Open AccessCandida albicans increases the pathogenicity of Staphylococcus aureus during polymicrobial infection of Galleria mellonella larvae
Author(s) -
Gerard Sheehan,
Laura Tully,
Kevin Kavanagh
Publication year - 2020
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.352
H-Index - 35
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.000892
Subject(s) - galleria mellonella , staphylococcus aureus , microbiology and biotechnology , biology , candida albicans , hemolymph , immune system , larva , corpus albicans , immunology , bacteria , virulence , biochemistry , genetics , botany , gene
This study detailed the responses of Galleria mellonella larvae to disseminated infection caused by co-infection with Candida albicans and Staphylococcus aureus . Doses of C. albicans (1×10 5 larva -1 ) and S. aureus (1×10 4 larva -1 ) were non-lethal in mono-infection but when combined significantly ( P <0.05) reduced larval survival at 24, 48 and 72 h relative to larvae receiving S. aureus (2×10 4 larva -1 ) alone. Co-infected larvae displayed a significantly higher density of S. aureus larva -1 compared to larvae infected solely with S. aureus . Co-infection resulted in dissemination throughout the host and the appearance of large nodules. Co-infection of larvae with C. albicans and S. aureus (2×10 4 larva -1 ) resulted in an increase in the density of circulating haemocytes compared to that in larvae infected with only S. aureus . Proteomic analysis of co-infected larval haemolymph revealed increased abundance of proteins associated with immune responses to bacterial and fungal infection such as cecropin-A (+45.4-fold), recognition proteins [e.g. peptidoglycan-recognition protein LB (+14-fold)] and proteins associated with nodule formation [e.g. Hdd11 (+33.3-fold)]. A range of proteins were also decreased in abundance following co-infection, including apolipophorin (-62.4-fold), alpha-esterase 45 (-7.7-fold) and serine proteinase (-6.2-fold). Co-infection of larvae resulted in enhanced proliferation of S. aureus compared to mono-infection and an immune response showing many similarities to the innate immune response of mammals to infection. The utility of G. mellonella larvae for studying polymicrobial infection is highlighted.