression was not related to the methylation profile of the promoter region of this gene. Most of these effects were observed in the male VDD+Ca2+ group, indicating that the effects were not due to alterations in Ca2+ metabolism. These data show that maternal VDD selectively impairs the morphology and function of ß cells in adult male offspring rats and that female offspring are fully protected from these deleterious effects.

Intrauterine insemination: prognostic factors.

OBJECTIVE: To evaluate the impact of possible maternal and paternal prognostic factors and ovarian stimulation protocols on clinical pregnancy and live birth rates in intrauterine insemination (IUI) cycles. METHODS: Retrospective observational study of 341 IUI cycles performed from January 2016 to November 2020 at the Assisted Reproduction Service of the Clinics Hospital of the Ribeirão Preto Medical School, University of São Paulo. Clinical pregnancy and live birth rates and their potential prognostic factors were evaluated. Wilcoxon's non-parametric test was used to compare quantitative variables, and the chi-square test to compare qualitative variables, adopting a significance level of p<0.05. A logistic regression model was performed to verify which exploratory variables are predictive factors for pregnancy outcome. RESULTS: The ovulation induction protocol using gonadotropins plus letrozole (p=0.0097; OR 4.3286, CI 1.3040 - 14.3684) and post-capacitation progressive sperm ≥ 5million/mL (p=0.0253) showed a statistically significant correlation with the live birth rate. Female and male age, etiology of infertility, obesity, multifollicular growth, endometrial thickness ≥ 7 mm, and time between human chorionic gonadotropin administration and IUI performance were not associated with the primary outcomes. In the group of patients with ideal characteristics (women aged< 40 years, BMI < 30 kg/m2, antral follicle count ≥ 5, partner aged< 45 years, and post-capacitation semen with progressive spermatozoa ≥ 5 million/mL), the rate of clinical pregnancy was 14.8%, while that of live birth, 9.9%. CONCLUSIONS: In this study, the ovulation induction protocol with gonadotropins plus letrozole and post-capacitation progressive sperm ≥ 5 million/mL were the only variables that significantly correlated with intrauterine insemination success.

Management of hypoactive sexual desire dysfunction at a specialized service in women's sexual health.

Hypoactive sexual desire dysfunction (HSDD) is prevalent among women. This retrospective cohort study aimed to verify the results of the strategies used by Gynecologists and Obstetricians (Ob-gyn) residents in the management of female HSDD. For this, we conducted a data collection of patient medical records of women with HSDD from the Human Sexuality Studies outpatient clinic of the Human Reproduction Center, Department of Gynecology and Obstetrics of FMRP-USP, from 2005 to 2019. Among the 437 women included, 361 (82.6%) answered the question concerning the effect of the protocol to which they were submitted, whereas 234 (64.8%) reported improvements in sexual desire. The univariate model showed that patients without chronic pelvic pain were 19.0% less likely to report improvements in HSDD than those with chronic pelvic pain (p = 0.03). Patients without depression and without orgasmic dysfunction were, respectively 32% and 23% more likely to show improvements in their HSDD than those who had depression or orgasmic dysfunction (respectively p = 0.001, p = 0.008). However, the multivariate model did not identify any associations. The assistance regarding HSDD by the Ob-gyn resident in training to deal with female sexual complaints may be effective in improving sexual complaints.

An artificial intelligence approach of feature engineering and ensemble methods depicts the rumen microbiome contribution to feed efficiency in dairy cows.

Genetic selection has remarkably helped U.S. dairy farms to decrease their carbon footprint by more than doubling milk production per cow over time. Despite the environmental and economic benefits of improved feed and milk production efficiency, there is a critical need to explore phenotypical variance for feed utilization to advance the long-term sustainability of dairy farms. Feed is a major expense in dairy operations, and their enteric fermentation is a major source of greenhouse gases in agriculture. The challenges to expanding the phenotypic database, especially for feed efficiency predictions, and the lack of understanding of its drivers limit its utilization. Herein, we leveraged an artificial intelligence approach with feature engineering and ensemble methods to explore the predictive power of the rumen microbiome for feed and milk production efficiency traits, as rumen microbes play a central role in physiological responses in dairy cows. The novel ensemble method allowed to further identify key microbes linked to the efficiency measures. We used a population of 454 genotyped Holstein cows in the U.S. and Canada with individually measured feed and milk production efficiency phenotypes. The study underscored that the rumen microbiome is a major driver of residual feed intake (RFI), the most robust feed efficiency measure evaluated in the study, accounting for 36% of its variation. Further analyses showed that several alpha-diversity metrics were lower in more feed-efficient cows. For RFI, [Ruminococcus] gauvreauii group was the only genus positively associated with an improved feed efficiency status while seven other taxa were associated with inefficiency. The study also highlights that the rumen microbiome is pivotal for the unexplained variance in milk fat and protein production efficiency. Estimation of the carbon footprint of these cows shows that selection for better RFI could reduce up to 5 kg of diet consumed per cow daily, potentially reducing up to 37.5% of CH4. These findings shed light that the integration of artificial intelligence approaches, microbiology, and ruminant nutrition can be a path to further advance our understanding of the rumen microbiome on nutrient requirements and lactation performance of dairy cows to support the long-term sustainability of the dairy community.

