Unit of Mycobacteriology and UPMM, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa (IHMT/UNL), Rua da Junqueira, 100, 1349-008 Lisbon, Portugal.
In Vivo. 2011 Mar-Apr;25(2):171-8.
BACKGROUND/AIM: Bacterial multidrug resistance may be mediated by the overexpression of efflux pumps. Conventional evaluation of efflux activity using efflux pump substrates, such as ethidium bromide, requires specialised instrumentation. The agar-based method, previously reported, has been modified to evaluate as many as twelve bacterial strains and has been termed the ethidium bromide-agar cartwheel method.
Agar plates containing different concentrations of ethidium bromide were swabbed with bacterial cultures. The cell efflux capacity increased with increasing ethidium bromide concentration, which produced fluorescence of the bacterial mass.
The method was shown to be useful for the detection of efflux activity among multidrug-resistant Gram-negative and Gram-positive clinical isolates, as confirmed by the determination of minimum inhibitory concentration for several antibiotics in the presence of known efflux pump inhibitors.
This method may be adapted to the clinical laboratory for the presumptive identification of multidrug-resistant isolates that overexpress efflux pump systems.
背景/目的：细菌的多药耐药性可能是由外排泵的过度表达介导的。使用吖啶橙等外排泵底物对外排活性进行常规评估需要专门的仪器。先前报道的基于琼脂的方法已被修改，以评估多达 12 种细菌菌株，并被称为吖啶橙琼脂车轮法。
用细菌培养物擦拭含有不同浓度吖啶橙的琼脂平板。随着吖啶橙浓度的增加，细胞外排能力增加，从而产生细菌群体的荧光。
该方法已被证明可用于检测耐多药革兰氏阴性和革兰氏阳性临床分离株的外排活性，这通过在存在已知外排泵抑制剂的情况下确定几种抗生素的最小抑菌浓度得到证实。
该方法可适用于临床实验室，用于推定鉴定过度表达外排泵系统的多药耐药分离株。
