Abstract
The global spread of high-risk clo1nes (HRCs) of multidrug-resistant (MDR) Pseudomonas aeruginosa has hindered infection control and treatment strategies worldwide. In Colombia, globally relevant HRCs such as ST235 and ST111 have been widely reported. In this study, we evaluated phenotypic and metabolic variations associated with intracellular survival and dissemination in P. aeruginosa. A total of 100 clinical isolates were collected from 22 hospitals in Colombia. The isolates had been previously characterized and classified as MDR or susceptible strains (SSs), and their sequence types (STs) had been earlier determined. Based on this prior characterization, isolates were grouped in this study as multidrug-resistant high-risk clones (HRC, n = 50; corresponding to sequence types ST235 and ST111), multidrug-resistant non-high-risk clones (NHRCs, n = 27; non-ST235/ST111), and susceptible strains (SS, n = 23; also, non-ST235/ST111). Phenotypic traits, including motility, spontaneous mutation frequency, biofilm formation, and pigment production, were evaluated. In addition, a subset of 30 isolates was assessed for intracellular survival in vitro and metabolomic profiling using liquid chromatography-mass spectrometry. HRC isolates exhibited significantly reduced motility compared with NHRC and SS isolates (swarming: HRC vs. NHRC, p = 0.0032; HRC vs. SS, p = 0.010; swimming: HRC vs. NHRC and SS, p < 0.0001; twitching: HRC vs. SS, p = 0.0004), as well as lower pigment production (pyocyanin: HRC vs. NHRC and SS, p < 0.0001; pyoverdine: HRC vs. NHRC, p < 0.0001). Metabolomic analysis revealed increased concentrations of metabolites associated with iron acquisition and siderophore-related pathways in HRC isolates. Overall, these findings suggest that P. aeruginosa HRCs display distinct phenotypic and metabolic patterns that may contribute to persistence and dissemination in clinical settings, contributing to their epidemiological success.