Visceral leishmaniasis in a captive crab-eating fox Cerdocyon thous.

Visceral leishmaniasis (VL) is a zoonotic disease with worldwide distribution. The crab-eating fox (Cerdocyon thous) is considered a wild reservoir of many zoonotical diseases, particularly VL. This study reported the presence of Leishmania infantum amastigotes in different organs of one captive C. thous found dead in a zoo. This animal was positive by the indirect fluorescence antibody test and had many clinical signs of VL. Intracellular amastigote forms of L. infantum were seen in neutrophils and macrophages in sample tissues from skin, lymph nodes (popliteal, submandibular, prescapular, and mesenteric), spleen, and liver. The numbers of positive cells and intracellular parasites were higher in macrophages than in neutrophils. In addition, polymerase chain reaction demonstrated extensive distribution of Leishmania DNA in C. thous tissues from multiple organs. The presence of intracellular amastigotes in neutrophils and macrophages as well as DNA of the parasite in tissues, specifically skin demonstrate that this crab-eating fox is an adequate host for L. infantum and reinforce the importance of VL for symptomatic wild canids kept in captivity in endemic areas.

Effects of hyperbaric oxygen on Pseudomonas aeruginosa susceptibility to imipenem and macrophages.

BACKGROUND: The seriousness to treat burn wounds infected with Pseudomonas aeruginosa led us to examine whether the effect of the carbapenem antibiotic imipenem is enhanced by hyperbaric oxygen (HBO). MATERIALS & METHODS: The effects of HBO (100% O2, 3 ATA, 5 h) in combination with imipenen on bacterial counts of six isolates of P. aeruginosa and bacterial ultrastructure were investigated. Infected macrophages were exposed to HBO (100% O2, 3 ATA, 90 min) and the production of reactive oxygen species monitored. RESULTS: HBO enhanced the effects of imipenen. HBO increased superoxide anion production by macrophages and likely kills bacteria by oxidative mechanisms. CONCLUSION: HBO in combination with imipenem can be used to kill P. aeruginosa in vitro and such treatment may be beneficial for the patients with injuries containing the P. aeruginosa.

[Parasitological, immunohistochemical and histopathological study for Leishmania chagasi detection in splenic tissues of dogs with visceral leishmaniasis]. / Exames parasitológicos, imunoistoquímicos e histopatológicos para detecção de Leishania chagasi em tecidos esplênicos de cães com leishmaniose visceral.

The purpose of this work was a Canine Visceral Leishmaniasis--CVL study by parasitological direct examination of Leishmania (L.) chagasi (imprinting and histological), immunohistochemical test and histopathological analysis using spleen tissues from 34 dogs euthanized by the Zoonotic Disease Control Centre from Ilha Solteira, SP, Brazil. According to the clinical signs, the dogs were divided in three groups: asymptomatics (8 dogs), oligosymptomatics (17 dogs) and symptomatics (9 dogs). After the accomplishment of all diagnostic tests, 22 dogs were considered positives (64.7%) and 12 (35.3%) were negatives to CVL. From these positive dogs, 1/22 (4.5%) was asymptomatic, 12/22(54.5%) were oligosymptomatics and 8/22 (40.1%) were symptomatics. The histopathological study in spleen tissues from positive, especially symptomatic dogs, showed a diffuse chronic inflammation with thickness of capsular and trabecular regions and there was extensive morphologic alteration of the red and white pulp by the presence of abundant macrophages full with amastigotes, the granulomatous inflammatory reaction and haemorrhagic areas. The data of this work from histopathologic examination and direct microscopic visualization of L. (L.) chagasi showed that the spleen was an useful organ to collect sample tissues for CVL diagnosis. The immunostaining detected the highest number of positive dogs and were considered an important and conclusive method to be used in addition to parasitological methods for CVL, particularly in asymptomatic or oligosymptomatic dogs.

Exames parasitológicos, imunoistoquímicos e histopatológicos para detecção de Leishmania chagasi em tecidos esplênicos de cães com leishmaniose visceral / Parasitological, immunohistochemical and histopathological study for Leishmania chagasi detection in spleenic tissues of dogs with visceral leishmaniasis

O propósito do presente trabalho foi o estudo da Leishmaniose Visceral Canina - LVC por meio de métodos parasitológicos e imunoistoquímicos para a detecção de formas amastigotas de Leishmania (L.) chagasi em baço, além de descrever a histopatologia das lesões esplênicas em 34 cães, com diferentes manifestações clínicas da LVC, eutanasiados pelo Centro de Controle de Zoonoses de Ilha Solteira, SP. Esses animais foram examinados clinicamente antes da eutánásia e de acordo com os sinais clínicos da LVC, foram classificados em três grupos: assintomáticos (8 cães), oligossintomáticos (17 cães) e sintomáticos (9 cães). Após a realização desses exames, dos 34 cães, 22 (64,7 por cento) estavam positivos e 12 (35,3 por cento) negativos. Desses cães positivos, 1/22 (4,5 por cento) era assintomático, 12/22 (54,5 por cento) eram oligossintomáticos e 9/22 (40,1 por cento) sintomáticos. Pela histopatologia, os cães, especialmente os sintomáticos apresentavam o baço com inflamação crônica e espessamento na região capsular e trabecular, além de extensa alteração morfológica na polpa vermelha e branca pela presença de grande quantidade de macrófagos repletos de amastigotas, pela reação granulomatosa inflamatória e pelas áreas hemorrágicas. Os exames histopatológicos e a detecção microscópica direta da L. (L.) chagasi revelaram que o baço é um órgão útil para auxiliar no diagnóstico da LVC. A coloração imunoistoquímica foi a que detectou o maior número de tecidos esplênicos positivos com amastigotas, além de elucidar os casos suspeitos pelos exames parasitológicos, principalmente, nos animais assintomáticos ou oligossintomáticos.

The purpose of this work was a Canine Visceral Leishmaniasis - CVL study by parasitological direct examination of Leishmania (L.) chagasi (imprinting and histological), immunohistochemical test and histopathological analysis using spleen tissues from 34 dogs euthanized by the Zoonotic Disease Control Centre from Ilha Solteira, SP, Brazil. According to the clinical signs, the dogs were divided in three groups: asymptomatics (8 dogs), oligosymptomatics (17 dogs) and symptomatics (9 dogs). After the accomplishment of all diagnostic tests, 22 dogs were considered positives (64.7 percent) and 12 (35.3 percent) were negatives to CVL. From these positive dogs, 1/22 (4.5 percent) was asymptomatic, 12/22 (54.5 percent) were oligosymptomatics and 8/22 (40.1 percent) were symptomatics. The histopathological study in spleen tissues from positive, especially symptomatic dogs, showed a diffuse chronic inflammation with thickness of capsular and trabecular regions and there was extense morphologic alteration of the red and white pulp by the presence of abundant macrophages full with amastigotes, the granulomatous inflammatory reaction and haemorragic areas. The data of this work from histopathologic examination and direct microcopic visualization of L. (L.) chagasi showed that the spleen was an useful organ to collect sample tissues for CVL diagnosis. The immunostaining detected the highest number of positive dogs and were considered an important and conclusive method to be used in addition to parasitological methods for CVL, particularly in asymptomatic or oligosymptomatic dogs.