Electronic Theses and Dissertation

Resistensi Methicillin Resistant Staphylococcus aureus (MRSA) terhadap antibiotik β-laktam disebabkan oleh ekspresi gen mecA yang mengkode PBP2a. Penelitian ini bertujuan untuk mengetahui kemampuan ekstrak etanol daun kari (Murraya koenigii (L.) Spreng) dan bakteri endofitnya sebagai antibakteri MRSA. Ekstraksi dilakukan dengan metode maserasi menggunakan etanol 70% dan menghasilkan rendemen sebesar 4,5%. Aktivitas antibakteri dilakukan dengan metode difusi agar. Hasil penelitian menunjukkan bahwa terdapat 17 isolat bakteri endofit yang berhasil
diisolasi. Ekstrak etanol daun kari memiliki kemampuan antibakteri MRSA yang lebih kuat dibandingkan dengan bakteri endofitnya, dengan nilai MIC berada pada konsentrasi 12,5%. Hasil analisis GC-MS menunjukkan terdapat 38 jenis senyawa fitokimia pada ekstrak etanol daun kari dengan senyawa dominan dehydroacetic acid (asam dehidroacetat). Dehydroacetic acid menunjukkan potensi antibakteri MRSA yang lebih kuat dibandingkan metyl salicylate karena memiliki lebih banyak ikatan hidrogen serta posisi pengikatan yang tumpang tindih dengan ligan kontrol pada sisi aktif protein PBP2a berdasarkan analisis molecular docking in silico.
Kata kunci: Daun kari, bakteri endofit, MRSA, antibakteri, MIC

Methicillin-Resistant Staphylococcus aureus (MRSA) resistance to β-lactam antibiotics is caused by the expression of the mecA gene encoding PBP2a. This study aims to determine the ability of ethanol extract of curry leaves (Murraya koenigii (L.) Spreng) and its endophytic bacteria as antibacterials against MRSA. Extraction was carried out using the maceration method using 70% ethanol and produced a yield of 4.5%. Antibacterial activity was determined using the agar diffusion method. The results showed that 17 endophytic bacterial isolates were successfully isolated. The ethanol extract of curry leaves had a stronger antibacterial ability against MRSA compared to its endophytic bacteria, with an MIC value at a concentration of 12.5%. The results of GC-MS analysis showed that there were 38 types of phytochemical compounds in the ethanol extract of curry leaves with the dominant compound being dehydroacetic acid. Dehydroacetic acid shows stronger antibacterial potential against MRSA than methyl salicylate because it has more hydrogen bonds and overlapping binding positions with the control ligand on the active site of the PBP2a protein based on in silico molecular docking analysis. Keywords: Curry leaves, endophytic bacteria, MRSA, antibacterial, MIC