Potential of Ocotea indecora Essential Oil for Controlling Drosophila suzukii: Molecular Predictions for Toxicity and Selectivity to Beneficial Arthropods.

The protection of soft-skinned fruits against Drosophila suzukii has relied primarily on the efficacy of a few synthetic molecules. Despite their short-term efficacy, these molecules can cause environmental pollution, unintendedly affect non-target organisms, and fail to provide sustainable control. The shortfalls of using synthetic pesticides warrant the search for alternatives, such as essential oils extracted from plants, with greater eco-friendlier properties. Here, we chemically characterized and evaluated the toxicity of the essential oil extracted from leaves of Ocotea indecora (Schott) Mez (Lauraceae) against D. suzukii via two exposure pathways (ingestion and contact). We also assessed the selectivity of the essential oil to two predatory natural enemies, Eriopis connexa and Chrysoperla externa and two pollinator bees, Apis mellifera and Partamona helleri. In addition, we conducted in silico predictions to investigate potential interactions between the major compound of the essential oil and the insects' transient receptor potential (TRP) channels. Our chromatographic analysis revealed sesquirosefuran (87%) as the major compound. Higher toxicity to adults of D. suzukii was observed in contact exposure (LC50 = 0.43 µL mL-1) compared to ingestion (LC50 = 0.72 µL mL-1). However, the essential oil did not cause mortality to the non-target organisms tested here, even when applied at 2.20 µL mL-1. Molecular predictions demonstrated that sesquirosefuran binds more stably to the TRP channels of D. suzukii than to those expressed in beneficial arthropods. Collectively, our findings provide the initial framework for the potential use of O. indecora essential oil as a sustainable alternative for managing D. suzukii infestations.

Boron-containing coating yields enhanced antimicrobial and mechanical effects on translucent zirconia.

OBJECTIVES: To evaluate the mechanical and antimicrobial properties of boron-containing coating on translucent zirconia (5Y-PSZ). METHODS: 5Y-PSZ discs (Control) were coated with a glaze (Glaze), silver- (AgCoat), or boron-containing (BCoat) glasses. The coatings' antimicrobial potential was characterized using S. mutans biofilms after 48 h via viable colony-forming units (CFU), metabolic activity (CV) assays, and quantification of extracellular polysaccharide matrix (EPS). Biofilm architectures were imaged under scanning electron and confocal laser scanning microscopies (SEM and CLSM). The cytocompatibility was determined at 24 h via WST-1 and LIVE&DEAD assays using periodontal ligament stem cells (PDLSCs). The coatings' effects on properties were characterized by Vickers hardness, biaxial bending tests, and fractography analysis. Statistical analyses were performed via one-way ANOVA, Tukey's tests, Weibull analysis, and Pearson's correlation analysis. RESULTS: BCoat significantly decreased biofilm formation, having the lowest CFU and metabolic activity compared with the other groups. BCoat and AgCoat presented the lowest EPS, followed by Glaze and Control. SEM and CLSM images revealed that the biofilms on BCoat were thin and sparse, with lower biovolume. In contrast, the other groups yielded robust biofilms with higher biovolume. The cytocompatibility was similar in all groups. BCoat, AgCoat, and Glaze also presented similar hardness and were significantly lower than Control. BCoat had the highest flexural strength, characteristic strength and Weibull parameters (σF: 625 MPa; σ0: 620 MPa; m = 11.5), followed by AgCoat (σF: 464 MPa; σ0: 478 MPa; m = 5.3). SIGNIFICANCE: BCoat is a cytocompatible coating with promising antimicrobial properties that can improve the mechanical properties and reliability of 5Y-PSZ.

Infecções urinárias e processo do cuidado: perfil etiológico e de sensibilidade no setor de clínica médica de um hospital público da Paraíba / Urinary infections and care process: etiological profile and sensitivity in the medical clinic sector of a public hospital in Paraiba / Infecciones urinarias y proceso asistencial: perfil etiológico y de sensibilidad en el sector clínico de un hospital público de Paraíba

Introdução: Há alguns fatores preditores para ocorrência de Infecção de Trato Urinário (ITU) no processo do cuidado na Clínica Médica (CM) de um Hospital Universitário (HU) como idade e tempo de internamento sendo o controle um desafio para a saúde pública. Objetivo: Descrever os principais agentes microbiológicos de ITU hospitalar na CM nos anos de 2015-16 e avaliar a suscetibilidade aos antimicrobianos. Metodologia: Trata-se de um estudo descritivo seccional e de busca na base de dados da CCIH do HU. Resultados: Em 2015 obteve se uma prevalência de 6,5% de ITU hospitalar, o agente biológico mais comum foi Klebsiella pneumoniae. Já em 2016, a prevalência foi de 5,3%; os agentes microbiológicos foram Candida spp. e Escherichia coli. Conclusão: A ITU hospitalar demonstra ser uma condição ainda bastante prevalente no HU, tendo como principal agente em 2015 a Klebsiella pneumoniae e em 2016 a Escherichia coli, ambos com uma maior susceptibilidade aos carbapenêmicos.

