Linkage of Fusidic Acid Resistance to the Penicillinase Plasmid in Staphylococcus aureus

Lacey, R. W.; Grinsted, J.

doi:10.1099/00221287-73-3-501

Cited by 45 publications

(57 citation statements)

References 15 publications

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“…Lacey & Grinsted (1972) showed that CCC-DNA could be detected in the pigmented strain FAR^ when it contained a penicillinase plasmid, but CCC-DNA could not be detected in derivatives of FAR^ which had lost the penicillinase plasmid but still formed pigment. Ethidium bromide/ CsC1-gradient centrifugation was carried out on radioactive lysates of antibiotic-sensitive derivatives of the pigmented strains 609 and 6936 : in neither case could a radioactive satellite of CCC-DNA be detected.…”

Section: Ethidium Bromide/ Cs Cl-gradien T Centrifugationmentioning

confidence: 99%

Ecological and Genetic Implications of Pigmentation in Staphylococcus aureus

Grinsted

Lacey

1973

Journal of General Microbiology

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S U M M A R YOn storage, pigmented (orange or yellow) strains of Staphylococcus aureus produce non-pigmented variants which are more susceptible to desiccation and to linoleic acid than are the corresponding wild strains. The association of these properties could explain why most staphylococci isolated from clinical sources are pigmented, although the pigmented character is lost at high frequency in vitro.The genes determining these properties are not borne by a typical plasmid since the capacity to produce pigment was not transducible, and no covalently closed circular DNA was detected in lysates of three pigmented strains. There was an apparent reduction in cellular DNA of 30 to 40 % associated with the loss of these genes; however, DNAIDNA hybridization could not distinguish between total cellular DNA from a pigmented strain (FARS) and that isolated from the corresponding non-pigmented variant.

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Section: Ethidium Bromide/ Cs Cl-gradien T Centrifugationmentioning

confidence: 99%

Ecological and Genetic Implications of Pigmentation in Staphylococcus aureus

Grinsted

Lacey

1973

Journal of General Microbiology

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“…a PF plasmid). Strain ~~4 0 0 2 was derived from U B~O O I by growth of the latter at 43 "C, which resulted in loss of ~U B I O I (Lacey & Grinsted, 1972). Strains ~~4 0 0 3 to ~~4 0 0 6 were spontaneous one-step fusidic acid resistant mutants derived from ~4 0 0 2 by selection on media containing fusidic acid.…”

Section: Methodsmentioning

confidence: 99%

“…However, since spontaneous mutation to fusidic acid resistance in S. aureus occurs at high frequency in vitro (Miller, 1971 ;Lacey & Grinsted, 1972) and because resistant staphylococci have sometimes been isolated after therapy (Lowbury et al,I 962), fusidic acid is usually administered in combination with other antibiotics, particularly the penicillins (Garrod et al, 1973).…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Resistance to Fusidic Acid in Staphylococcus aureus

Chopra

1976

Journal of General Microbiology

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“…In one of these (strain 649) there was a correlation between the presence of plasmid DNA and resistance to streptomycin, and it was inferred that this plasmid carried the genes coding for streptomycin resistance. The molecular weight of this plasmid is about 38 million daltons, which is at least twice that of any other staphylococcal plasmid characterised (Novick and Bouanchaud ;Lacey and Grinsted, 1972). The size of the plasmid that determines streptomycin resistance may explain why transduction of this resistance could not be detected.…”

Section: Discussionmentioning

confidence: 99%

“…I . GRINSTED AND R. W. LACEY Isolation of covalently closed circular DNA (CCC-DNA) on ethidium bromide-CsCl gradients, and analysis on sucrose gradients, was as described previously (Lacey and Grinsted, 1972). …”

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Genetic Variation of Streptomycin Resistance in Clinical Strains of Staphylococcus Aureus

Grinsted¹,

Lacey²

1973

Journal of Medical Microbiology

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STRAINS of Escherichia coli can be resistant to high levels of streptomycin (MIC>1000 pg per ml) or only to low levels of the drug (MIC 25 pg per ml) (Hanvood and Smith, 1969). High-level resistance is usually found in strains that have been exposed to streptomycin in the laboratory; the genes that specify this character are chromosomal and code for altered ribosomes (Weisblum and Davies, 1968). Strains isolated from clinical material usually exhibit low-level resistance; the genes coding for this are carried on R factors and specify inactivating enzymes . Low-level resistance to streptomycin in E. coli may be accompanied by resistance to spectinomycin because of the production of a single enzyme that inactivates both drugs (Davies, Brzezinska and Benveniste, 1971).Some strains of Staphylococcus aureus isolated from clinical material are resistant to high levels of streptomycin, a character determined by chromosomal genes (Lacey, 1972;Lacey and Chopra, 1972); in our experience, lowlevel resistance to the drug also occurs in clinical strains of s. aureus. We have examined the frequency of high-and low-level resistance in streptomycinresistant strains of s. aureus isolated from clinical material. The coincidence of resistance to streptomycin and to spectinomycin, which can occur in E. coli, prompted us to test the streptomycin-resistant strains of S. aureus for resistance to other aminoglycosides, particularly spectinomycin. In strains that exhibited low-level resistance to streptomycin, segregation studies suggested that the relevent genes were plasmid-borne; two such strains were examined for plasmid DNA. MATERIALS AND METHODSOrganisms. Strains of S. aureus were obtained from clinical material between 1967 and 1972 from sources predominantly in Bristol. Each strain was distinct in bacteriophagetyping pattern, antibiotic sensitivity or pigment production. The strains were isolated initially on antibiotic-free medium, then checked by disk-testing for antibiotic sensitivity. Single colonies were used to inoculate nutrient agar slopes, which were then stored at room temperature without subculture.Media, and methods for the determination of antibiotic sensitivity and delta-haemolysin production, bacteriophage typing, and for attempts at transduction were as described previously (Lacey, 1972). Treatment with nitrosoguanidine was by the method of Lacey (1971~); the cultures were treated with nitrosoguanidine (100 pg per ml) for sufficient time to give about 10 per cent. survival.

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Linkage of Fusidic Acid Resistance to the Penicillinase Plasmid in Staphylococcus aureus

Cited by 45 publications

References 15 publications

Ecological and Genetic Implications of Pigmentation in Staphylococcus aureus

Ecological and Genetic Implications of Pigmentation in Staphylococcus aureus

Mechanisms of Resistance to Fusidic Acid in Staphylococcus aureus

Genetic Variation of Streptomycin Resistance in Clinical Strains of Staphylococcus Aureus

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