Luana Carvalho Silva, Gustavo Henrique Migliorini Guidone, Bruno Henrique Dias de Oliva, Arthur Bossi do Nascimento, Nathalia Geovana Nascimento Dos Santos, Beatriz Lernic Schoeps, Bianca Mayumi Susuki, Bruna Larissa Covezzi, Luana Karolyne Salomão de Almeida, Eliana Carolina Vespero, Sergio Paulo Dejato da Rocha
These findings demonstrate that food-associated P. mirabilis serves as an active agroenvironmental reservoir for virulent and multidrug-resistant lineages, posing an unmonitored risk for zoonotic dissemination and human infection within the One Health framework.
Proteus mirabilis is an opportunistic pathogen frequently associated with urinary tract infections (UTIs), with its pathogenicity driven by coordinated virulence traits such as adhesion, biofilm formation, and toxin production. The systemic emergence of antimicrobial resistance (AMR) within this species raises critical concerns regarding its persistence across clinical and environmental niches. This study investigated the virulence profiles, AMR determinants, and molecular epidemiology of P. mirabilis isolates recovered from retail vegetables and human community-acquired UTIs (CA-UTIs) in southern Brazil. A total of 310 isolates were analyzed (110 from vegetables and 200 from UTIs). Multidrug resistance was observed in 36.6-42.0% of vegetable isolates and 16.0% of UTI isolates, while extended-spectrum β-lactamase (ESBL) production reached 32.0% in the vegetable group. Notably, the carbapenemase gene blaKPC-2 was identified in vegetable isolates, representing a critical food safety concern. High-consequence resistance genes, including blaCTX-M variants, fosA3, and qnrD, were widely distributed. Furthermore, all isolates harbored multi-element virulence profiles-particularly genes encoding fimbriae, proteases, and iron acquisition systems-and exhibited strong or very strong biofilm-forming phenotypes. Clonal analysis revealed tight genetic relatedness between vegetable and clinical isolates, including indistinguishable profiles. Whole-genome sequencing identified shared sequence types (STs), most notably the high-risk clone ST773, alongside internationally reported lineages such as ST135 and ST336. Moreover, conserved mobile genetic environments flanking blaKPC-2 were structurally characterized. These findings demonstrate that food-associated P. mirabilis serves as an active agroenvironmental reservoir for virulent and multidrug-resistant lineages, posing an unmonitored risk for zoonotic dissemination and human infection within the One Health framework.