青霉素G用于临床已有40年历史。六十年代以后,半合成青霉素和头孢菌素的发现为治疗耐青霉素G细菌的感染开辟了新的途径。但是细菌,尤其是肠杆菌属对青霉素类和头孢菌素类抗生素耐药的报告仍然不断。这种耐药性最常见的机制是细菌产生了某些使β内酰胺抗生素失活的β内酰胺酶。设法克服这种耐药性有以下几种途径 :(1) 寻找能耐青霉素酶和头孢菌素酶、并能充分穿透到作用部位的抗生素。到目前为止,至少已有耐酶的 Penicillin G has been used clinically for 40 years. After the 1960s, the discovery of semisynthetic penicillins and cephalosporins opened up new avenues for the treatment of penicillin-G-resistant infections. However, there are still reports of bacteria, especially Enterobacter, resistant to penicillins and cephalosporins. The most common mechanism of this resistance is that the bacteria produce some beta-lactamase that inactivates beta-lactam antibiotics. There are several ways of trying to overcome this resistance: (1) Look for antibiotics that are resistant to penicillinase and cephalosporinase and penetrate fully to the site of action. So far, at least, it has been resistant to enzymes