No single genetic strain of Clostridium difficile bacteria appears to be any more harmful than other strains, according to US researchers.
They said their findings contradicted previous research suggesting the emergence of the most severe C. difficile infections could be linked with a particular strain known as Ribotype 027 (R027).
“Clinical severity markers of C difficile infection, such as white blood cell count and albumin level, a protein in blood, are more important predictors of severe outcomes than any specific strain”
The new study used data from more than 700 patients at seven hospitals in the Houston area to assess disease severity at presentation and clinical outcomes with varying C. difficile strains.
Researchers conducted epidemiologic strain typing of C. difficile to identify both the prevalence of different strains, as well as the impact of distinct strains on disease severity and patient outcomes.
Although C. difficile R027 was the most prevalent strain associated with severe onset of the disease, it was found to not be any more likely to cause severe outcomes than other C. difficile strains.
However, researchers noted that continued use of non C. difficile antibiotics was a strong predictor of severe C. difficile infection outcomes in all strains.
The continued use of other antibiotics has previously been associated with prolonged diarrhoea and C. difficile infection treatment failure, they noted.
Strain typing remains a valuable source of information for tracking emergence of different strains and may potentially influence treatment decisions, said study lead author Samuel Aitken, from Houston Methodist Hospital in Texas.
But clinical severity markers appear to be more important predictors for the determining the severity of C. difficile infection patient outcomes, he said.
He added: “Clinical severity markers of C difficile infection, such as white blood cell count and albumin level, a protein in blood, are more important predictors of severe outcomes than any specific strain, especially in hospitals with no single predominant strain.”
The new study has been published online in the journal Infection Control & Hospital Epidemiology.