Antibiotic Resistance Again 1999.3.17

Antibiotic Resistance Again 1999.3.17

Currently popular antibiotics broadly fall into the following categories: ① β-lactamase inhibitors; ② macrolides; ③ aminoglycosides; ④ chloramphenicol; ⑤ quinolones. Pathogenic microorganisms develop resistance through: ① reinforcing their own cell membranes to resist antibiotic penetration, primarily by altering the composition and quantity of outer membrane proteins to change permeability, preventing antibiotics from crossing the outer membrane and reaching their targets; ② modifying the affinity between target proteins and antibiotics; ③ producing β-lactamase-inactivating enzymes, a phenomenon mainly observed in cephalosporin and penicillin antibiotics. In recent years, these types of antibiotics have developed rapidly and are widely used clinically, but resistance quickly emerges. In the 1970s, the pioneering cephalosporin I (cefathiamidine sodium); in the 1980s, the pioneering cephalosporin IV (cefamandole), V (cefazolin sodium), and VI (cefradine); in the 1990s, the pioneering cephalosporin Bi (cefoperazone) and菌必治 (ceftriaxone) soon showed resistance against numerous pathogens. Consequently, researchers specifically developed new formulations aimed at inhibiting β-lactamase-inactivating enzymes: Supradin, Metronidazole, Dakshulin, Fudaxin, and Cefixime. Please note: β-lactams are present in cephalosporins, penicillins, and other antibiotics, and the reason these drugs can kill bacteria is entirely due to the action of β-lactams. As the saying goes, “for every step the good advances, the evil takes two steps forward.” Over the long-term battle between pathogens and antibiotics, pathogens have evolved enzymes capable of rendering β-lactams ineffective, causing antibiotics to lose their efficacy and bacteria to gain resistance. These enzymes are called β-lactamase-inactivating enzymes, often simply referred to as β-lactamases. Today’s pharmaceutical industry strives to make existing cephalosporins and penicillins highly resistant to β-lactamases.