Girard A E, Schelkly W U, Murphy K T, Sawyer P S
Pfizer Central Research, Groton, CT 06340.
Am J Vet Res. 1987 Dec;48(12):1678-83.
Antibiotic susceptibilities of Pasteurella sp, Haemophilus pleuropneumoniae, and Staphylococcus aureus isolates were determined. The combination of sodium sulbactam, a beta-lactamase inhibitor, and ampicillin had a synergistic effect against all ampicillin-resistant pathogens, rendering them susceptible to ampicillin. Studies of cell-free beta-lactamase from Pasteurella and Haemophilus isolates confirmed the presence of a constitutive penicillinase. Inhibitory concentrations of sulbactam-ampicillin were bactericidal, as demonstrated by killing curves. Ampicillin-resistant Pasteurella and Haemophilus isolates did not develop resistance to sulbactam-ampicillin when passed as many as 8 times in the presence of sublethal concentrations of sulbactam-ampicillin. The in vitro synergistic activity of sulbactam-penicillin also was seen in an in vivo synergistic response in mice challenge exposed to an ampicillin-resistant P haemolytica.
测定了多杀巴斯德氏菌、胸膜肺炎放线杆菌和金黄色葡萄球菌分离株的抗生素敏感性。β-内酰胺酶抑制剂舒巴坦钠与氨苄西林的组合对所有耐氨苄西林病原体具有协同作用，使它们对氨苄西林敏感。对来自巴斯德氏菌和嗜血杆菌分离株的无细胞β-内酰胺酶的研究证实存在组成型青霉素酶。舒巴坦-氨苄西林的抑菌浓度具有杀菌作用，杀菌曲线证明了这一点。耐氨苄西林的巴斯德氏菌和嗜血杆菌分离株在亚致死浓度的舒巴坦-氨苄西林存在下传代多达8次时，未对舒巴坦-氨苄西林产生耐药性。舒巴坦-青霉素的体外协同活性在暴露于耐氨苄西林溶血巴氏杆菌的小鼠攻毒体内协同反应中也可见到。
