Aunt suffering with E. coli? Provide medical treatment (9)
I believe the answer is:
inoculate
'provide medical treatment' is the definition.
(inoculation is a medical procedure)
'aunt suffering with e coli?' is the wordplay.
'suffering with' is an anagram indicator.
'e'+'coli'='ecoli'
'aunt' anagrammed with 'ecoli' gives 'INOCULATE'.
(Other definitions for inoculate that I've seen before include "Give a jab" , "Graft" , "Immunise with antigens" , "Treat with a vaccine or serum" , "Inject against a disease" .)