Case Presentation:

An 81–year–old man with a history of chronic obstructive pulmonary disease, congestive heart failure and chronic kidney disease presented to our hospital with 6–day history of increasing shortness of breath, fever (self recorded 102 f), chills, rigors and cough with grey sputum. Physical examination revealed bilateral rales and no skin lesions. Total white blood cell count was 16.8. Intravenous ceftriaxone and azithromycin was started on admission. Two site blood cultures drawn prior to antibiotic administration demonstrated three of four culture bottles positive for Corynebacterium Minutissimum (C.minutissimum). Computed Tomography of the chest performed on day 4 of hospitalization revealed infiltrates bilaterally. Sputum Gram stain showed gram positive bacilli also consistent with corynebacterium; however, final speciation could not be achieved. Sensitivity testing for this organism has not been standardized therefore not available. Based on infectious disease recommendations, treatment was changed to ampicillin–sulbactam. His clinical course was complicated by mild decompensated congestive heart failure which responded to standard treatment. Diagnostic thoracentesis ruled out parapneumonic effusion with transudative, culture negative pleural fluid. A 14–day course of intravenous ampicillin–sulbactam resulted in complete clinical recovery.

Discussion:

C.minutissimum was first described in 1961 as the causative organism of erythrasma, a superficial skin infection. Since its description, there have been few case reports of invasive disease caused by this organism. MEDLINE search revealed 16 cases of invasive infection, almost all patients were either immunocompromised, had impaired skin barrier, had invasive indwelling devices/procedure or had endocarditis. Although it is not proven that this patient’s pneumonia was caused by C. minutissimum, it seems most probable in light of the sputum analysis revealing gram positive bacilli which in turn seems to be the source for bacteremia. No cases of pneumonia caused by this organism are reported. There is only one previously reported case of bacteremia by this organism in an immunocompetent patient. This patient had a skin infection which could have possibly led to the bacteremia since C. minutissimum is causal in erythrasma. No susceptibility testing is available for this organism. Concerns for multidrug resistance exist but the organism appears fully sensitive to vancomycin. Penicillins have been utilized as in our patient but vancomycin continues to be preferred in critically ill patients. Given the ever increasing number of immunocompromised patients and invasive procedures C. minutissimum can be a concerning pathogen in future.

Conclusions:

C. minutissimum is a rare cause for bacteremia.