title: Galleria mellonella as an in vivo model for assessing the protective activity of probiotics against gastrointestinal bacterial pathogens.
abstract: The antagonistic activity against gastrointestinal bacterial pathogens is an important property of probiotic bacteria and a desirable feature for pre-selection of novel strains with probiotic potential. Pre-screening of candidate probiotics for antibacterial activity should be based on in vitro and in vivo tests. This study investigated whether the protective activity of probiotic bacteria against gastrointestinal bacterial pathogens can be evaluated using Galleria mellonella larvae as an in vivo model. Larvae were pre-inoculated with either of two widely used probiotic bacteria, Lactobacillus rhamnosus GG or Clostridium butyricum Miyairi 588, and then challenged with Salmonella enterica Typhimurium, enteropathogenic Escherichia coli or Listeria monocytogenes. Survival rates increased in the probiotic pretreated larvae compared with control larvae inoculated with pathogens only. The hemocyte density increased as well in the probiotic pretreated larvae, indicating that both probiotics induce an immune response in the larvae. The antibacterial activity of probiotics against the pathogens was also assayed by an in vitro agar spot test: results were partially consistent with those obtained by the G. mellonella protection assay. The results obtained, as a whole, suggest that G. mellonella larvae are a potentially useful in vivo model that can complement in vitro assays for pre-screening of candidate probiotics.
authors.affiliation: Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Scalfaro
authors.affiliation: Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Iacobino
authors.affiliation: Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Nardis
authors.affiliation: Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Franciosa
mesh_terms: D000818:Animals; D000898:Antibiosis; D001422:Bacterial Adhesion; D046972:Clostridium butyricum / Q000502:physiology*; D003470:Culture Media; D054308:Enteropathogenic Escherichia coli / Q000472:pathogenicity / Q000502:physiology; D041981:Gastrointestinal Tract / Q000382:microbiology; D006434:Hemocytes / Q000502:physiology; D052201:Lacticaseibacillus rhamnosus / Q000502:physiology*; D007814:Larva / Q000382:microbiology; D008089:Listeria monocytogenes / Q000502:physiology*; D023421:Models, Animal; D009036:Moths / Q000382:microbiology*; D019936:Probiotics; D012486:Salmonella typhimurium / Q000502:physiology
chemical_list: D003470:Culture Media
keywords: Galleria mellonella; gastrointestinal pathogens; in vitro antibacterial activity; in vivo protection assay; probiotic bacteria