Inhibition of Biofilm formation of Imipenem-resistant Acinetobacter baumannii using Curcuma longa extracts, silver nanoparticles and Azithromycin
*Corresponding Author E-mail: firstname.lastname@example.org
Acinetobacter baumannii is opportunistic pathogenic bacteria, as gram-negative aerobic bacteria short rod-shaped (coccobacillus) widely distributed in the water and soil of natural environments which has emerged in recent decades as a global cause of nosocomial infections with high morbidity and mortality.
Material and methods
In current study, were collected different clinical specimens (150) individuals (males and females) at different ages including wounds, burns, blood, and urine. The study was conducted in Baquba Teaching Hospital in Diyala Governorate. Depending on bacteriological characteristics and biochemical tests, in addition to using the API -20E and VITEK-2 Compact kits,14 (9.3%) isolates of Acinetobacter baumannii were identified.
Of infection rates with Acinetobacter baumannii showed no significant difference between male (54.7%) and female patients (45.3%). The isolates were tested for sensitivity to (16) antibiotics using the Kirby-Bauer method, which showed that all isolates were (100%) resistant to Cefotaxime, Augmentin, Ceftriaxone, Cefepime, Ceftazidime, and Piperacillin. The isolates also showed a high resistance rate (92.9%) to Tetracycline and Ciprofloxacin and (85.7%) to Gentamicin and Co-Trimoxazole, while isolates showed a low resistance rate (42.8%) to Imipenem and a high sensitivity rate (85.7%) to Colistin, also our study showed that the (cold and hot) aqueous extracts and the alcoholic extract of Curcuma longa roots had a clear effect on the imipenem-resistant Acinetobacter baumannii at (12.5, 25, 50, 100 and 200)mg/ml concentrations, with inhibition diameters of (0.9, 14, 17 and 22) mm, (0, 8, 12, 15 and 19) mm, (0.9, 12, 13 and 15)mm respectively. The results of determination of MIC and Sub MIC values regarding the inhibitory effect of some substances on bacterial biofilms showed that MIC value for cold aqueous extract of curcuma roots was 6.25mg/ml and the Sub MIC value was 3.13mg/ml, while using the hot aqueous and alcoholic extracts of curcuma roots showed that MIC value for each of them was 12.5mg/ml and that Sub MIC value for each of them was 6.25mg/ml, as well as results also revealed MIC values for silver nanoparticles (AgNPs) against bacterial isolates was 20000μg/ml, and the Sub MIC value was 10,000μg/ml, whereas the MIC value for Azithromycin against bacteria was 512μg/ml, and the Sub MIC value was 256μg/ml. Results of ELISA demonstrated that the Sub MIC of curcuma aqueous and alcoholic extracts and Azithromycin had no effect on biofilm inhibition of A. baumannii bacteria, while using the 20 nm silver nanoparticles (AgNPs) showed biofilm inhibition.
Acinetobacter baumannii, Biofilm, Imipenem, Silver nanoparticles, Azithromycin.