Detection of carbapenem-resistance and biofilm formation genes, and genetic relatedness of Acinetobacter baumannii isolates

• Published in: Genetika (Beograd) Vol. 54; no. 3; pp. 1069 - 1082
• Main Authors: Simonovic, Marko, Lepsanovic, Zorica, Rakonjac, Bojan, Lazic, Srdjan
• Format: Journal Article
• Language: English
• Published: 2022
• ISSN: 0534-0012; 1820-6069
• DOI: 10.2298/GENSR2203069S

Acinetobacter baumannii is one of the most important nosocomial pathogen
worldwide. This study aimed to investigate the virulence potential and
genomic relatedness of A. baumannii strains isolated from patients
hospitalized in the Military Medical Academy (MMA) by detecting OXA-type
carbapenemases genes, biofilm-associated genes, and by RAPD analysis. PCR
was used to detect the blaoxa genes, ISAba-1 genetic element, and
biofilm-associated genes. The genomic relatedness was determined by RAPD
analysis using four different primers (AP2, DAF4. M13, and DECA).
blaoxa-51-like, blaoxa-23-like, blaoxa-24-like, and blaoxa-58-like were
present in 100%, 34.0%, 62.4%, and 3.1% of isolates, respectively. All
isolates had the ISAba1 sequence in their genome, in 35.1% of isolates it
was associated with the blaoxa-51-like, and in 97.0% with the blaoxa-23-like
gene. Biofilm-associated genes bap, ompA, epsA, csuA/BABCDE, and pgaABCD
were detected in 93.8%, 95.8%, 88.1%, 98.4%, and 98.9% isolates,
respectively. RAPD analysis showed a high degree of genome similarity and
clonal dispersion of the isolates. Detection of blaoxa genes, especially
biofilm-associated genes, in a high percentage of A. baumannii isolates
indicated their great pathogenic potential. RAPD analysis revealed a high
level of genomic similarity and clonal dispersion of the majority of
isolates through MMA. Further, a continuous introduction of individual
strains with different profiles contributes to the genetic diversity of A.
baumannii isolates. These results can be useful for further management and
tracking nosocomial outbreaks.