A cluster of seven cases of Clostridium tertium septicemia in neutropenic patients.

A cluster of seven febrile and severely neutropenic patients who developed Clostridium tertium septicemia during a 13-month period is described. The patients had received third generation cephalosporins for 7 to 13 days (mean 9 days) at the time Clostridium tertium was isolated from blood cultures. Two patients had perirectal and one patient pericaecal cellulitis. The organism was also isolated from bronchial secretions in one patient. No patient had diarrhea. Five of six strains tested were resistant to clindamycin (MIC 2-8 micrograms/ml), and six of seven strains moderately resistant to penicillin (MIC 1-4 micrograms/ml). In one patient Clostridium tertium grew from blood cultures although metronidazole had been administered for two days. Six patients recovered on antibiotic therapy. In view of the unusual susceptibility pattern of Clostridium tertium, an accurate diagnosis of infection with this organism is important for the choice of an appropriate antimicrobial treatment.