Antimicrobial activity of Ricinus comunis, Swietenia mahogani and Crusentia cujete ethanol extracts against multidrug resistant pathogens, recovered from a hospital environment

Abstract

Medicinal plants have been used as effective approaches to manage multidrug resistant pathogens, including infectious agents that cause nosocomial infections. This study aimed to investigate the antimicrobial potentials of ethanolic extracts of Ricinus comunis, Swietenia mahogani and Crusentia cujete against five multidrug resistant nosocomial pathogens namely; Staphylococcus aureus, Pseudomonas sp., Klebsiella sp., Escherichia coli and Candida sp., which were isolated from hospital fomites. Using standard microbiological methods, fomite swab samples from ward beddings and door handles from the casualty, women, and children ward of Dalhatu-Araf Specialist Hospital, Lafia, Nigeria, were assessed. A total of 251 microbial isolates, consisting of 8 bacterial and 6 fungal genera were recovered. The highest frequency of microbial pathogens was recorded in the casualty unit (98[39%]), followed by the women’s unit (90[36%]), while the children’s ward (63[25%]) was the least contaminated. S. aureus (25[42%]) and Aspergillus sp. (43[72%]) were the most isolated bacteria and fungi; respectively, while Salmonella sp. (7[12%]) and Trichoderma sp. (9[15%]) were the least isolated. However, there were no significantly statistical differences across wards and microbial isolates. The five selected isolates were tested for in vitro susceptibility against several standard antibiotics to check their multiple drug resistance. The tested microorganisms exhibited various levels of multidrug resistance patterns except for Candida sp. which was resistant to two classes of antibiotics (azole group and griseofulvin). On the other hand, Klebsiella sp. was resistant to eight antibiotics of four classes. The ethanolic leaf extract of C. cujete was more effective against all the selected microbial pathogens, while the bark extract of S. mahogani was substantially effective. R. comunis exhibited no inhibitory potential against any of the tested pathogens. All the plant extracts were not as effective against the tested microorganisms as the conventional antibiotics that were used as positive controls. Results obtained indicate the risk of nosocomial infections caused by multidrug resistant pathogens originating from the hospital environment. Good hygienic practices, public awareness on nosocomial infections and further research into ethnomedicine are hereby recommended.