colonisation VS infection

[selvanr4]

We get into a tight corner when we have a sick septic baby who is going downhill even with good cover. And we get a C&S report of Suction tip or ET Tube pointing to another bug and some other sensitive drug.
How can we differentiate colonisation from infection with the bug in these situation?
Your input is valuable.
selvan.r

[chandas]

Colonisation of endotracheal tubes is very common and the organisms thus cultured bear no relationship to the actual causative organisms in neonatal sepsis. The only benefit of knowing the colonisation is having knowledge of the organisms currently infesting the nursery. If an unsual pathogen starts colonising the ET tubes, it should prompt a look into infection control measures on the unit.