Abstract. The global spread of multidrug resistance challenges antimicrobial therapy, necessitating the search for alternative approaches. The present study assessed the antimicrobial efficacy of the methanolic leaf extracts of Ipomoea aquatica Forssk. (Kangkong), Eleusine indica (L.) Gaertn. (Paragis), Moreover, its combination at varying concentrations of 25%, 50%, 75%, and 100% against Klebsiella oxytoca using established microbiological techniques. Fifty (50) grams of powdered leaves from the Ipomoea aquatica Forssk. (Kangkong) plant was soaked in 375 mL of 95% methanol for 48 hours (2 days) with intermittent stirring— similarly, 50 grams of Eleusine indica (L.) Gaertn. (Paragis) were processed using the same method. The macerated powdered leaf samples were filtered using a Whatman filter paper No. 1 and extracted using a rotary evaporator. The obtained extracts were utilized to prepare varying concentrations of 25%, 50%, 75%, and 100% of methanolic leaf extracts for each plant. Positive control (Tigecycline) and negative control (10% DMSO), along with the preparation of extracts, were also prepared. The antimicrobial efficacy of these methanolic leaf extracts at different concentrations and the controls were evaluated against Klebsiella oxytoca using the disk diffusion method. The results obtained indicate that the methanolic leaf extracts of Ipomoea aquatica Forssk. (Kangkong) and Eleusine indica (L.) Gaertn. (Paragis) did not exhibit any inhibitory effects on Klebsiella oxytoca. Both plants' combined methanolic leaf extracts also showed non-inhibitory effects, indicating that Klebsiella oxytoca is resistant to both plant extracts and, thus, did not yield a synergistic effect. This study provides a scientific understanding of the antimicrobial efficacy of the plants' properties. Further investigation is needed to assess alternative extraction and methods to determine the antimicrobial efficacy of the plant extracts.

Keywords: Antimicrobial Efficacy; Eleusine indica; Ipomoea aquatica; Klebsiella oxytoca.