Smith S M
Microbiology Section, Veterans Administration Medical Center, East Orange, New Jersey 07019.
Antimicrob Agents Chemother. 1991 Feb;35(2):237-41. doi: 10.1128/AAC.35.2.237.
Most bacteria at an infection site obtain energy by the breakdown of glucose via microaerophilic or anaerobic pathways and in the process yield various end products. In this study, production of D-lactic acid by Staphylococcus aureus and Escherichia coli was correlated with glucose utilization by bacteria during exposure to antibiotics at subinhibitory, inhibitory, and suprainhibitory concentrations. D-Lactic acid production was further correlated with production of a tissue-destroying enzyme, hyaluronidase, by S. aureus. For E. coli, all agents tested showed dose-related bacterial killing, with the most noticeable being with ampicillin, piperacillin, and ciprofloxacin. Imipenem, ciprofloxacin, and chloramphenicol had the most dose-related effects on D-lactic acid production. With few exceptions, hyaluronidase production correlated well with D-lactic acid production in S. aureus. Subinhibitory concentrations of erythromycin and clindamycin effectively decreased accumulation of D-lactic acid and hyaluronidase. Determination of D-lactic acid production may perhaps serve as a means of independently monitoring the effects of antimicrobial agents on bacterial metabolic activity, which is an important aspect of antimicrobial action that remains relatively unexplored.
感染部位的大多数细菌通过微需氧或厌氧途径分解葡萄糖来获取能量，并在此过程中产生各种终产物。在本研究中，金黄色葡萄球菌和大肠杆菌产生D-乳酸与细菌在亚抑菌、抑菌和超抑菌浓度的抗生素作用下对葡萄糖的利用相关。金黄色葡萄球菌产生D-乳酸还与一种破坏组织的酶——透明质酸酶的产生相关。对于大肠杆菌，所有测试药物均显示出与剂量相关的细菌杀灭作用，其中氨苄西林、哌拉西林和环丙沙星最为显著。亚胺培南、环丙沙星和氯霉素对D-乳酸产生的剂量相关效应最为明显。除少数例外，金黄色葡萄球菌中透明质酸酶的产生与D-乳酸的产生密切相关。亚抑菌浓度的红霉素和克林霉素可有效减少D-乳酸和透明质酸酶的积累。测定D-乳酸的产生可能是一种独立监测抗菌药物对细菌代谢活性影响的方法，而抗菌活性是抗菌作用中一个相对未被充分探索的重要方面。
