Researchers have found that particular strains of a food-borne bug are able to invade the heart, causing serious and difficult-to-treat infections.
The bacteria Listeria monocytogenes is commonly found in soft cheese and chilled ready-to-eat products.
Listeria infections are usually mild, but for susceptible individuals and the elderly, it can infect the central nervous system, the placenta and the developing foetus, the Journal of Medical Microbiology reports.
About 10 per cent of serious listeria infections involve a cardiac infection, says Nancy Freitag, associate professor of microbiology and immunology at the University of Illinois and principal study investigator.
Read more: Food-borne bug causes heart infection - The Times of India http://timesofindia.indiatimes.com/life-style/health-fitness/health/Food-borne-bug-causes-heart-infection/articleshow/7371133.cms#ixzz1CKDyp8D3
The bacteria Listeria monocytogenes is commonly found in soft cheese and chilled ready-to-eat products.
Listeria infections are usually mild, but for susceptible individuals and the elderly, it can infect the central nervous system, the placenta and the developing foetus, the Journal of Medical Microbiology reports.
About 10 per cent of serious listeria infections involve a cardiac infection, says Nancy Freitag, associate professor of microbiology and immunology at the University of Illinois and principal study investigator.
Read more: Food-borne bug causes heart infection - The Times of India http://timesofindia.indiatimes.com/life-style/health-fitness/health/Food-borne-bug-causes-heart-infection/articleshow/7371133.cms#ixzz1CKDyp8D3
Food-borne bug causes fatal heart infection
ReplyDeleteWashington, Jan 27 – Researchers have found that particular strains of a food-borne bug are able to invade the heart, causing serious and difficult-to-treat infections.
The bacteria Listeria monocytogenes is commonly found in soft cheese and chilled ready-to-eat products.
Listeria infections are usually mild, but for susceptible individuals and the elderly, it can infect the central nervous system, the placenta and the developing foetus, the Journal of Medical Microbiology reports.
About 10 percent of serious listeria infections involve a cardiac infection, says Nancy Freitag, associate professor of microbiology and immunology at the University of Illinois and principal study investigator.
These infections are difficult to treat, with more than one-third proving fatal, but have not been widely studied and are poorly understood, according to an Illinois statement.
Freitag and her colleagues isolated ‘an unusual strain, and the infection itself was unusual,’ she said. Usually with endocarditis (infection of the heart) there is bacterial growth on heart valves, but in this case the infection had invaded the cardiac muscle.
The researchers were interested in determining whether patient predisposition led to heart infection or whether something different about the strain caused it to target the heart.
They found that when they infected mice with either the cardiac isolate or a lab strain, they found 10 times as much bacteria in the hearts of mice infected with the cardiac strain.
Further, researchers found that while the lab-strain-infected group often had no heart infection at all, 90 percent of the mice infected with the cardiac strain had heart infections.
The researchers obtained more strains of listeria, for a total of 10, and did the same experiment. They found that only one other strain also seemed to also target the heart.
Listeria ‘tricks’ intestinal cells to cause sickness: Indian origin scientist
ReplyDeleteWashington, Oct 26 : A new study has found that pathogenic listeria tricks intestinal cells into helping it pass through those cells to make people ill, and, if that doesn’t work, the bacteria simply goes around the cells.
Arun Bhunia of the University or Purdue and Kristin Burkholder of the University of Michigan Medical School, found that listeria, even in low doses, somehow triggers intestinal cells to express a new protein, heat shock protein 60, that acts as a receptor for listeria.
This may allow the bacteria to enter the cells in the intestinal wall and exit into a person’s bloodstream.
“It’s possible that host cells generate more of these proteins in order to protect themselves during a stressful event such as infection.
“Our data suggest that listeria may benefit from this by actually using those proteins as receptors to enhance infection,” said Burkholder.
Listeria monocytogenes is a foodborne bacteria that can cause fever, muscle aches, nausea and diarrhea, as well as headaches, stiff neck, confusion, loss of balance and convulsions if it spreads to the nervous system.
The findings have suggested that listeria may pass between intestinal cells to sort of seep out of the intestines and into the bloodstream to cause infection.
Measurable increases of the heat shock 60 protein were detected when listeria was introduced to cultured intestinal cells.
Bhunia and Burkholder also introduced listeria to intestinal cells in the upper half of a dual-chamber container and counted the number of bacteria that passed through the cells and appeared in the lower chamber.
The bacteria moved to the lower chamber faster than it is known to do when moving through cells, and did so even when a mutant form of the bacteria that do not invade the intestinal cells was used. This suggests the bacteria are moving around the cells, Bhunia said.
“The infective dose is very low. Even 100 to 1,000 listeria cells can cause infection. We believe that these mechanisms are what allow listeria to cause infections at such low levels,” said Bhunia.
The findings were published in the journal Infection and Immunity. (ANI)
Very useful information... Initially was reluctant for the fear of jargons, but found really useful information once I started reading.Good work to get these published here. Looking forward to more.
ReplyDelete-RajaGopalan.V