Antimicrobial effect of Dinoponera quadriceps (Hymenoptera: Formicidae) venom against Staphylococcus aureus strains.
OBJECTIVE
Dinoponera quadriceps venom (DqV) was examined to evaluate the antibacterial activity and its bactericidal action mechanism against Staphylococcus aureus.


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 6·25 and 12·5 μg ml(-1) for Staph. aureus ATCC 6538P, 12·5 and 50 μg ml(-1) for Staph. aureus CCBH 5330 and 100 and 100 μg ml(-1) 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.


CONCLUSIONS
Alteration in membrane permeability may be associated with the antimicrobial activity of hymenopteran venoms.
Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Ceara, Fortaleza, Ceara, Brazil.
D B
DB
Lima
A F C
AF
Torres
C P
CP
Mello
R R P P B
RR
de Menezes
T L
TL
Sampaio
J A
JA
Canuto
J J A
JJ
da Silva
V N
VN
Freire
Y P
YP
Quinet
A
A
Havt
H S A
HS
Monteiro
N A P
NA
Nogueira
A M C
AM
Martins
D000818:Animals; D000862:Ant Venoms / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001000:Ants; D013211:Staphylococcus aureus / Q000187:drug effects*
D000862:Ant Venoms; D000900:Anti-Bacterial Agents
Dinoponera quadriceps; Staphylococcus aureus; action mechanism; antimicrobial activity; venoms