Identification of β-Lactamase in Antibiotic-Resistant Bacillus cereus Spores▿

β-Lactamase type I is reported for the first time to occur in the sporulated form in a penicillin-resistant Bacillus species. The enzyme was readily characterized from the B. cereus 5/B line (ATCC 13061) by mass spectrometry and two-dimensional gel electrophoresis