Disseminated granulomatous encephalitis caused by Schizophyllum commune in a dog with severe neurological signs.

A 10-year-old spayed mixed breed dog presented with severe neurological signs. Computed tomography revealed a cranial mediastinal mass, osteolysis of the right second rib and second thoracic vertebra, tracheobronchial and mesenteric lymph node enlargement, pneumonia and pleural effusion. Magnetic resonance imaging detected lesions in the white matter of the right frontal lobe and left cerebral hemisphere with contrast-enhanced T1-weighted images showing demarcated enhancement. On cut section, the surface of the right cerebral frontal lobe and left cerebral hemisphere corticomedullary junctions were indistinct and the white matter was discoloured. Microscopically, multicentric granulomatous inflammation was seen in the brain, cranial mediastinal mass, masses on the right second rib, tracheobronchial and mesenteric lymph nodes, heart, kidneys, lungs and oesophagus. Necrosis and hyaline fungal structures were frequently observed in the centre of the granulomas. These fungi had septae, Y-shaped branching and were 2-3 µm in width. Sequence analysis of DNA from formalin-fixed paraffin-embedded samples identified the fungi as Schizophyllum commune. Based on these findings, this case was diagnosed as disseminated S. commune infection. This is the first report of granulomatous encephalitis caused by S. commune in a dog.

Proteomic analysis of granulomas from cattle and pigs naturally infected with Mycobacterium tuberculosis complex by MALDI imaging.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has recently gained prominence for its ability to provide molecular and spatial information in tissue sections. This technology has the potential to uncover novel insights into proteins and other molecules in biological and immunological pathways activated along diseases with a complex host-pathogen interaction, such as animal tuberculosis. Thus, the present study conducted a data analysis of protein signature in granulomas of cattle and pigs naturally infected with the Mycobacterium tuberculosis complex (MTC), identifying biological and immunological signaling pathways activated throughout the disease. Lymph nodes from four pigs and four cattle, positive for the MTC by bacteriological culture and/or real-time PCR, were processed for histopathological examination and MALDI-MSI. Protein identities were assigned using the MaTisse database, and protein-protein interaction networks were visualized using the STRING database. Gene Ontology (GO) analysis was carried out to determine biological and immunological signaling pathways in which these proteins could participate together with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Distinct proteomic profiles between cattle and pig granulomas were displayed. Noteworthy, the GO analysis revealed also common pathways among both species, such as "Complement activation, alternative pathway" and "Tricarboxylic acid cycle", which highlight pathways that are conserved among different species infected by the MTC. In addition, species-specific terms were identified in the current study, such as "Natural killer cell degranulation" in cattle or those related to platelet and neutrophil recruitment and activation in pigs. Overall, this study provides insights into the immunopathogenesis of tuberculosis in cattle and pigs, opening new areas of research and highlighting the importance, among others, of the complement activation pathway and the regulation of natural killer cell- and neutrophil-mediated immunity in this disease.

Oesophagostomum stephanostomum causing parasitic granulomas in wild chimpanzees (Pan troglodytes verus) of Taï National Park, Côte d'Ivoire.

Nematodes belonging to the genus Oesophagostomum frequently infect wild chimpanzees (Pan troglodytes) across widely separated field sites. Nodular lesions (granulomas) containing Oesophagostomum are commonly seen in the abdomen of infected chimpanzees post-mortem. At Taï National Park, Côte d'Ivoire, previous studies have identified larvae of a variety of Oesophagostomum spp. in wild chimpanzee stool, based on sequencing of larval DNA, and nodular lesions associated with Oesophagostomum, identified morphologically to the genus level but not sequenced. Here we present three recent cases of parasitic granulomas found post-mortem in chimpanzees at Taï. We complement descriptions of gross pathology, histopathology and parasitology with PCR and sequencing of DNA isolated from the parasitic nodules and from adult worms found inside the nodules. In all three cases, we identify Oesophagostomum stephanostomum as the causative agent. The sequences from this study were identical to the only other published sequences from nodules in nonhuman primates-those from the wild chimpanzees of Gombe, Tanzania.

Necrosis plays a role in the concentration of mycobacterial antigens in granulomas from Mycobacterium bovis naturally infected cattle.

