Research News
Salmonella typhimurium cells. Photo: Manfred Rohde/HZI
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Pressinfo Helmholtz-Zentrum für Infektionsforschung 'Salmonellen infizieren nicht nach Schema F'
Salmonella Strategy
Scientists from the Helmholtz Centre for Infection Research (HZI) in Braunschweig have discovered a hitherto unknown infection mechanism employed by salmonella when entering into intestinal cells: They let themselves be drawn into these cells via special fibres of their host cells, almost as if by muscle power.
The host cell's actin cytoskeleton forming thin filament structures, that mechanically stabilise the cell and at the same time allow cell motility, plays a part in the event of a salmonella infection. The most important element in the formation of actin filaments is the so-called Arp2/3 complex. In the case of the hitherto known path of infection, salmonella use the Arp2/3 complex to invade the host cell.
In the newly discovered path of infection the salmonella use the actin cytoskeleton of the host cell and profit from the reciprocal effect between actin filaments and the motor protein myosin II. Actin and myosin form filaments connected to the cell surface and which during an infection probably simply pull the bacteria inside. This is another way for the salmonella to reach its goal – the cell interior. This diversity in possible infection mechanisms possibly is the reason why the number of salmonella infections has been increasing for years now, according to the WHO, and why in addition to humans animals also can be affected.
