In Vitro Antimicrobial Activity of Piper retrofractum Fruit Extracts against Microbial Pathogens Causing Infections in Human and Animals.

Wattana Panphut,Tanakwan Budsabun,Pakkakul Sangsuriya

doi:10.1155/2020/5638961

Abstract

Long pepper (Piper retrofractum Vahl) is a Thai medicinal herb which has been used as one of the common ingredients in variety of Thai foods. Here, we investigated antimicrobial activities of crude bioactive metabolites extracted from fruits of P. retrofractum against 10 pathogenic organisms (bacteria and yeast) causing opportunistic infections in human or animals including Bacillus subtilis ATCC6633, Staphylococcus aureus ATCC25923, Enterococcus faecalis ATCC2921, Escherichia coli ATCC25922, Klebsiella pneumonia TISTR1843, Pseudomonas aeruginosa ATCC741, Salmonella typhi (clinical isolate), Vibrio parahaemolyticus (XN98 and 5HP), and Candida albicans ATCC90020. The results of disk diffusion test showed that the extract from methanol solvent exhibited greater antibacterial activity than other solvents with inhibition zones ranging from 0.5 to 8.0 mm, respectively. Subsequently, minimal inhibition concentration (MIC) determined by the colorimetric assay confirmed that methanol extracts showed consistent results with disk diffusion method. In summary, in vitro assays suggest that methanol is the best solvent for extraction of bioactive metabolites from P. retrofractum fruits. This crude extract can inhibit the majority of human and animal pathogens. This opens up a potential use of pepper fruits in prevention of food-contaminating microorganisms.

Highlights

Drug resistance of infectious microorganisms has been reported worldwide [1]. e most prevalent resistant species are the methicillin-resistant Staphylococcus aureus (MRSA), the extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, and multi-drug resistant Pseudomonas aeruginosa [2]
Microbial Cultures. e bacteria and fungi selected for this study are mostly human pathogens: Gram-positive bacteria, Bacillus subtilis ATCC6633, Enterococcus faecalis ATCC2921, and Staphylococcus aureus ATCC25923; Gramnegative bacteria, Pseudomonas aeruginosa ATCC741, Klebsiella pneumonia TISTR1843, Escherichia coli ATCC25922, Salmonella typhi, Vibrio parahaemolyticus (5HP and XN89), and yeast Candida albicans ATCC90020. e culture collections obtained from Suan Sunandha Rajabhat University and two V. parahaemolyticus isolates were kindly provided by Center for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Mahidol University, ailand
Agar media were poured into the plates to uniform depth of 5 mm and allowed to solidify. e microbial suspensions were prepared by spectrophotometer using culture broth with adding sufficient sterile medium to adjust the transmittance to that produced by a 0.5 McFarland standard match to an optical density (OD) 0.1 at 625 nm wavelength. is procedure will yield bacterial stock suspension 1 × 108 cfu/ml and yeast stock suspension of 1 × 106 to 5 × 106 cfu/ml. e microbial suspension was streaked over the surface of media using a sterile cotton swab to ensure the confluent growth of the organism. e disks used

Summary

Introduction

Drug resistance of infectious microorganisms has been reported worldwide [1]. e most prevalent resistant species are the methicillin-resistant Staphylococcus aureus (MRSA), the extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, and multi-drug resistant Pseudomonas aeruginosa [2]. The consumption of food-contaminating microorganisms, such as Enterococcus faecalis, Escherichia coli, Salmonella typhi, and Vibrio parahaemolyticus, can pose a serious threat to human health. E existence of these microorganisms causes spoilage and often a food-borne disease [3]. Candidiasis is a fungal infection caused by Candida albicans that can affect areas such as skin, genitals, throat, mouth, and blood circulation system. It is caused by the overgrowth of C. albicans [4]. Infection of V. parahaemolyticus causes acute hepatopancreatic necrosis disease (AHPND) in cultivated shrimp farm [6]. E disease spread rapidly and caused significant losses in Southeast Asian shrimp farms since 2009 [7] Infection of V. parahaemolyticus causes acute hepatopancreatic necrosis disease (AHPND) in cultivated shrimp farm [6]. e disease spread rapidly and caused significant losses in Southeast Asian shrimp farms since 2009 [7]

Methods

Results

Conclusion