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Penicillin

About: Penicillin is a research topic. Over the lifetime, 17916 publications have been published within this topic receiving 368480 citations. The topic is also known as: penicillin antibiotic & PCN.


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Journal ArticleDOI
TL;DR: Marked reductions in the minimum inhibitory concentrations (MICs) for a wide spectrum of beta-lactamase-producing clinical isolates were found, of particular interest were the decreased MICs of penicillin for Bacteroides fragilis and beta- lactamases-producing strains of Neisseria gonorrhoea in the presence of the clavulanic acid.
Abstract: The activity of clavulanic acid alone and in combination with penicillin, amoxycillin, and carbenicillin was studied. Marked reductions in the minimum inhibitory concentrations (MICs) for a wide spectrum of beta-lactamase-producing clinical isolates were found. Of particular interest were the decreased MICs of penicillin for Bacteroides fragilis and beta-lactamase-producing strains of Neisseria gonorrhoea in the presence of the clavulanic acid. Beta-lactamase-producing strains of Escherichia coli, Klebsiella spp., and indole-negative Proteus also showed considerably increased susceptibility to amoxycillin in combination with clavulanic acid. Two beta-lactamase-producing strains of Pseudomonas aeruginosa remained resistant to carbenicillin in the presence of clavulanic acid.

107 citations

Journal ArticleDOI
TL;DR: The acyl coenzyme A (CoA):6-aminopenicillanic acid (6-APA) acyltransferase of Penicillium chrysogenum AS-P-78 was purified to homogeneity, as concluded by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing.
Abstract: The acyl coenzyme A (CoA):6-aminopenicillanic acid (6-APA) acyltransferase of Penicillium chrysogenum AS-P-78 was purified to homogeneity, as concluded by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing. The enzyme is a monomer with a molecular weight of 30,000 +/- 1,000 and a pI of about 5.5. The optimal pH and temperature were 8.0 and 25 degrees C, respectively. This enzyme converts 6-APA into penicillin by using phenylacetyl CoA or phenoxyacetyl CoA as acyl donors. The pure enzyme showed a high specificity and affinity for 6-APA and did not accept benzylpenicillin, 7-aminocephalosporanic acid, cephalosporin C, or isocephalosporin C as substrates. The enzyme converted isopenicillin N into penicillin G, although with a lower efficiency than when 6-APA was used as the substrate. It did not show penicillin G acylase activity. The acyl CoA:6-APA acyltransferase required dithiothreitol or other thiol-containing compounds, and it was protected by thiol-containing reagents against thermal inactivation. The acyltransferase was inhibited by several divalent and trivalent cations and by p-chloromercuribenzoate and N-ethylmaleimide. The activity was absent in four different mutants that were blocked in penicillin biosynthesis.

107 citations

Journal ArticleDOI
TL;DR: Synergistic therapy with a penicillin and an aminoglycoside was effective clinically and appears to provide optimal medical treatment on the basis of microbiological data.
Abstract: Endocarditis caused by lactobacilli may lead to death or to relapse of infection, despite antimicrobial treatment. We report two cases of lactobacillus endocarditis in individuals with native bicuspid aortic valves who survived without relapse and review the 39 other cases reported in the literature. In only 15 previously reported cases have patients been cured with medical therapy alone. One of our patients, who was infected with Lactobacillus acidophilus, was cured by medical therapy alone, and our other patient, who was infected with Lactobacillus casei subspecies rhamnosus, required surgical replacement of his aortic valve. L. acidophilus was tolerant and L. casei subspecies rhamnosus was resistant to many antibiotics tested. Combinations of penicillin or daptomycin and gentamicin were synergistic by time-kill assay. Synergistic therapy with a penicillin and an aminoglycoside was effective clinically and appears to provide optimal medical treatment on the basis of microbiological data.

107 citations

Journal Article
TL;DR: Examination of the relation between Penicillin and chlamydiae is useful because it reveals how little is known of the evolutionary history of penicillin, peniculin-binding proteins, and peptidoglycan.
Abstract: Most eubacteria are sensitive to penicillin because the antibiotic inhibits synthesis of peptidoglycan, an essential constituent of their cell walls. A few eubacteria have no measurable peptidoglycan, and, with one exception, they are not susceptible to penicillin. The exception is the genus Chlamydia whose members are just as sensitive to penicillin as peptidoglycan-containing bacteria. A numbers of ways to resolve this anomaly, penicillin sensitivity without peptidoglycan, are proposed. It is concluded that there are serious objections to each one and that the chlamydial anomaly remains unresolved. However, examination of the relation between penicillin and chlamydiae is useful because it reveals how little is known of the evolutionary history of penicillin, penicillin-binding proteins, and peptidoglycan.

107 citations

Journal ArticleDOI
TL;DR: There has been a steady decline in the proportion of positive PenST results between 1995 and 2007, independent of study subject age and TSR, and increasing age and increasing TSR were associated with a lower rate of positivePenST results.
Abstract: Background: Data on the rate of positive penicillin skin test (PenST) results over time in large populations are rare. The factors that influence positive PenST results are incompletely understood. Objectives: We sought to correlate demographic variables to the rate of positive PenST results over time in a large group of patients with a history of penicillin allergy. Methods: Results from the first test for all patients tested for penicillin allergy in the Kaiser Permanente Health Care Program in San Diego County, CA, between 1995 and 2007 are reported. All patients were tested with penicillin, penicilloyl-poly-lysine, penilloate, penicilloate, and amoxicillin. Results: There were 255 positive PenST results in 3469 individuals. The rate of positive PenST results declined from >10% to <5% during the 13 years studied. The positive PenST result rate could be accounted for by the year of testing (R2 = 0.56; p = 0.003) without any significant contribution from the patient's age or the time since reaction (TSR). If the TSR was ≤13 years, the relative risk of a positive PenST result was 2.1 (95% confidence interval = 1.6–2.8). If the study subject's age was ≤38 years, the relative risk of a positive PenST result was 2.1 (95% confidence interval = 1.6–2.7). Females reported higher rates of penicillin allergy history than males did (11% compared with 6.6%; p < 0.0001), but there were no significant sex differences in the rate of positive PenST results. Conclusions: There has been a steady decline in the proportion of positive PenST results between 1995 and 2007, independent of study subject age and TSR. Increasing age and increasing TSR were associated with a lower rate of positive PenST results.

106 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023459
2022907
2021249
2020269
2019221
2018192