Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi 74800, Pakistan.
Biomed Res Int. 2013;2013:927323. doi: 10.1155/2013/927323. Epub 2013 Jun 20.
Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics.
尽管在抗菌化学疗法和支持性治疗方面取得了进展，但抗生素耐药性仍然是细菌感染管理中的一个重大问题。在这里，我们建议一种简单、廉价且易于实施的测定法，用于从天然产物或合成化学文库中筛选抗菌化合物，以评估它们与现有抗生素联合使用对抗多种耐药菌的潜力。我们用上述方法测试了核桃树树皮的水提取物，以确定其是否能增强选定抗生素的活性。将核桃树皮的水提取物加入到 Mueller-Hinton 琼脂中，然后在琼脂表面铺上一层多种耐药菌、伤寒沙门氏菌或肠致病性大肠杆菌。接下来，将浸有不同类别的抗生素的滤纸片放在琼脂表面上。将单独用提取物或抗生素孵育的细菌作为对照。结果表明，与单独用抗生素/提取物孵育的细菌相比，头孢他啶、头孢呋辛和氨苄西林纸片周围的抑菌圈显著增大（>30%）。总之，我们的测定法能够检测核桃提取物与一系列抗生素联合使用时对多种耐药菌的协同或相加作用。
