Intrauterine infusion of a pathogenic bacterial cocktail is associated with the development of clinical metritis in postpartum multiparous Holstein cows.

Metritis is a uterine disorder common in dairy cattle caused by bacterial infection, with greater incidence in the early postpartum period. The disease causes delayed uterine involution, with a fetid, watery, red-brown discharge, with animals presenting different clinical signs including fever, dullness, inappetence, decreased milk yield, and dehydration. We developed an in vivo model of clinical metritis in Holstein multiparous cows using a pathogenic cocktail of Escherichia coli, Fusobacterium necrophorum, and Trueperella pyogenes. A total of 36 multiparous cows were randomly allocated to 1 of 3 treatment groups of 12 animals each. Cows assigned to the control group received an intrauterine administration of sterile saline solution, those in the low-dose group received a bacterial inoculum containing 106 cfu of Escherichia coli, Trueperella pyogenes, and Fusobacterium necrophorum; and those in the high-dose group received 109 cfu of these same organisms, all within 24 h of parturition. Clinical signs; milk yield; dry matter intake; serum concentration of acute phase proteins, metabolites, and cytokines; and bacterial counts in vaginal discharge were measured from parturition until 14 d in milk. Based on clinical signs, cows in the low-dose group had a greater incidence of metritis (83.3%) compared with the control (9%) or high-dose (25%) group. The low-dose group also had lesser dry matter intake compared with controls and an acute phase protein profile that typified metritis. The low-dose group presented greater relative abundance of bacteria from the genus Fusobacterium in the vaginal discharge compared with control cows, and the high-dose group was similar to the control group. Unexpectedly, intrauterine infusion of cows with a lower dose of bacteria was more effective than a higher dose, indicating that the bacterial load may affect metritis incidence in a nonlinear manner. These findings demonstrate that clinical metritis can be experimentally induced in postpartum multiparous Holstein cows, creating a relevant model for the study of uterine diseases.

Cutaneous leishmaniasis in Cavia porcellus (guinea pig): case report / Leishmaniose cutânea em Cavia porcellus (cobaia): relato de caso

Leishmaniasis is a parasitic disease of worldwide spread. It is caused by protozoa of the genus Leishmania and is transmitted to animals and humans through the bite of sand flies. In Brazil, leishmaniasis is one of the zoonoses of major importance and expansion. The objective of this work is to describe the clinical, pathological, immunohistochemical and molecular findings of cutaneous leishmaniasis by Leishmania enriettii in guinea pig (Cavia porcellus). Three animals had nodular and alopecia lesions on the muzzle, ears and ulcerated lesions on the distal extremities of the pelvic limbs. The males (2) also had diffuse thickening of the scrotal skin. Samples of the ulcerated cutaneous lesions were evaluated by cytology which were observed as amastigote forms of Leishmania. One of the animals was euthanized and necropsied. Histopathology showed abundant dermal infiltrate of macrophages, plasma cells, lymphocytes and multinucleated giant cells. Numerous macrophages contained parasitoid vacuoles with amastigote forms, evidenced by immunohistochemical examination. The molecular characterization based on the SSUrDNA gene identified the species as L. enrietti. The diagnosis of cutaneous leishmaniasis in these cases was based on pathological findings and confirmed by immunohistochemistry, PCR and sequencing.(AU)

