Bacteroides fragilis subspecies in clinical isolates.

Isolates of Bacteroides fragilis from 83 infected patients were collected during 2 years. Of 103 isolates, 68% were subspecies fragilis. This was the single most common subspecies isolated from blood (12/17), intra-abdominal (11/28), wound (17/20), perirectal (11/16), pelvic (6/10), and other (8/11) sites. Sixteen patients had B. fragilis isolated in pure culture. Of these, 9/12 blood cultures and 4/4 cultures from other sites were ss. fragilis. The recent observation that ss. fragilis organisms are encapsulated whereas the other subspecies are generally unencapsulated was supported by indirect fluorescent antibody studies using antibodies prepared to the capsular material of ss. fragilis. All 33 strains of ss. fragilis and none of 13 strains of other subspecies were positive. The predominance of ss. fragilis in clinical isolates compared to its relative infrequency in normal fecal flora and its predominance in pure cultures, especially of blood, indicate that this is the most virulent of B. fragilis subspecies. This virulence may be related to encapsulation.

[1]  B. Polk,et al.  Isolation and identification of encapsulated strains of Bacteroides fragilis. , 1977, The Journal of infectious diseases.

[2]  J. Bartlett,et al.  The capsular polysaccharide of Bacteroides fragilis as a virulence factor: comparison of the pathogenic potential of encapsulated and unencapsulated strains. , 1977, The Journal of infectious diseases.

[3]  John L. Johnson,et al.  Reinstatement of Species Rank for Bacteroides fragilis, B. ovatus, B. distasonis, B. thetaiotaomicron, and B. vulgatus: Designation of Neotype Strains for Bacteroides fragilis (Veillon and Zuber) Castellani and Chalmers and Bacteroides thetaiotaomicron (Distaso) Castellani and Chalmers , 1976 .

[4]  Ronald N. Jones,et al.  Identification and Antimicrobial Susceptibility of 250 Bacteroides fragilis Subspecies Tested by Broth Microdilution Methods , 1976, Antimicrobial Agents and Chemotherapy.

[5]  D. Blazevic.  Antibiotic Susceptibility of the Subspecies of Bacteroides fragilis , 1976, Antimicrobial Agents and Chemotherapy.

[6]  K. Holmes,et al.  Polymicrobial etiology of acute pelvic inflammatory disease. , 1975, The New England journal of medicine.

[7]  E. H. Spaulding,et al.  The bacteriology of intra-abdominal infections. , 1974, The Surgical clinics of North America.

[8]  H. Werner,et al.  Bacteroides and appendicitis. , 1975 .

[9]  S. Finegold,et al.  Effect of diet on human fecal flora: comparison of Japanese and American diets. , 1974, The American journal of clinical nutrition.

[10]  J. Bartlett,et al.  Anaerobic infections. 1. , 1974, The New England journal of medicine.

[11]  Martin Wj.  Isolation and indentification of anaerobic bacteria in the clinical laboratory. A 2-year experience. , 1974 .

[12]  W. Moore,et al.  Human fecal flora: the normal flora of 20 Japanese-Hawaiians. , 1974, Applied microbiology.

[13]  A. Chow,et al.  Bacteroidaceae bacteremia: clinical experience with 112 patients. , 1974, Medicine.

[14]  E. H. Spaulding,et al.  Anaerobic bacterial infections of the female genital tract. , 1973, Obstetrics and gynecology.

[15]  J. Rosenblatt,et al.  PRACTICAL ASPECTS OF ANAEROBIC SEPSIS , 1973, Medicine.

[16]  W. Ledger,et al.  Bacteroides species as a cause of severe infections in obstetric and gynecologic patients. , 1971, Surgery, gynecology & obstetrics.