Emergence of Escherichia coli(E. coli) resistant organisms in Urinary Tract Infection(UTI) in pediatric patients

E. coli, the most common causative bacteria of urinary tract infections in childhood, has been developing increasing resistance to ampicillin. Estimates of the frequency of this range from 30 to 80 percent raising several questions. 1) Is the frequency of ampicillin resistance the same for patients of all ages with UTI? 2) Is it the same whether it is the first or a recurrent infection? 3) Is it related to previous antibiotic exposure? and 4) What should the choice of drug be and is it different depending on the patients age? In order to answer these questions we reviewed the urine culture results in the pediatric population at the Nassau County Medical Center for three months. Eighty-three cultures were positive for E.coli and were characterized as to whether or not they were ampicillin resistant, the age of the patient, and whether or not the patient recieved prior antibiotics. Forty-one(49%) of these cultures were ampicillin sensitive and forty-two(51%) were resistant. All the E. coli cultured in patients from age 0 to 2 months were resistant. From age 2 to 6 months they were all sensitive. Between the ages of 6 months and 10 years twenty-one of thirty-seven cultures were ampicillin resistant(58%). All cultures between ages 10 to 15 years were ampicillin sensitive and those from 15 to 20 years were resistant 52% of the time. The data presented strongly suggests that there may be some variation in the frequency of ampicillin resistant E. coli depending on the age of the patient and this maybe useful in determining the choice of antibiotic. Factors other than prior exposure to antibiotics may have a role in the emergence of ampicillin resistant E. coli. Review of a larger number of cultures is necessary to substantiate what we have found.