The dynamics that develop between cells and molecules in the host against infection by Mycobacterium bovis, leads to the formation of granulomas mainly present in the lungs and regional lymph nodes in cattle. Cell death is one of the main features in granuloma organization, however, it has not been characterized in granulomatous lesions caused by M. bovis. In this study we aimed to identify the profiles of cell death in the granuloma stages and its relationship with the accumulation of bacteria. We identified necrosis, activated caspase-3, LC3B/p62 using immunohistochemistry and digital pathology analysis on 484 granulomatous lesions in mediastinal lymph nodes from 23 naturally infected cattle. Conclusions: greater amounts of mycobacterial antigens were identified in granulomas from calves compared with adult cattle. The highest percentage of necrosis and quantity of mycobacterial antigens were identified in granuloma stages (III/IV) from adults. The LC3B/p62 profile was heterogeneous in granulomas between adults and calves. Our data suggest that necrosis is associated with a higher amount of mycobacterial antigens in the late stages of granuloma and the development of autophagy appears to play an heterogeneous effector response against infection in adults and calves. These results represent one of the first approaches in the identification of cell death in the four stages of granulomas in bovine tuberculosis.

Granulomatous meningoencephalitis and blindness associated with Mycobacterium tuberculosis complex infection in a senile female chimpanzee (Pan troglodytes).

A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis.

Isolation of vapB-positive Rhodococcus equi from submaxillary lymph nodes with or without granulomatous lesions in growing-finishing pigs in Japan.

To investigate the etiological role of vapB-positive Rhodococcus equi in pigs, R. equi was isolated from the submaxillary lymph nodes with or without macroscopically detectable lesions of apparently healthy growing-finishing pigs at a slaughterhouse in Toyama Prefecture, Japan. R. equi was isolated from 57 (24.6%) of 232 pigs with macroscopically detectable lymph node lesions, and 56 (98.2%) of the 57 isolates were vapB-positive. R. equi was isolated from 10 (2.4%) of 420 pigs without lymph node lesions, and six (60%) of the 10 isolates were vapB-positive. Plasmid DNA was isolated from the 62 vapB-positive isolates and digested with EcoRI and NsiI to obtain the plasmid profile. Fifty-two (83.9%), three (4.8%), and four (6.5%) isolates contained pVAPB subtypes 1, 2, and 3, respectively, while the remaining three isolates were of pVAPB subtypes 9, 13, and 14, respectively. Twelve specimens from lymph nodes with macroscopically detectable lesions were randomly selected for histopathological staining. Granulomatous lesions resembling tuberculosis were found in 11 of the 12 specimens, and the remaining specimen showed typical foci of malakoplakia in the lymph node. The isolation rates of R. equi and vapB-positive R. equi from lymph nodes with macroscopically detectable lesions were significantly higher (P<0.05) than those of lymph nodes without lesions, suggesting an etiologic association between vapB-positive R. equi and macroscopically detectable granulomatous lesions in porcine submaxillary lymph nodes. Previous reports on the prevalence of vapB-positive R. equi in pigs are reviewed and discussed.

Surgical treatment of bovine nasal granuloma and an allergological exploration.

Nasal granuloma in cattle results from inflammation within, and attendant proliferation of, the nasal mucosa possibly in response to an allergic response. However, the relationship between nasal granuloma and allergies remains unclear. Furthermore, severe cases have a poor prognosis because there is currently no effective treatment. Herein, we report three cases of nasal granuloma with severe stertorous breathing that were treated surgically. We also conducted an allergological exploration. Following surgical removal clinical signs did not recur in two of the three cases; however, stertorous breathing persisted in one case, and the cow was sacrificed 4 months later. A histopathological examination revealed that all nasal granulomas featured varying infiltrations of macrophages eosinophils, mast cells, and lymphocytes. The number of mast cells and the proportion of these cells that had degranulated were significantly higher in the granulomas than in normal nasal mucosae. In addition, serum histamine levels were higher in nasal granuloma cases than in normal cows, although serum immunoglobulin E levels were similar, and lymphocyte infiltration in the submucosal layer suggested type I and type IV allergies. Collectively, the results indicate the efficacy of complete surgical curettage for the treatment of allergic nasal granuloma in cattle. Further studies are required to identify the causes and risk factors of allergic nasal granuloma in cows.

