Granuloma leproide canino: estudo de 27 casos / Canine leproid granuloma: study of 27 cases

O granuloma leproide canino (GLC) é uma doença micobacteriana que cursa com lesão nodular, cutânea ou subcutânea, tipicamente auto limitante, decorrente de infecção pelo Mycobacterium. É uma doença dermatológica rara, usualmente relatada em países de clima tropical. O objetivo deste trabalho é caracterizar as alterações microscópicas e epidemiológicas de casos de GLC. Além disso, utilizar exames complementares para demonstração do Mycobacterium sp. na lesão analisada utilizando coloração de Ziehl-Neelsen, imuno-histoquímica e PCR para classificação e sequenciamento da espécie de Mycobacterium. Foram analisados 27 casos de GLC diagnosticados no período compreendido de 2005 a 2014 (21 exames histológicos e seis citológicos). A raça mais acometida foi Boxer (33,3%), seguida da Dachshund (11,1%). Foi frequente o acometimento de caninos de grande porte (64%) e de pelame curto (96%). Não foi possível estabelecer qualquer padrão de sazonalidade do GLC. As lesões se localizaram anatomicamente no pavilhão auricular na maioria dos casos (93%), constituindo-se de nódulos únicos ou múltiplos, ulcerados ou não. Em nenhum dos casos foi observado acometimento sistêmico. Lesões histológicas seguiram três padrões que variaram de nodulares a difusos, com infiltrado granulomatoso/piogranulomatoso com envolvimento de derme superficial e profunda. A observação de bacilos pela coloração de Ziehl-Neelsen confirmou o diagnóstico. Este teste demonstrou grande variação na quantidade de bacilos nas lesões, não relacionado estatisticamente ao tipo da lesão nem ao período evolutivo. A imuno-histoquímica foi positiva em 90% dos casos, e em alguns casos facilitou a identificação de bacilos, entretanto, em dois casos ocorreram resultados negativos mesmo havendo marcação pela coloração de Ziehl-Neelsen. Na técnica de PCR realizada em 18 amostras, 44% dos casos foram positivos, duas sequências inespecíficas, e demonstrou ainda, que Mycobacterium murphy foi responsável por 2 casos e Mycobacterium hodleri em um caso. Em outros três casos não se obteve 100% de semelhança entre o produto sequenciado e os demais Mycobacterium.(AU)

Canine leproid granuloma (CLG) is cutaneous diseases caused by mycobacteria that course with nodular cutaneous or subcutaneous lesion, typically self-limiting, due to Mycobacterium infection. It is an unusual dermatological disease, usually reported in tropical countries. The objective of the present study is to describe the epidemiological and histopathological findings of CLG. Furthermore, use additional tests for demonstration of Mycobacterium sp. in the lesion were performed, e.g. Ziehl-Neelsen staining, immunohistochemical and polymerase chain reaction (PCR) for classification and genetic sequencing of Mycobacterium species. Twenty seven cases of CLG diagnosed between 2005 and 2014 were studied (21 cases by histological examination and six by cytological examination). Boxer dogs were the breed most affected (33.3%) followed by Dachshund dog breed (11.1%). The disease affected dogs with mainly large size (64%) and short-coated (96%). There was no evidence predilection for occurrence in any season. The lesions were localized, in most cases, at the pinna (93%), comprise one or multiple nodules, ulcerated or not. None of the cases was observed with systemic involvement. Histopathological findings included three patterns of nodular to diffuse, with inflammatory infiltration granulomatous/pyogranulomatous that involved superficial and deep dermis. Definitive diagnosis was made by the presence of acid-fast bacilli by Ziehl-Neelsen stain, showing wide variation in the number of bacilli in the lesions, not being statistically correlated to the type of injury or the evolution period. Immunohistochemistry was effective, and in some cases facilitated the identification of bacilli, but in two cases were negative even with marking by Ziehl-Neelsen staining. The immunohistochemistry was positive in 90% cases, and in some cases facilitated the identification of bacilli, but in two cases were negative even with marking by Ziehl-Neelsen staining. The PCR technique was positive in 44% of cases, demonstrating that Mycobacterium murphy was responsible for two cases of GLC and Mycobacterium hodleri by a one case. In other three PCR-positive cases if not got 100% similarity between the sequenced and other Mycobacterium.(AU)

Infecção por Mycobacterium sp. em herbívoros selvagens de cativeiro no Rio Grande do Sul: estudo retrospectivo e detecção imuno-histoquímica (2003-2015) / Mycobacterium sp. in captive-reared wild herbivores in Rio Grande do Sul: a retrospective study and immunohistochemical detection (2003-2015)

