Molecular detection and genetic characterization of Ehrlichia canis and Ehrlichia sp. in neotropical primates from Brazil.

The Anaplasmataceae family includes obligate, arthropod-transmitted intracellular bacteria that can be zoonotic and potentially fatal. Studies focusing on the interaction between neotropical primates and the agents of this family are scarce. The present study aimed to identify agents of the Anaplasmataceae family in the whole blood of free-living and captive neotropical primates in the State of Mato Grosso, Central-West Brazil. Thirty-eight samples of six nonhuman primate (NHP) species were collected in seven municipalities and analysed through polymerase chain reaction (PCR), nucleotide sequencing, and phylogenetic analysis of the dsb, groEL, 16S rRNA, and gltA genes. DNA fragments similar to those of Ehrlichia canis were detected in Sapajus apella and Ehrlichia chaffeensis from Mico melanurus. The sequences generated in this study and homologous sequences retrieved from GenBank® were used for phylogenetic analyses to characterize the Ehrlichial agents detected in NHPs. The agents were then grouped into clades corresponding to different isolates from the NHP species. In addition, an Anaplasma sp. closely related to Anaplasma marginale was identified in two S. apella individuals. These findings shed light on the susceptibility of neotropical NHPs to Anaplasmataceae agents. These bacteria are known to be transmitted by ticks, which can also serve as possible sources of infection for other animals, including humans.

Commensal and multidrug-resistant Neisseria spp. sepsis in feline.

INTRODUCTION: Sepsis is a serious problem in felines with a mortality rate ranging from 29-79%. Neisseria spp. is considered a commensal microorganism of the oral cavity of dogs and cats and is usually isolated from human wounds resulting from bites of these animals. CASE REPORT: The present report describes clinical, imaging and laboratory findings of a feline with sepsis wherein commensal and multidrug-resistant (MDR) Neisseria spp. was isolated. The feline presented a history of four days of anorexia, dyspnea, prostration, and, pericardial, pleural and abdominal effusions. Pericardiocentesis was performed and hemorrhagic exudate was observed. The animal died after 11 days of treatment with gentamicin and amoxicillin combined with clavulanic acid. During necropsy, the abdominal cavity was found to be filled with greenish-yellow content and the pericardial sac was thickened with a large amount of purulent secretion. Histopathology revealed sepsis with necrotizing suppurative pericarditis, diffuse mononuclear pneumonia and necrotic pleuritis, leading to secondary bacterial infection. CONCLUSIONS: Commensal Neisseria spp. are important zoonotic bacteria, which trigger a serious disease in felines. However, it has not been reported to cause sepsis with pneumonia, suppurative necrotizing pericarditis and pericardial effusion.

Determination of multidrug-resistant populations and molecular characterization of complex Klebsiella spp. in wild animals by multilocus sequence typing.

Background and Aim: One of the most significant public health concerns is multidrug-resistant (MDR) microorganisms. Klebsiella spp. have been at the forefront of causing different types of infections such as bacteremia, urinary tract infections, pneumonia, enteritis, and sepsis in humans as well as animals. This study aimed to determine the genomic similarity between Klebsiella spp. isolated from wild animal samples and those described in the Institut Pasteur genomic database to verify the spread of resistant clones regionally in the state of Mato Grosso, and to compare the epidemiological data in different regions of Brazil and the world. Materials and Methods: Isolates from various sites of injury in wild animals were identified by sequencing the 16S rRNA gene. Antimicrobial susceptibility testing was performed using the disk diffusion method to verify the resistance profile, and then, multilocus sequence typing was performed to verify the population structure and compare the isolates from other regions of Brazil and the world. Results: Twenty-three sequence types (STs) were observed; of these, 11 were new STs, as new alleles were detected. There was no predominant ST among the isolates. All isolates were MDR, with high rates of resistance to sulfonamides, ampicillin, amoxicillin, and nitrofurantoin and low resistance to meropenem, imipenem, and amikacin. Conclusion: Improving our understanding of the population structure of Klebsiella spp. in wild animals may help determine the source of infection during outbreaks in humans or animals, as the One Health concept emphasizes the interlinks between humans, animals, and environmental health.

