How Clostridium difficile specializes in hospitals 2

How Clostridium difficile specializes in hospitals

How Clostridium difficile specializes in hospitals 3

Clostridium difficile bacteria / CDC, Janice Carr

Hinxton / UK Clostridium difficile, the most common cause of antibiotic-related diarrhea, has been genetically engineered to survive in hospitals. It is there, according to a study in Nature Genetics (2019; doi: 10.1038 / s41588-019-0478-8), a strain that forms resistant spores and, by using glucose more readily in light of today's eating habits, has a selective advantage over other bacteria.

C. difficile is not necessarily pathogenic. As an integral part of the normal intestinal flora, bacteria rarely cause problems. However, if antibiotic administration is destroyed by other intestinal bacteria, C. difficile can rapidly expand in the intestine and cause severe diarrhea.

C. difficile (CDI) infections are the most common cause of nosocomial drug and antibiotic diagnosis today. In hospitals, spores also cause problems that are highly disinfectant resistant and therefore difficult to eradicate.

The team, led by Trevor Lawley of the Wellcome Sanger Institute in Hinxton, Cambridge, has now genetically studied 906 C. isolates to identify the pathogen. Genome sequencing revealed that C. difficile, which is widespread in clinics, is so genetically distinct from other C. difficile that it almost forms its own bacterial species.

From a genetic difference, researchers conclude (assuming a constant mutation rate) that clade A, which is common in clinics, may have originated 76,000 years ago. For a long time, the bacterium was not widespread. Since the end of the 16th century, even before the founding of modern hospitals, Class A has become increasingly common.

However, the pathogen found ideal living conditions only in hospitals. This is less because it resists antibiotic attacks. Its main advantage could be that it replicates faster after treatment with antibiotics than others in the gut. Today, Clade A accounts for about 70 percent of C. difficile isolated in clinics.

Researchers attribute this to the genes that allow Claude A to make better use of glucose and other simple sugars. Music experiments have confirmed this. When the diet of the animals was enriched with sugar, C. difficile spread in the intestines more rapidly.

For clinical medicine, this may mean that the diet of patients after antibiotic treatment influences the risk of CDI. Clinical studies can be interesting.

Another benefit of Clade A may be its increased resistance to disinfectants. The pathogen forms spores, which are difficult to remove with normal Reinigungsbemhungen. This also explains why Clade A prevailed over other C. difficile tribes.

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