Colonization by Enterobacteriaceae of the respiratory tract of children with cystic fibrosis of the pancreas and their antibody response.

Of 72 patients with fibrosis, 49 harbored Enterobacteriaceae in the respiratory tract, 
including Escherichia coli, Klebsiella, and Enterobacter. Colonization by two to four 
genera was documented in 29 subjects. Staphylococcus aureus was recovered from 
44 of these 49 patients. The distribution of serogroups of E. 
coli was similar to that seen in patients with urinary tract 
infection. Antibody response against the O antigens of the patients' own 
Enterobacteriaceae was documented in 29 of these 49 children and encountered 
more often in patients with severe disease. Colonization by Enterobacteriaceae in 
the absence of Pseudomonas aeruginosa was seen more frequently in children 
with the mild form of the illness. 