Underlying Characteristics and Outcome of Extensively Resistant Acinetobacter baumannii Infection and Colonization in a Saudi Neonatal Intensive Care Unit

Extensively drug-resistant Acinetobacter baumannii (XDRAB) is a rapidly emerging pathogen causing threat to health care settings. The resultant morbidity and mortality rates are high due to limited therapeutic options. The present study demonstrates the characteristics of neonates, infected or colonized with XDRAB, antibiotic susceptibility patterns of the isolates, and neonatal outcomes. This retrospective study was conducted in the neonatal intensive care unit (NICU) of Dallah hospital, Riyadh, Saudi Arabia during the period January 2015 to December 2017. All neonates with positive XDRAB cultures from any location in the body were included, infected and colonized cases were compared. XDRAB was isolated from 16 neonates. Seventy-five percent of the affected neonates were preterm, with a median gestational age and birth weight of 32.5 weeks and 1,675g, respectively. The median time to XDRAB infection/colonization for all cases was 14 days. Seventy-five percent of the cases had central venous catheters and 50 percent had surgery/procedure performed during stay in NICU. Half of the affected neonates had underlying congenital anomalies and chronic medical conditions. Fourteen affected neonates (87%) received prior courses of cefotaxime. In 15 of 16 cases, XDRAB infection manifested clinically as late-onset sepsis with bacteremia and ventilator-associated pneumonia (VAP). XDRAB isolates were resistant to all beta-lactams and carbapenems. Resistance rate to other antibiotics was 93% for gentamicin and 50% for ciprofloxacin. All XDRAB isolates were susceptible to colistin. Seventy-five percent of the infected neonates died due to XDRAB sepsis, while 37% of the colonized group died of other underlying diseases. Fifty percent of the infected neonates died within 4 days of XDRAB infection. Prematurity, low birth weight, the use of vascular devices, and prior use of cefotaxime played a major role in XDRAB infection/colonization in our unit. It is crucial to consider early start of colistin, either alone or in combination therapy, especially for the neonates at high risk, for example, those with certain underlying chronic conditions who manifest with late-onset sepsis and/or VAP.