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Objectives: Critical priority carbapenem-resistant pathogens constitute a worldwide public health problem. Escherichia coli ST1193 is an emerging high-risk clone that demonstrates prolonged gut persistence, and association with community-onset urinary and bloodstream infections. The purpose of this study is to report microbiological and genomic data on the emergence of KPC-2-producing E. coli ST1193 in ready-to-eat (RTE) vegetable., Methods: RTE vegetables were purchased from markets in southeastern Brazil. Epiphytic and endophytic Gram-negative bacteria displaying resistance to broad-spectrum beta-lactams were identified by MALDI-TOF. WGS was conducted using the Illumina NextSeq platform. Antimicrobial susceptibility, conjugation, and acid tolerance assays were performed. Virulence behavior was evaluated using the Galleria mellonella infection model., Results: Epiphytic KPC-2-producing E. coli belonging to pandemic ST1193 was identified in RTE arugula. Genomic analysis predicted clinically relevant genes conferring resistance to β-lactams, fluoroquinolones, hazardous heavy metals, pesticides, disinfectants, and chlorine sanitizer. The bla KPC-2 gene was carried by a conjugative IncF plasmid. Resistance of E. coli KPC-2/ST1193 at pH 2.0 was confirmed, being associated with gadWX and ibaG pH tolerance genes, supporting survival to stomach acid prior to reaching small intestine, and potential for a dietary mode of host colonization. Virulent behavior was supported by wide virulome of the highly virulent phylogroup B2, whereas cgSNP-based phylogenomics revealed clonal relationship with healthcare-associated lineages circulating in the United States, China, Mexico, France and Brazil., Conclusions: We report the occurrence of KPC-2-producing E. coli of the highly virulent B2-ST1193 clone in RTE vegetable, highlighting a possible route of dissemination of WHO priority pathogens to humans., Competing Interests: Declaration of Interest Statement The authors Karine Dantas, Gregory Melocco, Fernanda Esposito, Herisson Fontana, Brenda Cardoso, and Nilton Lincopan, declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper entitled “Emergent Escherichia coli of the highly virulent B2-ST1193 clone producing KPC-2 carbapenemase may be transmissible through ready-to-eat vegetable”, (Copyright © 2024. Published by Elsevier Ltd.)

The emergence of highly successful genetic lineages of methicillin-resistant Staphylococcus aureus (MRSA) poses a challenge in human healthcare due to increased morbidity and mortality rates. The RdJ clone (CC5-ST105-SCCmecII-t002 lineage), previously identified in Rio de Janeiro, Brazil, was linked to bloodstream infections and features a mutation in the aur gene (encoding aureolysin). Additionally, clinical isolates derived from this clone were more effective at evading monocytic immune responses. This study aimed to detect the RdJ clone among clinical MRSA isolated in Santa Catarina (SC) and examine its antimicrobial resistance and phagocytosis evasion capabilities. Our findings revealed the RdJ clone in 20 % of MRSA isolates, all exhibiting multiresistance. RdJ clone isolates from SC did not demonstrate a decreased rate of phagocytosis compared to CC5 non-RdJ isolates. Structural analysis suggests that the aur mutation is unlikely to significantly impact aureolysin activity. Genomic analysis of one isolate unveiled a genetic variant of the RdJ clone, sharing lineage and gene distribution but lacking the aur mutation. This study enhances the understanding of the clinical and epidemiologic risks associated with the RdJ clone and the biological mechanisms underlying its spreading in SC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Competing Interests: We declare no competing interests. This work was supported by the Bill & Melinda Gates Foundation (Grand Challenges Explorations Brazil – New approaches to characterise the global burden of antimicrobial resistance, Grant OPP1193112); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2020/08224-9); and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 314336/2021-4 and 422984/2021-3). FV-P is a research fellow of the Agency for Research and Development (ANID) Scholarship Program Doctorado Becas Chile (2020–72 210 089). JB is a research fellow of FAPESP (2023/18292-0). NL is a research fellow of CNPq (314336/2021-4).

Reports of Gram-negative bacteria harboring multiple carbapenemase genes have increased in South America, leading to an urgent need for appropriate microbiological diagnosis. We evaluated phenotypic methods for detecting Klebsiella pneumoniae carbapenemase 2 (KPC-2) and New Delhi metallo-β-lactamase-1 (NDM-1) coexpression in members of the K. pneumoniae complex (i.e., K. pneumoniae, K. quasipneumoniae, and K. variicola) isolated from human and animal hosts, based on inhibition of ceftazidime-avibactam (CZA) and aztreonam (ATM) by dipicolinic acid (DPA), EDTA, or avibactam (AVI). While the presence of bla KPC-2 and bla NDM-1 genes was confirmed by whole-genome sequencing, PCR, and/or GeneXpert, coexpression was successfully detected based on the following: (i) a ≥5-mm increase in the zone diameter of ATM (30 µg) disks plus AVI (4 or 20 µg) and ≥4-mm and ≥10-mm increases in the zone diameters for "CZA 50" (30 µg ceftazidime [CAZ] and 20 µg AVI) and "CZA 14" (10 µg CAZ and 4 µg AVI) disks, respectively, when we added DPA (1 mg/disk) or EDTA (5 mM) in a combined disk test (CDT); (ii) a positive ghost zone (synergism) between ATM (30 µg) and CZA 50 disks and between CZA 50 and DPA (1 mg) disks, using the double-disk synergy test (DDST) at a disk-disk distance of 2.5 cm; (iii) ≥3-fold MIC reductions of ATM and CZA in the presence of AVI (4 µg/mL), DPA (500 µg/mL), or EDTA (320 µg/mL); and (iv) immunochromatography. Although our results demonstrated that inhibition by AVI, DPA, and EDTA may provide simple and inexpensive methods for the presumptive detection of coexpression of KPC-2 and NDM-1 in members of the K. pneumoniae complex, additional studies are necessary to confirm the accuracy of these methodologies by testing other Gram-negative bacterial species and other KPC and NDM variants coexpressed by WHO critical priority pathogens detected worldwide. IMPORTANCE Alerts regarding the emergence and increase of combinations of carbapenemases in Enterobacterales in Latin America and the Caribbean have recently been issued by PAHO and WHO, emphasizing the importance of appropriate microbiological diagnosis and the effective and articulated implementation of infection prevention and control programs. In this study, we evaluated methods based on inhibition of ceftazidime (CAZ), ceftazidime-avibactam (CZA), and aztreonam (ATM) by dipicolinic acid (DPA), EDTA, and avibactam (AVI) inhibitors for the identification of KPC-2- and NDM-1-coexpression in members of the K. pneumoniae complex recovered from human and animal hosts. Our results demonstrate that inhibition by AVI, DPA, and EDTA may provide simple and inexpensive methods for the presumptive detection of coexpression of KPC-2 and NDM-1 in members of the K. pneumoniae complex.