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Macroscopic and microscopic features. (a) Nodular ulcerated lesion on the dorsal aspect of the right pinna. (b) A high-power (40 × ) photomicrograph showing Ziehl–Neelsen-positive rod-shaped bacteria (arrow) within the cytoplasm of macrophages
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Canine leproid granuloma (CLG) is a mycobacterial cutaneous disease characterized by the presence of nodular skin lesions most commonly affecting the head and the dorsal aspect of the pinna. CLG has a wide distribution and has been reported in Africa, Australia, New Zealand, Brazil, and in the USA. To date the mycobacterium responsible for CLG has...
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Citations
... Conceição et al., (2011), citaram que a infecção pelo Mycobacterium spp., pode ganhar a forma de granulomas ou piogranulomas compactos. Ainda, Dedola et al., (2014) também encontraram em seu caso predomínio de macrófagos na citologia. Neste caso, a cultura não foi realizada, pois esta forma de diagnóstico não é indicada devido a micobactéria apresentar necessidades para crescimento muito específicas e ainda não determinadas (Malik et al., 2013). ...
O granuloma lepróide canino é uma dermatose nodular que pode acometer regiões cutânea e subcutânea, geralmente com localização em orelhas e extremidades. Sabe-se que a imunidade dos cães é uma importante aliada tanto para o combate ao seu desenvolvimento, como também para que ocorra a regressão espontânea em animais acometidos sem exérese cirúrgica ou uso de antibacterianos. Devido a isso, este trabalho tem por objetivo relatar um caso de granuloma lepróide em um cão, diagnosticado por citopatológico, dando ênfase em seu aparecimento secundário à imunossupressão resultante de tratamento quimioterápico prévio. O canino, macho, sem raça definida, de 9 anos e pesando 29,4kg foi atendido no Hospital Veterinário da Universidade de Passo Fundo, no Rio Grande do Sul, com queixa de lesão ulcerada e sanguinolenta no pênis. Foi realizada citologia por agulha fina e diagnosticado com tumor venéreo transmissível. Após a sexta sessão quimioterápica com sulfato de vincristina, apresentou nódulo em face externa da orelha esquerda medindo 1,5x1,2cm, de consistência firme, aspecto regular, não inflamado e aderido. Foram realizados citopatológico e coloração especial com Ziehl-Neelsen confirmando se tratar de uma inflamação granulomatosa decorrente de uma infecção causada por Mycobacterium spp. Enfatiza-se que a resposta imunológica do paciente é um importante variável a ser considerado no aparecimento de granuloma lepróide canino. E assim, esse diagnóstico diferencial deve sempre ser considerado em pacientes que passam a apresentar alterações cutâneas nodulares após estipulação de protocolos quimioterápicos.
... [95] Canine leprosy is a disease associated with members of the Mycobacterium simiae clade, and thus unrelated to M. leprae. [96,97] A thelitis-causing pathogen in dairy goats and cows appeared to be closely related to M. leprae, and was named M. uberis. [98][99][100] Environmental reservoirs (see Table 4) ...
Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) and the more recently discovered Mycobacterium lepromatosis (M. lepromatosis). The two leprosy bacilli cause similar pathologic conditions. They primarily target the skin and the peripheral nervous system. Currently it is considered a Neglected Tropical Disease, being endemic in specific locations within countries of the Americas, Asia, and Africa, while in Europe it is only rarely reported. The reason for a spatial inequality in the prevalence of leprosy in so-called endemic pockets within a country is still largely unexplained. A systematic review was conducted targeting leprosy transmission research data, using PubMed and Scopus as sources. Publications between January 1, 1945 and July 1, 2019 were included. The transmission pathways of M. leprae are not fully understood. Solid evidence exists of an increased risk for individuals living in close contact with leprosy patients, most likely through infectious aerosols, created by coughing and sneezing, but possibly also through direct contact. However, this systematic review underscores that human-to-human transmission is not the only way leprosy can be acquired. The transmission of this disease is probably much more complicated than was thought before. In the Americas, the nine-banded armadillo (Dasypus novemcinctus) has been established as another natural host and reservoir of M. leprae. Anthroponotic and zoonotic transmission have both been proposed as modes of contracting the disease, based on data showing identical M. leprae strains shared between humans and armadillos. More recently, in red squirrels (Sciurus vulgaris) with leprosy-like lesions in the British Isles M. leprae and M. lepromatosis DNA was detected. This finding was unexpected, because leprosy is considered a disease of humans (with the exception of the armadillo), and because it was thought that leprosy (and M. leprae) had disappeared from the United Kingdom. Furthermore, animals can be affected by other leprosy-like diseases, caused by pathogens phylogenetically closely related to M. leprae. These mycobacteria have been proposed to be grouped as a M. leprae-complex. We argue that insights from the transmission and reservoirs of members of the M. leprae-complex might be relevant for leprosy research. A better understanding of possible animal or environmental reservoirs is needed, because transmission from such reservoirs may partly explain the steady global incidence of leprosy despite effective and widespread multidrug therapy. A reduction in transmission cannot be expected to be accomplished by actions or interventions from the human healthcare domain alone, as the mechanisms involved are complex. Therefore, to increase our understanding of the intricate picture of leprosy transmission, we propose a One Health transdisciplinary research approach.
