Correlation Between ISAba1 Upstream ampC Gene and Resistance to Cefotaxime in Acinetobacter baumannii: A Serious Threat to Nosocomial Infections


Background: Infections due to Acinetobacter baumannii have become a significant challenge in modern healthcare systems. The global upsurge of multidrug resistance in A. baumannii has created widespread problems in the treatment of patients.

Objectives: We examined the prevalence ISAmpC and its correlation with cefotaxime resistance.

Materials and Methods: Standard biochemical tests were used to identify isolates. Genomic species of the genus Acinetobacter were confirmed by Amplified Ribosomal DNA Restriction Analysis (ARDRA). The susceptibility of 50 A. baumannii isolates to a variety of antimicrobial agents was determined using the disk diffusion method and E-test strips. PCR was used to investigate the connection of insertion sequences and the ampC gene. Clonal relatedness was determined by Repetitive Extragenic Palindromic PCR.

Results: ISAba1 located upstream of blaampC was found in 24 (48%) of the A. baumannii isolates. In all of the studied isolates that had ISAmpC, the MIC for cefotaxime was 64 - 256 μg/mL. Based on the REP-PCR patterns among the resistant isolates, the highest number of ISAmpC positive isolates belonged to type B (n = 19) and type C (n = 12).

Conclusions: ISAba1 has become an important factor in A. baumannii’s resistance to cefotaxime.