title: Novel model to study virulence determinants of Escherichia coli K1.
abstract: It is shown here for the first time that locusts can be used as a model to study Escherichia coli K1 pathogenesis. E. coli K-12 strain HB101 has very low pathogenicity to locusts and does not invade the locust brain, whereas the injection of 2 x 10(6) E. coli K1 strain RS218 (O18:K1:H7) kills almost 100% of locusts within 72 h and invades the brain within 24 h of injection. Both mortality and invasion of the brain in locusts after injection of E. coli K1 require at least two of the known virulence determinants shown for mammals. Thus, deletion mutants that lack outer membrane protein A or cytotoxic necrotizing factor 1 have reduced abilities to kill locusts and to invade the locust brain compared to the parent E. coli K1. Interestingly, deletion mutants lacking FimH or the NeuDB gene cluster are still able to cause high mortality. It is argued that the likely existence of additional virulence determinants can be investigated in vivo by using this insect system.
authors: Department of Biology, School of Biological and Chemical Sciences, Birkbeck, University of London, London WC1E 7HX, United Kingdom. n.khan@sbc.bbk.ac.uk
authors: Naveed Ahmed
authors: NA
authors: Khan
authors: Graham John
authors: GJ
authors: Goldsworthy
mesh_terms: D000818:Animals; D016470:Bacteremia / Q000382:microbiology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D001812:Blood-Brain Barrier / Q000382:microbiology; D001921:Brain / Q000382:microbiology; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D048168:Escherichia coli K12 / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D048188:Locusta migratoria / Q000382:microbiology*; D008297:Male; D008565:Membrane Proteins; D020814:Meningitis, Escherichia coli / Q000235:genetics / Q000382:microbiology; D037521:Virulence Factors / Q000502:physiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D037521:Virulence Factors; C060296:cytotoxic necrotizing factor type 1; C078167:OMPA outer membrane proteins