Detection of beta-lactamase activity with nitrocefin of multiple strains of various microbial genera.

The production or presence of beta-lactamase(s) was studied by the rapid method utilizing the chromogenic cephalosporin compound nitrocefin in cultures of multiple strains belonging to the same genus as well as groups of microorganisms. The genera were: Staphylococcus spp., Streptococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, indole-positive Proteus spp., Enterobacter spp., Serratia marcescens, rare Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae and Neisseria gonorrhoeae. With this sensitive and rapid assay for beta-lactamase, it was possible to verify and separate the beta-lactamase producing cultures from the non-producers and include the useful strains to on-going research, such as beta-lactam screen, beta-lactamase inhibitory study and lytic properties of beta-lactams. The data also provide evidence for the possible role of beta-lactamase(s) in the physiology, biochemistry and pathogenicity of bacterial strains. The nitrocefin method was found a very specific and extremely useful procedure for the detection and estimation of beta-lactamase activity.