Abstract

In recent times, the increasing resistance of microorganisms to conventional antibiotics is a major public health concern. This has necessitated the search for alternative antimicrobial agents, such as plant extracts. Thus, the most important reason for this research was to investigate the individual and combined effects of aloe vera and garlic as antimicrobial agents against two pathogens, Staphylococcus aureus and Salmonella enterica..

The study involved the collection of samples of Staphylococcus from the nose of three volunteers and samples of Salmonella from fowl dung in three different poultries. Staphylococcus was cultured on Mannitol salt agar (MSA) and sub-cultured on nutrient agar while Salmonella was enriched in selenite F broth, then sub-cultured on Salmonella Shigella agar (SSA).

Gram staining, and biochemical tests (catalase followed by coagulase for Staphylococcus and motility and Triple Sugar Iron (TSI) for Salmonella) were performed to confirm the identity of the microorganisms.

The Kirby-Bauer (agar well diffusion) method was used to determine the ZOI of the plant extracts. Dilutions of 1:2, 1:4, 1:8 and 1:16 were prepared for both water and ethanol extracts individually as well as the combined plant extracts. The ZOI was measured in millimeters and a statistical analysis was performed using the student t-test.

The results indicated that both aloe vera and garlic extract have antibacterial activity against Staphylococcus and Salmonella.

The effectiveness of the extracts varied depending on the concentration and the solvent used for the extraction. In general, garlic extract in ethanol showed the highest activity against both bacteria, with a maximum ZOI of 31mm against Staphylococcus and 23mm against Salmonella.

The combined extract showed reduced effectiveness; In water, the combined extract showed no activity on the 1:8 and 1:16 dilutions against Staphylococcus and very little activity against Salmonella. In ethanol, the combined extracts showed some activity against both bacteria, but not as much as the individual extracts.

Overall, the results suggest that aloe vera and garlic have potential as natural antibacterial agents against S. aureus and S. enterica. These findings could be beneficial in the development of alternative and sustainable methods for controlling bacterial infections, particularly in low-resource settings.

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