Uncommon mandibular osteomyelitis in a cat caused by Nocardia africana

Abstract

BackgroundNocardiosis is an unusual infection in companion animals characterized by suppurative to pyogranulomatous lesions, localized or disseminated. Cutaneous-subcutaneous, pulmonary and systemic signs are observed in feline nocardiosis. However, osteomyelitis is a rare clinical manifestation in cats. Nocardia cyriacigeorgica (formerly N. asteroides sensu stricto), Nocardia brasiliensis, Nocardia otitidiscaviarum, and Nocardia nova are the most common pathogenic species identified in cats, based on recent molecular classification (16S rRNA gene). The present report is, to our knowledge, the first case of mandibular osteomyelitis in a cat caused by Nocardia africana, diagnosed based upon a combination of methods, including molecular techniques.Case presentationA one-year-old non-neutered female cat, raised in a rural area, was admitted to the Companion Animal Hospital-PUCPR, São José dos Pinhais, State of Paraná, Brazil, with a history a progressive facial lesion, difficulty apprehending food, loss of appetite, apathy and emaciation. Clinical examination showed fever, submandibular lymphadenitis, and a painless, 8 cm diameter mass, which was irregularly-shaped, of firm consistency, and located in the region of the left mandible. The skin around the lesion was friable, with diffuse inflammation (cellulitis), multiple draining sinuses, and exudation of serosanguinous material containing whitish “sulfur” granules.Diagnosis was based initially in clinical signs, microbiological culture, cytological, and histopathological findings, and radiographic images. Molecular sequencing of 16S rRNA of isolate allowed diagnosis of Nocardia africana. Despite supportive care and antimicrobial therapy based on in vitro susceptibility testing the animal died.ConclusionThe present report describes a rare clinical case of feline osteomyelitis caused by Nocardia africana, diagnosed based upon a combination of clinical signs, microbiological culture, cytological and histopathological findings, radiographic images, and molecular methods. The use of modern molecular techniques constitutes a quick and reliable method for Nocardia species identification, and may contribute to identification to new species of Nocardia that are virulent in cats.

Radioulnar Ischaemic Necrosis in a Dog with Concurrent Osteomyelitis and Bone Sequestration

“…Fineneedle aspirates are minimally invasive and have been successfully used to diagnose bony lesions in both veterinary and human medicine. 2,[13][14][15][16][17] Although histopathology from a surgical biopsy could have strengthened our diagnosis, it was not performed due to the positive clinical response in the recheck interim and the difficulty of reaching the lesion.…”

Suppurative granulomatous sinorhinitis associated with <i>Nocardia spp.</i> infection in a cat

“…The definitive diagnosis of nocardiosis is generally based on microbiological culture and phenotypical characterization [ 4 ]. Recently, new molecular techniques have been introduced to identify different species of the genus Nocardia [ 4 ]. This case describes suppurative granulomatous sinorhinitis in a cat affected with nocardiosis.…”

“…Animals affected with nocardiosis are usually effectively treated with appropriate antibiotics based on an antimicrobial susceptibility test [ 4 ]. Successful treatment of cats with nocardiosis has been reported mostly for skin lesions [ 1 , 4 ].…”

“…Animals affected with nocardiosis are usually effectively treated with appropriate antibiotics based on an antimicrobial susceptibility test [ 4 ]. Successful treatment of cats with nocardiosis has been reported mostly for skin lesions [ 1 , 4 ]. In contrast, fatal cases were reported for other forms of nocardiosis following standard antibiotic treatment [ 4 , 10 ].…”

“…Successful treatment of cats with nocardiosis has been reported mostly for skin lesions [ 1 , 4 ]. In contrast, fatal cases were reported for other forms of nocardiosis following standard antibiotic treatment [ 4 , 10 ]. In this case, radiation therapy was performed, because the intranasal mass increased in spite of antibiotic treatment.…”