Clinical Importance of Infections due to Bacteroides fragilis and Role of Antibiotic Therapy

Abstract

SummaryOut of 200 infections due to Bacteroides fragilis occurring over a period of three years 133 were related to the intestinal tract, 55 to the genitourinary tract, and the remainder were in bedsores and ulcers; 56% occurred in patients undergoing major intestinal surgery.B. fragilis was isolated in pure culture from 56% of the infections. In mixed culture it was most commonly associated with Klebsiella and Enterobacter species.Other anaerobic bacteria were isolated in 9% of the mixed cultures.Altogether 131 (65-5%) of the patients recovered without antibiotic therapy or further surgery, but 59 (29 5%) developed complications and 10 (50') died. The commonest complication was abscess formation, and the incidence was highest with infections associated with malignancy (44%) and lowest with obstetric infections (5%). The mortality was 5% overall but in the presence of bacteraemia it rose to 33%.Only 43 patients received appropriate chemotherapy. Clindamycin was the most effective antibiotic, having a recovery rate of 78%, but this rate was little better than in untreated patients (65%). The role of prophylactic antibiotic therapy in preventing bacteroides infection remains to be studied.The incidence of the isolation of bacteroides from wound infections after major intestinal surgery rose from 13% in 1970 to 81% in 1973. This increase was due to both the accurate collection and care of specimens while in transit to the laboratory and the use of selective media for the isolation of bacteroides in laboratory culture. The importance of these precautions is emphasized.

Behaviour of Synthetic Absorbable Sutures with and without Synergistic Enteric Infection

“…In 1974, Leigh [13] first demon strated that by appropriate culture tech niques, a fourfold increase in the isolation of this organism from infected wounds was pos sible. Other workers have emphasised the plurality o f organisms in most infections that originate in the gastrointestinal tract and have discussed the possibility o f synergism between aerobes and anaerobes [8].…”

The Role of Robertson's Cooked-Meat Broth in the Bacteriological Evaluation of Surgical Specimens

“…Several studies with either Robertson's cooked meat broth (RCMB) or Stuart's transport medium (STM) have demonstrated that the use of a transport medium increases the bacteriological isolation rate (Leigh, 1974;Leigh et al, 1974;Kelly and Warren, 1978). To date, no study has compared the relative values of RCMB and STM, but a recent study by Pollock et al (1978) in which bacteria were more often isolated from tissue fragments placed in RCMB than from swabs is relevant to the case that we wish to make in this paper.…”

The pathogenicity of Bacteroides fragilis and related species estimated by intracutaneous infection in the guinea-pig

“…The group previously classified as Bacteroides fragilis has received much attention because it represents the anaerobic species most often associated with infection (Leigh, 1974). Until recently, B. fragilis was divided into five subspecies: fragilis, ovatus, distasonis, thetaiotaomicron and vulgatus, but differences between the subspecies based on DNA homology were found to be large enough to warrant reclassification into species (Cato and Johnson, 1976).…”