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SATURDAY - AAR-622 - Characterization of a Pan-Resistant Pseudomonas aeruginosa Containing blaNDM-1 and blaIMP-1

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Author Block: D. R. Lonsway1, A. Bhatnagar1, R. Balbuena1, R. Stanton1, G. McAllister1, A. Laufer Halpin1, C. Offiong2, J. Landry2, P. C. Patel3, M. R. Saenz Jr.3, D. C. Ham1, M. S. Walters1, J. K. Rasheed1, M. Karlsson1; 1CDC, Atlanta, GA, 2City of Houston Dept. of Hlth.and Human Services, Houston, TX, 3Texas Dept. of State Hlth.Services, Austin, TX
Disclosure Block: D.R. Lonsway: None. A. Bhatnagar: None. R. Balbuena: None. R. Stanton: None. G. McAllister: None. A. Laufer Halpin: None. C. Offiong: None. J. Landry: None. P.C. Patel: None. M.R. Saenz Jr.: None. D.C. Ham: None. M.S. Walters: None. J.K. Rasheed: None. M. Karlsson: None.
Background: Metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa has emerged as a significant healthcare-associated pathogen that often displays multidrug resistance. We report on a highly antibiotic-resistant P. aeruginosa cultured in September 2018 from a urine specimen collected from a 63-year-old male. The patient, who had a history of a kidney transplant and diabetes, was hospitalized in two separate institutions in Texas and reported recent healthcare exposure in India. Methods: Initial characterization of the isolate using real-time PCR confirmed the presence of two MBL genes, blaNDM and blaIMP. The isolate was subsequently referred to the Centers for Disease Control and Prevention (CDC) for expanded antimicrobial susceptibility testing, confirmation of the carbapenemase genes and whole genome sequencing (WGS). Results: Using reference broth microdilution, the isolate displayed resistance to all drugs tested, including β-lactam + β-lactamase inhibitor combination agents, cephems, monobactams, carbapenems, aminoglycosides, fluoroquinolones, and polymyxins. Aztreonam-avibactam, cefepime-tazobactam, imipenem-relebactam, and plazomicin MICs were >64/4, >64/8, >64/4 and 32 µg/ml, respectively. The fosfomycin MIC was >1024 µg/ml by Etest. The P. aeruginosa isolate was found by WGS to be sequence type (ST) 244 and contained blaNDM-1 and blaIMP-1. WGS also revealed several other significant antibiotic resistance genes: blaPME-1, blaOXA-10, blaOXA-50, and blaOXA-129 (β-lactam resistance); qnrVC1 (quinolone resistance); aph(3’) and aph(6) (aminoglycoside resistance); and fosA (fosfomycin resistance). Conclusion: Newer drugs/drug combinations such as plazomicin and aztreonam-avibactam showed limited activity in vitro against a pan-resistant P. aeruginosa harboring two MBL genes reported to CDC in 2018. In response to this case, the Texas healthcare facilities, where the patient was hospitalized, implemented prospective surveillance as part of the CDC containment strategy and have continued to monitor for both carbapenem-resistant Enterobacteriaceae and P. aeruginosa. Through the recently established Antibiotic Resistance Laboratory Network, CDC has increased capacity nationwide to rapidly detect highly antibiotic-resistant organisms, including both carbapenemase-producing Enterobacteriaceae and P. aeruginosa.