Risk factors and molecular epidemiology of Acinetobacter baumannii bacteremia in neonates

Abstract Background Acinetobacter baumannii infections in neonates are not uncommon but rarely studied. Methods Clinical and molecular epidemiology of 40 patients with A . baumannii bacteremia in the neonatal intensive care units (NICUs) of a medical center from 2004 to 2014 was analyzed. Results Multi-drug resistance was found in only 3 isolates (7.5%). Sequence types (STs) of A . baumannii defined by multilocus sequencing typing were diverse, and 72.4% identified isolates belonged to novel STs. Majority of the isolates were susceptible to antibiotics tested. Among the 3 imipenem-resistant A . baumannii (IRAB) isolates, 2 (66.7%) belonged to ST684, a novel ST. All of the 3 isolates were susceptible to tigecycline and colistin. The predominant mechanism of imipenem resistance in these neonatal isolates is IS Aba1 - bla OXA-80 , which has never been reported in Asia before. Most infected newborns were premature (95%), with very low birth weight (70%  Conclusions To reduce mortality of IRAB infection, it is crucial to consider giving effective agents, such as colistin, in 2 days for high risk neonates who has been given imipenem or used HFOV.