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Penicillinase was the first β-lactamase to be identified. It was first isolated by Abraham and Chain in 1940 from E. coli (which are gram-negative) even before penicillin entered clinical use, [ 5 ] but penicillinase production quickly spread to bacteria that previously did not produce it or produced it only rarely.
The side effects of penicillin can be altered by taking other medications at the same time. Taking oral contraceptives along with penicillin may lower the effects of the contraceptive. When probenecid is used concurrently with penicillin, kidney excretion of probenecid is decreased resulting in higher blood levels of penicillin in the ...
PBPs normally catalyze the cross-linking of the bacterial cell wall, but they can be permanently inhibited by penicillin and other β-lactam antibiotics. (NAM = N-acetylmuramic acid; NAG = N-acetylglucosamine) [2] Penicillin-binding proteins (PBPs) are a group of proteins that are characterized by their affinity for and binding of penicillin.
β-Lactam antibiotics are indicated for the prevention and treatment of bacterial infections caused by susceptible organisms. At first, β-lactam antibiotics were mainly active only against gram-positive bacteria, yet the recent development of broad-spectrum β-lactam antibiotics active against various gram-negative organisms has increased their usefulness.
Penicillin can easily enter bacterial cells in the case of Gram-positive species. This is because Gram-positive bacteria do not have an outer cell membrane and are simply enclosed in a thick cell wall. [45] Penicillin molecules are small enough to pass through the spaces of glycoproteins in the cell wall.
The extended-spectrum penicillins are a group of antibiotics that have the widest antibacterial spectrum of all penicillins. [1] Some sources identify them with antipseudomonal penicillins, [2] others consider these types to be distinct. [3] This group includes the carboxypenicillins and the ureidopenicillins.
Penicilloic acid is any of several acids which are obtained from the penicillins by the hydrolytic opening of the lactam ring (as by the action of a beta-lactamase). Hypersensitivity is the most important adverse effect of the penicillins .
Dicloxacillin is a narrow-spectrum β-lactam antibiotic of the penicillin class. [1] It is used to treat infections caused by susceptible (non-resistant) Gram-positive bacteria . [ 1 ] It is active against beta-lactamase -producing organisms such as Staphylococcus aureus , which would otherwise be resistant to most penicillins .