Microbial sensitivity detection to greater wax moth' larvae extracts and their excrements

The aim of research is to study the synergistic properties of antibiotics and G. mellonella products. The objects of the study were solutions made from the larvae of the large wax moth and their waste products in different concentrations. A conditionally pathogenic microflora, Escherichia coli, was sown on a nutrient medium (meat-peptone agar) using a disk-diffusion method. The study was carried out in vitro, microorganisms were cultivated in a thermostat at + 28–37º С, the study of the growth of colonies of microorganisms was assessed after 24 hours. Discs with antibiotics (cefazolin, erythromycin, penicillin, levomycin, doxycycline, etc.) were added to the infected medium with E. coli. Each Petri dish contained 4 discs with different antibiotics. Various solutions were added to the disk: an aqueous extract from G. mellonella larvae, light and heavy fractions isolated from the waste products of these larvae in a volume of 0.01 ml. The results showed that the area of inhibition of a 15% solution of the light fraction of waste products is, on average, 2–2.5 times larger with all antibiotics (at P ≤ 0.001), with the exception of erythromycin. In this experiment, a high degree of synergy was noted in terms of the area of inhibition with 15% solutions of light and heavy fractions of waste products. The culture of microorganisms used showed a high degree of resistance to erythromycin, penicillin, lincomycin. In this regard, further study of these antibiotics was impractical, they were excluded from the experiment. It has been proven that the waste products of G. mellonella larvae weaken the antibiotic resistance of E. coli and enhance the effect of a number of antibiotics (levomycytin, enrofloxacin, gentamicin, doxycycline). The aqueous extract of the larvae of the larger wax moth showed no bacterial activity against E. coli.