Tag Archives: Gram positive bacteria

New compound to fight superbugs

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Chemists at the North Carolina State University have created a compound that makes existing antibiotics 16 times more effective against recently discovered antibiotic-resistant “superbugs.”

These so-called superbugs are actually bacterial strains that produce an enzyme known as New Delhi metallo-ß-lactamase (NDM-1).

Bacteria that produce this enzyme are practically impervious to antibiotics because NDM-1renders certain antibiotics unable to bind with their bacterial targets. Since NDM-1 is found in Gram-negative bacteria like K. pneumoniae, which causes pneumonia, urinary tract, and other common hospital-acquired infections, it is of particular concern.

“To begin with, there are fewer antibiotic options for treating infections caused by Gram-negative bacteria than for those caused by Gram-positive bacteria,” said Dr. Roberta Worthington, NC State research assistant professor of chemistry.

“Gram-negative bacteria with the NDM-1 enzyme effectively neutralize the few weapons we have in our arsenal, making them especially difficult, if not impossible, to treat with existing antibiotic therapy,” he explained.

MRSA

MRSA

Previously, NC State chemist Dr. Christian Melander had found that a compound derived from a class of molecules known as 2-aminoimidazoles “recharged” existing antibiotics, making them effective against Gram-positive antibiotic-resistant bacteria like the Staphylococcus strain MRSA.


So Melander, Worthington and graduate students Cynthia Bunders and Catherine Reed set to work on a variety of the compound that might prove similarly effective against their Gram-negative brethren.

Worthington and Melander have now described a compound that, when used in conjunction with the antibiotic imipenem, increased the antibiotic’s effectiveness against the antibiotic-resistant K. pneumoniae 16-fold. The researchers believe that these early results are very promising for future treatments.

“We’ve demonstrated that we have the ability to take out the scariest superbug out there. Hopefully further research will allow us to make the compound even more effective, and make these infections little more than a nuisance,” Melander claimed.

Bisin the wonder preservative

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A naturally occurring preservative which extends the shelf life of foods as well as killing bacteria could mark the end of food use-by dates.

The preservative, called bisin, has the potential to keep foods fresh for years. It is the first natural preservative to kill gram negative bacteria which can spoil food, as well as food poisoning bugs such as E.coli and salmonella.

All other natural preservatives used in the food industry are only effective against gram positive bacteria.

Bacteria are classified as gram negative or positive depending on the make-up of their cell wall.

Researchers at the University of Minnesota have patented the preservative in the US, and say it could be added to foods such as meats, cheeses, dairy products, canned foods, sea foods, salad dressings and even wines within the next three years.

Bisin keeps your food fresh

Bisin keeps your food fresh

Dan O’Sullivan, a professor of food science and nutrition at the university, told the Sunday Times: “It seems to be much better than anything which has gone before.

“It doesn’t compromise nutrient quality – we are not adding a chemical, we are adding a natural ingredient.


“It’s aimed at protecting foods from a broad range of bugs that cause disease.”

The researchers are now trying to determine the best conditions for producing bisin, and to work out exactly how effective it is at preventing bacterial growth.

Each year in the UK, around 85,000 people are affected by food poisoning, a figure which is likely to be an underestimate as many cases go unreported.

Cases normally peak in the summer months, many due to undercooked barbecued food and foods which have gone off in the warm weather.