Physical size of the donor locus and transmission of Haemophilus influenzae ampicillin resistance genes by deoxyribonucleic acid-mediated transformation

Journal Article · Thu Jan 01 04:00:00 EST 1976 · J. Bacteriol., v. 125, no. 1, pp. 197-204

OSTI ID:4125064

Bendler, III, J W

The properties of donor deoxyribonucleic acid (DNA) from three clinical isolates and its ability to mediate the transformation of competent Rd strains to ampicillin resistance were examined. A quantitative technique for determining the resistance of individual Haemophilus influenzae cells to ampicillin was developed. When this technique was used, sensitive cells failed to tolerate levels of ampicillin greater than 0.1 to 0.2 $mu$g/ml, whereas three resistant type b $beta$-lactamase-producing strains could form colonies 1- to 3-$mu$g/ml levels of the antibiotic. DNA extracted from the resistant strains elicited transformation of the auxotrophic genes in a multiply auxotrophic Rd strain. For two of the donors, transformation to ampicillin resistance occurred after the uptake of a single DNA molecule approximately 10$sup 4$-fold less frequently than transformation of auxotrophic loci and was not observed to occur at all with the third. The frequency of transformation to ampicillin resistance was two- to fivefold higher in strain BC200 (Okinaka and Barnhart, 1974), which was cured of a defective prophage. All three clinical ampicillin-resistant strains were poor recipients, but the presence of the ampicillin resistant genes in strain BC200 did not reduce its competence. (auth)

• Research Organization: Medical Coll. of Wisconsin, Milwaukee
• NSA Number: NSA-33-017342
• OSTI ID: 4125064
• Journal Information: J. Bacteriol., v. 125, no. 1, pp. 197-204, Journal Name: J. Bacteriol., v. 125, no. 1, pp. 197-204; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

*ANTIBIOTICS-- SENSITIVITY
*HAEMOPHILUS-- GENETICS
560131* --Biomedical Sciences
Applied Studies--Radiation Effects--Radiation Effects on Microorganisms--Basic Studies
DNA
GENES
N48310* --Life Sciences--Radiation Effects on Microorganisms- -Basic Studies
ULTRAVIOLET RADIATION