Comparative pathogenicity of Nocardia seriolae in Nile tilapia (Oreochromis niloticus), milkfish (Chanos chanos) and Asian seabass (Lates calcarifer).

Nocardiosis, caused by Nocardia seriolae, has been a prominent disease in Southeast Asian aquaculture in the last three decades. This granulomatous disease reported in various fish species is responsible for significant economic losses. This study investigated the pathogenicity of N. seriolae in three cultured species in Taiwan: Nile tilapia (omnivore), milkfish (herbivore) and Asian seabass (carnivore). Administration of an infective dose of 1 × 106 CFU/ fish in tilapia, seabass and milkfish demonstrated mortalities of 100%, 90% and 75%, respectively. Additionally, clinical signs namely, granuloma and lesions displayed varying intensities between the groups and pathological scores. Polymerase chain reaction (PCR) amplification specific for N. seriolae was confirmed to be positive (432 bp) using NS1/NG1 primers. Post-mortem lesions revealed the absence of granulomas in tilapia and milkfish and their presence in the seabass. Interestingly, the gut in tilapia showed an influx of eosinophils suggesting its role during the acute stages of infection. However, post-challenge, surviving milkfish exhibited granulomatous formations, while surviving seabass progressed toward healing and tissue repair within sampled tissues. Overall, in conclusion, these results demonstrate the versatility in the immunological ability of individual Perciformes to contain this pathogen as a crucial factor that influences its degree of susceptibility.

Evaluation of Ki-67, goblet cell and MUC2 mucin RNA expression in dogs with lymphoplasmacytic and granulomatous colitis.

Intestinal mucus barrier disruption may occur with chronic inflammatory enteropathies. The lack of studies evaluating mucus health in dogs with chronic colitis arises from inherent challenges with assessment of the intestinal mucus layer. It is therefore unknown if reduced goblet cell (GBC) numbers and/or mucin 2 (MUC2) expression, which are responsible for mucus production and secretion, correlate with inflammation severity in dogs with granulomatous colitis (GC) or lymphocytic-plasmacytic colitis (LPC). It is undetermined if Ki-67 immunoreactivity, which has been evaluated in dogs with small intestinal inflammation, similarly correlates to histologic severity in GC and LPC. Study objectives included comparing Ki-67 immunoreactivity, GBC population and MUC2 expression in dogs with GC, LPC and non-inflamed colon; and exploring the use of ribonucleic acid (RNAscope®) in-situ hybridization (ISH) to evaluate MUC2 expression in canine colon. Formalin-fixed endoscopic colonic biopsies were obtained from 48 dogs over an eight-year period. A blinded pathologist reviewed all biopsies. Dogs were classified into the GC (n=19), LPC (n=19) or no colitis (NC) (n=10) group based on final histopathological diagnosis. Ki-67 immunohistochemistry, Alcian-Blue/PAS staining to highlight GBCs, and RNAscope® ISH using customized canine MUC2-targeted probes were performed. At least five microscopic fields per dog were selected to measure Ki-67 labelling index (KI67%), GBC staining percentage (GBC%) and MUC2 expression (MUC2%) using image analysis software. Spearman's correlation coefficients were used to determine associations between World Small Animal Veterinary Association histologic score (WHS) and measured variables. Linear regression models were used to compare relationships between WHS with KI67%, GBC%, and MUC2%; and between GBC% and MUC2%. Median WHS was highest in dogs with GC. Median KI67% normalised to WHS was highest in the NC group (6.69%; range, 1.70-23.60%). Median GBC% did not correlate with colonic inflammation overall. Median MUC2% normalised to WHS in the NC group (10.02%; range, 3.05-39.09%) was two- and three-fold higher than in the GC and LPC groups respectively. With increased colonic inflammation, despite minimal changes in GBC% overall, MUC2 expression markedly declined in the LPC group (-27.4%; 95%-CI, -49.8, 5.9%) and mildly declined in the GC and NC groups. Granulomatous colitis and LPC likely involve different pathways regulating MUC2 expression. Decreased MUC2 gene expression is observed in dogs with chronic colitis compared to dogs without colonic signs. Changes in MUC2 expression appear influenced by GBC activity rather than quantity in GC and LPC.

Macrophage polarization in lymph node granulomas from cattle and pigs naturally infected with Mycobacterium tuberculosis complex.

