An agar diffusion method using paper disks on plates seeded with Clostridium perfringens and incubated anaerobically to assay serum levels of metronidazole is described. The lowest serum metronidazole concentration that could be measured was 0.7 mug/ml, and the average error was 4% for 5 mug/ml. This assay could measure metronidazole in the presence of gentamicin or in the presence of penicilli...

Thirty-seven Enterococcus faecium strains with different levels of penicillin susceptibility were studied in time-kill experiments with a fixed concentration (5 micrograms/ml) of gentamicin combined with different penicillin concentrations (6 to 600 micrograms/ml). Synergy was defined as a relative decrease in counts of greater than 2 log10 CFU per milliliter after 24 h of incubation when the c...

Penicillins can be metabolized to penicilloic acids in man, the extent being dependent on the penicillin structure. In the phenoxy penicillin series, phenoxymethyl penicillin was found to be particularly unstable, but the higher homologues were more stable. In the isoxazolyl series, oxacillin was unstable, and progressive insertion of halogen in the phenyl ring increased stability. Ampicillin a...

Despite in vitro demonstrations of synergism against enterococci, combinations of cephalosporin and aminoglycoside antibodies have been ineffective in the therapy of enterococcal endocarditis. Penicillin-gentamicin, cephalothin-gentamicin, and cefazolin-gentamicin were used to treat enterococcal endocarditis in rabbits. A direct relation was observed between the rate of cure and the degree by w...

A large volume of data on variations in serum penicillin levels has been obtained from work carried out with depot preparations of procaine benzyl penicillin in oil (to be published). Figure 1 shows frequency histograms of blood levels obtained in humans 24 hours after a single fixed dose of the same preparation. Large groups of individuals were involved and there was an interesting difference ...

A method for the production of antibodies specifically directed against penicillin is described. The inability of this antibody to significantly reduce the antibiotic activity of penicillin is noted. Evidence to show the variability of specificities of various sera, some directed for the most part against the side chain, others against the nucleus is presented. Studies on serum fractions separa...

Methods Retrospective analysis of clinical files and results of skin testing and DPT (drug provocation tests) from January 2011 to December 2013. All patients were studied according to standardized diagnostic procedures of ENDA/EAACI: serum sIgE (specific IgE) (ImmunoCAP, ThermoFisher) to penicillin G/V, amoxicillin and ampicillin; skin prick and IDT (intradermal tests) to PPL/MD (DAP, Diater),...

An in vitro model simulating amoxicillin and cefotaxime concentrations in human serum (after standard doses) was used to explore the activities of these drugs over time against penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae strains. An initial inoculum reduction percentage of > or = 90% was obtained with amoxicillin and maintained for 2 to 8 h, regardless of the strain...

OBJECTIVE To assess whether, on the basis of one blood test, penicillin allergy might be excluded sufficiently for general practitioners to give oral penicillin to patients claiming a history of penicillin allergy. DESIGN Prospective study of patients referred by general practitioners. SETTING Outpatient allergy clinic in a district general hospital. PATIENTS 175 referred patients who gav...