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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.
Penicillins are a widely used group of medications that are effective for the treatment of a wide variety of bacterial infections in human adults and children as well as other species. Some side effects are predictable, of which some are common but not serious, some are uncommon and serious and others are rare. [ 2 ]
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.
The β-lactam core structures. (A) A penam.(B) A carbapenam.(C) An oxapenam.(D) A penem.(E) A carbapenem.(F) A monobactam.(G) A cephem.(H) A carbacephem.(I) An oxacephem. This is a list of common β-lactam antibiotics—both administered drugs and those not in clinical use—organized by structural class.
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.
occasionally penicillins including penicillin, ampicillin and ampicillin-sulbactam, amoxicillin and amoxicillin-clavulnate, and piperacillin-tazobactam (not all vancomycin-resistant Enterococcus isolates are resistant to penicillin and ampicillin) occasionally doxycycline and minocycline
Penicillin resistance in Staphylococcus aureus [3] appeared very soon after penicillin entered general clinical use in 1943, and the mechanism of resistance was the production of β-lactamase. Modification of the penicillin molecule so that it was resistant to being broken down by β-lactamase was able to temporarily overcome this problem.
Penicillinase is a bacterial enzyme produced by bacteria resistant to other β-lactam antibiotics which hydrolyses the antibiotic, rendering it non-functional. Methicillin is not bound and hydrolysed by penicillinase, meaning it can kill the bacteria, even if this enzyme is present.