Remember Koch’s Postulates? These are the four criteria designed to establish a causal relationship between a causative microbe and a disease,
The bacterium Mycoplasma pneumoniae is carried at high rates in the upper respiratory tracts of healthy children and usual diagnostic tests cannot differentiate between such asymptomatic carriage and actual respiratory tract infection, according to a new study. These findings are important as they suggest that clinicians may need to reconsider the clinical significance of a positive test result for the presence of this bacterium.
We know of at least eight viruses which cause cancer in humans, but apart from Helicobacter pylori there are no firmly established cases of bacteria causing tumours. Having said that, there are a number of bacteria which have been shown to be associated with certain cancers, but the relationship between cancer and bacteria is not as clear cut as in the casue of human tumour viruses. A recent paper in PLOS ONE adds to the list of bacteria associated with particular tumours.