Content of glycogen and trehalose and activity of alpha-amylase and trehalase in Galleria mellonella larvae infected with entomopathogenic nematodes Steinernema affinis and S. feltiae

Introduction. The influence of infection with two species of entomopathogenic nematodes of Steinernematidae family on metabolism of glycogen and trehalose of the host was studied. Material and methods. Last instar larvae (L₇) of Galleria mellonella were experimentally infected with Steinernema affinis and S. feltiae. At 6, 12, 18 and 24 h after infection concentrations of trehalose and glycogen as well as activity of trehalase and α-amylase were determined. Results. The content of glycogen was lower in insects infected with S. feltiae than in the controls and animals infected with S. affinis. The content of trehalose was higher in insects from both infected groups than in the controls. Its concentration was slightly higher in larvae infected with S. affinis than in those infected with S. feltiae. The activity of α-amylase after infection with S. affinis was low. It was significantly higher in insects infected with S. feltiae. In animals of both infected groups, following a significant reduction at 6 h, the activity of trehalase remained at a similar level, higher than in the controls. In the paper the effects of infection with (i) different species of entomopathogenic nematodes and (ii) the importance of the developmental stage of the insect-host for changes in its metabolism of glycogen and trehalose were discussed

The activity of hydrolases of larval stages of Anisakis simplex [Nematoda]

Activity of hydrolases during the third and fourth larval stage of Anisakis simplex was identified by applying the API ZYM test method. In A. simplex larvae the activity of phosphatases was high, particularly that of acid phosphatase (40 nmol/mg-'). Among esterases lack of activity of lipase (Cj 4) is worth noticing while the activity of esterases (C4) and (Cg) was high. The activity of those later two enzymes was higher in L larvae than in Ly larvae. The highest activity in the subclass of glucosidases was recorded for B-fucosidase and N-acetyl-B-glucosaminidase. A higher activity in L3 larvae than in Ly larvae was recorded for: B-glucuronidase and N-acetyl-B-glucosaminidase (2-fold) and B-fucosidase (3-fold). Differently the activity of B-galactosidase and B-glucosidase was higher in L4 larvae than in L3 larvae. The tests did not show activity of o-galactosidase, 8-glucosidase and amannosidase on both larval forms

Activity of superoxide dismutase in Galleria mellonella larvae infected with entomopathogenic nematodes Steinernema affinis and S. feltiae

Background. The influence of infection with two species of entomopathogenic nematodes of Steinernematidae family on the activity of superoxide dismutase (SOD) of the host was studied. Material and methods. Last instar larvae of Galleria mellonella were experimentally infected with Steinernema affinis and S. feltiae at 20 invasive juveniles per insect. At 6, 12, 18, 24 and 36 h after infection activity of SOD was determined in extracts from infected and control insects. Results. The activity of SOD decreased gradually in the controls during the experiment. The activity of enzyme was 2-4-times higher in insects from both infected groups than in the control. During the first 12 h of infection the activity of SOD in insects infected with S. feltiae was higher than in those infected with S. affinis, then the activity of enzyme in the insects of both infected groups stayed at a similar level. A significant decrease of SOD activity in infected was recorded in second day of the infection