Introduction: There are some predictive factors for the occurrence of Urinary Tract Infection (UTI) in the care process at the Medical Clinic (CM) of a University Hospital (HU) such as age and length of stay, being control a challenge for public health. Objective: To describe the main microbiological agents of hospital UTI in CM in the years 2015-16 and to assess susceptibility to antimicrobials. Methodology: It is a descriptive and sectional study with research through the database of hospital infection control committee (HICC). Results: In 2015, there was a 6.5% prevalence of hospital UTI, the most common biological agent was Klebsiella pneumoniae. In 2016, the prevalence was 5.3%; the microbiological agents were Candida spp. and Escherichia coli. Conclusion: Hospital UTI proves to be still a very prevalent condition in HU, having Klebsiella pneumoniae as its main agent in 2015 and Escherichia coli in 2016, both with greater susceptibility to carbapenems.

Introducción: Existen algunos factores predictores de aparición de Infección del Tracto Urinario (ITU) en el proceso asistencial en la Clínica Médica (CM) de un Hospital Universitario (HU), como la edad y el tiempo de estancia, y su control es un reto para la salud pública. Objetivo: Describir los principales agentes microbiológicos de ITU de adquisición hospitalaria en la CM en 2015-16 y evaluar la susceptibilidad antimicrobiana. Metodología: Se trata de un estudio descriptivo, transversal, basado en una búsqueda en la base de datos CCIH del HU. Resultados: En 2015, la prevalencia de ITU adquirida en el hospital fue del 6,5%, y el agente biológico más frecuente fue Klebsiella pneumoniae. En 2016, la prevalencia fue del 5,3%; los agentes microbiológicos fueron Candida spp. y Escherichia coli. Conclusión: La ITU hospitalaria sigue siendo una patología muy prevalente en la UH, siendo Klebsiella pneumoniae el principal agente en 2015 y Escherichia coli en 2016, ambos con mayor susceptibilidad a carbapenems.

Diagnosis of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

ABSTRACT Hyperprolactinemia is a frequent cause of menstrual irregularity, galactorrhea, hypogonadism, and infertility. The most common etiologies of hyperprolactinemia can be classified as physiological, pharmacological, and pathological. Among pathological conditions, it is essential to distinguish prolactinomas from other tumors and pituitary lesions presenting with hyperprolactinemia due to pituitary stalk disconnection. Proper investigation considering clinical data, laboratory tests, and, if necessary, imaging evaluation, is important to identify the correct cause of hyperprolactinemia and manage the patient properly. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and medication-induced hyperprolactinemia in women.

Treatment of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

ABSTRACT Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia. Treatment with these agents is effective in 80%-90% of the cases. Infertility treatment of patients with hyperprolactinemia is also carried out with dopamine agonists, aiming for the normalization of prolactin levels. The risk of symptomatic growth of prolactinomas during pregnancy is dependent on the tumor's size, duration of previous treatments, and prolactin levels. Notably, the corresponding risk is relatively low in cases of microprolactinomas (<5%). Remission of hyperprolactinemia occurs in about 30% of the patients after drug treatment and may also occur after pregnancy and menopause. The use of some drugs, such as antidepressants and antipsychotics, is a frequent cause of hyperprolactinemia, and managing this occurrence involves unique considerations. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and drug-induced hyperprolactinemia in women.

Leishmania (Sauroleishmania) tarentolae versus pathogenic species: comparative evaluation of protease activity, glycoconjugates, resistance to complement and metabolome composition

BACKGROUND Leishmania tarentolae is a non-pathogenic species found in lizards representing an important model for Leishmania biology. However, several aspects of this Sauroleishmania remain unknown to explain its low level of virulence. OBJECTIVES We reported several aspects of L. tarentolae biology including glycoconjugates, proteolytic activities and metabolome composition in comparison to pathogenic species (Leishmania amazonensis, Leishmania braziliensis, Leishmania infantum and Leishmania major). METHODS Parasites were cultured for extraction and purification of lipophosphoglycan (LPG), immunofluorescence probing with anti-gp63 and resistance against complement. Parasite extracts were also tested for proteases activity and metabolome composition. FINDINGS Leishmania tarentolae does not express LPG on its surface. It expresses gp63 at lower levels compared to pathogenic species and, is highly sensitive to complement-mediated lysis. This species also lacks intracellular/extracellular activities of proteolytic enzymes. It has metabolic differences with pathogenic species, exhibiting a lower abundance of metabolites including ABC transporters, biosynthesis of unsaturated fatty acids and steroids, TCA cycle, glycine/serine/threonine metabolism, glyoxylate/dicarboxylate metabolism and pentose-phosphate pathways. MAIN CONCLUSIONS The non-pathogenic phenotype of L. tarentolae is associated with alterations in several biochemical and molecular features. This reinforces the need of comparative studies between pathogenic and non-pathogenic species to elucidate the molecular mechanisms of virulence during host-parasite interactions.