Determination of the Antibacterial Activity against Microorganism after Co-culture with Resistant Pathogenic Bacteria

Abstract

In this study the effect of the antibacterial activity was determined after co-culture of sensitive strain with resistant pathogenic bacteria. Disc diffusion method was used to find out the antibacterial activity after co-culture of sensitive strain with resistant pathogenic bacteria. Here, co-culture was performed with Acinetobacter baumannii and Salmonella typhi and also with Acinetobacter baumannii and Shigella flexneri. In our study, before co-culture Acinetobacter baumannii and Salmonella typhi were sensitive strains, whereas Shigella flexneri was resistant. After co-culture of two sensitive strains (Acinetobacter baumannii and Salmonella typhi), Acinetobacter baumannii showed sensitivity when treated with different concentrations (20 μg/ml, 40 μg/ml, 80 μg/ml and 160 μg/ml) of cefixime. However, no zone of inhibition was observed when Salmonella typhi was treated with different concentrations (20 μg/ml, 40 μg/ml, 80 μg/ml and 160 μg/ml) of cefixime. Co-culture of sensitive Acinetobacter baumanniiwas done with resistant Shigella flexneri. Acinetobacter baumanniis till showed sensitivity when treated with different concentrations (20 μg/ml, 40 μg/ml, 80 μg/ml and 160 μg/ml) of azithromycin. However, zone diameter was reduced to 25% when treated with azithromycin after co-culture with resistant strain of Shigella flexneri. No zone of inhibition was observed when Shigella flexneri was treated with different concentrations (20μg/ml, 40μg/ml, 80μg/ml and 160μg/ml) of azithromycin. Sensitive strain of Acinetobacter baumannii has shown 25% reduction of zone of inhibition when co-culture was done with Shigella flexneri.