Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the causative agent of localized or severe systemic
infections. Systemic
infections due to F.necrophorum are known as
Lemierre's syndrome,
postanginal sepsis or
necrobacillosis. The most common
clinical course of severe
infections in humans is a progressive illness from
tonsillitis to
septicemia in previously healthy young adults. A septic
thrombophlebitis arising from the tonsillar veins and extending into the internal jugular vein leads to
septicemia and septic emboli contributing to the development of necrotic
abscesses especially in lungs and other tissues such as liver, bone and joints. In this case report, a previously healthy man with
pneumonia and
empyema due to F.necrophorum has been presented. A 22 year-old man suffering from
sore throat for seven days was admitted to emergency department with ongoing
fever and
dysphagia for three days. On admission he was already taking
amoxicillin-clavulanic acid and his complaints were relieved with continuation of
therapy to a total of 10 days. However, five days after the
cessation of treatment he developed productive
cough,
fever and generalized
myalgia. On physical examination, there were
crackles on right lower lung, and chest X-ray revealed pulmonary consolidation on the right middle lobe.
Levofloxacin therapy was started based on the diagnosis of
pneumonia. While polymorphonuclear leucocytes and intracellular gram-negative bacilli were seen in Gram stained sputum smear, sputum culture was reported as normal flora. Although the patient's status had started to improve with treatment, his condition deteriorated with development of
fever and
dyspnea. Chest X-ray revealed consolidation, pulmonary infiltrates,
pleural effusion and air-fluid level on the right.
Meropenem,
clarithromycin and
linezolid were initiated and a
chest tube was inserted with the preliminary diagnosis of
necrotizing pneumonia,
empyema and type-1
respiratory failure. While there was no growth on bronchoalveolar lavage fluid culture, thoracentesis material inoculated into thioglycolate broth revealed turbidity. Further inoculation onto Schaedler
agar which was incubated under anaerobic conditions, yielded growth of
catalase negative, indol positive, gram-negative anaerobic bacilli identified as F.necrophorum by BBL Crystal system (Becton Dickinson, USA). The detailed history of the patient revealed that fish bone had stuck in his throat a week ago.
Clarithromycin and
linezolid were discontinued and he was recovered within six weeks of
meropenem treatment. F.necrophorum
infection should be considered in the differential diagnosis of persistent head and neck
infections with rapidly progressive metastatic necrotic lesions especially in healthy young adults and
clindamycin or metranidazol should be added to the treatment protocols.