... Three distinct lineages of unculturable mycobacteria have also been described that cluster with M. sherrisii and M. stomatopiae (by 16S): "M. tarwinense", the most common cause of feline leprosy in Australia (O'Brien et al., 2017b); a yet unnamed Mycobacterium causing canine leproid granuloma syndrome (Dedola et al., 2014;Foley et al., 2002;Hughes et al., 2000) and "M. tilburgii" detected by molecular methods in tissue specimens from adults and children with disseminated disease, some with a documented immunodeficiency (Hartwig et al., 2011;Temmerman et al., 2014;Wagner et al., 2006). ...
Seventy years have passed since Ernest H. Runyon presented a phenotypic classification approach for nontuberculous mycobacteria (NTM), primarily as a starting point in trying to understand their clinical relevance. From numerical taxonomy (biochemical testing) to 16S rRNA gene sequencing to whole genome sequencing (WGS), our understanding of NTM has also evolved. Novel species are described at a rapid pace, while taxonomical relationships are re-defined in large part due to the accessibility of WGS. The evolutionary course of clonal complexes within species is better known for some NTM and less for others. In contrast with M. tuberculosis, much is left to learn about NTM as a whole.
Canine leproid granuloma (CLG) is a chronic form of dermatitis that has been associated with nontuberculous mycobacterial infections in Africa, Oceania, the Americas, and Europe. We report here a case of CLG associated with a member of the Mycobacterium tuberculosis complex (MTBC), which could be of public health concern. An 8-y-old pet dog developed 0.5-1-cm diameter, raised, firm, nonpruritic, alopecic, painless skin nodules on the external aspects of both pinnae. Histologic examination revealed severe pyogranulomatous dermatitis with intracellular Ziehl-Neelsen-positive bacilli that were immunoreactive by immunohistochemistry using a polyclonal primary antibody that recognizes tuberculous and nontuberculous Mycobacterium species. DNA extracted from formalin-fixed, paraffin-embedded skin sections was tested by a Mycobacterium genus-specific nested PCR assay targeting the 16S rRNA gene. BLAST sequence analysis of 214-bp and 178-bp amplicons showed 99.5% identity with members of the MTBC; however, the agent could not be identified at the species level. Although CLG has been associated traditionally with nontuberculous mycobacterial infections, the role of Mycobacterium spp. within the MTBC as a cause of this condition, and the role of dogs with CLG as possible sources of MTBC to other animals and humans, should not be disregarded given its zoonotic potential.
This report describes the clinical features and molecular diagnosis of a case of canine leproid granuloma (CLG) caused by mycobacterial strains of the Mycobacterium simiae complex in Brazil. A 12-year-old non-neutered male Labrador Retriever dog was presented with a two-week history of progressive painless cutaneous lesions. Ulcerated nodules with hematic crusts were observed on the dorsal surface of the right and left pinna and on the metacarpal, metatarsal, and digits. Complete blood count, serum biochemistry, aspiration cytology of cutaneous lesions, biopsy for histopathological evaluation, culture for aerobic and anaerobic bacteria, polymerase chain reaction (PCR) and DNA sequencing to identify mycobacterial species were performed. According to the clinical and histopathological findings, a diagnosis of CLG was established. Despite the negative result of the bacterial culture, mycobacterial identification was made by sequencing the hsp65 gene. Our findings highlight that mycobacterial species closely related to members of the M. simiae clade can be causative agents of CLG.
This short communication describes the clinical and morphological findings, diagnosis and treatment of a case of Mycobacterium avium infection in a golden retriever that presented with a progressive nasal swelling and lymphadenopathy. Although well documented in cats, where cutaneous lesions are frequently recognised, canine M avium infection is less commonly reported, and cutaneous lesions are rare. To the authors’ knowledge this is the first documented case of canine M avium infection that presented with a cutaneous lesion but no systemic clinical signs. It occurred in a dog with no previously reported breed predisposition and highlights that in cases of cutaneous histiocytic infiltrate in dogs mycobacterial infection should remain a differential diagnosis, even in the absence of suggestive organisms on histopathological examination.
Mycobacterial diseases are being more frequently diagnosed in companion animals in first opinion practice in the UK. These infections can be challenging both to diagnose and manage; this and a following article aim to give an overview of the relevant background and epidemiology, diagnosis, management and prognosis for companion animal mycobacteriosis (CAM). This first article discusses the different mycobacterial species involved with CAM, the epidemiology and the various clinical presentations which may result from infection.
