Open AccessEffect of Chemotherapeutic Agents upon Microorganisms Isolated from Cancer Patients
Author(s) -
Millicent C. Goldschmidt,
Gerald P. Bodey
Publication year - 1972
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.1.4.348
Subject(s) - pseudomonas , microbiology and biotechnology , cyclophosphamide , escherichia coli , pseudomonas aeruginosa , biology , cytosine , methotrexate , pharmacology , bacteria , chemotherapy , immunology , dna , biochemistry , genetics , gene
Attempting to explain the predominance ofPseudomonas in leukemic patients, five of the most common gram-negative organisms isolated from sites of infection in cancer patients were exposed to several of the chemotherapeutic agents used in the treatment of this disease (methotrexate, cytosine arabinoside, cyclophosphamide, and 6-mercaptopurine). At concentrations of 125 μg/ml or higher, methotrexate inhibited all organisms exceptPseudomonas . Cytosine arabinoside inhibitedEscherichia andKlebsiella but appeared to stimulate the growth ofPseudomonas slightly at the higher concentrations. Thus, significant differences existed in individual susceptibilities to these agents. Clinical isolates were more resistant than the corresponding laboratory strains not previously exposed to these compounds. The resistance ofEscherichia coli to cyclophosphamide was decreased 26% when it was grown in mixed culture withPseudomonas . OnlyPseudomonas was resistant to all of these compounds whether in pure or mixed culture. These observations may help to explain, in part, the predominant role thatPseudomonas plays as an infectious agent in leukemic patients.