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.

Skin testing and oral penicillin challenge in patients with a history of remote penicillin allergy

Abstract: Background Penicillin administration is usually contraindicated in penicillin-allergic patients with positive skin test results. Objective To examine whether penicillin oral challenge for patients with a history of remote non-life-threatening allergic reaction to penicillin can be well tolerated irrespective of skin test results. Methods In a prospective open-label trial, 8,702 individuals were screened between November 1998 and January 2000. Of 687 patients with a non-life-threatening allergic reaction to penicillin, occurring longer than 3 years earlier, 169 were enrolled. Regardless of the response to penicillin skin testing, patients received the usual 1-day dosage of penicillin and amoxicillin, on 2 separate occasions. Two to 6 years later, a follow-up was conducted to assess the outcomes of further penicillin administration. Results A total of 272 combined skin tests and oral challenges were performed on 169 patients. Among 137 challenges with a positive skin test result and 135 patients with a negative skin test result, 9 (6.6%) and 5 (3.7%) ( P = .29), respectively, developed a mild rash to oral challenge. At follow-up, 2 to 6 years afterward, 3 of 55 patients (5.5%) who were given a full treatment course of penicillin developed a mild skin eruption. Conclusions Positive penicillin skin test results for patients with a remote history of non-life-threatening allergic reaction to penicillin were not associated with a greater prevalence of adverse reactions to oral challenge with penicillin than negative results. Because skin testing is considered the gold standard and the safest method for predicting tolerance to penicillin administration, oral penicillin challenge may be used as a diagnostic method only in these specific patients when skin testing is not feasible.

Penicillin resensitization among hospitalized patients

Abstract: The purpose of this study was to determine the frequency of resensitization to penicillin after oral or intravenous treatment with β-lactam antibiotics in hospitalized patients with histories of penicillin allergy. Seventeen adults (aged 24 to 76 years) and one child (aged 10 years) were treated intravenously and/or orally with β-lactam antibiotics after negative skin tests were obtained with benzylpenicilloyl polylysine, potassium penicillin G, and alkaline hydrolysis products of penicillin G as minor determinant mixture. Repeat skin testing was performed 1 to 12 months after the therapy. Three patients (16%) became skin test positive after the treatment. Two patients reacted to potassium penicillin G alone, and the other patient reacted to benzylpenicilloyl polylysine and minor determinant mixture. These three patients were among the 15 patients who were treated with intravenous antibiotics. This study reveals a high percentage of skin test conversion after intravenously administered penicillin therapy and confirms the present practice of advising patients with a history of penicillin allergy who have successfully completed penicillin treatment to have a repeat skin test before future exposure to β-lactam antibiotics.

Penicillin resistance in the subgingival microbiota associated with adult periodontitis.

Abstract: In this investigation, the penicillin-resistant and beta-lactamase-producing subgingival microbiota associated with adult periodontitis was identified, and the impact of a recent exposure to penicillin on the recovery of resistant organisms from this microbiota was assessed. Subjects with adult periodontitis were examined clinically and microbiologically. Twenty-one subjects had a documented history of penicillin therapy within the previous 6 months whereas an additional 21 subjects had no history of antibiotic use within 1 year. Subgingival plaque samples were cultured anaerobically on nonselective and penicillin-containing elective media. MICs and beta-lactamase production were determined for the isolates from the elective medium. The penicillin-resistant microbiota consisted primarily of gram-negative organisms, including Bacteroides, Veillonella, Haemophilus, Eikenella, and Capnocytophaga species. The prevalence (P less than 0.05) and proportions (P less than 0.005) of both penicillin-resistant pigmented Bacteroides and Veillonella species were significantly greater in subjects with recent penicillin exposure. Of the penicillin-resistant genera identified, beta-lactamase production was detected in species of pigmented Bacteroides, Capnocytophaga, and Streptococcus. The prevalence of beta-lactamase-producing Bacteroides species was significantly greater in subjects with recent penicillin exposure (P less than 0.05). Of the antibiotics examined, no single agent was uniformly effective against all of the penicillin-resistant strains, but metronidazole and clindamycin were active against all of the penicillin-resistant pigmented Bacteroides strains.

Synergistic Antibacterial Effect of Silver Nanoparticles Combined with Ineffective Antibiotics on Drug Resistant Salmonella typhimurium DT104

Abstract: Synergistic antibacterial activity of combined silver nanoparticles (AgNPs) with tetracycline (polykeptide), neomycin (aminoglycoside), and penicillin (β-lactam) was tested against the multidrug resistant bacterium Salmonella typhimurium DT104. Dose-dependent inhibition of Salmonella typhimurium DT104 growth is observed for tetracycline-AgNPs and neomycin-AgNPs combination with IC50 of 0.07 μg/mL and 0.43 μg/mL, respectively. There is no inhibition by the penicillin-AgNPs combination. These results suggest that the combination of the ineffective tetracycline or neomycin with AgNPs effectively inhibits the growth of this bacterium. The synergistic antibacterial effect is likely due to enhanced bacterial binding by AgNPs assisted by tetracycline or neomycin, but not by penicillin.