Bacteremia Due to Bacteroidaceae: A Review of 92 Cases

Abstract

The clinical courses of 92 patients who had bacteremia due to Bacteroidaceae were reviewed. The overall mortality rate was 21% (19 patients). There was no significant difference between mortality rates when patients were grouped by anticipated clinical course of underlying disease (nonfatal, ultimately fatal, and rapidly fatal) and when they were grouped by type of antibacterial therapy (appropriate, including clindamycin, chloramphenicol, lincomycin, and carbenicillin; or inappropriate, signifying no antibiotic treatment or treatment with antibiotics other than the four listed above). However, there was a correlation between recovery of the patient and portal of entry of the infectious agent; patients whose source of infection was the gastrointestinal tract had a mortality rate of 29% (17 of 58 patients), whereas there were no deaths among the 26 women whose presumed source of bacteremia was the genital tract. Increasing age appeared to be an important factor as well; 17 of 19 deaths occurred in patients who were older than 40 years. There was no significant difference between the mortality rate of patients who were treated with clindamycin (15%, eight of 52 patients) and that of patients who were treated with chloramphenicol (44%, four of nine).

Variation in susceptibility patterns of species within the Bacteroides fragilis group

“…Members of the B. fragilis group are the commonest of the intestinal anaerobes isolated from bacteremia (4,15). It is generally accepted that this group of organisms is also the most frequently isolated from other anaerobic infections (12,18).…”

“…The pH was adjusted to 7.3 with 1 N NaOH. Amounts (6 ml) were dispensed in screw-capped tubes and autoclaved at 12 lb for 15 Procedure. The NCCLS agar dilution proposed reference method was used to determine the minimum inhibitory concentration of eight antimicrobial agents.…”

Susceptibility testing of anaerobic bacteria

“…In general, there are numerous studies to show that agents with good in vitro activities against a broad range of anaerobic pathogens are more likely to produce favorable clinical outcomes than less active agents (2,10,11,13,15,16). Several studies showed lower mortality rates in patients with anaerobic bacteremia treated with appropriate antimicrobial agents than in patients receiving poorly active drugs (4,5,17,20). More difficult, however, may be the attempt to correlate specific susceptibility results with clinical success or failure in individual cases.…”

Inactivation of cefoxitin and moxalactam by Bacteroides bivius beta-lactamase

“…B. fragilis is usually recovered from intraabdominal infections (2,19,22), whereas B. bivius is frequently isolated from obstetric and gynecologic infections (1,12,33). Both species produce a ,-lactamase which may play an important role in their resistance to P-lactams (15,16,25,32,37).…”