New Delhi Metallo-β-Lactamase (NDM-1)-Producing Providencia stuartii Isolates Recovered During the COVID-19 Pandemic in a Teaching Hospital in Southern Brazil

Introduction: Several Enterobacterales species harboring New Delhi metallo-β-lactamase (NDM-1) have been reported worldwide. Among them is Providencia stuartii (P. stuartii), an emerging pathogen in nosocomial infections. Objective: This study aimed to perform the clinical and genomic characterization of NDM-1-producing P. stuartii isolates recovered from hospitalized patients during the COVID-19 pandemic in Southern Brazil. Materials and Methods: A retrospective observational study was conducted between April and September 2021 at a Brazilian teaching hospital. Fifty P. stuartii isolates were identified, and carbapenem-resistant isolates underwent phenotypic and molecular characterization. Genetic relatedness was assessed by Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), and selected isolates were subjected to whole-genome sequencing using the Illumina NextSeq platform to determine sequence types, resistance genes, virulence determinants, and plasmid content. Statistical analyses were performed using SPSS version 20.0. Results: Among the 50 isolates, 21 (42%) harbored the blaNDM-1 gene. Most isolates were recovered from tracheal aspirates (57.2%), followed by blood (23.8%), urine (9.5%), and skin and soft tissue samples (9.5%). Significant associations were observed between NDM-1-producing isolates and SARS-CoV-2 infection (p = 0.013), central venous catheter use (p = 0.012), mechanical ventilation (p = 0.006), hemodialysis (p = 0.033), previous antimicrobial exposure, and mortality (p = 0.021). Genomic analysis revealed the presence of blaNDM-1, blaOXA-1, and multiple resistance determinants associated with aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and folate pathway inhibitors. ERIC-PCR demonstrated low genetic variability among isolates, suggesting possible clonal dissemination within the hospital environment. Conclusions: This study reports the emergence of NDM-1-producing P. stuartii during the COVID-19 pandemic in a Brazilian teaching hospital. The low genetic variability among isolates and the multidrug-resistant profile highlight the potential for nosocomial dissemination and reinforce the importance of genomic surveillance and infection control strategies.