Resistance to penicillin has developed through two mechanisms : chromasomally mediated resistance ( CMRNG ) and penicillinase-mediated resistance ( PPNG ).
12.
Penicillinase is a bacterial enzyme produced by bacteria resistant to other B-lactam antibiotics which hydrolyses the antibiotic, rendering it nonfunctional.
13.
"' Cephalosporin "': This is an example of a wide spectrum antibiotic that is relatively stable to penicillinase although this stability varies with different cephalosporins.
14.
Penicillinase-mediated resistance in " N . gonorrhoeae " is mediated by the plasmid borne TEM-1 type beta-lactamase which falls under the third general mechanism for beta-lactam resistance.
15.
Later in the same year, an isolate of " Escherichia coli " was examined, and it was found to have contained a ?-lactam ring enzyme capable of hydrolyzing penicillin ( penicillinase ).
16.
The first discovery of " S . aureus " to have contained the penicillinase enzyme occurred in 1944, and in only 4 years the first outbreak of penicillin-resistant " S . aureus " took place in a United Kingdom hospital.
17.
Penicillinase was the first ?-lactamase to be identified : It was first isolated by Abraham and Chain in 1940 from Gram-negative " E . coli " even before penicillin entered clinical use, but penicillinase production quickly spread to bacteria that previously did not produce it or produced it only rarely.
18.
Penicillinase was the first ?-lactamase to be identified : It was first isolated by Abraham and Chain in 1940 from Gram-negative " E . coli " even before penicillin entered clinical use, but penicillinase production quickly spread to bacteria that previously did not produce it or produced it only rarely.
19.
"' Beta-lactamases "'( "'?-lactamases "') are enzymes ( ) produced by bacteria ( also known as penicillinase ) that provide resistance to ?-lactam antibiotics such as penicillins, cephamycins, and carbapenems ( ertapenem ), although carbapenems are relatively resistant to beta-lactamase.
