Rockville, MD – No, it’s not the cockroach, but rather a strain of pink bacteria that can survive 1.5 million rads of gamma irradiation – a dose 3,000 times the amount that would kill a human. This dose of radiation shreds the bacteria’s genome into hundreds of pieces.

Deinococcus radiodurans is an extremophilic bacterium and one of the most radiation-resistant organisms known. It can survive cold, dehydration, vacuum, and acid, and therefore is known as a polyextremophile. It has been listed as the world’s toughest known bacterium in The Guinness Book Of World Records.

Rehovot, Israel — January 9, 2003 —Weizmann Institute scientists have found what makes the bacterium Deinococcus radiodurans the most radiation-resistant organism in the world: The microbe’s DNA is packed tightly into a ring.

Gamma irradiation is a physical/chemical means of sterilization, because it kills bacteria by breaking down bacterial DNA, inhibiting bacterial division. Energy of gamma rays passes through the equipment, disrupting the pathogens that cause contamination.

Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them. Gamma rays can pass completely through the human body; as they pass through, they can cause ionizations that damage tissue and DNA.

The ionizing radiation sends enough energy into the bacterial or mold cells in the food to break chemical bonds. This damages the pathogens enough for them to die or no longer multiply, which reduces illness or spoilage.

radiodurans is best known for its extreme resistance to ionizing radiation; not only can it grow continuously in the presence of chronic radiation (6 kilorads/h), but also it can survive acute exposures to gamma radiation exceeding 1,500 kilorads without dying or undergoing induced mutation.

The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer.

However, Deinococcus radiodurans is unaffected by exposure to up to 3 million rads of gamma radiation. Indeed, the bacterium, whose name translates to “strange berry that withstands radiation,” holds a place in The Guinness Book of World Records as “the world’s toughest bacterium.”

In this article the worldwide epidemiology of resistant Gram-negative bacteria causing UTIs, with a special focus on extended spectrum beta lactamase (ESBL) positive pathogens, as well as new threats such as multi-drug-resistant (MDR) clones (e.g. E. coli 131 (ST131) and K. pneumoniae ST258), are reviewed.

There are two known reasons for the radiation resistance of species of Deinococcus. Firstly, the structure of the two membranes that surround the Gram-negative bacterium contributes, albeit in a minor way.

Multi-drug-resistant Gram-negative bacteria causing urinary tract infections: a review Urinary tract infections (UTIs) are among the most frequent infectious diseases affecting humans, and represent an important public health problem with a substantial economic burden.