A leishmaniose é uma doença parasitária de distribuição mundial. É causada por protozoários do gênero Leishmania e é transmitida para animais e seres humanos por meio da picada de flebotomíneos. No Brasil, a leishmaniose é uma das zoonoses de maior importância e expansão. O objetivo deste trabalho é descrever os achados clínicos, patológicos, imuno-histoquímicos e moleculares de leishmaniose cutânea por Leishmania enriettii em cobaia (Cavia porcellus). Três animais apresentavam lesões nodulares e alopécicas no focinho e orelhas, além de lesões ulceradas nas extremidades distais dos membros pélvicos. Nos machos (2), foi observado espessamento difuso da pele escrotal. Amostras das lesões cutâneas ulceradas foram avaliadas por citologia, nas quais foram observadas formas amastigotas de Leishmania. Um dos animais foi submetido à eutanásia e necropsiado. Na histopatologia, foi observado infiltrado dérmico abundante de macrófagos, plasmócitos, linfócitos e com células gigantes multinucleadas. Numerosos macrófagos continham vacúolos parasitóforos com formas amastigotas, evidenciados por meio do exame de imuno-histoquímica. A caracterização molecular baseada no gene de SSUrDNA identificou a espécie como L. enrietti. O diagnóstico de leishmaniose cutânea nesses casos foi baseado nos achados patológicos e confirmado pelas técnicas de imuno-histoquímica, PCR e sequenciamento.(AU)

Trypanocidal activity of free and nanoencapsulated curcumin on Trypanosoma evansi.

This study aimed to evaluate in vitro and in vivo trypanocidal activity of free and nanoencapsulated curcumin against Trypanosoma evansi. In vitro efficacy of free curcumin (CURC) and curcumin-loaded in lipid-core nanocapsules (C-LNCs) was evaluated to verify their lethal effect on T. evansi. To perform the in vivo tests, T. evansi-infected animals were treated with CURC (10 and 100 mg kg(-1), intraperitoneally [i.p.]) and C-LNCs (10 mg kg(-1), i.p.) during 6 days, with the results showing that these treatments significantly attenuated the parasitaemia. Infected untreated rats showed protein peroxidation and an increase of nitrites/nitrates, whereas animals treated with curcumin showed a reduction on these variables. As a result, the activity of antioxidant enzymes (superoxide dismutase and catalase) differs between groups (P<0.05). Infected animals and treated with CURC exhibited a reduction in the levels of alanine aminotransferase and creatinine, when compared with the positive control group. The use of curcumin in vitro resulted in a better parasitaemia control, an antioxidant activity and a protective effect on liver and kidney functions of T. evansi-infected adult male Wistar rats.

Iron chelation therapy as a treatment for Pythium insidiosum in an animal model.

OBJECTIVES: Iron plays an important role in the pathogenesis of Pythium insidiosum. Human pythiosis frequently occurs in iron-overloaded thalassaemic patients and experimentally infected animals develop iron deficiency anaemia. Therefore, we sought to determine the in vitro and in vivo activities of the iron chelator deferasirox against P. insidiosum. METHODS: In vitro, the MIC and minimum fungicidal concentration (MFC) values of deferasirox for 17 strains of P. insidiosum were determined in accordance with CLSI document M38-A2. In vivo studies were carried out in 20 inoculated rabbits divided into four groups: placebo, immunotherapy obtained from vortexed P. insidiosum cultures (14 day intervals), deferasirox (15 mg/kg/day) and a combination of immunotherapy and deferasirox. Five non-infected animals were used as controls. RESULTS: The MIC and MFC values of deferasirox for P. insidiosum ranged from 12.5 to 50 mg/L and from 50 to 100 mg/L, respectively. Treatment with deferasirox alone ameliorated anaemia and normalized the serum iron levels and hepatic iron concentration in the animals. However, the mean lesion size, although decreased, did not differ significantly from that in the placebo group. The results of immunotherapy plus iron chelation therapy were worse than those of immunotherapy alone. Moreover, the disease spread to the lung tissue in 5 out of 10 deferasirox-treated animals. CONCLUSIONS: Despite its limited in vitro and in vivo activity, deferasirox improved iron deficiency anaemia in P. insidiosum-infected rabbits. Further studies are needed to investigate the immunomodulatory properties observed in this study and the benefits and drawbacks of using iron-chelating drugs as an adjuvant therapy in pythiosis.

Insights into the pathophysiology of iron metabolism in Pythium insidiosum infections.

