be·ta-lac·ta·mase /-ˈlæktəˌmes, ˌmez/
  be·ta-lac·ta·mase /-ˈlæktəˌmes, ˌmez/ 名詞
  β-內胺黴
  beta-lactamase
       n : enzyme produced by certain bacteria that inactivates
           penicillin and results in resistance to that antibiotic
           [syn: penicillinase]