Spondylodiscitis due to an emergent fungal pathogen: Blastoschizomyces capitatus, a case report and review of the literature

MRI and clinical features of acute fungal discitis/osteomyelitis

OBJECTIVES

To compare imaging and clinical features of fungal and Staphylococcus aureus discitis-osteomyelitis (DO) for patients presenting for CT-guided biopsies.

METHODS

Our study was IRB-approved and HIPAA-compliant. A group of 11 fungal DO (FG) with MRI within 7 days of the biopsy and a control group (CG) of 19 Staphylococcus aureus DO were evaluated. Imaging findings (focal vs diffuse paravertebral soft tissue abnormality, partial vs complete involvement of the disc/endplate), biopsy location, pathology, duration of back pain, immune status, history of intravenous drug, history of prior infection, current antibiotic treatment, and history of invasive intervention. Differences were assessed using the Fisher exact test and Kruskal-Wallis test. Naïve Bayes predictive modeling was performed.

RESULTS

The most common fungal organisms were Candida species (9/11, 82%). The FG was more likely to have focal soft tissue abnormality (p = 0.040) and partial disc/endplate involvement (p = 0.053). The clinical predictors for fungal DO, in order of importance, back pain for 10 or more weeks, current antibiotic use for 1 week or more, and current intravenous drug use. History of invasive instrumentation within 1 year was more predictive of Staphylococcus aureus DO.

CONCLUSION

MRI features (focal partial soft tissue abnormality and partial involvement of the disc/endplate) in combination with clinical features may help to predict fungal species as a causative organism for DO.

KEY POINTS

• MRI features of discitis-osteomyelitis (focal partial soft tissue abnormality and partial involvement of the disc/endplate) in combination with clinical features may help to predict fungal species as a causative organism for DO.

Rare fungal infectious agents: a lurking enemy

In the expanding population of immunocompromised patients and those treated in intensive care units, rare fungal infectious agents have emerged as important pathogens, causing invasive infections associated with high morbidity and mortality. These infections may present either as de novo or as breakthrough invasive infections in high-risk patients with hematologic malignancies receiving prophylactic or empirical antifungal therapy or in patients with central venous catheters. Diagnosis and treatment are challenging. Physicians should have a high index of suspicion because early diagnosis is of paramount importance. Conventional diagnostic methods such as cultures and histopathology are still essential, but rapid and more specific molecular techniques for both detection and identification of the infecting pathogens are being developed and hopefully will lead to early targeted treatment. The management of invasive fungal infections is multimodal. Reversal of risk factors, if feasible, should be attempted. Surgical debridement is recommended in localized mold infections. The efficacy of various antifungal drugs is not uniform. Amphotericin B is active against most yeasts, except Trichosporon, as well as against Mucorales, Fusarium, and some species of Paecilomyces and dimorphic fungi. The use of voriconazole is suggested for the treatment of trichosporonosis and scedosporiosis. Combination treatment, though recommended as salvage therapy in some infections, is controversial in most cases. Despite the use of available antifungals, mortality remains high. The optimization of molecular-based techniques, with expansion of reference libraries and the possibility for direct detection of resistance mechanisms, is awaited with great interest in the near future. Further research is necessary, however, in order to find the best ways to confront and destroy these lurking enemies.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

Vertebral osteomyelitis: eight years' experience of 100 cases

To evaluate the etiology and characteristics of vertebral osteomyelitis cases in our country, patients with vertebral osteomyelitis between January 2000 and December 2007 were included in this study. Clinical and laboratory data of the patients were collected from the medical records retrospectively. Of these 100 patients, 44 had pyogenic, 24 had brucellar, and 32 had tuberculous spondylodiscitis. The age of the patients ranged from 13 to 82 years, with a mean of (SD±) 55 ± 15.6 years. Within the pyogenic group, 10 (22.7%) patients had a spinal surgery history, and in 18 patients of the pyogenic group, an etiological agent was isolated. Ten (56%) of these 18 were methicillin-sensitive Staphylococcus aureus. While all of the patients included in this study suffered from pain, 49 of these had fever. Sixty-nine percent of the patients had lumbar involvement. The etiological distribution may differ according to geographical areas. Although brucella and tuberculosis (TB) are endemic in our country, pyogenic vertebral osteomyelitis was more frequent. The most common involved area in our patients was the lumbar vertebrae. Although thoracic involvement may be more predominant in tuberculous vertebral osteomyelitis, it does not strongly suggest TB. Magnetic resonance imaging may exclude some disorders mimicking vertebral osteomyelitis and may delineate the degree of the involvement. Microbiological and/or histopathological examination of computerized tomography-guided fine-needle aspiration biopsies are the mainstays for the diagnosis. Suspicion and early diagnosis seem critical for preventing sequelae development.