1. The plethora of resistance mechanisms in Pseudomonas aeruginosa: transcriptome analysis reveals a potential role of lipopolysaccharide pathway proteins to novel β-lactam/β-lactamase inhibitor combinations
- Author
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Mariana Castanheira, Timothy B. Doyle, Cory M. Hubler, Timothy D. Collingsworth, Sean DeVries, and Rodrigo E. Mendes
- Subjects
Lipopolysaccharides ,Microbiology (medical) ,Tazobactam ,Lactams ,Gene Expression Profiling ,Immunology ,Microbial Sensitivity Tests ,Microbiology ,beta-Lactamases ,Anti-Bacterial Agents ,Cephalosporins ,Pseudomonas aeruginosa ,Humans ,Immunology and Allergy ,Pseudomonas Infections ,beta-Lactamase Inhibitors ,Monobactams - Abstract
Whole genome and transcriptome analysis of 213 Pseudomonas aeruginosa isolates resistant to antipseudomonal β-lactams collected in 30 countries was performed to evaluate resistance mechanisms against these agents.Isolates were susceptibility tested by reference broth microdilution. Whole genome and transcriptome sequencing were performed, and data were analysed using open-source tools. A statistical analysis of changes in the expression of5500 genes was compared to the expression of PAO1.The high-risk clones ST235 and ST111 were the most prevalent among90 sequence types (STs). Metallo-β-lactamase (MBLs) genes were detected in 40 isolates. AmpC and MexXY were the most common genes overexpressed in approximately 50% of the 173 isolates that did not carry MBLs. Isolates overexpressing pmrA and pmrB, the norspermidine production genes speD2 and speE2, and the operon arnBCADTEF-ugd were noted among strains resistant to ceftolozane-tazobactam and ceftazidime-avibactam, despite the lack of polymyxin resistance often associated to increased expression of these genes. Overexpression of MuxABC-OpmB, OprG, and OprE proteins were associated with resistance to ceftolozane-tazobactam in addition to the usual genes involved in cephalosporin, monobactam, and carbapenem resistance. Statistical analysis identified discrete mutations in ArmZ, OprD, and AmpC that correlated to antipseudomonal β-lactam resistance.P. aeruginosa resistance mechanisms are complex. This analysis suggests the role of multiple genes in resistance to antipseudomonal β-lactams, including some not commonly described.
- Published
- 2022