Introduction of high-fat and very-high-fat diets associated with fructose drink in critical development periods causes cardiovascular damage in rats at the beginning of adult life.

OBJECTIVES: Exposure to an obesogenic environment at critical stages of human development may lead to cardiovascular damage during early adulthood, such as left ventricular hypertrophy (LVH). The objective of this study is to investigate whether the consumption of diets with different levels of fat associated with fructose drink, introduced to newly weaned rats, leads to cardiovascular damage. METHODS: Male Wistar rats (age 21 d) were divided into the following groups: Control (C group) fed an American Institute of Nutrition 93G diet (16.3 % kcal of lipid); high-fat diet (HF group: 45% kcal of lipids), and very-high-fat diet (VHF group: 60% kcal of lipids). The HF and VHF groups also received a fructose solution (10%) for hydration. RESULTS: After 70 d, the animals in the HF and VHF groups presented with cardiovascular damage as a comorbidity of obesity, with increased creatine kinase-MB levels, high heart and left ventricle (LV) mass, and an increase in the LV:tibia ratio. The positive correlation was observed between serum leptin levels and LV mass. In addition, the signal transducer and activator of transcription 3 content in LV was lower. CONCLUSIONS: The administration of diets with different fat and carbohydrate contents associated with fructose drinks introduced to newly weaned rats leads to LVH during early adulthood. The data suggest that the change in leptin-signal transducer and activator of transcription 3 pathway signaling in the groups is related to the occurrence of LVH.

Molecular detection of Toxoplasma gondii and Neospora caninum in neotropical primates.

BACKGROUND: Toxoplasma gondii and Neospora caninum infections in primates are potentially fatal and directly impact the conservation of these animals and public health. MATERIALS AND METHODS: A total of 38 blood/clot samples collected from free-living and captive neotropical primates undergoing clinical care or found dead by environmental authorities in the Mato Grosso State, Brazil, were analyzed by PCR for DNA detection of T. gondii and N. caninum. Furthermore, eight animals were submitted to immunohistochemistry for the detection of T. gondii. RESULTS: DNA of T. gondii and N. caninum was amplified in 11 (28.95%) 10 (26.32%) of samples analyzed, respectively. Coinfection was observed in three individuals. One animal returned a positive result in the immunohistochemistry for the detection of T. gondii. CONCLUSION: These findings reflect a concern for the conservation of these animals, as the pathogen-host interaction is unpredictable and infections by these protozoa can lead to animal mortality, which has a substantial impact on endangered species.

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.

A Novel Host of an Emerging Disease: SARS-CoV-2 Infection in a Giant Anteater (Myrmecophaga tridactyla) Kept Under Clinical Care in Brazil.

A young male free-ranging giant anteater (Myrmecophaga tridactyla) was found with paralysis of pelvic limbs on a highway and kept under human care. Radiographs confirmed multiple incomplete fractures in the thoracolumbar vertebrae. Due to the poor prognosis, euthanasia was chosen. The infection was established by viral SARS-CoV-2 RNA detection in the rectal swab, spleen and kidney samples. Immunohistochemistry detected the viral nucleocapsid protein in sections of the lungs, liver, spleen, lymph nodes, and large intestine sections, and spike protein antigen in the lung tissue. Pilosa order species should be included as potential hosts of natural infection of SARS-CoV-2.

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.(AU)

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Abstract Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.

Glial Fibrillary Acidic Protein and Ionized Calcium-Binding Adapter Molecule 1 Immunostaining Score for the Central Nervous System of Horses With Non-suppurative Encephalitis and Encephalopathies.

Like humans, horses are susceptible to neurotropic and neuroinvasive pathogens that are not always readily identified in histological sections. Instead, alterations in astrocytes and microglia cells can be used as pathological hallmarks of injured nervous tissue in a variety of infectious and degenerative diseases. On the other hand, equine glial cell alterations are poorly characterized in diseases. Therefore, in this study, we provide a statistically proved score system to classify astrogliosis and microgliosis in the central nervous system (CNS) of horses, based on morphological and quantitative analyses of 35 equine cases of encephalitis and/or encephalopathies and four non-altered CNS as controls. For this system, we used glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (Iba1) immunohistochemistry, allied to statistical analysis to confirm that the scores were correctly designated. The scores of alterations ranged from 0 (non-altered) to 3 (severely altered) and provided a helpful method for describing astrocytic and microglial alterations in horses suffering from inflammatory and degenerative lesions. This system could be a template for comparative studies in other animal species and could aid algorithms designed for artificial intelligence methods lacking a defined morphological pattern.

