头霉素

头霉素C产生菌选育初筛方法的改进

A practical primary screening method of cephamycin C-producing strain breeding

碳氮源对发酵生产头霉素C的初步研究

Preliminary study on the influence of carbon / nitrogen sources to the fermentation of cephamycin C

目的提高棒状链霉菌的克拉维酸生产能力，去除副产物头霉素C。

Objective To improve the production of clavulanic acid and to genetically delete cephamycin C in the fermentation of Streptomyces clavuligerus .

同时发现在发酵培养基中添加生长因子、硫源和前体可以明显提高头霉素C的产量。

Meanwhile the fermentation potency of cephamycin C was found to be increased obviously by the additions of growth factor , sulfur sources and amino acids in the fermentation medium .

阴沟肠杆菌临床株对青霉素类、头霉素类、阿莫西林／棒酸以及一、二代头孢菌素有较高的耐药性，主要是由于AmpC酶的存在。

It is often resistant to penicillins , cefoxitin , amoxillin / clavulanic acid and first and second generation cephalosporins because of AmpC enzyme .

结论：头霉素类抗生素可作为治疗ESBLs菌株引起的重症感染的可选药物，且对我院分离的产ESBLS大肠杆菌和肺炎克雷伯菌，头孢美唑体外活性略优于头孢西丁。

Conclusions : cephamycins can be the alternatives for ESBLs producing strains , and in vitro antimicrobial activity of Cefmetazole against Extended-Spectrum Beta-lactamases producing was higher than that of Cefoxitin in west china hospital .