Wexler H M
Research Service, Veterans Administration Medical Center, Los Angeles, California 90073.
Clin Infect Dis. 1993 Jun;16 Suppl 4:S328-33. doi: 10.1093/clinids/16.supplement_4.s328.
Demand for susceptibility testing of anaerobes has increased, but no consensus on procedure and interpretation has been achieved. The need for reliable methods for testing anaerobic bacteria extends from small hospital laboratories to large research centers. Agar dilution testing is too costly and labor intensive for many clinical laboratories. Microbroth dilution is more convenient; however, some fastidious anaerobes do not grow well enough in this system, and the choice of antimicrobial agents may not reflect the hospital formulary. Disapproval of the broth disk elution system leaves fewer options open to clinical laboratories and emphasizes the need for more convenient and reliable techniques. Some newer methods are undergoing evaluation. Variables in susceptibility testing of anaerobes include the media and methods used, organisms chosen, breakpoints chosen, and endpoint determination. This latter variable is probably the most problematic since no endpoint based on interaction of organism and antimicrobial agent rather than on subjective observation has been defined. Also, clustering of MICs around the breakpoint may lead to significant variability in reported methods. A more accurate MIC measurement is needed. Adherence of laboratories to approved methods and careful reporting of methods and the interpretive breakpoints would facilitate interlaboratory comparisons and the identification of emerging resistance.
对厌氧菌药敏试验的需求有所增加，但在操作程序和结果判读方面尚未达成共识。从小医院实验室到大型研究中心，都需要可靠的方法来检测厌氧细菌。琼脂稀释法对许多临床实验室来说成本过高且劳动强度大。微量肉汤稀释法更方便；然而，一些苛求性厌氧菌在该系统中生长不佳，而且抗菌药物的选择可能无法反映医院的药品目录。肉汤纸片洗脱系统不被认可，这使得临床实验室的选择更少，并凸显了对更方便可靠技术的需求。一些更新的方法正在进行评估。厌氧菌药敏试验中的变量包括所使用的培养基和方法、所选的微生物、所选的折点以及终点判定。后一个变量可能是最成问题的，因为尚未定义基于微生物与抗菌药物相互作用而非主观观察的终点。此外，最低抑菌浓度（MIC）在折点附近的聚集可能导致报告方法出现显著差异。需要更准确地测量MIC。实验室遵守批准的方法，并仔细报告方法和解释性折点，将有助于实验室间的比较以及新出现耐药性的识别。
