Potency and selectivity indices of acetone leaf extracts of nine selected South African trees against six opportunistic Enterobacteriaceae isolates from commercial chicken eggs. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Elisha, Ishaku; Jambalang, Alexander; Botha, Francien; Buys, Elna; McGaw, Lyndy; Eloff, Jacobus
• Is Part Of: BMC complementary and alternative medicine. Volume 17:Issue 1(2017)
• Page Start: 1
• Page End: 8
• Publication Date: 2017-12
• Subjects: Antimicrobial -- Plant extracts -- Nosocomial -- Opportunistic pathogens -- Hens' egg isolates; Alternative medicine -- Periodicals; Complementary Therapies -- Periodicals; 615.505
• DOI: 10.1186/s12906-017-1597-3
• Languages: English
• ISSNs: 1472-6882

Abstract

Abstract Background The rise in antimicrobial resistance in a plethora of nosocomial and opportunistic bacterial pathogens often isolated from commercial eggs, poses a serious public health concern. The existence of these contaminants may also serve as a drawback in the current efforts of improving the well-being of immunocompromised patients. The aim of this study was to determine the efficacy of plant extracts that had good activity onEscherichia coli in previous word on pathogens isolated from eggs for possible use in combating pathogens from eggs. Methods Acetone leaf extracts of nine trees with good activities againstEscherichia coli were tested for their in vitro antibacterial activity against six opportunistic bacterial isolates from commercial eggs (Stenotrophomonas maltophilia, Klebsiella pneumoniae, Salmonella serotype Typhimurium, Proteus mirabilis, Enterobacter cloacae andEscherichia coli) using a serial microdilution method with tetrazolium violet as indicator of growth. Cytotoxicity was determined using a tetrazolium-based colorimetric assay against Vero kidney cells, and selectivity index calculated. Results The MIC values range of the different extracts againstStenotrophomonas maltophilia was 0.08-0.31 mg/ml, Klebsiella pneumonia 0.08-0.63 mg/ml, Salmonella ser. Typhimurium 0.08-0.63 mg/ml, Proteus mirabilis 0.02-1.25 mg/ml, Enterobacter cloacae 0.08-0.31 mg/ml andEscherichia coli 0.08-0.16 mg/ml respectively.Escherichia coli was the most sensitive whileProteus mirabilis was most resistant pathogen to the different test extracts, with mean MIC values of 0.08 mg/ml and 0.46 mg/ml respectively.Cremaspora triflora extracts had good activity against all the pathogenic egg isolates, with the exception ofProteus mirabilis. Maesa lanceolata andElaeodendron croceum had the best total antibacterial activity (TAA), while generally the selectivity index of the extract was low (SI < 1). Conclusion The exceptional activity ofC. triflora extracts suggests that the plant has potential as a therapeutic agent against some members of the Enterobacteriaceae. Further pharmacological investigations may be interesting in the search for new antimicrobial leads.