Anaerobic bacteremia in patients with acute leukemia

Fusobacterium nucleatum: a rare cause of bacteremia in neutropenic patients with leukemia and lymphoma

Although anaerobic bacteremias are uncommon in oncohematologic patients, nevertheless they have been considered an emergent problem in the last few years. Fusobacterium nucleatum is an anaerobic Gram-negative bacillus commonly present in the oral cavity and in the respiratory and genito-urinary tracts. Over a 10-year period 18 episodes of F. nucleatum bacteremia in patients with hematological malignances (15 leukemias and 3 lymphomas) have been observed in our Department of Hematology. Predisposing factors included oropharyngeal mucositis and severe neutropenia owing to intensive chemotherapy. In our experience no septic shock occurred and the outcome of bacteremias caused by F. nucleatum was favorable.

Significance of Clostridium tertium bacteremia in neutropenic and nonneutropenic patients: review of 32 cases

In the nonneutropenic host, bacteremia due to Clostridium tertium is rare and of unclear significance. We describe a patient in whom presentation with Clostridium tertium bacteremia was the harbinger of Crohn's disease. In order to understand the significance of C. tertium bacteremia in neutropenic and nonneutropenic hosts, we review all 32 cases of C. tertium bacteremia that occurred at Duke University Medical Center from 1992 to 1999.

Infections in neutropenic patients I: aetiology

Improvement in supportive care including the introduction of new antibiotics, antiviral and antifungal agents and haematopoietic growth factors have all contributed to a decreased chemotherapy-related mortality and morbidity in cancer patients. However, infections/septic shock during neutropenia still constitutes a major threat to these patients. Most patients develop fever during neutropenia and in 20-40% a manifest bacteremia is documented. In patients with prolonged neutropenia, the risk for fungal infections is increased. The spectrum of bacterial, fungal and viral infections in the neutropenic patient is reviewed.

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.

Clinical implications of positive blood cultures

Positive blood cultures can be classified according to their veracity (true-positive or false-positive culture), clinical severity (inconsequential or life threatening), place of origin (community acquired or nosocomial), source (primary or secondary), duration (transient, intermittent, or continuous), pattern of occurrence (single episode, persistent, or recurrent), or intensity (high or low grade). In general, however, positive blood cultures identify a patient population at high risk of death. In my studies, patients with positive blood cultures were 12 times more likely to die during hospitalization than patients without positive blood cultures. Many bacteremias and fungemias occur in complicated clinical settings, and it appears that only about one-half of the deaths among affected patients are due directly to infection. Hence, it is appropriate to speak of "crude mortality" and "attributable mortality." Among hospitalized patients, recent trends include rising incidences of Staphylococcus aureus and coagulase-negative staphylococcal and enterococcal bacteremias and a dramatic increase in the incidence of fungemias. The diagnostic and therapeutic implications of blood cultures positive for specific microorganisms continue to evolve and are the subject of a large and growing medical literature.