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Updated: Oct 27, 2026
Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Phenotypic and molecular characterization of ESBL, AmpC, and carbapenemase-producing Acinetobacter baumannii isolates
Reyhaneh Rahimzadeh1, Forough Babazadeh1, Jafar Mohammadshahi2
1Department of Microbiology, School of Medicine, Ardabil University of Medical Science, Ardabil, Iran.
Background:
This study aimed to identify ESBL/AmpC- and carbapenemase-producing Acinetobacter baumannii isolates.
Materials And Methods:
In this cross-sectional study, a total of 180 A. baumannii isolates were recovered from clinical samples (2018-2022). Modified Hedge Test (MHT), Disc Potentiation Test (DPT) and Double Disc Test (DDT) methods were used for the recognition of carbapenemase, ESBL and AmpC-producing A. baumannii, respectively. The presence of carbapenemase, ESBL, and AmpC encoding genes was verified using the Polymerase Chain Reaction (PCR) method. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) was employed for differentiating about 80 isolates with high imipenem MIC.
Results:
out of 180, 44.5%(n = 80),98%(n = 177),17.5%(n = 32),4.5%(n = 8) of isolates were positive in MHT, Metallo-β-lactamase, AmpC and ESBL phenotypic tests, respectively. 44.44% of isolates had MIC ≥ 8 µg/ml for imipenem. CTX(41.5%), TEM(31.5%),OXA23(36.6%),OXA24(53.3%)24 and OXA51(96%) were the most prevalent detected genes. Under the ERIC-PCR fingerprinting method, 5 ERIC types were detected.
Conclusion:
ESBL/AmpC- and carbapenemase-producing A.baumannii isolates are a serious threat to human public health. Identifying these superbugs is critical for the proper management of relevant infections.
