English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Several mutants isolated after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis of Streptomyces cacaoi strain KCCS-0352, were resistant to benzylpenicillin ranging in concentration from 1,000 to 5,000 micrograms/ml (4- to 20-fold more resistant than the parent). These mutants also acquired resistance to mecillinam, cephamycin C and methicillin. The affinity for beta-lactams of penicillin-binding proteins (including PBP-2--a possible lethal target of beta-lactams in Streptomyces cacaoi) in the mutants decreased. Addition of Triton X-100 or ethylenediaminetetraacetic acid, but not toluene, reduced the minimum inhibitory concentration of beta-lactams. In vitro accessibility of [14C]benzylpenicillin to whole cells and membrane fractions was lower in the mutants than in the parent. The binding of beta-lactams to penicillin-binding proteins in both the parent and mutants was increased by pretreatment with Triton X-100 or ethylenediaminetetraacetic acid. The results of this study of penicillin-binding suggest that penicillin-binding proteins play a major role in "acquired" resistance as well as "intrinsic" resistance.

Mechanisms of acquired penicillin-resistance in Streptomyces cacaoi. Role of penicillin-binding proteins in penicillin resistant mutants.