A Streptococcus pneumoniae infection model in larvae of the wax moth Galleria mellonella

B A Evans, D E Rozen

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


The bacterium Streptococcus pneumoniae is a leading human opportunistic pathogen. The limitations of the current vaccine have led to increased recognition of the need to understand bacterial behaviour and competitive dynamics using in vivo models of infection. Here, we investigate the potential application of the larvae of the wax moth Galleria mellonella as an informative infection model. Larvae were challenged with a range of doses of S. pneumoniae isolates differing in known virulence factors to determine the LD(50) values. Infection dynamics were determined by obtaining bacterial counts from larvae over a time course. Differences in virulence between serotypes could be distinguished in this host. Infection with strains differing in known virulence factors demonstrated predicted differences in virulence. Acapsulate and pneumolysin-negative strains were less virulent than their respective wild types. A large reduction in virulence was seen in strains lacking cell wall D-alanylation. The mortality of G. mellonella larvae is attributable to bacterial growth within larvae, while surviving larvae are able to clear infections by reducing bacterial numbers. These data demonstrate that G. mellonella larvae represent an in vivo infection model with applications for investigating aspects of bacterial-host interactions such as the role of antimicrobial peptide activity and resistance.

Original languageEnglish
Pages (from-to)2653-2660
Number of pages8
JournalEuropean Journal of Clinical Microbiology & Infectious Diseases
Issue number10
Publication statusPublished - Oct 2012


  • Animals
  • Bacterial Load
  • Bacterial Proteins
  • Disease Models, Animal
  • Genes, Bacterial
  • Host-Pathogen Interactions
  • Larva
  • Lethal Dose 50
  • Moths
  • Pneumococcal Infections
  • Species Specificity
  • Streptococcus pneumoniae
  • Streptolysins
  • Virulence Factors

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