Antibacterial activity of the Acacia nilotica gum against Klebsiella pneumoniae in vitro

Abstract

This study was conducted to study the antibacterial activity of the Acacia nilotica gum aqueous solution. For this purpose the aqueous solution of the Acacia nilotica gum was prepared and studied its chemical constituent and antibacterial activity in vitro against Klebsiella pneumoniae either alone or as a combination with ciprofloxacin by using minimum inhibitory concentration (MIC) and well diffusion method. The results showed that the Arabic gum solution contain different chemical constituents; tannins, flavonoids, saponins, and terpenoids, and the (MIC) was 200mg/ml. The results also showed that the Arabic gum had weak effect against Klebsiella pneumoniae in vitro where the zones were 11.50±0.57, 10.00±1.14, 0.00±0.00 and 0.00±0.00mm at 400mg/ml 200mg/ml 100mg/ml and 50mg/ml respectively, which are significantly (P<0.05) less than those of ciprofloxacin that were 24.00±0.89, 18.30±0.94, 13.00±0.35 and 11.20±1.01 at 2µg, 1µg, 0.5µg and 0.25µg respectively. In concern to the combination (Arabic gum +ciprofloxacin), the resulted zones were less than those obtained from ciprofloxacin alone which were 21.00±1.03, 17.70±1.31, 12.00±0.89 and10.00±0.94 with significant difference just at doubled MIC. In conclusion, the Acacia nilotica gum aqueous solution had weak effect against Klebsiella pneumoniae in vitro with no synergistic effect with ciprofloxacin.