Molecular detection of trypanosomatids in neotropical primates in the state of Mato Grosso, Midwest, Brazil.

Trypanosomatids are uniflagellate protozoa belonging to the Trypanosomatidae family. The genera Trypanosoma and Leishmania are of paramount importance as they contain species that cause serious diseases, such as Chagas disease and Leishmaniasis, respectively. The objective of the present study was to identify trypanosomatids present in the whole blood of free-living and captive neotropical primates in Mato Grosso State, Midwest Brazil. Between 2017 and 2019, 38 blood samples were collected from seven different neotropical primate species in seven cities in the state. Through molecular techniques, including polymerase chain reaction (PCR) to amplify a fragment of the kinetoplast DNA (kDNA) and 18S ribosomal RNA (18S rRNA) gene, sequencing, and phylogenetic analysis, nine Leishmania spp. [seven L. infantum and two L. (Leishmania) amazonensis] and two Trypanosoma spp. (T. minasense and T. rangeli) were identified. This study contributes to understanding the occurrence and epidemiology of trypanosomatids in Mato Grosso State and the importance of neotropical primates as trypanosome hosts and possible infection sources for other animals and humans. Future identification of other blood pathogens in neotropical primates will assist in disease control and prevention strategies.

Sepsis in cougar (Puma concolor) associated with Chromobacterium violaceum.

The genus Chromobacterium is widely distributed in the environment and is composed of Gram-negative, aerobic, or facultative anaerobic bacilli that occur in violet-colored colonies. These bacteria rarely cause infections, but when it occurs, it spreads quickly and has a high mortality. Because diseases are infrequent, the diagnosis is often delayed, and it takes time for suitable treatment to be initiated, leading to increased mortality due to the rapid progression of the disease. After the death of a cougar, serologically positive for feline leukemia virus, at the Center for Medicine and Research on Wild Animals of the Federal University of Mato Grosso, an autopsy was carried out, and fragments of its organs were sent for bacterial culture. Significant lesions were found, mainly in the liver and lungs, and upon bacterial isolation, violet-colored colonies were obtained from all of the referred organs, suggestive of C. violaceum, which was later confirmed by 16S DNA sequencing. The objective of this study was to report a case of death associated primarily with disseminated infection caused by C. violaceum in a FeLV-positive wild cougar in July 2018; no other occurrence in this species has yet been described.

Isolation and genotyping of Toxoplasma gondii in the Midwestern Brazil revealed high genetic diversity and new genotypes.

We aimed to describe the genetic diversity of Toxoplasma gondii strains isolated from domestic animals, wildlife and humans in the Midwestern Brazil. For this purpose, fragments of tissue samples (heart, brain and lung) from 35 dogs, four cats, 105 wildlife, and amniotic fluids from eight pregnant women were collected and submitted to mouse bioassay test. In a total, 22 isolates from nine dogs, one cat, ten wild animals and two women were obtained. The DNA was extracted from T. gondii isolates (lungs and brains of infected mice) and from "primary samples" (aliquots of tissue homogenate from wild animals and amniotic fluids from pregnant women) in order to screen using a Polymerase Chain Reaction (PCR) targeting a repeated 529-base pairs fragment of the T. gondii genome. All positive PCR samples were genotyped using restriction fragment length polymorphism (RFLP) analysis. To the best of our knowledge, this was the first study to report isolates of T. gondii from Leopardus pardalis, Crax fasciolata, and Dasyprocta azarae. Moreover, multilocus PCR-RFLP revealed 11 T. gondii RFLP genotypes, comprising nine previously described, including the archetypal lineage #2 type III (n = 1); two clonal Brazilian lineages, #6 type BrI (n = 1) and #8 type BrIII (n = 5); #14 (n = 2), #41 (n = 1), #108 (n = 1), #140 (n = 2), #166 (n = 4), #190 (n = 1), one potentially mixed, and two new described genotypes in two isolates. Our results confirmed the high diversity of T. gondii strains in Brazil, including identical genotypes circulating among humans, domestic dogs and wildlife.

