Studies of antibiotic resistant mutants of Bacteroides fragilis obtained by Cs-137 ionizing radiation

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6402633

Azghani, A O

The genus Bacteroides is an obligate anaerobic bacillus normally found in the upper respiratory tract, the colon, and the genitourinary system. The project reported here was undertaken because of the high frequency of hospital infections attributed to B. fragilis, and the increased resistance of the bacteria to commonly used antibiotics. Cs-137 gamma irradiation was used to induce antibiotic resistant mutants in B. fragilis in the presence of Escherichia coli B/r membrane fragments, employed as reducing agent. Based on a dose-survival curve, an effective radiation dose of 1.54 x 10/sup 4/R (3.99 C/Kg) was used to induce mutations to rifampicin and tetracycline resistance in the test organism. The antibiotic resistant mutants of B. fragilis were utilized to reveal the mechanism by which this group of organisms becomes resistant to select chemotherapeutic agents. Studies on tetracycline resistant mutants of B. fragilis isolated after irradiation, suggest that the resistance to this antibiotic is associated with the outer membrane permeability. The difference in inhibitory action of rifampicin on RNA polymerase activity, from rifampicin sensitive and resistant strains of B. fragilis, reveals that this enzyme is a possible suitable target for inhibition of bacterial growth in anaerobes by rifampicin.

• Research Organization: Texas Woman's Univ., Denton (USA)
• OSTI ID: 6402633
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL ISOTOPES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BACILLUS
BACTERIA
BACTERIAL DISEASES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL CONSTITUENTS
CELL MEMBRANES
CESIUM 137
CESIUM ISOTOPES
DISEASES
DRUGS
ELECTROMAGNETIC RADIATION
GAMMA RADIATION
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
INFECTIOUS DISEASES
INHIBITION
IONIZING RADIATIONS
ISOTOPES
MEMBRANES
MICROORGANISMS
MUTANTS
NUCLEI
ODD-EVEN NUCLEI
PERMEABILITY
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOISOTOPES
SENSITIVITY
TETRACYCLINES
YEARS LIVING RADIOISOTOPES