Topic
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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TL;DR: It is concluded that multivariate analysis provides clues for empirical therapy for pneumococcal infection and previous use of beta-lactam antibiotics by patients with noninvasive disease as parameters associated with increased risk.
Abstract: Pneumococcal disease was studied prospectively to determine the risk factors associated with resistance to penicillin and other antibiotics. One hundred twelve clinically significant pneumococcal isolates were recovered from 95 patients. Approximately one-half (49.47%) of the cases were due to penicillin-resistant strains. Multivariate analysis showed that previous use of beta-lactam antibiotics (odds ratio [OR], 2.81; 95% confidence interval [CI], 0.95-8.27), alcoholism (OR, 5.22; 95% CI, 1.43-19.01), and noninvasive disease (OR, 4.53; 95% CI, 1.54-13.34) were associated with penicillin resistance, whereas intravenous drug use (OR, 0.14; 95% CI, 0.03-0.74) was not. Statistical analyses of the variables associated with resistance to multiple antibiotics detected age of younger than 5 years (OR, 16.79; 95% CI, 1.60-176.34) or of 65 years or older (OR, 4.33; 95% CI, 1.42-13.21) and previous use of beta-lactam antibiotics by patients with noninvasive disease (OR, 7.92; 95% CI, 1.84-34.06) as parameters associated with increased risk. We conclude that multivariate analysis provides clues for empirical therapy for pneumococcal infection.
179 citations
TL;DR: In this article, a man with gonorrhoeal urethritis was shown to have complete resistance to 10 μg of penicillin G. Disc diffusion sensitivity testing showed that the organism produced penicillase.
179 citations
TL;DR: Significantly fewer children who had received either penicillin or cefadroxil had persistence of each of the three objective signs and each ofThe three subjective symptoms in GABHS pharyngitis than did children who received placebo.
179 citations
TL;DR: The genetic basis of the non-beta-lactamase ampicillin resistance in these strains appears to be chromosomally mediated, and the major mechanism of resistance is altered penicillin-binding proteins; however, other mechanisms, including permeability, may also play a role.
Abstract: Ampicillin resistance in Haemophilus influenzae is most often due to the plasmid-mediated production of TEM beta-lactamase. We studied four strains with high-level ampicillin resistance (MIC of 32 micrograms/ml with an inoculum of 10(5) CFU on solid media) which did not produce detectable beta-lactamase activity with two different detection methods. Two of the four strains contained extrachromosomal DNA by agarose gel electrophoresis. Conjugation failed to transfer ampicillin resistance; in contrast, transformation yielded ampicillin-resistant transformants in three of the four strains. These transformants did not contain detectable extrachromosomal DNA. In addition, mobilization of the resistance determinant by transformation to, or conjugation with, recombination-deficient strains was unsuccessful. DNA-DNA hybridization experiments revealed no homology of the DNA of these strains with two R plasmids (one coding for ampicillin resistance, the other for chloramphenicol and tetracycline resistance). We conclude that the genetic basis of the non-beta-lactamase ampicillin resistance in these strains appears to be chromosomally mediated. We investigated the mechanism of resistance in these strains. Enzymatic modification of penicillin was not detected by autoradiography of a thin-layer chromatogram of cell sonic extracts of three ampicillin-resistant transformant strains incubated with [14C]penicillin. To assess changes in permeability of the cell envelope, a plasmid coding for beta-lactamase was conjugated into these strains, and the hydrolysis of penicillin by intact cells and cell sonic extracts was compared. Only one of three transformant strains had significantly diminished permeability. Outer membrane proteins of these strains analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed apparent differences in comparison with the isogenic ampicillin-susceptible recipient strain. Autofluorography of a sodium dodecyl sulfate-polyacrylamide gel electrophoresis of Sarkosyl-solubilized crude membrane (the putative inner membranes) from these ampicillin-resistant transformant strains incubated with [3H]penicillin compared with the isogenic ampicillin-susceptible recipient strain revealed reduced binding to PBP 3 and 6, 3 and 4, or 4. In addition, affinity binding studies revealed decreased affinity of PBP 4 for ampicillin of all four transformants tested. We conclude that the major mechanism of resistance in these strains is altered penicillin-binding proteins; however, other mechanisms, including permeability, may also play a role.
178 citations
Journal Article•
178 citations