In vitro susceptibility of drug-resistant fungi and urinary bacteria to Psidium guajava L. leaf extract

Abstract

Drug-resistant pathogens are responsible for high mortality and morbidity rates. Plant remedies are known to treat microbial infections.  This research was aimed to determine the susceptibility of drug-resistant fungi (Candida albicans) and bacteria (Staphylococcus aureus and  Escherichia coli) responsible for candidiasis and urinary tract infection to Psidium guajava L. leaf extracts. The P. guajava leaves were  subjected to extraction using two solvents (methanol and ethanol) with varied polarity and concentrated with a rotary evaporator. Qualitative phytochemical screening of the extracts was done. Antimicrobial susceptibility testing was done to identify the resistant  pathogens. The antimicrobial effect of the extracts was established using the agar-well diffusion method at a given concentration. The  methanol and ethanol extracts had both phenols but tannins were absent rather. Flavonoids were detected in the ethanol extract. Multi- drug resistance was observed among the pathogens particularly, E.coli. The antibiotics with 100% resistance by the bacterial pathogens  were Amoxicillin and Erythromycin whereas C. albicans showed resistance to Ketoconazole. The extracts of P. guajava L. leaves had an  inhibitory effects against drug-resistant E. coli and C. albicans, whereas S. aureus was resistant to the extracts. The methanol extract had a  higher antibacterial activity with mean±SD zone of inhibition 28.0±1.56 mm and 35.5±2.25 mm against E.coli and C. albicans respectively.  In an in-vitro study with such high susceptibility to methanol extract; it is paramount to consider P. guajava L. leaf as a good  candidate with natural therapeutics against drug-resistant urinary tract infection and candidiasis, an outcome that could necessities  further pharmacological elucidation.