Beta-lactam antibiotics are the largest and most commonly used group of antimicrobial agents world-wide. They show very good tolerability and many of the drugs can be administrated orally. Bacteria expressing extended-spectrum beta-lactamases (ESBLs), enzymes hydrolysingpenicillins and cephalosporins, may not respond to therapy using some of these antibiotics. The isolates are also often co-resistant to other antimicrobial agents, thus further limiting treatment options. Of the 36 isolates collected from well water in OruIjebu, Ogun State and screened using Gram’s staining technique, 7 (19.44%) were Gram positive while 29(80.56%) were Gram negative. Out of the Gram’s negatives, 23 were identified as members of the enterobacteriaceae family Of the 23 enterobacterial isolates subjected to ESBL detection using DDST