Tuberculosis in animals is caused by members of the Mycobacterium tuberculosis complex (MTC), with the tuberculous granuloma being the main characteristic lesion. The macrophage is the main cell type involved in the development of the granuloma and presents a wide plasticity ranging from polarization to classically activated or pro-inflammatory macrophages (M1) or to alternatively activated or anti-inflammatory macrophages (M2). Thus, this study aimed to analyze macrophage polarization in granulomas from cattle and pig lymph nodes naturally infected with MTC. Tuberculous granulomas were microscopically categorized into four stages and a panel of myeloid cells (CD172a/calprotectin), M1 macrophage polarization (iNOS/CD68/CD107a), and M2 macrophage polarization (Arg1/CD163) markers were analyzed by immunohistochemistry. CD172a and calprotectin followed the same kinetics, having greater expression in late-stage granulomas in pigs. iNOS and CD68 had higher expression in cattle compared with pigs, and the expression was higher in early-stage granulomas. CD107a immunolabeling was only observed in porcine granulomas, with a higher expression in stage I granulomas. Arg1+ cells were significantly higher in pigs than in cattle, particularly in late-stage granulomas. Quantitative analysis of CD163+ cells showed similar kinetics in both species with a consistent frequency of immunolabeled cells throughout the different stages of the granuloma. Our results indicate that M1 macrophage polarization prevails in cattle during early-stage granulomas (stages I and II), whereas M2 phenotype is observed in later stages. Contrary, and mainly due to the expression of Arg1, M2 macrophage polarization is predominant in pigs in all granuloma stages.

Neutrophil extracellular traps (NETs) and Th-2 dominant immune responses in chronic granulomatous chromobalstomycosis.

Chromoblastomycosis (CBM), a chronic, granulomatous, suppurative mycosis of the skin and subcutaneous tissue, is caused by several dematiaceous fungi. The formation of granulomas, tissue proliferation, and fibrosis in response to these pathogenic fungi is believed to be intricately linked to host immunity. To understand this complex interaction, we conducted a comprehensive analysis of immune cell infiltrates, neutrophil extracellular traps (NETs) formation, and the fibrosis mechanism in 20 CBM lesion biopsies using immunohistochemical and immunofluorescence staining methods. The results revealed a significant infiltration of mixed inflammatory cells in CBM granulomas, prominently featuring a substantial presence of Th2 cells and M2 macrophages. These cells appeared to contribute to the production of collagen I and III in the late fibrosis mechanism, as well as NETs formation. The abundance of Th2 cytokines may act as a factor promoting the bias of macrophage differentiation toward M2, which hinders efficient fungal clearance while accelerates the proliferation of fibrous tissue. Furthermore, the expression of IL-17 was noted to recruit neutrophils, facilitating subsequent NETs formation within CBM granulomas to impede the spread of sclerotic cells. Understanding of these immune mechanisms holds promise for identifying therapeutic targets for managing chronic granulomatous CBM.

Antemortem Diagnosis and Successful Long-term Management of Disseminated Intracoelomic Xanthogranulomatous Disease in an Eclectus Parrot (Eclectus roratus).

A 12-year-old male eclectus parrot (Eclectus roratus) was referred for evaluation of coelomic distention. Computed tomography and blood work revealed coelomic effusion with free coelomic mineral-attenuating material and elevations in the bile acids and aspartate aminotransferase activity, respectively. Coelomic effusion was consistent with macrophagic inflammation with abundant intracellular lipids. Initial treatment with meloxicam resulted in minimal patient improvement. Disseminated xanthogranulomatous inflammation was suspected based on imaging and diagnostic laboratory results, which were consistent with those previously reported. Biopsy samples of liver tissue and intracoelomic masses confirmed this diagnosis. Treatment was initiated with prednisolone 1 mg/kg/d for 6 months, followed by 0.5 mg/kg/d for 3 months. Clinical improvement was assessed based on owner evaluation, plasma bile acid concentrations, and repeated computed tomographic scans. After 2 months of treatment, the owner reported improved behavior and appetite; this persisted throughout treatment and when the bird was reexamined 17 months following the cessation of steroid therapy. Bile acid concentrations were normal 10 months after the prednisolone therapy was discontinued. Diagnostic imaging showed minimal coelomic effusion 10 months after the last prednisolone dose was administered, with improved ventilation of the air sacs and static to improved dystrophic mineral foci. This report describes the antemortem diagnosis and treatment of disseminated coelomic xanthogranulomatous disease in a psittacine species, with an observed measurable therapeutic response.

