Infant botulism was confirmed in a 5-month-old female by both isolation of Clostridium botulinum
type B and by detection of type B botulinum neurotoxin in rectal washout and faeces. DNA
fingerprinting of nine isolates from faeces yielded two different amplified-fragment length
polymorphism (AFLP) patterns. C. botulinum was isolated from two of 14 food and drink items from
the patient’s home: C. botulinum type A was recovered from an opened container of dried rice
pudding and C. botulinum type B from opened infant formula milk powder. Ten C. botulinum type B
isolates from the opened infant formula yielded four AFLP patterns, two of which were
indistinguishable from the clinical isolates. Fifteen unopened foods were tested and C. botulinum
type B of a unique AFLP pattern was recovered from one unopened infant formula of the same batch
as the opened container. It is suggested that multiple C. botulinum were present in both food and the
intestine during infant botulism.