Nocardia nova as the causative agent in spondylodiscitis and psoas abscess

Clinical hypothyroidism in a cat associated with sulfonamide administration for the management of intracranial nocardiosis

A 2-year-old cat was referred for suspected generalised seizure activity and reclusive behaviour, with a history of non-resolving facial abscess. Magnetic resonance imaging (MRI) revealed a contrast enhancing lesion occupying the left calvarium and adjacent peripheral tissues. The intracranial lesion was causing significant mass effect, with oedema and transtentorial herniation. Nocardia nova was isolated from the lesion and identified by DNA sequencing. Treatment consisted of debridement via craniotomy and ventral bulla osteotomy, and combination antibiotic therapy with clarithromycin, amoxycillin and trimethoprim-sulfonamide (sulfadoxine parenterally, then sulfadiazine orally). After several weeks of antibiotic therapy, the cat developed weakness, bicavitary effusion, myxoedema, non-regenerative anaemia and azotaemia. Total thyroxine (TT4) was below the detectable limit and canine thyroid stimulating hormone (cTSH) assay was markedly elevated at 7.53 ng/mL (reference interval 0.15-0.3 ng/mL). Discontinuation of sulfonamides and administration of levothyroxine resulted in resolution of clinical signs. The cat was subsequently able to discontinue levothyroxine, with recovery of euthyroid state. To the authors' knowledge, this is the first report of clinical hypothyroidism in a cat treated with sulfonamide antibiotics and may influence antimicrobial selection and monitoring during therapy. This report also described the management of an atypical presentation of nocardiosis with intracranial extension.

Meningitis and spondylodiscitis due to Nocardia nova in an immunocompetent patient

BACKGROUND

Disseminated nocardiosis is a very rare disease. By now only few cases of meningitis and spondylodiscitis have been reported. To our knowledge, this is the first case of meningitis caused by Nocardia nova.

CASE PRESENTATION

We report on a case of bacteraemia, meningitis and spondylodiscitis caused by N. nova in an immunocompetent patient. We describe the long, difficult path to diagnosis, which took two months, including all diagnostic pitfalls. After nocardiosis was diagnosed, intravenous antibiotic therapy with ceftriaxone, later switched to imipenem/cilastatin and amikacin, led to rapid clinical improvement. Intravenous therapy was followed by oral consolidation with co-trimoxazole for 9 months without any relapse within 4 years.

CONCLUSIONS

Establishing a diagnosis of nocardiosis is a precondition for successful antibiotic therapy. This requires close communication between clinicians and laboratory staff about the suspicion of nocardiosis, than leading to prolonged cultures and specific laboratory methods, e.g. identification by 16S rDNA PCR.

Nocardia elegans primary iliopsoas abscess: A case report and literature review

Nocardia species are rare causative agents of psoas abscess, more frequently occurring as part of disseminated infection. Only sporadic cases have been reported so far, with Nocardia asteroides and Nocardia farcinica being the most common causative agents. Nocardia elegans is an opportunistic pathogen, accounting for only 0.3-0.6% of infections caused by Nocardia species, usually affecting the respiratory tract.In this study, a previously healthy 74-year-old man was admitted to the University Hospital of Heraklion with fever and intense pain radiating from the lumbar region to the groin and the left thigh, increasing with movement. Imaging findings revealed a large abscess in the left iliopsoas. Blood and pus aspirate cultures yielded a pure culture of Nocardia that was identified by 16S rRNA sequence as N. elegans. The patient was successfully treated with drainage of the abscess along with administration of ceftriaxone, linezolid and trimethoprim-sulfamethoxazole. To our knowledge, this is the first report of iliopsoas abscess caused by N. elegans. Early, accurate diagnosis and timely treatment with drainage of the abscess and long-term administration of antimicrobial agents optimize the outcome.

Spinal nocardiosis: A rare tuberculosis mimic in an HIV infected patient

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Early microbiological sampling is crucial when spinal tuberculosis is suspected.

