Imipenem Resistance Mediated by <i>bla</i>_OXA-913 Gene in <i>Pseudomonas aeruginosa</i>

• Main Authors: Dong-Chan Moon (Author), Abraham Fikru Mechesso (Author), Hee-Young Kang (Author), Su-Jeong Kim (Author), Ji-Hyun Choi (Author), Hyun-Ju Song (Author), Soon-Seek Yoon (Author), Suk-Kyung Lim (Author)
• Format: Book
• Published: MDPI AG, 2021-09-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Treatment of infectious diseases caused by carbapenem-resistant <i>Pseudomonas aeruginosa</i> is becoming a greater challenge. This study aimed to identify the imipenem resistance mechanism in <i>P. aeruginosa</i> isolated from a dog. Minimum Inhibitory Concentration (MIC) was determined by the broth microdilution method according to the Clinical and Laboratory Standards Institute recommendations. We performed polymerase chain reaction and whole-genome sequencing to detect carbapenem resistance genes. Genomic DNA of <i>P. aeruginosa</i> K19PSE24 was sequenced via the combined analysis of 20-kb PacBio SMRTbell and PacBio RS II. Peptide-Peptide Nucleic Acid conjugates (P-PNAs) targeting the translation initiation region of <i>bla</i>_OXA-913 were synthesized. The isolate (K19PSE24) was resistant to imipenem and piperacillin/tazobactam yet was susceptible to most of the tested antimicrobials. Whole-genome sequencing revealed that the K19PSE24 genome comprised a single contig amounting to 6,815,777 base pairs, with 65 tRNA and 12 rRNA genes. K19PSE24 belonged to sequence type 313 and carried the genes <i>aph(3)-IIb</i>, <i>fosA</i>, <i>catB7</i>, <i>crpP</i>, and <i>bla</i>_OXA-913 (an allele deposited in GenBank but not described in the literature). K19PSE24 also carried genes encoding for virulence factors (exoenzyme T, exotoxin A, and elastase B) that are associated with adhesion, invasion, and tissue lysis. Nevertheless, we did not detect any of the previously reported carbapenem resistance genes. This is the first report of the <i>bla</i>_OXA-913 gene in imipenem-resistant <i>P. aeruginosa</i> in the literature. Notably, no viable colonies were found after co-treatment with imipenem (2 µg/mL) and either of the P-PNAs (12.5 µM or 25 µM). The imipenem resistance in K19PSE24 was primarily due to <i>bla</i>_OXA-913 gene carriage.

Item Description

10.3390/antibiotics10101188
2079-6382