A pilot study on antimicrobial activity of Psidium guajava leaf extracts against clinical species of Klebsiella pneumoniae

Abhadionmhen, Abel Onolunosen; Obiyan, Omonye Florence; Garba, Timothy Useni; Lana, Omotayo Emerson; Usiabulu, Oreye Queen

doi:10.30502/jhhhm.2025.464148.1094

A pilot study on antimicrobial activity of Psidium guajava leaf extracts against clinical species of Klebsiella pneumoniae

Document Type : Original

Authors

Abel Onolunosen Abhadionmhen ¹

Omonye Florence Obiyan ²

Timothy Useni Garba ²

Omotayo Emerson Lana ³

Oreye Queen Usiabulu ⁴

¹ Department of Microbiology, Federal University Wukari, Taraba State, Nigeria.; Tropical Disease Unit, Department of Microbiology, Federal University Wukari, Taraba State, Nigeria.

² Department of Microbiology, Federal University Wukari, Taraba State, Nigeria.

³ Department of Public Health, Teesside University, Middlesbrough, United Kingdom.

⁴ Department of Public Health, University of Bedsfordshire, United Kingdom.

10.30502/jhhhm.2025.464148.1094

Abstract

Background and Objective: Recurrent asymptomatic urinary tract infections caused by Klebsiella pneumoniae highlight the need for alternative treatments due to increasing antimicrobial resistance. This study aimed to isolate Klebsiella pneumoniae and evaluate the potential of Psidium guajava leaf extracts as a natural treatment for these infections.
Materials and Methods: Aqueous extracts of Psidium guajava were prepared at concentrations of 0.025, 0.05, 0.1, and 0.2 mg/ml from both dried and fresh leaves. Mid-stream urine samples were collected from presumed healthy individuals. Microbiological and biochemical analyses were conducted on the samples. Antimicrobial activity was assessed using the agar well diffusion method, with Klebsiella pneumoniae ATCC 13883 serving as the reference strain.
Results and Conclusion: Aqueous extraction at higher concentrations enhanced antimicrobial activity. Cold water extracts of fresh leaves showed better inhibition at higher concentrations (total range of 0-10 mm for four extracts), while hot water extracts inhibited Klebsiella pneumoniae in the range of 4-10 mm. Dried leaf extracts were more potent, with inhibition zones of 7–17 mm for cold water and 10-20 mm for hot water, demonstrating the superior efficacy of dried leaves over fresh. Psidium guajava leaf extracts demonstrate antimicrobial potential against Klebsiella pneumoniae, suggesting a promising alternative for urinary tract infections. Further trials are needed to confirm safety, efficacy, and mechanisms of action, offering potential treatment options where conventional antibiotics fail.

Keywords

Antibacterial efficacy

Antimicrobial resistance

Klebsiella pneumoniae

Psidium guajava

Urinary tract infections

Subjects