Molecular characterization and genotypic diversity of extensively drug-resistant Acinetobacter baumannii from endotracheal aspirates in a pediatric intensive care unit in Sulaimani, Iraq
摘要
Extensively drug-resistant (XDR) Acinetobacter baumannii poses a significant threat in pediatric intensive care units (PICUs), particularly in regions with limited surveillance data. This study characterized the bacterial profile of endotracheal aspirate samples from a PICU in Sulaimani, confirmed A. baumannii identification using blaOXA−51 PCR, assessed antimicrobial resistance patterns, and determined genotypic diversity using ERIC-PCR.
Methods and resultsFrom August 2023 to March 2025, 100 consecutive Gram-negative isolates were recovered from mechanically ventilated pediatric patients. VITEK2 was used for identification and susceptibility testing. XDR Acinetobacter isolates underwent molecular confirmation via blaOXA−51 PCR, and confirmed isolates were genotyped using ERIC-PCR with UPGMA analysis. Among the 100 total isolates, A. baumannii accounted for 21 isolates alongside Pseudomonas aeruginosa (n = 33) and Klebsiella pneumoniae (n = 20). Given its clinical significance, A. baumannii was selected for further molecular characterization. Overall, 26 isolates exhibited XDR phenotypes, 12 of which were A. baumannii by VITEK2; 10 were confirmed by blaOXA−51 PCR (83.3%). All confirmed isolates were resistant to β-lactams, carbapenems, aminoglycosides, and fluoroquinolones, while remaining susceptible to colistin. ERIC-PCR revealed one dominant clone (Cluster A, 50%), two minor clusters (20% each), and one singleton (10%), indicating moderate genetic diversity with evidence of sustained clonal circulation.
ConclusionsThis study provides the first molecular epidemiological characterization of XDR A. baumannii in an Iraqi PICU, revealing clonal persistence of a successful epidemic strain and critical gaps in phenotypic identification. These findings emphasize the need for routine molecular surveillance, targeted infection control, and antimicrobial stewardship in resource-limited settings.