Protein restriction during pregnancy impairs intra-islet GLP-1 and the expansion of ß-cell mass.

We evaluated whether protein restriction during pregnancy alters the morphometry of pancreatic islets, the intra-islet glucagon-like peptide-1 (GLP-1) production, and the anti-apoptotic signalling pathway modulated by GLP-1. Control non-pregnant (CNP) and control pregnant (CP) rats were fed a 17% protein diet, and low-protein non-pregnant (LPNP) and low-protein pregnant (LPP) groups were fed a 6% protein diet. The masses of islets and ß-cells were similar in the LPNP group and the CNP group but were higher in the CP group than in the CNP group and were equal in the LPP group and the LPNP group. Both variables were lower in the LPP group than in the CP group. Prohormone convertase 2 and GLP-1 fluorescence in α-cells was lower in the low-protein groups than in the control groups. The least PC2/glucagon colocalization was observed in the LPP group, and the most was observed in the CP group. There was less prohormone convertase 1/3/glucagon colocalization in the LPP group than in the CP group. GLP-1/glucagon colocalization was similar in the LPP, CP and CNP groups, which showed less GLP-1/glucagon colocalization than the LPNP group. The mRNA Pka, Creb and Pdx-1 contents were higher in islets from pregnant rats than in islets from non-pregnant rats. Protein restriction during pregnancy impaired the mass of ß-cells and the intra-islet GLP-1 production but did not interfere with the transcription of genes of the anti-apoptotic signalling pathway modulated by GLP-1.

Clinical-dermatological, histological abnormalities and prevalence of Trypanosoma caninum and Leishmania infantum in dogs from Midwest region of Brazil.

Leishmania infantum is a trypanosomatid that causes parasitic dermatopathy in dogs. Trypanosoma caninum is another trypanosomatid, which infects the skin of dogs, although cutaneous abnormalities are absent. This study aimed to investigate the occurrence of T. caninum infection and its associated cutaneous and histological changes and compare it with the occurrence of L. infantum infection in dogs. The study included 150 dogs, of which T. caninum infection was identified in 3 (2%) and L. infantum infection in 15 (10%) of them, with no association (p>0.05) of these infections with the breed, gender, age, or cutaneous abnormalities. The cutaneous abnormalities were based on 1 (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. infantum, respectively. The dermatohistopathological abnormalities in the dogs infected with T. caninum included mild perivascular lymphohistioplasmacytic infiltrates in the clinically asymptomatic ones, while in those with dermatological abnormalities, acanthosis, epidermal orthokeratotic hyperkeratosis, melanomacrophages, and co-infection with Microsporum sp. and Trichophyton sp. were observed. InL. infantum infected, the histopathological findings included chronic granulomatous inflammatory infiltrates and structures compatible with amastigotes. Despite the low frequency of T. caninum infection, our findings suggest that this trypanosomatid, unlike L. infantum, does not cause any macroscopic skin abnormalities.

Early protein restriction increases intra-islet GLP-1 production and pancreatic ß-cell proliferation mediated by the ß-catenin pathway.

PURPOSE: In the present study, we investigated whether intra-islet GLP-1 production and its modulation have a role in apoptosis, proliferation or neogenesis that is compromised by protein restriction during the foetal and suckling periods. METHODS: Exendin-4, a GLP-1 receptor agonist (treated groups), or saline (non-treated groups) was intraperitoneally administered for 15 days from 75 to 90 days of age in female adult rats consisting of offspring born to and suckled by mothers fed a control diet (control groups) and who had the same diet until 90 days of age or offspring born to and suckled by mothers fed a low-protein diet and who were fed the control diet after weaning until 90 days of age (protein-restricted group). RESULTS: The ß-cell mass was lower in the protein-restricted groups than in the control groups. Exendin-4 increased ß-cell mass, regardless of the mother's protein intake. The colocalization of GLP-1/glucagon was higher in the protein-restricted rats than in control rats in both the exendin-4-treated and non-treated groups. The frequency of cleaved caspase-3-labelled cells was higher in the non-treated protein-restricted group than in the non-treated control group and was similar in the treated protein-restricted and treated control groups. Regardless of treatment with exendin-4, Ki67-labelled cell frequency and ß-catenin/DAPI colocalization were elevated in the protein-restricted groups. Exendin-4 increased the area of endocrine cell clusters and ß-catenin/DAPI and FoxO1/DAPI colocalization regardless of the mother's protein intake. CONCLUSIONS: Protein restriction in early life increased intra-islet GLP-1 production and ß-cell proliferation, possibly mediated by the ß-catenin pathway.

