β-lactam antibiotics are the most frequently prescribed class of drugs worldwide, due to its efficacy and good safety profile. However, the emergence of β-lactamase producing bacterial strains eliminated the use of β-lactam antibiotics as a chemotherapeutic choice. To restore their usability, a non-antibiotic adjuvant in conjunction with β-lactam antibiotics is now being utilised. Cholic acid potentially acts as an adjuvant since it can blunt the pro-inflammatory activity in human. Our main objective is to scrutinise the inhibition of β-lactamase-producing bacteria by adjuvant cholic acid, synergism of the test drugs and the primary mechanism of enzymatic reaction. Antibacterial effect of the cholic acid-ampicillin (CA-AMP) on 7 β-lactamase positive isolates were evaluated accordingly to disc diffusion assay, antibiotic susceptibility test, as well as checkerboard analysis. Then, all activities were compared with ampicillin alone, penicillin alone, cholic acid alone and cholic acid-penicillin combination. The CA-AMP displayed notable antibiotic activity on all test bacteria and depicted synergistic influence by representing low fractional inhibitory concentration index (FIC ≤ 0.5). According to kinetic analyses, CA-AMP behaved as an uncompetitive inhibitor against beta lactamase, with reducing values of Michaelis constant (K_m) and maximal velocity (V_max) recorded. The inhibitor constant (Ki) of CA-AMP was equal to 4.98 ± 0.3 µM, which slightly lower than ampicillin (5.00 ± 0.1 µM).

由于其有效性和良好的安全性，β-内酰胺类抗生素是世界上最常用的一类药物。然而，产生β-内酰胺酶的细菌菌株的出现消除了β-内酰胺抗生素作为化疗选择的使用。为了恢复它们的可用性，现在正在使用与 β-内酰胺抗生素结合的非抗生素佐剂。胆酸可能充当佐剂，因为它可以减弱人类的促炎活动。我们的主要目的是仔细研究佐剂胆酸对产β-内酰胺酶细菌的抑制作用、受试药物的协同作用和酶促反应的主要机制。胆酸-氨苄青霉素 (CA-AMP) 对 7 个 β-内酰胺酶阳性分离株的抗菌作用根据圆盘扩散试验、抗生素敏感性试验、以及棋盘分析。然后，将所有活性与单独的氨苄青霉素、单独的青霉素、单独的胆酸和胆酸-青霉素组合进行比较。CA-AMP 对所有测试细菌都显示出显着的抗生素活性，并通过代表低分数抑制浓度指数 (FIC ≤ 0.5) 来描述协同影响。根据动力学分析，CA-AMP 表现为一种非竞争性的 β 内酰胺酶抑制剂，米氏常数（K_m ) 和最大速度 (V _max ) 记录。CA-AMP 的抑制剂常数 (Ki) 等于 4.98 ± 0.3 µM，略低于氨苄青霉素 (5.00 ± 0.1 µM)。