Clindamycin Resistance in the Bacteroides fragilis Group: Association with Hospital-Acquired Infections

Abstract

A retrospective study was conducted to assess the relationships between clindamycin resistance in members of the Bacteroides fragilis group, previous antimicrobial therapy, and the context for the development of infection, whether in the community or during hospitalization. Eighty-five clindamycin-resistant clinical strains (one isolate per patient) isolated from January 1988 to October 1994 were matched (one to one) with clindamycin-susceptible isolates recovered during the same period, and the charts of the patients from whom the isolates were recovered were reviewed retrospectively. Of the clindamycin-resistant strains, 65% were recovered from patients with hospital-acquired infections compared with 40% of the clindamycin-susceptible strains (odds ratio [OR], 2.75; 95% confidence interval [CI], 1.41-5.38; P = .002). Prior antimicrobial therapy for > or = 48 hours was also associated with clindamycin resistance (OR, 2.33; 95% CI, 1.16-4.70; P = .02). However, clindamycin resistance remained associated with hospital-acquired infections independent of prior antimicrobial therapy (Mantel-Haenszel weighted average OR, 2.22; 95% CI, 1.03-4.89; P = .04). Clinicians should consider the risks for clindamycin resistance when treating hospital-acquired infections caused by members of the B. fragilis group.

Anaerobic Infections in the Surgical Patient: Microbial Etiology and Therapy

“…An intriguing hypothesis for this phenomenon suggests that the MIC values for clindamycin may have decreased within a subset of patients who have multiple or prolonged hospitalizations. The highest level of resistance has been observed among patients with hospital-acquired infections compared with community-acquired infections [37]. Metronidazole continues to maintain a high level of activity against clinically significant anaerobic bacteria, including virtually all gram-negative strains.…”

Routine Anaerobic Blood Cultures: Back Where We Started?

“…Several retrospective reviews of infection with Bacteroides species [16][17][18][19] and the landmark article by Nguyen et al [15] in 2000 clearly support this position. In the article by Nguyen and colleagues, a prospective observational study of 128 cases of bacteremia involving the B. fragilis group, mortality, microbial persistence, and clinical failure occurred more frequently among patients who did not receive an appropriate antibiotic agent to treat infection with resistant members of the B. fragilis group [15].…”

Trends in Antimicrobial Resistance among Clinical Isolates of the Bacteroides fragilis Group from 1992 to 1997 in Montreal, Canada

“…In our hospital, the total consumption of clindamycin decreased from 5.47 kg in 1992 to 3.95 kg in 1997. Therefore, factors other than clindamycin use alone may be a predisposition to the development of clindamycin resistance among B. fragilis group isolates in hospitals (4). In summary, over the past 6 years, there has been a significant increase in the rate of resistance to clindamycin among isolates of the B. fragilis group: this increase seriously calls into question the use of clindamycin as well as the use of cefoxitin or piperacillin for the initial empirical treatment of B. fragilis group infections.…”