RT Journal Article SR Electronic T1 Effect of antibiotic use on antimicrobial antibiotic resistance and late-onset neonatal infections over 25 years in an Australian tertiary neonatal unit JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP F244 OP F250 DO 10.1136/archdischild-2016-310905 VO 102 IS 3 A1 David Carr A1 Elizabeth Helen Barnes A1 Adrienne Gordon A1 David Isaacs YR 2017 UL http://fn.bmj.com/content/102/3/F244.abstract AB Background Antibiotic resistance is a worldwide problem. We describe 25 years of responsible antibiotic use in a tertiary neonatal unit.Methods Data on neonatal infections and antibiotic use were collected prospectively from 1990 to 2014 at a single tertiary Sydney neonatal intensive care unit attached to a maternity unit. There are approximately 5500 deliveries and 900 nursery admissions per year.Results The mean annual rate of late-onset sepsis was 1.64 episodes per 100 admissions. The mean number of late-onset sepsis episodes per admission to the neonatal unit decreased by 4.0% per year (95% CI 2.6% to 5.4%; p<0.0001) and occurred particularly in infants born weighing <1500 g. No infants with negative cultures relapsed with sepsis when antibiotics were stopped after 48–72 hours. Antibiotic use decreased with time. The proportion of colonising methicillin-resistant Staphylococcus aureus isolates decreased by 7.4% per year (95% CI 0.2% to 14.1%; p=0.043). The proportion of colonising Gram-negative bacilli isolates resistant to either third-generation cephalosporins or gentamicin increased by 2.9% per year (95% CI 1.0% to 4.9%; p=0.0035). Most were cephalosporin-resistant; gentamicin resistance was rare. An average of one baby per year died from late-onset sepsis, the rate not varying significantly over time. The mortality from episodes of late-onset sepsis was 25 of 332 (7.5%).Conclusion Stopping antibiotics after 2–3 days if neonatal systemic cultures are negative is safe. However, it does not prevent the emergence of cephalosporin-resistant Gram-negative organisms.