A tuberculose é uma enfermidade infectocontagiosa, debilitante, causada por bacilos álcool-ácido resistentes (BAAR), pertencentes ao complexo Mycobacterium tuberculosis (CMT). As micobacterioses têm importância em Medicina Veterinária devido ao seu potencial zoonótico e sua distribuição mundial, afetando todas as classes de vertebrados. Em animais selvagens as micobacterioses têm sido um problema relatado principalmente em cativeiro. Contudo, há relatos de sua ocorrência também em animais de vida livre, colocando em risco e dificultando os programas de erradicação da tuberculose em animais de produção. O diagnóstico nas espécies selvagens em geral é post mortem, uma vez que o teste de tuberculina não está padronizado para essas espécies, assim como não é confiável para triagem. São consideradas para o diagnóstico lesões de necropsia, observação microscópica de BAAR na coloração de Ziehl-Neelsen (ZN) e, principalmente, isolamento e identificação do agente. No entanto, apenas os achados morfológicos macro e microscópicos não permitem distinguir a espécie de Mycobacterium envolvida. A técnica de imuno-histoquímica (IHQ) com anticorpo policlonal anti-M. tuberculosis confirma a infecção pelo CMT, mas não é específica, pois pode ocorrer marcação de outras micobactérias. As características histológicas, os achados na coloração de ZN e na IHQ de 13 casos de herbívoros selvagens diagnosticados com tuberculose no Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS) no período de 2003 a 2015 são descritos. A partir das amostras em blocos de parafina foram confeccionadas novas lâminas histológicas, coradas com hematoxilina e eosina (HE) e ZN. Cortes foram submetidos à técnica de IHQ para detecção do CMT. Todos os animais eram adultos, provenientes de cativeiro e incluíram lhama (5/13), cervo sambar (4/13), camelo (1/13), cervo vermelho (1/13), anta brasileira (1/13) e antílope Nilgai (1/13). Na IHQ observou-se imunomarcação acentuada (4/13), moderada (4/13) ou discreta (4/13), exceto em um caso, em que não havia quantidade suficiente de material. As características histológicas, bem como os achados na coloração de ZN e na técnica de IHQ confirmaram o diagnóstico de infecção por Mycobacterium sp. e foram considerados métodos rápidos e eficientes, de forma que podem ajudar na prevenção da disseminação da doença em animais.(AU)

Tuberculosis is a debilitating infecto-contagious disease, caused by an acid-fast bacillus (AFB) that belong to different species of the Mycobacterium tuberculosis complex (MTC). Mycobacteriosis are important diseases in veterinary medicine because of their zoonotic potential and worldwide distribution, affecting all classes of vertebrates. In wild animals the mycobacteriosis have been reported mainly as a problem in captivity. There are also reports in free-ranging wildlife, endangering and hampering tuberculosis erradication programs in animal production. The diagnosis of the disease in wildlife is usually postmortem, because the tuberculin test is not standardized for wildlife species, and also it is not reliable for screening. The postmortem diagnosis is based on macroscopic findings, microscopic detection of AFB at Ziehl-Neelsen staining (ZN), and mainly isolation and identification of the agent. However, only gross and microscopic exams do not allow to distinguish the species of Mycobacterium involved. The immunostaining with polyclonal anti-Mycobacterium tuberculosis confirms tuberculosis infection, but is not specific; there may be marking of other mycobacteria. The aim of this study was to describe the histologic findings, of ZN staining and immunohistochemistry technique (IHC) of 13 cases of wildlife herbivores diagnosed with tuberculosis in the Setor de Patologia Veterinária of the Universidade Federal do Rio Grande do Sul (SPV-UFRGS) during the 2003- 2015 period. Formalin fixed paraffin embedded tissues were recut, stained with hematoxylin and eosin and ZN, and samples were submitted to the IHC (anti-M. tuberculosis marking, streptavidin-biotin peroxidase method). All animals included were adults living in captivity and belonged to the following species: llama (5/13), sambar deer (4/13), camel (1/13), red deer (1/13), Brazilian tapir (1/13) and Nilgai antelope (1/13). The IHC revealed immunostaining of accentuated (4/13), moderate (4/13) and discrete (4/13) intensity, except in a case with insufficient material. The histological features, findings in ZN staining and IHC in the wild herbivores with tuberculosis lesions allowed the diagnosis of infection with Mycobacterium sp., turning into fast and efficient methods of diagnosis, which can help to prevent the spread of this disease in animals from the same herd.(AU)

