Modimola, Margaret SelinaGreen, EzekielNjobeh, PatrickSenabe, JeremiahFouche, GerdaMcGaw, Lyndy JoyNkadimeng, Sanah MalomileMathiba, KgamaMthombeni, Julian2023-03-082023-03-082022-10-18Modimola, M.S.; Green, E.; Njobeh, P.; Senabe, J.; Fouche, G.; McGaw, L.; Nkadimeng, S.M.; Mathiba, K.; Mthombeni, J. Investigating the Toxicity of Compounds Yielded by Staphylococci on Vero Cells. Toxins 2022, 14, 712. https://DOI.org/10.3390/toxins14100712.2072-6651 (online)10.3390/toxins14100712https://repository.up.ac.za/handle/2263/90020DATA AVAILABILITY STATEMENT : Part of the data is available on https://uoj-researchportal.esploro. exlibrisgroup.com/esploro/outputs/doctoral/Secondary-metabolites-produced-by-Staphylococcusspecies/9910534007691?institution=27UOJ_INST (accessed on 24 August 2022).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 Staphylococci strains Staphylococcus aureus, staphylococcus epidermidis and staphylococcus saprophyticus were used in the experiments. These strains are well known to cause hospital and community-acquired infections. Secondary metabolites from S. aureus 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 (GCHRTOF- MS) and identified with Nuclear Magnetic Resonance (NMR). From S. epidermidis, two compounds were isolated: oleamide and methyl palmitate; three from S. aureus, including fluoranthene, 3-methyl-2-phenyl-1H-pyrrole, and cyclo(L-Leu-L-Propyl); while S. saprophyticus 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 LC50 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.en© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Vero cellsCytotoxicFluorantheneMethyl palmitateSecondary metabolitesStaphylococciGas chromatography high-resolution time-of-flight mass spectrometry (GCHRTOF- MS)Nuclear magnetic resonance (NMR)Article