RT Journal Article SR Electronic(1) A1 Abhari, Soha Seyyedi A1 Badmasti, Farzad A1 Modiri, Leila A1 Aslani, Mohamad Mehdi A1 Asmar, MehdiYR 2019 T1 Circulation of imipenem-resistant Acinetobacter baumannii ST10, ST2 and ST3 in a university teaching hospital from Tehran, Iran JF Journal of Medical Microbiology, VO 68 IS 6 SP 860 OP 865 DO https://doi.org/10.1099/jmm.0.000987 PB Microbiology Society, SN 1473-5644, AB Purpose. Multi-drug resistant (MDR) Acinetobacter baumannii has introduced a worldwide health crisis. The purposes of this study were to characterize the clonal relatedness among MDR clinical strains and to introduce a new two-locus typing method confirmed by multi-locus sequence typing (MLST). Methodology. In this study, we determined antimicrobial resistance, detected genes associated with carbapenem resistance and characterized clonal relatedness among 99 clinical isolates extracted from 82 hospitalized inpatients in a university hospital. Results. Of the 99 A. baumannii isolates, 92.9% (92/99) were resistant to imipenem and 97.9% (97/99) had an MDR profile. We found that the high prevalence of blaVIM [94.9% (94/99)] and blaOXA-23-like [93.93% (93/99)] is the main mechanism of carbapenem resistance. This study proposes a new two-locus typing (blaOXA-51-like and ampC) method for the rapid identification of clonal complexes (CCs). The results of this method and confirmation by MLST show that clinical isolates carry blaOXA-68 as well as ampC-10 or ampC-20 genes belonging to CC10 (ST10); blaOXA-66 and ampC-2 belonging to CC2 (ST2); and blaOXA-71 and ampC-3 belonging to CC3 (ST3). One isolate had blaOXA-90 with an undetermined allele number of ampC belonging to ST513. Conclusion. The high prevalence of MDR strains and the circulation of four limited clones, including ST10 (45/99), ST2 (41/99), ST3 (12/99) and ST513 (1/99), in the clinical setting highlights the importance of a rigorous infection control programme. The two-locus typing method has more discrimination than the application of each method separately and it could be applied for the rapid determination of the CC without performing MLST., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000987