Pyogranulomatous pleuropneumonia caused by Nocardia asiatica in a dog coinfected with canine morbillivirus (canine distemper virus).

Nocardia asiatica causing pyogranulomatous pleuropneumonia is reported for the first time in a dog coinfected with canine morbillivirus (CM), diagnosed based on epidemiological, clinical, haematological, images, microbiological, histopathological, polymerase chain reaction and hsp65 gene sequencing findings. The immunosuppression of CM probably favoured the opportunistic behaviour of N. asiatica. Despite the therapeutic measures, the animal died, mainly due to respiratory distress. The association of methods to improve early diagnosis, therapy procedures and prognosis of canine nocardiosis is discussed, as well as the close relationship between pets and their owners, which may favour the transmission of pathogens such as Nocardia from pets-to-humans, which poses an emerging public health issue.

Sorocea guilleminiana Gaudich.: Wound healing activity, action mechanisms, and chemical characterization of the leaf infusion.

ETHNOPHARMACOLOGICAL RELEVANCE: Sorocea guilleminina Gaudich. is a tree or shrub endemic to Brazil. Its leaves are used in Brazilian folk medicine for the healing of wounds, stomach problems, inflammation and as diuretic. The present study evaluates the activity and action mechanisms of the healing properties of the aqueous extract of S. guilleminiana leaves (AESg), in experimental models in vivo and in vitro, as well as performs a phytochemical analysis of the extract. MATERIALS AND METHODS: The AESg was prepared by infusion: Ten g of dry leaves powder in 1 L hot water, soaked for 15 min, filtered, lyophilized, and stored at -30 °C. Phytochemical analyses were realized by colorimetry and HPLC/ESI/MS. Its' in vitro cytotoxicity was evaluated on fibroblastic N3T3 cells. The potential of the wound healing activity in vivo was evaluated using excision and incision wound rat models, by histopathology of the injured skin along with the determination of nitric oxide, cytokines (IL-1ß, IL-10, and TNF-α), and antioxidant parameters (GSH, MPO and CAT). In vitro wound healing activity was also demonstrated in scratched N3T3 cells, by measuring the proliferation/migration rate. RESULTS: The phytochemical analysis of the AESg revealed a strong presence of polar compounds, especially flavonoids (4 majoritarian), as well as terpenes and/or sterols (2 majoritarian). The AESg showed no toxicity in the N3T3 cell line (IC50 > 800 µg/mL). Topical treatment with the AESg showed an increase (p < 0.05) in wound contraction with 2 mg/g cream on days 5 and 9 (43.56% and 6.70% increase, respectively), and with 50 mg/g on days 7 and 9 (10.88% and 7.91%, respectively), compared to the vehicle (non-ionic neutral cream). Topical application of AESg (2 or 50 mg/g non-ionic cream) in incised wounds caused an increase in the force necessary for the rupture of the wound when compared to the vehicle group. No changes in cytokines (IL-1ß, IL-10, or TNF-α) or NO accumulation was found with up to 50 mg/g AESg treatment. For antioxidant activity on the incision wound, an increase in GSH levels was denoted with the AESg use, at the lowest and highest dose (2 and 50 mg/g) by 75.86% and 61.20% respectively, when compared to the vehicle. Also, the CAT activity was accentuated by AESg at the highest dose (50 mg/g) by 85.87%. Finally, the AESg at all doses attenuated MPO activity significantly in the incision wound by 71.35%, 73.21%, 78.08%, respectively. In the scratch test on N3T3 cells, the treatment with AESg resulted also in an increase in fibroblast proliferation/migration rate, compared to the vehicle. CONCLUSION: AESg is not cytotoxic. The results confirm the popular use of the leaf infusion of S. guilleminiana for the treatment of cutaneous wounds, possibly by stimulating the proliferation of fibroblasts with a consequent deposition of collagen, fastening rearrangement of collagen fibers, and greater transformation into myofibroblasts, essential in the healing process. Preliminary chemical analyzes of AESg revealed the presence mainly of phenolic compounds, being salicylic acid, gallic acid, pinocembrin and isoquercitrin the majoritarian ones.