Coinfection by Mycobacterium marinum and Mycolicibacterium fortuitum in a captive adult diamondback water snake causing disseminated mycobacteriosis with acute cutaneous ulceration.

An adult male captive diamondback water snake (Nerodia rhombifer) was found dead after a 1-d history of lethargy and cutaneous ulcers. The snake had eaten 2 sunfish (Mola spp.) 5 d before death. Gross examination revealed white-to-tan nodules in the lung and liver and segmental intestinal impactions with digested fish. Histopathology confirmed disseminated granulomas with numerous intrahistiocytic acid-fast bacteria in the skin, skeletal muscle, lung, liver, and intestines. Mycobacterium marinum and Mycolicibacterium fortuitum were identified by culture of the hepatic granuloma, followed by PCR and rpoB gene sequencing. To our knowledge, this is the first description of M. marinum and M. fortuitum coinfection in this species. Although M. fortuitum has been isolated from reptiles, lesions associated with its presence in tissues have not been described previously. Interestingly, the mineralization within granulomas that we observed in our case is not reported in mycobacterial infection in reptiles, whereas this finding is common in mammals.

Granulomatous dermatitis caused by Exserohilum mcginnisii infection in a cow.

A 5-y-old, Piedmontese cow had a 4-mo history of ongoing development of skin masses. This was the only cow affected in a herd of 20 cows. Up to 12, hairless, red-to-black, raised nodules-to-plaques were distributed along the dorsum and tail head. Biopsies were taken for histopathology and ancillary testing. An ulcerated skin section contained dermal infiltrates of eosinophils, plasma cells, neutrophils, macrophages, lymphocytes, and multinucleate giant cells, and pyogranulomas. Fungal hyphae were seen within the dermis, multinucleate giant cells, and pyogranulomas. In pyogranulomas, fungi were surrounded by a Splendore-Hoeppli reaction. Dematiaceous (pigmented) hyphae were rarely observed with H&E-stained and unstained (cleared and mounted) sections, but stained well with a Fontana-Masson stain. Exserohilum mcginnisii was identified by fungal culture, followed by PCR assay and sequencing. Exserohilum is a dematiaceous fungus that causes disease in humans and rarely in animals. The use of unstained sections and Fontana-Masson stain are important to demonstrate pigment because dematiaceous fungi have little melanin and appear as hyaline hyphae histologically. PCR assay and sequencing aid in the differentiation and classification of fungal species. To our knowledge, E. mcginnisii dermal granulomas have not been reported previously in cattle.

Clinical and pathological findings in five dogs with nodular histiocytic iritis in the United Kingdom: A case series.

PURPOSE: The aim of this study was to describe the clinical presentation, histopathology, management, and outcome of nodular histiocytic iritis, an intraocular variant of nodular granulomatous episcleritis (NGE). METHODS: A retrospective review of the medical records of five dogs with intraocular NGE-type inflammation as diagnosed by histopathology. RESULTS: Four Border Collies and one crossbreed dog, aged 1.5-3.4 years (mean age 2.38 years). The clinical presentation was an extensive, raised, pale iris lesion of variable location. All cases were unilateral. The physical examination was normal. Complete blood count/serum biochemistry (n = 1) and thoracic radiography (n = 1) were normal. Ocular ultrasound (n = 2) was normal apart from increased iris thickness. Enucleation (n = 4) or excisional biopsy (iridectomy, n = 1) was performed because of suspected neoplasia. Following enucleation, the remaining, contralateral eye did not develop additional lesions (9 days-3.7 years follow-up). There was no recurrence following sector iridectomy with 5 months topical 1% prednisolone acetate (3.9 years follow-up). The histopathologic findings in all five cases indicated a focal histiocytic and lymphoplasmacytic anterior uveitis (iritis), similar to that seen in cases of NGE. CONCLUSION: Nodular histiocytic iritis presents as unilateral iris thickening in isolation and young Collies appear to be predisposed. The histopathological findings are similar to NGE. Although the clinical presentation resembles intraocular neoplasia, an inflammatory process should be considered, which may be amenable to medical management. Definitive diagnosis may be obtained by iris sampling.