Mycobacterium genavense infection in two species of captive snakes

Mycobacterium is an important zoonotic agent with companion, livestock and wildlife animals reportedly playing a role as reservoirs. Although its association with reptiles has been described, the disease cycle remains to be fully established, particularly in snakes. Accordingly, this study aimed to report the occurrence of mycobacteriosis with clinical pneumonia in one exotic python snake (Python molurus) and one native green snake (Philodryas olfersii) from the Sorocaba Zoo, São Paulo state, Brazil. Methods: Diagnosis was based on necropsy, histopathological examination, Ziehl-Neelsen stain and immunohistochemistry. Results: Using a nested PCR followed by DNA sequencing and bioinformatics analysis, the causative Mycobacterium species was identified as Mycobacterium genavense. Conclusion: Mycobacterium genavense is an infectious zoonotic agent of animal and public health concerns.

Características clínicas, factores de riesgo y perfil de susceptibilidad de las infecciones por micobacterias documentadas por cultivo, en un hospital universitario de alta complejidad en Medellín (Colombia) / Clinical features, risk factors and susceptibility profile of mycobacterial infections documented by culture in a university hospital of high complexity in Medellin (Colombia)

Introduction: Tuberculosis (TB) remains an entity of high prevalence and mortality worldwide. The rising drug resistance is a public health problem. Besides, non-tuberculosis mycobacterial (NTM) infections are described with increasing frequency in areas of high prevalence of TB. Objectives: To determine epidemiological, clinical and microbiological characteristics of mycobacterial infections documented by culture. Materials and Methods: An observational, descriptive study in hospitalized patients. Results: M. tuberculosis complex was identified in 90,9% of 187 patients; 9,1% had NTM, 64% were male and the mean age was 40 years (range 1-88 years). The main co-morbidities were HIV / AIDS (23.5%), use of corticosteroids (13.3%) and chronic kidney disease (9.6%). Clinical forms were pulmonary (56.6%), extra-pulmonary (23.9%) and disseminated (19.2 The most common extra-pulmonary compromise was nodal (7.4%) and gastrointestinal (7%). 10.6% of M. tuberculosis were multi-drugresistant (MDR) and 2.12% had extended drug resistance (XDR). Mycobacterium avium andM. abscessus were the most frequent NTM. Overall mortality was 10%. Conclusions: In our study immune suppression is the main risk factor for extrapulmonary and disseminated disease. Resistance, MDR and XDR is higher in inpatients with TB. MNT infections are not uncommon in our country.

Introducción: Tuberculosis (TBC) es aún una entidad de alta prevalencia y mortalidad en el mundo. La resistencia ascendente a fármacos es un problema de salud pública. Además se describen con mayor frecuencia infecciones por micobacterias no tuberculosas (MNT) en áreas de alta prevalencia de TBC. Objetivos: Determinar características epidemiológicas, clínicas y microbiológicas de las infecciones por micobacterias documentadas por cultivo. Materiales y Métodos: Estudio observacional, descriptivo, en pacientes hospitalizados. Resultados: De 187 pacientes, en 90,9% se identificó complejo M. tuberculosis y en 9,1% MNT; 64% fueron hombres. Edad promedio 40 años (rango 1-88 años). Las principales co-morbilidades fueron infección por VIH/SIDA (23,5%), uso de corticoesteroides (13,3%) y enfermedad renal crónica (9,6%). Las formas clínicas fueron pulmonares (56,6%), extra-pulmonares (23,9%) y diseminadas (19,2%). El compromiso extra-pulmonar más frecuente fue ganglionar (7,4%) y gastrointestinal (7%). En M. tuberculosis 10,6% fueron multidrogoresistentes (MDR) y 2,12% con resistencia extendida (XDR). Mycobacterium avium y M. abscessus fueron las MNT más frecuentes. La mortalidad general fue 10%. Conclusiones: Inmuno-supresión es el principal factor de riesgo para enfermedad extrapulmonar y/o diseminada y la resistencia a fármacos en pacientes hospitalizados con TBC es llamativa, con mayor incidencia de MDR y XDR. Las infecciones por MNT no son infrecuentes en nuestro medio.

Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.

Mycobacteria and innate cells: critical encounter for immunogenicity.

