Galleria mellonella infection models for the study of bacterial diseases and for antimicrobial drug testing

Figures & data

Table 1. Components of the G. mellonella innate immune response.

a) cellular response
hemocytes	prohemocytes	^Citation5
	plasmatocytes	^Citation5,7
	granular cells	^Citation5,7
	coagulocytes	^Citation5
	spherulocytes	^Citation5
	oenocytoids	^Citation5,43
b) humoral response
opsonins	apolipophorin-III (apoL-III)	^Citation13-15,18-20,121
	peptidoglycan recognition proteins (PGRPs)	^Citation22
	cationic protein 8 (GmCP8)	^Citation23
	hemolin	^Citation25,26
antimicrobial peptides
(AMPs)	lysozyme	^Citation27,29,41,70
	cecropin	^Citation27,30,61,89
	moricin-like peptides	^Citation27,31
	gloverin	^Citation22,27,34,89
	galiomycin	^Citation27,70
	gallerimycin	^Citation27,35,70
	Galleria defensin	^Citation27,28,33,41
	Gm proline-rich peptides 1 and 2	^Citation27,33,41
	Gm anionic peptide 1 and 2	^Citation27,29,33,41
	inducible serine protease inhibitor 2	^Citation27
	heliocin-like peptide	^Citation27
	x-tox	^Citation27,36
	Gm apolipophoricin	^Citation33
melanization	phenoloxidase pathway	^Citation37-39,122

Figure 1. Photographic images of G. mellonella larvae. A: Image of a healthy G. mellonella last instar larvae with a typical creamy color and a size of 2 to 2.5 cm. B: Images of infected larvae showing different stages of disease. Melanization, which comprises the synthesis and deposition of melanin to encapsulate pathogens at the wound site followed by hemolymph coagulation and opsonization typically starts with distinctive black spots on the cream colored larvae (third image from left). Complete melanization (black larvae, left image) correlates with death of the larvae soon after. A decrease in cocoon formation can also be used as a marker for disease in G. mellonella larvae (right image) The numbers on the bottom of Fig. 1B are the health index scores (see also Table 2).

Table 2. The G. mellonella Health Index Scoring System.⁴⁹

Category	Description	Score
activity	no movement	0
	minimal movement on stimulation	1
	move when stimulated	2
	move without stimulation	3
cocoon formation	no cocoon	0
	partial cocoon	0.5
	full cocoon	1
melanization	black larvae	0
	black spots on brown larvae	1
	≥3 spots on beige larvae	2
	<3 spots on beige larvae	3
	no melanization	4
survival	dead	0
	alive	2

Browne N, Heelan M, Kavanagh K. An analysis of the structural and functional similarities of insect hemocytes and mammalian phagocytes. Virulence 2013; 4:597-603; PMID:23921374; http://dx.doi.org/10.4161/viru.25906

 PubMed Web of Science ®Google Scholar

Seitz V, Clermont A, Wedde M, Hummel M, Vilcinskas A, Schlatterer K, Podsiadlowski L. Identification of immunorelevant genes from greater wax moth (Galleria mellonella) by a subtractive hybridization approach. Dev Comp Immunol 2003; 27:207-15; PMID:12590972; http://dx.doi.org/10.1016/S0145-305X(02)00097-6

 PubMed Web of Science ®Google Scholar

Kim CH, Shin YP, Noh MY, Jo YH, Han YS, Seong YS, Lee IH. An insect multiligand recognition protein functions as an opsonin for the phagocytosis of microorganisms. J Biol Chem 2010; 285:25243-50; PMID:20519517; http://dx.doi.org/10.1074/jbc.M110.134940

 PubMed Web of Science ®Google Scholar

Brown SE, Howard A, Kasprzak AB, Gordon KH, East PD. A peptidomics study reveals the impressive antimicrobial peptide arsenal of the wax moth Galleria mellonella. Insect Biochem Mol Biol 2009; 39:792-800; PMID:19786100; http://dx.doi.org/10.1016/j.ibmb.2009.09.004

 PubMed Web of Science ®Google Scholar

Cytrynska M, Mak P, Zdybicka-Barabas A, Suder P, Jakubowicz T. Purification and characterization of eight peptides from Galleria mellonella immune hemolymph. Peptides 2007; 28:533-46; PMID:17194500; http://dx.doi.org/10.1016/j.peptides.2006.11.010

 PubMed Web of Science ®Google Scholar

Loh JM, Adenwalla N, Wiles S, Proft T. Galleria mellonella larvae as an infection model for group A streptococcus. Virulence 2013; 4:419-28; PMID:23652836; http://dx.doi.org/10.4161/viru.24930

 PubMed Web of Science ®Google Scholar