Nocardia asteroides recovery from a dog with steroid- and antibiotic-unresponsive idiopathic polyarthritis

Abstract

This report describes a fatal case of idiopathic polyarthritis in a dog that was partially responsive to vigorous immunosuppressive treatment. Synovial fluids were cultured for L-forms at the following stages of disease: (i) acute arthritic relapse, (ii) incomplete remission, and (iii) death. No(a,(rdia asteroides UCD 1-581 was recovered from the L-form broth culture of the specimen taken during acute relapse, 5 weeks after inoculation, but not at any other stage of disease. Numerous conventional microbiological cultures were unproductive during all phases. Changes occurring in L-form plates included the formation of large irregular mineral deposits and many transferable bodies resembling pseudocolonies. Microscopic examination revealed the presence of many intracellular goldenbrown granules and acid-fast bodies in macrophages of the lung and bronchial lymph node tissues. The granules are believed to be the variants embedded in calcium deposits similar to those which developed in the L-form cultures in vitro. Fluorescence of these acid-fast bodies with antibody specific for superoxide dismutase of N. asteroides GUH-2 and labeled anti-immunoglobulin G established their relationship to the isolate. The unrelenting course of disease and the persistence of N. asteroides as an L-form in this animal despite vigorous immunosuppression suggest that this organism plays a direct role in the etiology of this disease.

Nocardia species: host-parasite relationships.

“…In addition to the human cases, L-forms of N. asteroides were isolated from a naturally acquired infection in a dog with both steroidand antibioticunresponsive polyarthritis (141). The authors concluded that these L-forms played a direct role in the etiology of the polyarthritis in this dog (141). These reports show that L-forms of Nocardia spp.…”

“…Naturally acquired nocardial infection in dogs with no predisposing underlying illness may be relatively common, and the young German shepherd appears to be one of the most susceptible to nocardial infection (53,93,131,141,281,381,407). Therefore, dogs represent a good animal model for studying naturally acquired nocardial infection because they manifest all of the same clinical features of pulmonary and systemic disease that are recognized in humans (93,131,141,281,381,407,436). However, since 1902 there has been only sporadic use of the dog as an animal model to study nocardial pathogenicity.…”

Cutaneous nocardiosis in two dogs receiving ciclosporin therapy for the management of canine atopic dermatitis

“…Immunosuppression appears to be a predisposing factor for the development of nocardiosis in humans and cats, although both healthy and immunocompromised individuals can be affected . In dogs, infection occurs predominantly in immunocompromised individuals secondary to the administration of immunomodulatory drugs, including ciclosporin combined with or without ketoconazole, prednisolone, dexamethasone, cyclophosphamide, azathioprine, chlorambucil and aurothioglucose …”

On the Importance of Bacterial L‐Forms in Pigeons*

“…-Host defense mechanisms (MATTMAN and KARRIS, 1966;BUXTON and PHILLIPS, 1980;BEAMAN, 1982;BUCHANAN et a]., 1983;LEVINA et al, 1983).…”