High-risk Pseudomonas aeruginosa clones ST308, ST773, and ST233 associated with carbapenem-resistant and extensively drug-resistant isolates from hospital and community settings in Casablanca, Morocco

OBJECTIVES: The spread of high-risk extensively drug-resistant (XDR) Pseudomonas aeruginosa (Pa) clones is a global threat to public health. In Morocco, data on circulating clones and genomic features of Pa isolates are lacking. Accordingly, this study performed whole-genome sequencing (Illumina NextSeq500) of 18 Pa isolates from hospitals (n = 10) and the community (n = 8) to identify their sequence type (ST) affiliation, antimicrobial resistance determinants, virulence factors, and phylogenetic relationships. METHODS: Isolates were selected based on alarming resistance profiles from strains collected in Casablanca, Morocco, between January and December 2021. RESULTS: These isolates were assigned sequence type 773 (n = 11), 308 (n = 5), and 233 (n = 1), in addition to a novel ST4902 for one hospital isolate. Carbapenem resistance in hospital isolates was primarily attributed to acquired carbapenemases (NDM-1 in ST773 and ST308 clones). In contrast, resistance in one hospital (CSPa93) and one community isolate (cSPa43) was associated with mutations in the outer membrane protein. Fluoroquinolone resistance correlated with the carriage of qnrVC1 and crpP genes, along with mutations in the quinolone resistance-determining regions. The isolates also carried diverse aminoglycoside modifying enzymes and 16S rRNA methyltransferase genes. Genomic analysis also identified multiple virulence genes in these isolates, notably exoU in ST308 and ST773 isolates. Phylogenetic analysis further revealed hospital-adapted strains being genetically related to each other and to community strains. CONCLUSION: This first genomic investigation of circulating XDR Pa clones in both hospital and community settings in Morocco using whole-genome sequencing highlights the urgent need for enhanced surveillance and targeted strategies to contain the spread of XDR high-risk clones.