THE JOURNAL OF INFECTIOUS DISEASES. VOL. 140, xo. 1 • JULY 1979 © 1979 by The University of Chicago. 0022-1899/79/4001-0014$00.7.')
Susceptibility of Isolates of Bacteroides to the Bactericidal Activity of Normal Human Serum From the Medical and Research Service, Wadsworth Veterans Administration Medical Center, and the Department of Medicine, UCLA Center for Health Sciences, Los Angeles, California
Dennis A. Casciato, Jon E. Rosenblatt,* Rodney Bluestone, Leonard S. Goldberg, and Sydney M. Finegold
Anaerobic bacteria constitute a major proportion of the normal microflora of the respiratory, intestinal, and genitourinary tracts in humans [1-3J. With improved technology for culturing these organisms, anaerobes, especially those of the Bacteroides [ragilis group, have been recognized as frequent causes of important clinical infections [4-6]. The B. [ragilis group consists of five organisms previously regarded as subspecies of B. [ragilis; these organisms have recently been reinstated to species rank [7]. Of the members of this group, B. [ragilis is cultured from infections in humans more often than any of the other species (Bacteroides ouatus, Bacteroides uulgatus, Bacteroides distasonis, and Bacteroides thetaiotaomicron) [8,9]. We have previously described the killing of B. [ragilis by normal human polymorphonuclear neutrophils and serum [10]. In the present study
we report on the bactericidal activity of normal human serum against 71 isolates of the B. [ragilis group. The data were analyzed for relationships between bactericidal activity of serum and the source of the specimen or the particular species tested. Materials and Methods
Bacteria. Isolates of the B. [ragilis group were speciated on the basis of fermentation of trehalose, rhamnose, and mannitol and the production of indole [11J. Strains were randomly selected from stock cultures by researchers without prior knowledge of the species. The bacteria were harvested from blood agar plates, washed, and suspended to an OD of 0.600 at 620 nm (-- 109 bacteria/ml) with use of a Gilford spectrophotometer (Gilford Instrument Laboratories, Oberlin, Ohio). Inocula for the bactericidal assay were dilutions I: 100 or 1: 1,000 of the suspension in minimal essential medium with Eagle's salts without glutamine (Grand Island Biological, Grand Island, N.Y.) containing 0.1
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Susceptibility of Isolates of Bacteroides to the Bactericidal Activity of Normal Human Serum From the Medical and Research Service, Wadsworth Veterans Administration Medical Center, and the Department of Medicine, UCLA Center for Health Sciences, Los Angeles, California
Dennis A. Casciato, Jon E. Rosenblatt,* Rodney Bluestone, Leonard S. Goldberg, and Sydney M. Finegold
Anaerobic bacteria constitute a major proportion of the normal microflora of the respiratory, intestinal, and genitourinary tracts in humans [1-3J. With improved technology for culturing these organisms, anaerobes, especially those of the Bacteroides [ragilis group, have been recognized as frequent causes of important clinical infections [4-6]. The B. [ragilis group consists of five organisms previously regarded as subspecies of B. [ragilis; these organisms have recently been reinstated to species rank [7]. Of the members of this group, B. [ragilis is cultured from infections in humans more often than any of the other species (Bacteroides ouatus, Bacteroides uulgatus, Bacteroides distasonis, and Bacteroides thetaiotaomicron) [8,9]. We have previously described the killing of B. [ragilis by normal human polymorphonuclear neutrophils and serum [10]. In the present study
we report on the bactericidal activity of normal human serum against 71 isolates of the B. [ragilis group. The data were analyzed for relationships between bactericidal activity of serum and the source of the specimen or the particular species tested. Materials and Methods
Bacteria. Isolates of the B. [ragilis group were speciated on the basis of fermentation of trehalose, rhamnose, and mannitol and the production of indole [11J. Strains were randomly selected from stock cultures by researchers without prior knowledge of the species. The bacteria were harvested from blood agar plates, washed, and suspended to an OD of 0.600 at 620 nm (-- 109 bacteria/ml) with use of a Gilford spectrophotometer (Gilford Instrument Laboratories, Oberlin, Ohio). Inocula for the bactericidal assay were dilutions I: 100 or 1: 1,000 of the suspension in minimal essential medium with Eagle's salts without glutamine (Grand Island Biological, Grand Island, N.Y.) containing 0.1
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