An aflagellate mutant Yersinia enterocolitica biotype 1A strain displays altered invasion of epithelial cells, persistence in macrophages, and cytokine secretion profiles in vitro.
Despite being classically defined as non-pathogenic, there is growing evidence that biotype 1A Yersinia enterocolitica isolates may be aetiological agents of disease in humans. In previous studies, a potential link between motility and the ability of biotype 1A strains to invade cultured epithelial cells was observed. In an attempt to further investigate this finding, a flagella mutant was constructed in a human faecal Y. enterocolitica biotype 1A isolate. The flagella mutation abolished the ability of the strain to invade cultured human epithelial cells, although adherence was not affected. The aflagellate mutant was also attenuated in its ability to survive within cultured macrophages, being cleared after 3 h, whilst the wild-type persisted for 24 h after infection. Examination of cytokine secretion by infected macrophages also suggested that the flagella of biotype 1A strains act as anti-inflammatory agents, decreasing production of tumour necrosis factor (TNF)-alpha whilst increasing secretion of interleukin (IL)-10. Preliminary studies using porcine in vitro organ culture (IVOC) tissue suggested that the flagella mutant was also attenuated in its ability to colonize intestinal tissue.
McNally
Alan
A
Department of Food and Environmental Safety, Veterinary Laboratories Agency, New Haw, Surrey, UK.
La Ragione
Roberto M
RM
Department of Food and Environmental Safety, Veterinary Laboratories Agency, New Haw, Surrey, UK.
Best
Angus
A
Department of Food and Environmental Safety, Veterinary Laboratories Agency, New Haw, Surrey, UK.
Manning
Georgina
G
Department of Food and Environmental Safety, Veterinary Laboratories Agency, New Haw, Surrey, UK.
Newell
Diane G
DG
Department of Food and Environmental Safety, Veterinary Laboratories Agency, New Haw, Surrey, UK.
D000818:Animals; D001422:Bacterial Adhesion; D002460:Cell Line; D003106:Colon / Q000382:microbiology; D015169:Colony Count, Microbial; D016207:Cytokines / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005407:Flagella / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007082:Ileum / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology*; D046529:Microscopy, Electron, Transmission; D009924:Organ Culture Techniques; D013552:Swine; D014774:Virulence / Q000235:genetics*; D015009:Yersinia Infections / Q000382:microbiology*; D015008:Yersinia enterocolitica / Q000235:genetics / Q000254:growth & development* / Q000276:immunology / Q000302:isolation & purification
D016207:Cytokines