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Background: The dissemination of NDM-1 carbapenemases (New Delhi Metallo-β-lactamase) is a global public health problem, mainly in developing countries. The aim of this study was to characterize the spread of NDM-producing bacteria in the Southern Brazilian states analyzing epidemiological, molecular, and antimicrobial susceptibility aspects., Methods: A total of 10,684 carbapenem-resistant isolates of Enterobacterales, Pseudomonas spp. and Acinetobacter spp. obtained from several hospitals in eight cities in Southern Brazil were screened, and 486 NDM-producing bacteria were selected., Results: The incidence varied from 0.5 to 77 cases/100.000 habitants. ST11, ST15, ST340 and ST674 were the most common in K. pneumoniae. A total of 5 plasmids were identified in one K. pneumoniae strain: Col440I, Col440II, IncFIA(HI1), IncFIB(K), IncFIB(pQil)/ IncFII(K), and IncR., Conclusions: The number of patients with NDM-producing bacteria has increased in Southern Brazil, whose gene is present in different plasmids, explaining the expansion of this enzyme., Competing Interests: Declaration of Competing Interest Felipe Tuon is a CNPq researcher. The other authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The presence of 16S rRNA methyltranferases (16S-RMTases) in carbapenemase-producing Enterobacterales (CPE) is a major concern because it inactivates all clinical use of aminoglycosides, including plazomicin. The aim of this study is to investigate the prevalence of 16S-RMTases in CPE nonsusceptible to plazomicin collected in different Brazilian hospitals., Methods: All isolates with plazomicin MIC ≥ 4 µg/mL (n = 67) were screened for the presence of 16S-RMTases by sequencing., Results: 54 (80.6%) isolates encoded 16S-RMTase genes (41 rmtB1, 7 armA, 3 rmtD2, 1 rmtD1 and 2 rmtC). Among 41 samples rmtB1 positive, 40 co-harbored bla KPC-2 and 1 bla OXA-48 gene. Of the seven isolates harboring armA gene, 6 were New Delhi Metallo-beta-lactamase (NDM)-producer. rmtD was only found in isolates Klebsiella pneumoniae Carbapenemase (KPC)-producers, one in Serratia marcescens with rmtD2, not reported in Brazil., Conclusion: The co-existence of 16S-RMTase and CPE is worrisome because of limited treatment options and the endemic characteristic of (KPC) and NDM in Brazil., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Plazomicin is a next-generation aminoglycoside with activity against Enterobacteriaceae, including carbapenemase-producing Enterobacteriaceae (CPE). The aim of this study was to evaluate the activity of plazomicin against CPE (Klebsiella spp., Escherichia coli, Serratia spp., Enterobacter spp., Citrobacter spp., Morganella spp., Proteus spp., Providencia spp.) from different Brazilian hospitals. A total of 4000 carbapenem-resistant Enterobacteriaceae isolates were collected from clinical samples in 50 Brazilian hospitals during 2013-2015. Of these, 499 carbapenem-resistant isolates (CLSI criteria) were selected for further evaluation via broth microdilution to assess for the activity of plazomicin, colistin, tigecycline, meropenem, amikacin, and gentamicin. Additionally, the isolates were assessed for the presence of carbapenemase genes (bla KPC , bla NDM , bla OXA-48-like , bla IMP , bla BKC , bla GES , and bla VIM ) by polymerase chain reaction (PCR). When PCR was positive to bla OXA-48-like , bla IMP , bla GES , and bla VIM, the carbapenemase genes were sequenced. bla KPC was the most prevalent carbapenemase gene found (n=397), followed by bla NDM (n=81), bla OXA-48 (n=12), and bla IMP-1 (n=3). Other genes were identified in only 1 isolate each: bla BKC-1 , bla GES-16 , bla GES-1 , bla OXA-370 , and bla VIM-1 . One isolate had 2 carbapenemase genes (bla KPC and bla NDM ). Thirty-three percent of the isolates were nonsusceptible to colistin, 24% to tigecycline, 97% to meropenem, 51% to amikacin, and 81% to gentamicin (via EUCAST criteria). The plazomicin MIC 50/90 was 0.5/64mg/L, with 85% of MICs ≤2mg/L and 87% of MICs ≤4mg/L. Elevated MICs to plazomicin were not associated with a specific carbapenemase or bacterial species. The MICs of plazomicin against CPE were lower than those of other aminoglycosides. Plazomicin is a promising drug for the treatment of CPE infections., (Copyright © 2017 Elsevier Inc. All rights reserved.)