Antimicrobial Resistance, Genetic Lineages, and Biofilm Formation in Pseudomonas aeruginosa Isolated from Human Infections: An Emerging One Health Concern

Abstract

Pseudomonas aeruginosa (PA) is a leading nosocomial pathogen and has great versatility due to a complex interplay between antimicrobial resistance and virulence factors. PA has also turned into one the most relevant model organisms for the study of biofilm-associated infections. The objective of the study focused on analyzing the antimicrobial susceptibility, resistance genes, virulence factors, and biofilm formation ability of thirty-two isolates of PA. PA isolates were characterized by the following analyses: susceptibility to 12 antimicrobial agents, the presence of resistance genes and virulence factors in PCR assays, and the quantification of biofilm production as evaluated by two distinct assays. Selected PA isolates were analyzed through multilocus sequence typing (MLST). Thirty PA isolates have a multi-resistant phenotype, and most of the isolates showed high levels of resistance to the tested antibiotics. Carbapenems showed the highest prevalence of resistance. Various virulence factors were detected and, for the quantification of biofilm production, the effectiveness of different methods was assessed. The microtiter plate method showed the highest accuracy and reproducibility for detecting biofilm-producing bacteria. MLST revealed four distinct sequence types (STs) in clinical PA, with three of them considered high-risk clones of PA, namely ST175, ST235, and ST244. These clones are associated with multidrug resistance and are prevalent in hospitals worldwide. Overall, the study highlights the high prevalence of antibiotic resistance, the presence of carbapenemase genes, the diversity of virulence factors, and the importance of biofilm formation in PA clinical isolates. Understanding these factors is crucial for effective infection control measures and the development of targeted treatment strategies.

Multiple-Locus Variable-Number Tandem Repeat Analysis Genotyping of Biofilm-Producing Pseudomonas aeruginosa Clinical Isolates

“…Additionally, a significant association between antimicrobial resistance and biofilm production has been identified. This correlation is attributed to the extracellular polymeric substances (EPS) produced in biofilms, which impede the entry of antibiotics into the bacterial cells (16). Consistent with our findings, a four-year study in the United States from 2012 to 2015 by Sader et al revealed that the only antimicrobial agents with a sensitivity rate exceeding 90% were associated with CAZ (17).…”

Overcoming antibiotic resistance: non-thermal plasma and antibiotics combination inhibits important pathogens

“…Biofilm formation also increases ATBR in this bacterium. Data indicate a correlation between the occurrence of MDR bacteria, biofilm formation and the expression of virulence, underlining the role of P. aeruginosa as a key model in the study of biofilm-related ATBR (Eladawy et al 2021 , Gajdács et al 2021 , Silva et al 2023 ).…”

Outbreak of Pseudomonas aeruginosa High-Risk Clone ST309 Serotype O11 Featuring blaPER-1 and qnrVC6

“…The high associated mortality of P. aeruginosa can be attributed to several factors, including the frequent occurrence of diverse antibiotic resistance mechanisms, its ability to produce biofilm [6], its association with certain virulence factors [7], and its ability to persist in hospital and natural environments [8]. This is particularly noteworthy in high-risk clones (HRCs), a term often used to refer to multidrug-resistant or extensively drug-resistant P. aeruginosa clones with wide distribution, usually associated with epidemic outbreaks, and exemplified by ST235, ST111, ST233, ST244, ST357, ST308, ST175, ST277, ST654, and ST298 [7].…”