RT Journal Article SR Electronic(1) A1 Azizi, Omid A1 Shakibaie, Mohammad Reza A1 Badmasti, Farzad A1 Modarresi, Farzan A1 Ramazanzadeh, Rashid A1 Mansouri, Shahla A1 Shahcheraghi, FereshtehYR 2016 T1 Class 1 integrons in non-clonal multidrug-resistant Acinetobacter baumannii from Iran, description of the new blaIMP-55 allele in In1243 JF Journal of Medical Microbiology, VO 65 IS 9 SP 928 OP 936 DO https://doi.org/10.1099/jmm.0.000315 PB Microbiology Society, SN 1473-5644, AB Infections and outbreaks caused by multidrug-resistant Acinetobacter baumannii (MDR-AB) are prevalent and have been reported worldwide over the past 20 or more years. Class 1 integron in MDR-AB plays an important role in the spread of antibiotic resistance in clinical settings. This study has been conducted to evaluate the detection of metallo-β-lactamase, characterization of class 1 integron and determination of clonal relatedness among A. baumannii hospital isolates. Sixty-five clinical isolates of MDR-AB were recovered from two Iranian hospital’s intensive care units from February to August 2013. Integrase (intI1) and bla IMP genes were detected in 70.8 % (n=46/65) and 9.23 % (n=6/65) of the isolates using PCR assay, respectively. No other metallo-β-lactamase genes (bla VIM, bla SIM and bla NDM) were detected. PCR sequencing of integron gene cassette revealed the following arrays: bla OXA10-aacA4-bla IMP-55-cmlA5 (as a novel array was designated In1243), aacC1 and aadA1. Analysis of bla IMP gene revealed a new allele designated as bla IMP-55. Gene transfer experiment by conjugation showed the 36 kb conjugative plasmid harbouring In1243. The clonal assessment by repetitive extragenic palindromic PCR demonstrated a high-degree relatedness among the strains, but strains harbouring In1243 displayed a different repetitive extragenic palindromic PCR profile. In this study, we found that a novel class 1 integron (In1243) that encoded a new bla IMP allele resided on a transferable plasmid in non-clonal strains of MDR-AB., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000315