Identification of Acinetobacter baumannii and detection of ß - lactam antibiotic resistance genes in clinical samples by multiplex PCR

Abstract Acinetobacter baumannii is the leading cause of hospital-acquired infection in Vietnam. Of note, antibiotic resistance genes are significantly popular in clinical isolates of A. baumannii . Therefore, rapid identification of A. baumannii and determination of antibiotic resistance genes will help to make effective clinical decisions related to antibiotic use. This paper proposes a multiplex PCR to identify Acinetobacter baumannii and detect their ß-lactam antibiotic resistance genes in clinical isolates. Multiplex PCR was applied to amplified rec A gene and region ITS 16S - 23S rDNA for Rapid detection of A. baumannii. The two antibiotic resistance genes - bla OXA-51-like , amp C gene - were detected by multiplex PCR and three genes coding Extended-spectrum beta-lactamases - bla CTX-M , bla TEM , bla SHV genes - were subjected to PCR. 49 bacteria strains were subjected to colony PCR. The result showed that 46 strains were A. baumannii and 3 strains belonged to the genus Acinetobacter. The multiplex PCR showed that all of 46 A. baumannii containing the bla OXA-51-like gene and the Amp C gene; 34 strains possess the gene bla TEM and none of them has bla CTX-M and bla SHV genes. The results of the multiplex PCR are the same as those of the in vitro antibiotic sensitivity testing of A. baumannii . However, applying the multiplex PCR directly from the bacteria colony, we can proceed simultaneously with the bacterial identification and the antibiotic resistance gene detection. Highlights 100% of isolates of A. baumannii contains the bla OXA-51-like gene and the Amp C gene. 34/46 isolates possess the gene bla TEM , however, do not contain bla CTX-M and bla SHV genes. Combined disc test with cefotaxime/clavulanic acid/boronic acid is an excellent method to analyse ESBL phenotype.