Synergism between Bacteroides fragilis and Staphylococcus aureus in experimental tibial osteomyelitis

J. Peter Rissing, Thomas B. Buxton, Jack A. Horner, R. Ken Shockley, John Fremont Fisher, Richard Harris

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We explored the potential role of microbial synergy in an experimental rat osteomyelitis model. Osteomyelitis was assessed by gross pathologic conditions and quantitative cultivation of rat tibiae for the implanted organisms 21 days after challenge. When Staphylococcus aureus was used alone, the 50% infective dose (ID50) and the 100% infective dose (ID100) were 400 and 25,000 colonyforming units (CFU), respectively. When Bacteroides fragilis was inoculated alone, the ID50 was 150,000 organisms, and the ID100 was not confidently determined. Subinfectious numbers of B. fragilis added to the staphylococcal inocula yielded an ID100 as low as 20 staphylococci. Mixed inocula with 20 or 200 staphylococci and increasing numbers of B. fragilis yielded a dose-dependent increase in the number of staphylococci isolated from osteomyelitic tibiae. Multiple linear regression analysis confirmed the two inocula and their interaction to be significantly predictive of the 21-day quantitative assessment of staphylococci (r = 0.80). Synergy was most striking at low bacterial inocula. When even large numbers of S. aureus were added to B. fragilis, the B. fragilis inoculum required to initiate B. fragilis osteomyelitis was essentially unchanged. We conclude that small numbers of B. fragilis allow remarkably low numbers of S. aureus (20 or 200 CFU) to establish osteomyelitis in the rat.

Original languageEnglish (US)
Pages (from-to)433-438
Number of pages6
JournalThe Journal of Laboratory and Clinical Medicine
Volume110
Issue number4
StatePublished - Jan 1 1987

Fingerprint

Bacteroides fragilis
Osteomyelitis
Staphylococcus aureus
Rats
Staphylococcus
Linear regression
Regression analysis
Tibia
Linear Models
Regression Analysis

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Medicine(all)

Cite this

Synergism between Bacteroides fragilis and Staphylococcus aureus in experimental tibial osteomyelitis. / Rissing, J. Peter; Buxton, Thomas B.; Horner, Jack A.; Shockley, R. Ken; Fisher, John Fremont; Harris, Richard.

In: The Journal of Laboratory and Clinical Medicine, Vol. 110, No. 4, 01.01.1987, p. 433-438.

Research output: Contribution to journalArticle

@article{2e8dd23a2cd04378a56d5e774224d3ab,
title = "Synergism between Bacteroides fragilis and Staphylococcus aureus in experimental tibial osteomyelitis",
abstract = "We explored the potential role of microbial synergy in an experimental rat osteomyelitis model. Osteomyelitis was assessed by gross pathologic conditions and quantitative cultivation of rat tibiae for the implanted organisms 21 days after challenge. When Staphylococcus aureus was used alone, the 50{\%} infective dose (ID50) and the 100{\%} infective dose (ID100) were 400 and 25,000 colonyforming units (CFU), respectively. When Bacteroides fragilis was inoculated alone, the ID50 was 150,000 organisms, and the ID100 was not confidently determined. Subinfectious numbers of B. fragilis added to the staphylococcal inocula yielded an ID100 as low as 20 staphylococci. Mixed inocula with 20 or 200 staphylococci and increasing numbers of B. fragilis yielded a dose-dependent increase in the number of staphylococci isolated from osteomyelitic tibiae. Multiple linear regression analysis confirmed the two inocula and their interaction to be significantly predictive of the 21-day quantitative assessment of staphylococci (r = 0.80). Synergy was most striking at low bacterial inocula. When even large numbers of S. aureus were added to B. fragilis, the B. fragilis inoculum required to initiate B. fragilis osteomyelitis was essentially unchanged. We conclude that small numbers of B. fragilis allow remarkably low numbers of S. aureus (20 or 200 CFU) to establish osteomyelitis in the rat.",
author = "Rissing, {J. Peter} and Buxton, {Thomas B.} and Horner, {Jack A.} and Shockley, {R. Ken} and Fisher, {John Fremont} and Richard Harris",
year = "1987",
month = "1",
day = "1",
language = "English (US)",
volume = "110",
pages = "433--438",
journal = "Translational Research",
issn = "1931-5244",
publisher = "Mosby Inc.",
number = "4",

}

TY - JOUR

T1 - Synergism between Bacteroides fragilis and Staphylococcus aureus in experimental tibial osteomyelitis

AU - Rissing, J. Peter

AU - Buxton, Thomas B.

AU - Horner, Jack A.

AU - Shockley, R. Ken

AU - Fisher, John Fremont

AU - Harris, Richard

PY - 1987/1/1

Y1 - 1987/1/1

N2 - We explored the potential role of microbial synergy in an experimental rat osteomyelitis model. Osteomyelitis was assessed by gross pathologic conditions and quantitative cultivation of rat tibiae for the implanted organisms 21 days after challenge. When Staphylococcus aureus was used alone, the 50% infective dose (ID50) and the 100% infective dose (ID100) were 400 and 25,000 colonyforming units (CFU), respectively. When Bacteroides fragilis was inoculated alone, the ID50 was 150,000 organisms, and the ID100 was not confidently determined. Subinfectious numbers of B. fragilis added to the staphylococcal inocula yielded an ID100 as low as 20 staphylococci. Mixed inocula with 20 or 200 staphylococci and increasing numbers of B. fragilis yielded a dose-dependent increase in the number of staphylococci isolated from osteomyelitic tibiae. Multiple linear regression analysis confirmed the two inocula and their interaction to be significantly predictive of the 21-day quantitative assessment of staphylococci (r = 0.80). Synergy was most striking at low bacterial inocula. When even large numbers of S. aureus were added to B. fragilis, the B. fragilis inoculum required to initiate B. fragilis osteomyelitis was essentially unchanged. We conclude that small numbers of B. fragilis allow remarkably low numbers of S. aureus (20 or 200 CFU) to establish osteomyelitis in the rat.

AB - We explored the potential role of microbial synergy in an experimental rat osteomyelitis model. Osteomyelitis was assessed by gross pathologic conditions and quantitative cultivation of rat tibiae for the implanted organisms 21 days after challenge. When Staphylococcus aureus was used alone, the 50% infective dose (ID50) and the 100% infective dose (ID100) were 400 and 25,000 colonyforming units (CFU), respectively. When Bacteroides fragilis was inoculated alone, the ID50 was 150,000 organisms, and the ID100 was not confidently determined. Subinfectious numbers of B. fragilis added to the staphylococcal inocula yielded an ID100 as low as 20 staphylococci. Mixed inocula with 20 or 200 staphylococci and increasing numbers of B. fragilis yielded a dose-dependent increase in the number of staphylococci isolated from osteomyelitic tibiae. Multiple linear regression analysis confirmed the two inocula and their interaction to be significantly predictive of the 21-day quantitative assessment of staphylococci (r = 0.80). Synergy was most striking at low bacterial inocula. When even large numbers of S. aureus were added to B. fragilis, the B. fragilis inoculum required to initiate B. fragilis osteomyelitis was essentially unchanged. We conclude that small numbers of B. fragilis allow remarkably low numbers of S. aureus (20 or 200 CFU) to establish osteomyelitis in the rat.

UR - http://www.scopus.com/inward/record.url?scp=0023575535&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023575535&partnerID=8YFLogxK

M3 - Article

VL - 110

SP - 433

EP - 438

JO - Translational Research

JF - Translational Research

SN - 1931-5244

IS - 4

ER -