Eng R H, Cherubin C, Smith S M, Buccini F
Antimicrob Agents Chemother. 1985 Nov;28(5):601-6. doi: 10.1128/AAC.28.5.601.
Seven beta-lactam antibiotics were studied for both their antimicrobial activity and the degree to which they produced inoculum effect on Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium. Aztreonam, cefoperazone, and ceftazidime were poorly bactericidal, caused marked bacterial filamentation, and exhibited a large inoculum effect on E. coli, K. pneumoniae, and S. typhimurium. Cefotaxime and ceftriaxone were more rapidly bactericidal, caused only a moderate amount of filamentous forms, and exhibited a modest inoculum effect, while cefoxitin and imipenem both were rapidly bactericidal and exhibited only a minimal-to-no-inoculum effect. The inoculum effect did not correlate with drug stability during incubation with the bacteria. Inoculum effect on these species of the family Enterobacteriaceae appears to be a manifestation of increase in optical density secondary to the development of filamentous bacterial forms with an increase in bacterial mass during exposure to antibiotics which are not rapidly bactericidal. These observations have a clear significance for the susceptibility testing of beta-lactam antibiotics when turbidity is used as a parameter to determine presence of bacterial growth.
对七种β-内酰胺类抗生素的抗菌活性以及它们对大肠杆菌、肺炎克雷伯菌和鼠伤寒沙门氏菌产生接种物效应的程度进行了研究。氨曲南、头孢哌酮和头孢他啶杀菌效果不佳，导致明显的细菌丝化，并且对大肠杆菌、肺炎克雷伯菌和鼠伤寒沙门氏菌表现出较大的接种物效应。头孢噻肟和头孢曲松杀菌速度更快，仅产生中等数量的丝状形态，并且表现出适度的接种物效应，而头孢西丁和亚胺培南均杀菌迅速，仅表现出极小至无接种物效应。接种物效应与细菌培养期间的药物稳定性无关。肠杆菌科这些菌种的接种物效应似乎是由于在接触非快速杀菌的抗生素期间，丝状细菌形态发展导致细菌量增加，进而引起光密度增加的一种表现。当使用浊度作为确定细菌生长存在的参数时，这些观察结果对于β-内酰胺类抗生素的药敏试验具有明确的意义。
