Spreading of Aminoglycoside-Modifying Enzymes among Escherichia coli Isolated from Clinical Specimens in Chungcheong Province

• Main Authors: Ji Youn Sung, Pil Seung Kwon
• Format: Article
• Language: English
• Published: The Korean Society for Clinical Laboratory Science 2020-06-01
• Series: Korean Journal of Clinical Laboratory Science
• Subjects: aac(3′)-ii gene; aminoglycoside; aminoglycoside-modifying enzyme; e. coli
• ISSN: 1738-3544; 2288-1662

The antimicrobial resistance rate in bacteria has increased over the last several decades. The transfer of antimicrobial resistant determinants on mobile genetic elements could cause the accelerated emergence and spread of multidrug resistant bacteria. This study investigated the aminoglycoside resistance determinants transferred by mobile genetic elements in a total of 33 aminoglycoside non-susceptible E. coli isolated from clinical specimens in Chungcheong province. 16S ribosomal RNA methyl-transferases (RMTases) and aminoglycoside-modifying enzyme (AME) genes were detected via PCR and DNA sequencing. The most common AME genes were aac(3′)-II gene (54.5%), followed by aph(3′)-Ia (18.2%) and aac(6′)-Ib (15.2%). None of the evaluated RMTase genes were detected in the 33 isolates. Seventeen of the 18 isolates harboring aac(3′)-II gene were resistant to gentamicin, and 16 of them were resistant to tobramycin. The 5 isolates harboring aac(6′)-Ib gene were all resistant to tobramycin. In this study, we confirmed that one of the important mechanisms of aminoglycoside resistance in E. coli isolated from human is the acquisition of AME genes. Continuing investigations of antimicrobial resistant determinants in bacteria isolated from human may be required to prevent dissemination of antimicrobial resistant bacteria.