Protective immunity against mycobacterial infections such as Mycobacterium tuberculosis is mediated by interactions between specific T cells and activated macrophages.To date,many aspects of mycobacterial immunity have shown that innate cells are the key elements that substantially influence the subsequent adaptive host response.During the early phases of infection,phagocytic cells and innate lymphocyte subsets play a pivotal role.Here we summarize the findings of recent investigations on macrophages,dendritic cells and gammadelta T lymphocytes in the response to mycobacteria.

Resposta imune celular a diferentes antígenos micobacterianos em indivíduos infectados por Mycobacterium tuberculosis: avaliação por elispot, elisa e linfoproliferação / Immune cellular response at differents mycobacterians antigens infected by Mycobacterium tuberculosis: evaluation by Elispot, Elisa and lymphoproliferation

A tuberculose é uma doença crônica granulomatose caracterizada por um déficit de imunidade antígeno específica do hospedeiro, cuja resposta imune é ativamente regulada por citicinas. No Brasil há mais de 50 milhões de habitantes infectados pelo Mycobacterium tuberculosis. O objetivo foi avaliar qa linfoproliferação e a produção de citocinas por células mononucleares do sangue periférico (PBMC) estimuladas por quatro diferentes antígenos do M. tuberculosis... / Tuberculosis is chronic granulomatous disease characterized by a deficit of the antigen-specific immunity of the host, whose immune response is actively regulated by cytokines...

In vivo effect of delipidified cell component of Mycobacterium leprae in relation to infection with leprosy bacteria in mice.

The delipidified cell component (DCC) of Mycobacterium leprae was used as an immunomodulatory agent in Swiss white mice. The peritoneal macrophages of these mice were activated to produce increased amount of reactive oxygen intermediates like hydrogen peroxide (H2O2) and superoxide. These macrophages also attained the ability to kill M. Leprae in vitro as shown by several assay systems including the conventional mouse foot-pad technique. The increased levels of superoxide seem to be responsible for the killing of M. leprae as addition of the enzyme superoxide dismutase, which breaks down O2, resulted in survival of these bacilli inside the macrophages. The increased production of H2O2 does not seem to be responsible for killing M. leprae. The results indicate that the DCC of M. leprae acts as an effective immunomodulator in mice leading to the activation of macrophages with increased production of H2O2 and superoxide as well as enabling them to kill M. leprae via the action of superoxide anions.

La intradermo-reacción con sensitinas en población paraguaya no becegeizada / Intradermal reaction with sensitins in paraguayan population who had never received BCG vaccine

Este trabajo constituye la 2a. parte del trabajo previo denominado "La intradermo-reacción con sensitinas en población paraguaya". En la presente investigación hemos incluído exclusivamente a individuos que no habían recibido la vacuna BCG, encontrando, sobre 44 pacientes estudiados, una tasa de reactores significativos de 29,7 por ciento a las sensitinas utilizadas. Dentro de estos pacientes reactores, constatamos en ambos estudios un neto predominio de reactores al M. avium (60 por ciento y 90,9 por ciento respectivamente). Con esto, queda comprobada la alta tasa de infección de la población paraguaya a las micobacterias no TBC y específicamente al M. avium

Caracterización de la infección experimental con Mycobacterium lepraemurium en dos cepas de ratones / Development of experimental infection with Mycobacterium lepraemurium in two strains of mice

Se desarrolló un modelo de lepra experimental e 2 cepas de ratones, CB/J y CBi, en base: a) el estudio histológico del granuloma en la pata trasera, 200 días despues dela inoculación con 0,30 micronl de mycobacterium lepraemurium (6 x 10**8 ML/ml); b) la evaluación en el granuloma, de linfocitos T, identificados con la técnica inmunohistoquimica de alfa-naftil acetato de estearasa; c) la diseminación a distancia de la infección. La cepa CBA/J, de baja resistencia, presentó un cuadro histológico compuesto por células vacuoladas BAAR positivas sin infiltración linfocitaria, escasa presencia de linfocitos T y generalizada y abundante diseminación a distancia (símil lepromatosa humana. La cepa CBi, de mediana a alta resistencia, mostró en el granuloma de la pata (en un 30-40% de los animales), un cuadro histológico compuesto por células vacuoladas e infiltrado linfocitario, presencia abundante de células T y poca diseminación a distancia (símil "borderline" humana). Las dos cepas presentan diferenetes susceptibilidad a un desafío único con la micobacteria, y pueden ser de utilidad para conocer los componentes inmunogenéticos de esa condición, mediante selección y cruzas adecuadas, así como ralizar, en los ratones CBi, ensayos de inmunoprotección que apoyen los estudios de vacunación en lepra humana