Dinoponera quadriceps venom as a source of active agents against Staphylococcus aureus (original) (raw)
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Aims: Dinoponera quadriceps venom (DqV) was examined to evaluate the antibacterial activity and its bactericidal action mechanism against Staphylococcus aureus. Methods and Results: DqV was tested against a standard strain of methicillin-sensitive Staphylococcus aureus (MSSA), Staph. aureus ATCC 6538P and two standard strains of methicillin-resistant Staphylococcus aureus (MRSA), Staph. aureus ATCC 33591 and Staph. aureus CCBH 5330. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the rate of kill and pH sensitivity of the DqV were determined by microdilution tests. Bactericidal and inhibitory concentrations of DqV were tested to check its action on Staph. aureus membrane permeability and cell morphology. The MIC and MBC of DqV were 6Á25 and 12Á5 lg ml À1 for Staph. aureus ATCC 6538P, 12Á5 and 50 lg ml À1 for Staph. aureus CCBH 5330 and 100 and 100 lg ml À1 for Staph. aureus ATCC 33591, respectively. Complete bacterial growth inhibition was observed after 4 h of incubation with the MBC of DqV. A lowest MIC was observed in alkaline pH. Alteration in membrane permeability was observed through the increase in crystal violet uptake, genetic material release and morphology in atomic force microscopy. Conclusions: The results suggest antibacterial activity of DqV against Staph. aureus and that the venom acts in the cell membrane. Significance and Impact of the Study: Alteration in membrane permeability may be associated with the antimicrobial activity of hymenopteran venoms.
Antiparasitic effect of Dinoponera quadriceps giant ant venom
Toxicon, 2016
Neglected tropical diseases (NTD) are treated with toxic therapy of limited efficacy. Previously, we studied the antimicrobial effect of Dinoponera quadriceps venom (DqV) against bacteria. To continue the study, we report in this short communication the antimicrobial effect of DqV against Leishmania amazonensis and Trypanosoma cruzi. DqV inhibits the promastigote forms of L. amazonensis and all T. cruzi developmental forms, with low toxicity in host cells. DqV causes cell death in T. cruzi through necrotic and apoptotic mechanisms observed by staining the cells with annexin V-FITC (AX) and propidium iodide (PI), loss of mitochondrial membrane potential by flow cytometry analyses and confocal microscopy and morphological alterations, such as loss of membrane integrity and cell shrinkage by scanning electron microscopy (SEM). In conclusion, we suggest there is an antimicrobial effect also on parasites.