Pythium insidiosum causes life-threatening disease in mammals. Animals with pythiosis usually develop anemia, and most human patients are reported to have thalassemia and the major consequence of thalassemia, iron overload. Therefore, this study evaluated the iron metabolism in rabbits experimentally infected with P. insidiosum. Ten infected rabbits were divided into two groups: one groups received a placebo, and the other was treated with immunotherapy. Five rabbits were used as negative controls. The hematological and biochemical parameters, including the iron profile, were evaluated. Microcytic hypochromic anemia was observed in the infected animals, and this condition was more accentuated in the untreated group. The serum iron level was decreased, whereas the transferrin level was increased, resulting in low saturation. The level of stainable iron in hepatocytes was markedly decreased in the untreated group. A high correlation was observed between the total iron binding capacity and the lesion size, and this correlation likely confirms the affinity of P. insidiosum for iron. The data from this study corroborate the previous implications of iron in the pathogenesis of pythiosis in humans and animals.

Pathological findings associated with experimental infection by Trypanosoma evansi in cats.

Five cats were experimentally inoculated with Trypanosoma evansi in order to evaluate the pathological changes induced by this protozoan infection. Clinical signs observed included vomiting, diarrhoea, hyperthermia, weight loss, facial oedema, corneal opacity, lymphadenopathy and hindlimb instability. Reduction in hematocrit was observed from 7 days post-infection (dpi) (P<0.05). One cat died at 40 dpi and the other four cats were humanely destroyed. Necropsy examination was performed in two cats at 56 dpi and two cats at 120 dpi. Gross findings in all cats included generalized muscle atrophy, pale mucosae, icterus of the subcutaneous and serosal tissue and the intima of arteries, lymphadenopathy and splenomegaly. Other findings included corneal opacity, subcutaneous oedema (mainly of the head) and hydropericardium. Trypomastigotes of T. evansi were observed in impression smears prepared from the aqueous humor. Microscopically, there was lymphoid hyperplasia of the spleen and lymph nodes. The animals with corneal opacity had mild corneal oedema and accumulation of fibrin and inflammatory cells (neutrophils and plasma cells) in the anterior chamber. Similar inflammatory cells infiltrated the iris, ciliary body, corneoscleral limbus and conjunctiva.

Influence of Trypanosoma evansi in blood, plasma, and brain cholinesterase of experimentally infected cats.

Changes in blood, plasma and brain cholinesterase activities in Trypanosoma evansi-infected cats were investigated. Seven animals were infected with 10(8) trypomastigote forms each and six were used as control. Animals were monitored for 56 days by examining daily blood smears. Blood samples were collected at days 28 and 56 post-inoculation to determine the activity of acetylcholinesterase (AChE) in blood and the activity of butyrylcholinesterase (BChE) in plasma. AChE was also evaluated in total brain. The activity of AChE in blood and brain, and the activity of BChE in plasma significantly reduced in the infected cats. Therefore, the infection by T. evansi influenced cholinesterases of felines indicating changes in the responses of the cholinergic system.

Diminazene aceturate in the control of Trypanosoma evansi infection in cats.

The aim of this study was to investigate the efficacy of diminazene aceturate in the control of the infection by Trypanosoma evansi in cats. Fourteen animals were infected with 10(8) trypomastigote forms each and six were used as negative control (group A). Seven of the infected cats were used as positive control (group B) and seven were treated with diminazene aceturate (3.5 mg kg(-1)) for 5 consecutive days (group C). Biochemical and hematological parameters were evaluated during the experiment. Blood with anticoagulant was collected at day 49 post-inoculation and preserved in ethanol for DNA extraction. Samples were analyzed using PCR T. evansi-specific to assess the effectiveness of treatment. The treatment with diminazene aceturate had an efficacy of 85.7%. Alanine aminotransferase, gamma-glutamyltransferase, urea, and creatinine values remained within the normal physiological range in the treated cats. Hemogram was normalized in all the cured animals. Therefore, the therapy used is effective in controlling T. evansi in cats.