Studies of the action of venom and venom constituents on
Escherichia coli.
The antibacterial activity of honeybee venom (Apis mellifera) ,
three snake venoms (Naja naja sputatrix, Vipera russellii and
Crotalus adamanteus) and the polypeptide melittin (a component of
honeybee venom) was investigated against the gram-negative organism
Escherichia coli.
Minimum inhibitory concentration (MIC) values were determined
and action against proliferating and non-proliferating cells was in
the order: Apis mellifera venom > melittin > Naja naja sputatrix >
Vipera russellii venom > Crotalus adamanteus venom.
Cell lysis was determined by absorbancy changes and was caused
by the more active venoms (Apis mellifera and Naja naja sputatrix)
and melittin.
Alteration of the permeability of the cell envelope of Escherichia
coli cells harvested in mid-log phase was followed principally by
measuring β-galactosidase release from cells. Venom activity
decreased in the same order as MIC above.
Phospholipases A₂ from Apis mellifera and Naja naja sputatrix
venoms, melittin and polymixin B (polypeptide antibiotic) increased
β-galactosidase release. No synergism between the phospholipases A₂
and melittin was seen under the conditions employed.
Separation of Apis mellifera and Naja naja sputatrix venoms
was carried out by gel filtration and electrophoresis. The action
of venom components implies that the antibacterial activity of whole
venom is not totally accounted for by that of the venom polypeptide
toxins melittin or direct lytic factor (DLF).
That the antibacterial activity of Apis mellifera and Naja naja sputatrix venoms and melittin is due at least in part to
membrane disruption is supported by electron microscopy studies