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Awareness of nocardiosis in the immune compromised patient is important.

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Tuberculosis and nocardiosis may be similar in their non-specific presentation.

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Nocardia’s presentation is variable and depends on its clinical form and severity.

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To date, few cases of spinal infection with N. beijingensis have been described.

Despite advances in treatment, human immunodeficiency virus/tuberculosis (HIV/TB) coinfection remains highly prevalent in selected low- and middle income countries. The diagnosis of tuberculosis frequently proves challenging in the setting of advanced HIV, as patients may present with atypical features. A high index of suspicion must be maintained for TB in this setting, but it is critical that alternative diagnoses are considered. A myriad of opportunistic infections may mimic TB and a definitive microbiological diagnosis prior to TB treatment should always be sought. We report on a case of a young, HIV positive male who presented with a delayed diagnosis of nocardiosis that was thought to be TB of the spine. Despite extensive laboratory and radiological investigations, the diagnosis was only made after tissue was cultured. Earlier diagnosis of this mimic would have led to appropriate therapy and may have improved the outcome for this patient.

Rare case of osteomyelitis of tibial shaft caused by Nocardia cyriacigeorgica

Nocardiosis is a rare infection caused by the aerobic actinomycete of the Nocardia genus. In most cases, nocardiosis manifests as a lung infection or a bone lesion. Due to the nonspecific and mild clinical manifestations of nocardiosis, the establishment of definite diagnosis can be difficult. When antibiotic therapy is incorrectly targeted, only the symptoms of the disease are suppressed. The mainstay in the treatment of Nocardia osteomyelitis has so far been the combined surgical debridement with long-term, initially intravenous, antibiotic administration. We present the successful conservative treatment of a nocardiosis osteomyelitis of the tibia caused by the Nocardia cyriacigeorgica species in an 81-year-old female patient that manifested itself as a secondary affection on top of a primary nocardiosis infection of the lung. From microbiological examination, N. cyriacigeorgica was discovered; the identification was made using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) with an identification score of 1.9. The sensitivity was evaluated using E test. Sensitivity to trimethoprim/sulfamethoxazole, amikacin, imipenem, and linezolid was demonstrated. The bacteria were shown to be resistant to ciprofloxacin. For treatment, trimethoprim/sulfamethoxazole was used due to the value of minimum inhibitory concentration, which was 0.25 mg/L. The initial dose of 960 mg of trimethoprim/sulfamethoxazole every 8 h was reduced to 960 mg every 12 h after 3 months. The total duration of treatment was 7.5 months. Under the established treatment, the bone and lung lesions healed. Nocardiosis of the long bone is considered a rare disease and its precise diagnosis has not yet been standardized. We used the MALDI-TOF MS method for the identification of the causal organism which is a fast and reliable method according to current world literature even when compared with the rRNA genetic sequencing reference method. Our case study presents a rare case of osteomyelitis of tibial shaft caused by N. cyriacigeorgica and its successful conservative treatment.

Bacterial, fungal, parasitic, and viral myositis

Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. A parasitic cause of myositis is suggested by the travel history and presence of eosinophilia. Viruses may cause diffuse muscle involvement with clinical manifestations, such as benign acute myositis (most commonly due to influenza virus), pleurodynia (coxsackievirus B), acute rhabdomyolysis, or an immune-mediated polymyositis. The diagnosis of myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by microbiologic or serologic testing. Therapy is based on the clinical presentation and the underlying pathogen.

Streptobacillus moniliformis as the causative agent in spondylodiscitis and psoas abscess after rooster scratches

We report a case of Streptobacillus moniliformis spondylodiscitis accompanied by a psoas abscess in an 80-year-old man scratched by a rooster. S. moniliformis was identified from abscess fluid by use of 16S rRNA gene sequencing. After 18 weeks of antimicrobial therapy, the clinical condition of the patient improved.