Senior D F, Gaskin J M, Buergelt C D, Franks P P, Keefe T J
Res Vet Sci. 1985 Jul;39(1):42-6.
Clavulanic acid (CA) competitively inhibits beta-lactamase hydrolysis of penicillins in vitro. Treatment with amoxycillin combined with clavulanic acid (A-CA) was compared with placebo in a blind study in cats with experimental cystitis caused by Escherichia coli demonstrating in vitro resistance to amoxycillin. Bacterial cystitis was induced in 20 cats by bladder infusion of 5 ml of 0.05 per cent alcoholic salicylic acid followed after 24 hours by a brain-heart infusion broth of E coli (10(8) colony forming units ml-1) previously found to be resistant to amoxycillin in vitro (minimum inhibitory concentration over 512 micrograms ml-1). Four days after infection, cats were randomly divided into two groups of 10 and treated with amoxycillin combined with clavulanic acid or placebo for 10 days. When compared to the placebo-treated group, the A-CA treated group showed: reduced quantitative bacterial counts in urine on days 7 (P less than 0.001) and 14 (P less than 0.02); reduced culture positive urine on days 7 (P less than 0.001) and 14 (P less than 0.001); and less severe inflammation on histological examination of the bladder and urethra (P less than 0.01). It was concluded that A-CA was effective in reducing the bacterial count and reducing the histopathological changes in the bladder and urethra in an experimental model of acute bacterial cystitis in cats infected with an E coli demonstrating in vitro resistance to amoxycillin.
克拉维酸（CA）在体外可竞争性抑制β-内酰胺酶对青霉素的水解作用。在一项针对由大肠杆菌引起的实验性膀胱炎猫的盲法研究中，将阿莫西林联合克拉维酸（A-CA）治疗与安慰剂进行了比较，这些猫的大肠杆菌在体外对阿莫西林具有耐药性。通过向20只猫的膀胱内注入5毫升0.05%的酒精性水杨酸来诱导细菌性膀胱炎，24小时后再注入先前发现对阿莫西林体外耐药（最低抑菌浓度超过512微克/毫升）的大肠杆菌脑心浸液肉汤（10⁸菌落形成单位/毫升）。感染4天后，将猫随机分为两组，每组10只，分别用阿莫西林联合克拉维酸或安慰剂治疗10天。与安慰剂治疗组相比，A-CA治疗组在第7天（P<0.001）和第14天（P<0.02）时尿液中的细菌定量计数降低；在第7天（P<0.001）和第14天（P<0.001）时培养阳性尿液减少；膀胱和尿道组织学检查显示炎症较轻（P<0.01）。得出的结论是，在感染了体外对阿莫西林耐药的大肠杆菌的猫急性细菌性膀胱炎实验模型中，A-CA可有效减少细菌数量并减轻膀胱和尿道的组织病理学变化。
