Enterobacteria are among the main etiological agents of environmental bovine mastitis and are often resistant to antimicrobials, especially to β-lactams due to the production of beta-lactamases and some enterobacteria produce broad-spectrum beta-lactamases (ESBL), constituting the bacteria the ability to degrade β-lactams, in addition to presenting broad spectrum on various antimicrobials such as ceftazidime, cefotaxime and aztreonam, which are strongly inhibited by clavulanic acid [4,10]. This evidence concerns the gene LACTB and Bovine mastitis.