A Potential High-Risk Clone of Pseudomonas aeruginosa ST463

Yanyan Hu; Wenjing Peng; Yifan Wu; Hui Li; Qi Wang; Huahua Yi; Rong Zhang; Bing Shao; Kui Zhu

doi:10.3389/fmicb.2021.670202

A Potential High-Risk Clone of Pseudomonas aeruginosa ST463

Front Microbiol. 2021 May 28:12:670202. doi: 10.3389/fmicb.2021.670202. eCollection 2021.

Authors

Yanyan Hu¹, Wenjing Peng², Yifan Wu², Hui Li³, Qi Wang¹, Huahua Yi⁴, Rong Zhang¹, Bing Shao³, Kui Zhu²

Affiliations

¹ Clinical Microbiology Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Zhejiang University, Hangzhou, China.
² National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China.
³ Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing, China.
⁴ Department of Respiratory and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Abstract

Pseudomonas aeruginosa is one of the most common opportunistic pathogens, which causes severe nosocomial infections because of its well-known multidrug-resistance and hypervirulence. It is critical to curate routinely the epidemic P. aeruginosa clones encountered in the clinic. The aim of the present study was to investigate the connection between virulence factors and antimicrobial resistance profiles in epidemic clones. Herein, we found that ST463 (O4), ST1212 (O11), and ST244 (O5) were prevalent in 30 isolates derived from non-cystic fibrosis patients, based on multilocus sequence type (MLST) and serotype analysis. All isolates were multidrug-resistant (MDR) and each was resistance to at least three classes of antibiotics in antimicrobial susceptibility tests, which was consistent with the presence of the abundant resistance genes, such as bla _OXA-50, bla _PAO, aph(3'), catB7, fosA, crpP, and bla _KPC-2. Notably, all bla _KPC-2 genes were located between ISKpn6-like and ISKpn8-like mobile genetic elements. In addition, classical exotoxins encoded by exoU, exoS, and pldA were present in 43.44% (13/40), 83.33% (25/30), and 70% (21/30) of the isolates, respectively. The expression of phz operons encoding the typical toxin, pyocyanin, was observed in 60% of isolates (18/30) and was quantified using triple quadrupole liquid chromatograph mass (LC/MS) assays. Interestingly, compared with other MLST types, all ST463 isolates harbored exoU, exoS and pldA, and produced pyocyanin ranging from 0.2 to 3.2 μg/mL. Finally, we evaluated the potential toxicity of these isolates using hemolysis tests and Galleria mellonella larvae infection models. The results showed that ST463 isolates were more virulent than other isolates. In conclusion, pyocyanin-producing ST463 P. aeruginosa, carrying diverse virulence genes, is a potential high-risk clone.

Keywords: Pseudomonas aeruginosa; ST463; hypervirulence; multi-drug resistance; pyocyanin.