Food quality affects the expression of antimicrobial peptide genes upon simulated parasite attack in the larvae of greater wax moth

Abstract

Predator‐prey interactions are an important evolutionary force affecting the immunity of the prey. Parasitoids and mites pierce the cuticle of their prey, which respond by activating their immune system against predatory attacks. Immunity is a costly function for the organism, as it often competes with other life‐history traits for limited nutrients. We tested whether the expression of antimicrobial peptides (AMP) of the larvae of the greater wax moth Galleria mellonella (L.) (Lepidoptera: Pyralidae) changes as a consequence of insertion of a nylon monofilament, which acts like a synthetic parasite. The treatment was done for larvae grown on a high‐quality vs. a low‐quality diet. The expression of Gloverin and 6‐tox were upregulated in response to the insertion of the nylon monofilament. The expression of 6‐tox, Cecropin‐D, and Gallerimycin were significantly higher in the ‘low‐quality diet’ group than in the ‘high‐quality diet’ group. As food quality seems to affect AMP gene expression in G. mellonella larvae, it should always be controlled for in studies on bacterial and fungal infections in G. mellonella.

Oxytetracycline reduces the diversity of tetracycline-resistance genes in the Galleria mellonella gut microbiome

“…The strains were oxytetracycline-sensitive. The presence of such isolates is consistent with previous studies, showing that Galleria mellonella is a monoxenic insect associated with Enterococcus species [12, 13, 16]. When assayed for antibiotic susceptibility, the strain is normally resistant to β-lactam antibiotics and susceptible to tetracyclines [15].…”

“…The strain has no role in insect digestion [14], but together with the host provides colonisation resistance against invading pathogens [15]. However, it is important to appreciate that diet diversity has an effect on gut microbiome composition [16], as well as other parameters, such as expression of some stress-related genes and antimicrobial peptide genes [17].…”

A Diet with Amikacin Changes the Bacteriobiome and the Physiological State of Galleria mellonella and Causes Its Resistance to Bacillus thuringiensis

“…The moth microbiota is mainly composed of bacteria belonging to the phylum Firmicutes; these typically are different species of Gram-positive Enterococci (E. faecalis, E. mundtii, E. innessi, etc.) [12,[28][29][30][31][32]. Enterococci can produce a variety of antimicrobial peptides that help suppress gut infections [4,33]; gut Firmicutes are known to have a general ability to degrade insecticides [20,34].…”

Effect of an antibiotic on gut microbiota and activity of digestive and antioxidant enzymes of Galleria mellonella

“…Микрофлора кишечника вощинной огнёвки представлена преимущественно бактериями Enterococcus ssp. (Firmicutes, Enterococcaceae) и Enterobacteria (Proteobacteria, Enterobacteriaceae) [Krams et al, 2017;Polenogova et al, 2019]. Зачастую, энтерококки ассоциируются с продукцией противомикробных пептидов, необходимых для подавления развития различных инфекций [Hammer, Moran, 2019] и снижения «интенсивности» токсикозов [Zhang et al, 2022].…”