Pasteurella canis infection in a non-human primate black-tailed marmoset (Mico melanurus)-A case report.

This study reports the pathological and microbiological findings of pneumonia in a Mico melanurus caused by Pasteurella canis, confirmed for molecular analyses. It demonstrated the importance that wild species represent in the epidemiology of pasteurellosis in anthropic environments, when inserted into urban areas.

Clinical-dermatological, histological abnormalities and prevalence of Trypanosoma caninum and Leishmania infantum in dogs from Midwest region of Brazil / Anormalidades clínico-dermatológicas, histológicas e prevalência de Trypanosoma caninum e Leishmania infantum em cães da região Centro-Oeste do Brasil

Abstract Leishmania infantum is a trypanosomatid that causes parasitic dermatopathy in dogs. Trypanosoma caninum is another trypanosomatid, which infects the skin of dogs, although cutaneous abnormalities are absent. This study aimed to investigate the occurrence of T. caninum infection and its associated cutaneous and histological changes and compare it with the occurrence of L. infantum infection in dogs. The study included 150 dogs, of which T. caninum infection was identified in 3 (2%) and L. infantum infection in 15 (10%) of them, with no association (p>0.05) of these infections with the breed, gender, age, or cutaneous abnormalities. The cutaneous abnormalities were based on 1 (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. infantum, respectively. The dermatohistopathological abnormalities in the dogs infected with T. caninum included mild perivascular lymphohistioplasmacytic infiltrates in the clinically asymptomatic ones, while in those with dermatological abnormalities, acanthosis, epidermal orthokeratotic hyperkeratosis, melanomacrophages, and co-infection with Microsporum sp. and Trichophyton sp. were observed. InL. infantum infected, the histopathological findings included chronic granulomatous inflammatory infiltrates and structures compatible with amastigotes. Despite the low frequency of T. caninum infection, our findings suggest that this trypanosomatid, unlike L. infantum, does not cause any macroscopic skin abnormalities.

Resumo Leishmania infantum é um tripanosomatídeo que causa dermatopatia parasitária em cães. Trypanosoma caninum é outro tripanosomatídeo, que infecta a pele de cães, embora anormalidades cutâneas sejam ausentes. Este estudo teve como objetivo investigar a ocorrência da infecção por T. caninum e suas alterações cutâneas e histológicas associadas e compará-las com a ocorrência da infecção por L. infantum em cães. O estudo incluiu 150 cães, dos quais a infecção por T. caninum foi identificada em 3 (2%) e a infecção por L. infantum em 15 (10%) deles, sem associação (p>0,05) dessas infecções com a raça, sexo, idade ou anormalidades cutâneas. As alterações cutâneas foram observadas em 1 (4,8%) e 12 (57,1%) cães infectados por T. caninum e L. infantum, respectivamente. As anormalidades dermato-histopatológicas nos cães infectados por T. caninum incluíram infiltrados linfo-histioplasmocitários perivasculares leves nos clinicamente assintomáticos, enquanto naqueles com anormalidades dermatológicas, foram observados acantose, hiperqueratose ortoqueratótica epidermal e melanomacrófagos e co-infecção por Microsporum sp. e Trichophyton sp. Nos cães infectados por L. infantum, os achados histopatológicos incluíram infiltrados inflamatórios granulomatosos crônicos e estruturas compatíveis com amastigotas. A despeito da baixa frequência da infecção por T. caninum, nossos achados sugerem que esse tripanosomatídeo, diferentemente de L. infantum, não causa anormalidades macroscópicas na pele.