title: Susceptibility of Haemophilus influenza to ampicillin as determined by use of a modified, one-minute beta-lactamase test.
abstract: Fifty-seven cultures of Haemophilus influenzae were tested for production of beta-lactamase by use of a modified, 1-min test. Only the 24 cultures that were ampicillin resistant, whether type b or not, yielded positive results for the enzyme; all ampicillin-susceptible isolates were uniformly negative. The beta-lactamase procedure is simple to perform and requires only commonly available reagents.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects / Q000201:enzymology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D010405:Penicillinase; D013997:Time Factors
chemical_list: D000667:Ampicillin; D010405:Penicillinase