New mode of spread of deadly bacteria in food

Microbiologist Professor Keith Ireton of Florida State University has announced an active mechanism that plays an important role in the spread of deadly bacteria in food that had never been known before. .

Listeria monocytogenes is a bacterium that can cause pregnant women to miscarry, causing meningitis in the elderly or people with a weak immune system. The bacterium is linked to an outbreak of disease originating from crops used to produce food in the United States and Canada.

In 2002, outbreaks of listeriosis in many states - a dangerous disease caused by Listeria - confirmed 46 cases of infection, 7 deaths and 3 cases of fetal failure. From January to August 1985, there was another outbreak with 142 cases of listeriosis.

Scientists have long since discovered that Listeria bacteria spread from one cell to another in the human body. Bacteria grow in a cell and move quickly to form a finger-shaped structure that protrudes from the cell and pushes to adjacent cells. Then the bacteria will continue to cause disease to the adjacent cells.

Professor Ireton and his team discovered a second process that supports the spread of bacteria to healthy cells that had never been known before. This process gradually weakened the ability of the second cell to protect itself from infection and appeared in this week's edition of the scientific journal Nature Cell Biology.

Listeria bacteria move through the cytoplasm of cells in the human body using part of the cell frame called actin fibers, Listeria bacteria are blue and actin fibers are red. It can be seen from the photo that actin filaments form a tail-like structure behind the bacteria. These actin fibers work to push Listeria through the cytoplasm of cells in the human body. The arrows in the picture show a bacterium moving in the cytoplasm. (Photo: Keith Ireton)

The cell membrane, or the outermost layer of normal healthy cells, stretches.That strain is expected to prevent Listeria from spreading to adjacent uninfected cells. However, Ireton's lab found that a type of protein in Listeria called InIC appears to reduce cell membrane tension in infected cells, which will do so. For the movement of bacteria to penetrate cell membranes and then spread to adjacent healthy cells easier.

Ireton's lab also released a report showing how InIC reduces tension is the function of blocking Tuba protein in the human body. Normally, the function of tuba in uninfected human cells is to create the tension of the cell membrane. The InIC protein in Listeria inhibits Tuba activity, reduces stress and helps bacteria spread to adjacent cells.

Professor Ireton said: 'The finding shows that pathogenic bacteria can be spread by controlling cell membrane tension in human cells that have not previously been published in scientific literature. Our discovery may have something to do with pathogenic bacteria that cause Rocky Mountain typhus and Shigellosis because these bacteria are similar to Listeria bacteria about being able to move into the stomach. master cells and spread to other cells ".

Professor Ireton argues that more research is needed, but finding this mechanism will support future treatment and perhaps open a door for understanding the pathogens that cause disease like how.

Other members working in the group with Ireton include Tina Rajabian and Scott D. Gray-Owen from Torronto College, Balramakrishna Gavicherla from Florida State University, Martin Heisig, Stefanie Müller-Altrock and Werner Goebel from University of Würzburg Germany.