Pseudomonas aeruginosa is a high-priority bacterial agent that causes healthcare-acquired infections (HAIs), which often leads to serious infections and poor prognosis in vulnerable patients. Its increasing resistance to antimicrobials, associated with SPM production, is a case of public health concern. Therefore, this study aims to determine the antimicrobial resistance, virulence, and genotyping features of P. aeruginosa strains producing SPM-1 in the Northern region of Brazil. To determine the presence of virulence and resistance genes, the PCR technique was used. For the susceptibility profile of antimicrobials, the Kirby–Bauer disk diffusion method was performed on Mueller–Hinton agar. The MLST technique was used to define the ST of the isolates. The exoS⁺/exoU⁻ virulotype was standard for all strains, with the aprA, lasA, toxA, exoS, exoT, and exoY genes as the most prevalent. All the isolates showed an MDR or XDR profile against the six classes of antimicrobials tested. HRC ST277 played a major role in spreading the SPM-1-producing P. aeruginosa strains.

Background: The global impact of the SARS-CoV-2 pandemic on antimicrobial resistance (AMR) patterns has been significant. In northern Brazil, Carbapenem-resistant Klebsiella pneumoniae (CRKP) are a major concern, with an observed shift from Klebsiella pneumoniae carbapenemase (KPC) to New Delhi metallo-β-lactamase (NDM) during the pandemic. Methods: This cross-sectional study analyzed 775 carbapenem-resistant K. pneumoniae isolates collected from 25 hospitals in the Brazilian Amazon Region (states of Pará and Acre) between 2018 and 2021. The isolates were tested for the presence of carbapenemase genes (bla_KPC, bla_NDM, bla_OXA-48, bla_IMP, bla_VIM, bla_AIM, bla_DIM, bla_GIM and bla_SIM). Results: Of the isolates analyzed, n = 653/775 (84%) were carbapenemase producers, with the most prevalent being bla_KPC n = 446/775 (57.5%) and bla_NDM n = 243/775 (31.4%). A significant increase in NDM producers was observed during the pandemic, rising from n = 1/250 (8.4%) pre-pandemic to n = 222/525 (42.3%) during the pandemic, while KPC producers declined from n = 172/250 (68.8%) to n = 274/525 (52.2%) (p < 0.001). Adult intensive care units (ICUs) were the primary source of isolates n = 357/775 (46%), with a notable increase in tracheal secretion and surveillance swab samples during the pandemic. Regression analysis confirmed a strong upward trend in the prevalence of bla_NDM (R² = 0.778). Conclusions: The shift from KPC to NDM producers in northern Brazil highlights an evolving AMR landscape, partly driven by the pandemic. Strengthened infection control measures, antimicrobial stewardship and continuous surveillance are essential to mitigate the spread of NDM-producing K. pneumoniae in settings with limited resources.

Clinical emergent bacterial pathogens are a great threat to the global health system, chiefly Gram-negative carbapenem-resistant Enterobacterales and the Klebsiella pneumoniae species complex. Here, we present the molecular and phenotypic characterization of Klebsiella quasipneumoniae subs. similipneumoniae IEC57090 strain, belonging to ST138 and showing a multidrug resistance phenotype. The bla_NDM-7 present in one of the two resistance plasmids carried by the isolate, the antibiotic resistance genes fosA, oqxAB, and acrR, and gene mutations on porins ompK36 and ompK37, both associated with cephalosporin and carbapenem resistance, were detected. Virulence factors such as the clusters of type I and III fimbria, type IV pili genes, and genes associated with the K1 capsule, siderophore production, and multiple mobile genetic elements (MGE) were predicted. The emergence of silent pathogens in clinical environments highlights the importance of active research on new threads that may compromise the last resources of antimicrobials, such as carbapenems, specifically on mobile genetic elements containing carbapenemases in emergent pathogens, which can spread these antimicrobial resistance elements. This study reinforces that molecular biology vigilance can prevent outbreaks and help to better understand antimicrobial resistance and pathogens in clinical environment dynamics.