Integrated Computational and In Vitro Evaluation of Azadirachta indica Leaf Extract against Multi-drug Resistant Citrobacter koseri and Staphylococcus saprophyticus: An Attempt for Antibacterial Drug Development

Azadirachta indica is well-known for its therapeutic potential against bacteria, while Staphylococcus saprophyticus and Citrobacter koseri are significant public health threats due to their potential to cause skin infections. This study aims to identify phytocompounds from the methanolic extract of A. indica leaves and evaluate their efficacy to inhibit those bacteria through in vitro and computational approaches. The bacteria were isolated from boil-derived human pus samples. The samples were inoculated for enrichment in diluted tryptic soy broth for four hours and then streaked on tryptic soy agar and incubated at 37 C for 24 hours. To verify the species of the selected colonies, 16S rDNA amplification was conducted via polymerase chain reaction using a previously published method. A QIA quick PCR purified kit was used to purify the amplified products following the protocol of the manufacturer. The purified products were sent to Macrogen Inc., South Korea, for amplicon sequencing according to the Sanger sequencing method, and the nucleotide sequences of the samples were compared with the basic local alignment tool to confirm the species of the bacteria. The MEGA software was used to align and construct a dendrogram with the sequences of other organisms, which presented the greatest degree of similarity. Following the identification of the isolates, the efficacy of the plant extract and antibiotics was assessed.