title: Development, characterization, and initial evaluations of S1. A new chromogenic cephalosporin for beta-lactamase detection.
abstract: A novel, chromogenic cephalosporin reagent (S1) for beta-lactamase testing was produced that shares physicochemical characteristics with nitrocefin (formerly 87/312). S1 and nitrocefin in a disk-testing format for beta-lactamase performed at 100% agreement for detecting enzyme-producing isolates of Bacteroides fragilis group, Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, Staphylococcus aureus, and selected Enterobacteriaceae. The time required to achieve an initial color change or a strong positive reaction was comparable for both chromogenic reagents for all organisms except the Gram-positive species. S1 reaction times were approximately 50% faster than nitrocefin for beta-lactamase-positive enterococci and S. aureus. These results from the developmental studies and a commercially prepared disk lot indicate that S1 is a promising beta-lactamase disk test reagent with the ability to detect all significant enzyme-producing species strains, some significantly earlier than the nitrocefin disk method.
authors.affiliation: Department of Pathology, University of Iowa College of Medicine, Iowa City 52242, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Sutton
authors.forename: D J
authors.initials: DJ
authors.lastname: Biedenbach
authors.forename: A
authors.initials: A
authors.lastname: Yen
authors.forename: R N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D001419:Bacteria / Q000201:enzymology*; D001431:Bacteriological Techniques; D002511:Cephalosporins / Q000494:pharmacology*; D002863:Chromogenic Compounds / Q000138:chemical synthesis / Q000494:pharmacology; D007202:Indicators and Reagents / Q000138:chemical synthesis / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D002863:Chromogenic Compounds; D007202:Indicators and Reagents; D001618:beta-Lactamases; C021720:nitrocefin