Monitoring the immune response of macrophages in tuberculous granuloma through the expression of CD68, iNOS and HLA-DR in naturally infected beef cattle.

Bovine tuberculosis still represents a universal threat that creates a wider range of public and animal health impacts. One of the most important steps in the pathogenesis of this disease and granuloma formation is the phagocytosis of tuberculous bacilli by macrophages. Mycobacteria replicate in macrophages, which are crucial to the pathophysiology of mycobacterial infections; however, scarce information is available about the dynamics of the granuloma-stage immunological response. Therefore, immunohistochemistry was used in this work to evaluate the expression of CD68, iNOS, and HLA-DR in different stages of TB granulomas from naturally infected cattle with tuberculosis. Two thousand, one hundred and fifty slaughtered beef cattle were examined during the period from September 2020 to March 2022. Sixty of them showed gross tuberculous pulmonary lesions and samples were collected from all of them for histopathological examination, Ziehl-Neelsen (ZN) staining, and bacteriological culturing. Selected samples that yielded a positive result for ZN and mycobacterial culturing were subjected to an immunohistochemical study of CD68, iNOS, and HLA-DR expression by macrophages according to granuloma stages. Immunohistochemical analysis revealed that the immunolabeling of CD68+, iNOS+, and HLA-DR+ macrophages significantly reduced as the stage of granuloma increased from stage I to stage IV (P < 0.003, P < 0.002, and P < 0.002, respectively). The distribution of immunolabeled macrophages was similar for the three markers, with immunolabeled macrophages distributed throughout early-stage granulomas (I, II), and surrounding the necrotic core in late-stage granulomas (III, IV). Our results suggest a polarization to the pro-inflammatory environment and increased expression of CD68+, iNOS+, and HLA-DR+ macrophages in the early stages of granulomas (I, II), which may play a protective role in the immune response of naturally infected beef cattle with tuberculosis.

A case of lipogranulomatous conjunctivitis in a horse.

OBJECTIVE: To describe a case of lipogranulomatous conjunctivitis in a horse. ANIMAL STUDIED: A client-owned 12-year-old Standardbred gelding presenting with chronic conjunctivitis and palpebral masses. METHODS: Complete ophthalmic examination, surgical excision, histopathology, and bacterial culture of biopsy samples were performed. RESULTS: Upper and lower eyelids of both eyes were affected, with multiple yellow-to-white nodules on the palpebral conjunctiva, adjacent to the eyelid margin. Nodule removal was achieved via partial tarsal plate excision. Histopathological examination revealed granulomatous inflammation and large droplets of presumed free lipid in the conjunctival lamina propria. The animal was diagnosed with lipogranulomatous conjunctivitis. No postoperative ocular discomfort was observed for months; however, 3 years later, new conjunctival nodules were noticed, requiring a second surgical procedure on three of the eyelids. Transient entropion in the left lower eyelid was observed 2 months after the second surgery, and no recurrence of conjunctival nodules was observed after 18 months of follow-up. CONCLUSION: To our knowledge, this is the first report of lipogranulomatous conjunctivitis in horses.

Oral immunization with heat-inactivated Mycobacterium bovis reduces local parasite dissemination and hepatic granuloma development in mice infected with Leishmania amazonensis.

Aiming to explore whether oral immunization with heat-inactivated Mycobacterium bovis (HIMB) protects mice against Leishmania infection, 18 female BALB/c mice were randomly assigned to the immunized group, that received oral HIMB, or the control group, and were infected by inoculation of 10,000 Leishmania amazonensis promastigotes in the footpad. Spleen culture was positive in 55.55% of immunized mice and in 100% of control mice (p = 0.082). The number of immunolabeled amastigotes number in the popliteal lymph node was lower in the immunized group (p = 0.009). The immunized group presented fewer mature granulomas in the liver (p = 0.005) and more Lys + macrophages (p = 0.002) and fewer CD3+ T lymphocytes (p < 0.001) per hepatic granuloma. We conclude that immunization with HIMB via the oral route limited local parasite dissemination and hepatic granuloma development in mice challenged with Leishmania amazonensis through stimulation of macrophages, which is compatible with trained immunity.