Study of Combination Regimens of Anti-Amoebic Drugs for the Treatment of Amoebic Dysentery Caused by E. histolytica

Abstract

Entamoeba histolytica is the etiological agent of amoebic dysentery and amoebic liver abscess. Amoebiasis is one of the most common health problems in the developing countries. Almost 50 million people each year are infected by Amoebiasis. Poverty, ignorance, overcrowding, poor sanitation and malnutrition favor transmission and increase disease burden. The objective of the study is to determine the sensitivity of the combination regimens of anti-amoebic drugs against clinical isolates of E. histolytica. The clinical isolates of E. histolytica were treated with metronidazole, ornidazole, metronidazole+ornidazole, secnidazole, metronidazole + secnidazole, tinidazole, and metronidazole+tinidazole at different concentrations (12, 6, 3 &1.5 mg/ml). Drug sensitivity assay of the samples was carried out by using microtiter plates containing 50 μl of parasite suspension (3×106 parasites/ml). Plates were incubated at 37ºC. After 4 hours the viable parasites were counted by haemocytometer under microscope. Viable counts of the E. histolytica in each concentration of drugs were compared to the control. Result showed that combination of metronidazole and ornidazole (1.5 mg/ml) inhibit the growth of E histolytica and it has found significantly different when compared with the control (p<0.05). Combination of tinidazole and metronidazole at the concentration of 6 and 12mg/ml has also found statistically significant (p<0.05) to inhibit the growth of E. histolytica when compared with the control. At the concentration of 3 mg/ml, only tinidazole was significantly different when compared with the control to inhibit the growth of E histolytica. We conclude that treatment with combination drugs may be a useful alternative to inhibit the growth of E. histolytica. Prior to the clinical study, further study is needed to explore different combinations of drugs at different concentrations and time intervals to determine the in vitro sensitivity against E. histolytica isolates.