Antimicrobial Activity of Nigella sativa Seeds Extracts Against Carbapenem and Colistin Resistant Gram Negative Bacilli in Khartoum State

Abstract

Introduction: One of the most serious issues in medicine is increasing resistance of Gram negative bacilli to antimicrobial agents especially broad spectrum antibiotics such as carbapenems and colistins. This fact is associated with higher mortality and morbidity rates, prolonged hospital stays and increased treatment related costs.Medicinal plants appeared to be the best alternative source for new antimicrobial drugs.. Nigella sativa is an herbaceous plant whose seeds have beenused for centuries for treatment of various ailments, including infectious diseases, and is an important drug of Unani Medicine Narrated Abu Hurairah, “I heard Allah’s Apostle saying, ‘There is healing in black cumin for all diseases except death’.” Objective: This study aimedto detect antibacterial Activity of Nigella sativa extract against carbapenem and colistin resistant gram negative bacilli from Khartoum State Method: Cross-sectional study and laboratory based study was carried out on 90 isolates from different specimenninety types of pathogenic bacteria were isolated and identified using Gram stain, biochemical reactions and tested for their susceptibility to Carbapenem and colistin antibiotic was performed for all Gram-negative bacilli isolates, then detection of carbapenemase enzyme production for the resistant isolates was performed using modified Hodge test and EDTA combing test. Those were resistant to carbapenem and colistin were tested for their sensitivity to Nigellasativa extracts. Result: The isolated Gram-negative bacilli comprising of 41(45.6%)E.coli, 25 (27.8%) Klebsiella species, 14(15.6%)Proteus species, 4(4.4%) Pseudomonas species, 3(3.3%) Enterobacter species and 3(3.3%) Citrobacter species. . Carbapenem (Imipenem and meropenem) susceptibility testing showed that 31% of Gram-negative rods isolates were Carbapenem resistant. Modified hodge test positive result (63%) EDTA combing test positive result(69%). Colistin susceptibility testing showed that 16.7% of Gram-negative rods isolates were Colistin resistant. Methanol extractof Nigella sativa showed antibacterial activity all clinical isolates with highest effect in concentration 50.