Investigating the Toxicity of Compounds Yielded by <i>Staphylococci</i> on Vero Cells

Bacterial secondary metabolites play a major role in the alleviation of diseases; however, the cytotoxicity of other metabolites cannot be ignored as such metabolites could be detrimental to human cells. Three <i>Staphylococci</i> strains <i>Staphylococcus aureus</i>, <i&g...

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Bibliographic Details
Main Authors: Margaret Selina Modimola, Ezekiel Green, Patrick Njobeh, Jeremiah Senabe, Gerda Fouche, Lyndy McGaw, Sanah Malomile Nkadimeng, Kgama Mathiba, Julian Mthombeni
Format: Article
Language:English
Published: MDPI AG 2022-10-01
Series:Toxins
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Online Access:https://www.mdpi.com/2072-6651/14/10/712
Description
Summary:Bacterial secondary metabolites play a major role in the alleviation of diseases; however, the cytotoxicity of other metabolites cannot be ignored as such metabolites could be detrimental to human cells. Three <i>Staphylococci</i> strains <i>Staphylococcus aureus</i>, <i>staphylococcus epidermidis</i> and <i>staphylococcus saprophyticus</i> were used in the experiments. These strains are well known to cause hospital and community-acquired infections. Secondary metabolites from <i>S. aureus</i> isolated from milk of cows with clinical features of mastitis (swollen udders and the production of watery clotted milk), S. saprophyticus (ATCC 35552), and S. epidermidis (ATCC 51625) were exposed to a minimal medium then screened using Gas Chromatography High-Resolution Time-of-flight Mass Spectrometry (GC-HRTOF-MS) and identified with Nuclear Magnetic Resonance (NMR). From <i>S. epidermidis</i>, two compounds were isolated: oleamide and methyl palmitate; three from <i>S. aureus,</i> including fluoranthene, 3-methyl-2-phenyl-1H-pyrrole, and cyclo(L-Leu-L-Propyl); while <i>S. saprophyticus</i> yielded succinic acid, 1,2,6-hexantriol, veratramine, and 4-methyl-pentyl-amine. The secondary metabolites were tested for cytotoxicity using the Vero cell line. Fluoranthene exhibited toxicity with an LC<sub>50</sub> of 0.0167 mg/mL to Vero cells, while the other metabolites did not. Methyl palmitate was the least toxic of all of the metabolites. The results imply that none of the compounds, except fluoranthene, pose any danger to human cells.
ISSN:2072-6651