<abstract xmlns="http://www.w3.org/1999/xhtml">

<italic>Acinetobacter baumannii</italic> is a non-fermentative Gram-negative bacterium that can cause nosocomial infections in critically ill patients. Carbapenem-resistant <italic>A. baumannii</italic> (CRAB) has spread rapidly in clinical settings and has become a key concern. The main objective of this study was to identify the distribution of integrons and biofilm-formation-related virulence genes in CRAB isolates. A total of 269 <italic>A. baumannii</italic> isolates (219 isolates of CRAB and 50 isolates of carbapenem-sensitive <italic>A. baumannii</italic> (CSAB)) were collected. Carbapenemase genes (<italic>bla</italic>KPC, <italic>bla</italic>VIM, <italic>bla</italic>IMP, <italic>bla</italic>NDM, and <italic>bla</italic>OXA-23-like) and biofilm-formation-related virulence genes (<italic>abal</italic>, <italic>bfms</italic>, <italic>bap</italic>, and <italic>cusE</italic>) were screened with PCR. Class 1 integron was screened with PCR, and common promoters and gene cassette arrays were determined with restriction pattern analysis combined with primer walking sequencing. Whole-genome sequencing was conducted, and data were analyzed for a <italic>bla</italic>OXA-23-like-negative isolate. All 219 CRAB isolates were negative for <italic>bla</italic>KPC, <italic>bla</italic>VIM, <italic>bla</italic>IMP, and <italic>bla</italic>NDM, while <italic>bla</italic>OXA-23-like was detected in 218 isolates. The detection rates for <italic>abal</italic>, <italic>bfms</italic>, <italic>bap</italic>, and <italic>cusE</italic> in 219 CRAB were 93.15%, 63.93%, 88.13%, and 77.63%, respectively. Class 1 integron was detected in 75 CRAB (34.25%) and in 3 CSAB. The single gene cassette array <italic>aacA4-catB8-aadA1</italic> with relatively strong PcH2 promoter was detected in class 1 integrons. The <italic>bla</italic>OXA-23-like-negative CRAB isolate was revealed to be a new sequence type (Oxford 3272, Pasteur 2520) carrying <italic>bla</italic>OXA-72, <italic>bla</italic>OXA-259, and <italic>bla</italic>ADC-26. In conclusion, <italic>bla</italic>OXA-23-like was the main reason for CRAB’s resistance to carbapenems. A new (Oxford 3272, Pasteur 2520) CRAB sequence type carrying the <italic>bla</italic>OXA-72, <italic>bla</italic>OXA-259, and <italic>bla</italic>ADC-26 was reported.
</abstract>

Acinetobacter baumannii is a non-fermentative Gram-negative bacterium that can cause nosocomial infections in critically ill patients. Carbapenem-resistant A. baumannii (CRAB) has spread rapidly in clinical settings and has become a key concern. The main objective of this study was to identify the distribution of integrons and biofilm-formation-related virulence genes in CRAB isolates. A total of 269 A. baumannii isolates (219 isolates of CRAB and 50 isolates of carbapenem-sensitive A. baumannii (CSAB)) were collected. Carbapenemase genes (blaKPC, blaVIM, blaIMP, blaNDM, and blaOXA-23-like) and biofilm-formation-related virulence genes (abal, bfms, bap, and cusE) were screened with PCR. Class 1 integron was screened with PCR, and common promoters and gene cassette arrays were determined with restriction pattern analysis combined with primer walking sequencing. Whole-genome sequencing was conducted, and data were analyzed for a blaOXA-23-like-negative isolate. All 219 CRAB isolates were negative for blaKPC, blaVIM, blaIMP, and blaNDM, while blaOXA-23-like was detected in 218 isolates. The detection rates for abal, bfms, bap, and cusE in 219 CRAB were 93.15%, 63.93%, 88.13%, and 77.63%, respectively. Class 1 integron was detected in 75 CRAB (34.25%) and in 3 CSAB. The single gene cassette array aacA4-catB8-aadA1 with relatively strong PcH2 promoter was detected in class 1 integrons. The blaOXA-23-like-negative CRAB isolate was revealed to be a new sequence type (Oxford 3272, Pasteur 2520) carrying blaOXA-72, blaOXA-259, and blaADC-26. In conclusion, blaOXA-23-like was the main reason for CRAB’s resistance to carbapenems. A new (Oxford 3272, Pasteur 2520) CRAB sequence type carrying the blaOXA-72, blaOXA-259, and blaADC-26 was reported.

Analysis of the Class 1 Integrons, Carbapenemase Genes and Biofilm Formation Genes Occurrence in <italic>Acinetobacter baumannii</italic> Clinical Isolates

Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Analysis of the Class 1 Integrons, Carbapenemase Genes and Biofilm Formation Genes Occurrence in  Clinical Isolates

Acinetobacter baumannii is a non-fermentative Gram-negative bacterium that can cause nosocomial infections in critically ill patients. Carbapenem-resistant A....

Analysis of the Class 1 Integrons, Carbapenemase Genes and Biofilm Formation Genes Occurrence in Acinetobacter baumannii Clinical Isolates

Article Category: Original Paper

Published Online: May 29, 2024

Page range: 189 - 197

Received: Dec 09, 2023

Accepted: Mar 28, 2024

DOI: https://doi.org/10.33073/pjm-2024-017

Keywords
integron, virulence gene, carbapenem, antimicrobial resistance,

© 2024 Yu Xiu et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Analysis of the Class 1 Integrons, Carbapenemase Genes and Biofilm Formation Genes Occurrence in Acinetobacter baumannii Clinical Isolates

Article Category: Original Paper

Published Online: May 29, 2024

Page range: 189 - 197

Received: Dec 09, 2023

Accepted: Mar 28, 2024

DOI: https://doi.org/10.33073/pjm-2024-017

Keywordsintegron, virulence gene, carbapenem, antimicrobial resistance,

© 2024 Yu Xiu et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
integron, virulence gene, carbapenem, antimicrobial resistance,