青霉素介紹于临床已20多年,它对某些革兰氏阳性細菌和革兰氏阴性球菌在血濃度0.02微克/毫升时,就可抑制其生长,濃度稍高就有杀菌作用。除偶致过敏反应外,在抗菌素中是毒性較小的一种。它的缺点是自腎脏排泄快,不稳定,加热,或酸、硷、氧化剂、酵素、重金属盐、乙醇、以及阳光等均能将它迅速破坏。某些細菌,特別是革兰氏阴性菌(如大腸桿菌),对青霉素不敏感,并产生一种青霉素的灭活酶称青霉素酶,它是青霉素的一种特殊拮抗物貭。临床上原来敏感的葡萄球菌,当其轉变为抗青霉素菌株时,就能产生大量青霉素酶,因而发生抗葯性。产生青霉素酶特別多的有枯草杆菌、大腸杆菌、变形杆菌、綠膿杆菌、抗青霉素的葡萄球菌和各种革兰氏阴性菌。近十年来抗青 Penicillin has been introduced in clinical practice for more than 20 years. It inhibits the growth of certain Gram-positive bacteria and Gram-negative cocci at a blood concentration of 0.02 μg / ml, and has a bactericidal effect at slightly higher concentrations. In addition to occasional allergic reactions, antibiotics are less toxic. Its disadvantage is that it can quickly destroy the kidneys quickly excreted, unstable, heated, or acid, alkaline, oxidants, enzymes, heavy metal salts, ethanol, and sunlight. Certain bacteria, especially Gram-negative bacteria such as E. coli, are insensitive to penicillin and produce a penicillin-inactivating enzyme called penicillinase, a specific antagonist of penicillin. Clinically sensitive Staphylococcus aureus, when it is transformed into an anti-penicillin strain, can produce a large number of penicillinase, resulting in resistance. Bacillus subtilis, Escherichia coli, Proteus, Pseudomonas aeruginosa, penicillin-resistant Staphylococcus aureus and a variety of gram-negative bacteria. Anti-youth in the past decade