Cephalosporins, which belong to the beta-lactam therapeutic class, are increasingly used throughout the world. Few large studies on this issue have been conducted, and most of them have been performed as part of penicillin hypersensitivity studies. We described our 26-year experience exploring cephalosporin drug hypersensitivity, from which we identified epidemiological and cross-reactivity data. We included 476 patients who reported drug hypersensitivity reaction (DHR) to cephalosporin and underwent an allergy workup between January 1992 and July 2018 in the Allergy Unit of the University Hospital of Montpellier (France). According to their structural side chain R1 homology, we worked with 4 classes of cephalosporins. Logistic regression analysis was used to search for risk factors for hypersensitivity to cephalosporin (positive skin test [ST] or drug provocation test [DPT] results). Cephalosporin hypersensitivity was proven in 22.3% of the patients referred in our Unit, according to positive ST (51.red in less than 10% of the positive patients. Almost a quarter of the tested patients were confirmed as hypersensitive to cephalosporins; sensitivity of skin testing was 51.9%, and thus, half of the positive patients needed a DPT to prove the diagnosis.Almost a quarter of the tested patients were confirmed as hypersensitive to cephalosporins; sensitivity of skin testing was 51.9%, and thus, half of the positive patients needed a DPT to prove the diagnosis. Efflux pumps are transmembrane proteins associated with bacterial resistance mechanisms. Bacteria use these proteins to actively transport antibiotics to the extracellular medium, preventing the pharmacological action of these drugs. This study aimed to evaluate in vitro the antibacterial activity of 1,8-naphthyridines sulfonamides, as well as their ability to inhibit efflux systems of Staphylococcus aureus strains expressing different levels of the NorA efflux pump. The broth microdilution test was performed to assess antibacterial activity. Efflux pump inhibition was evaluated in silico by molecular docking and in vitro by fluorometric tests, and the minimum inhibitory concentration (MIC) was determined. The MIC was determined in the association between 1,8-naphthyridine and norfloxacin or ethidium bromide. The 1,8-naphthyridines did not show direct antibacterial activity. GPR84 antagonist 8 nmr However, they effectively reduced the MIC of multidrug-resistant bacteria by associating with norfloxacin and ethidium bromide, in addition to increasing the fluorescence emission. In silico analysis addressing the binding between NorA and 1,8-naphthyridines suggests that hydrogen bonds and hydrophilic interactions represent the interactions with the most favourable binding energy, corroborating the experimental data. Our data suggest that 1,8-naphthyridines sulfonamides inhibit bacterial resistance through molecular mechanisms associated with inhibition of the NorA efflux pump in S. aureus strains.Our data suggest that 1,8-naphthyridines sulfonamides inhibit bacterial resistance through molecular mechanisms associated with inhibition of the NorA efflux pump in S. aureus strains. The spread of carbapenemase-producing Enterobacterales (CPE) with colistin resistance is a critical public health issue. We genetically characterized the clinical isolate Enterobacter roggenkampii OIPH-N260, which harboured carbapenemase genes bla and bla with multiple resistance genes, including mcr-9 and bla . This isolate was characterized by whole-genome sequencing, comparative analysis of resistance plasmids, susceptibility tests, bacterial conjugation, S1-nuclease digested pulsed-field-gel electrophoresis, and Southern blot hybridization. The OIPH-N260 isolate exhibited resistance to most β-lactams and colistin. It co-harboured two resistance plasmids, the bla - and bla -encoding IncP6 plasmid pN260-3 and mcr-9- and bla -encoding IncHI2 plasmid pN260-1. The comparative analysis of pN260-3 indicated that a unique bla -surrounding region was inserted into the bla -encoding plasmid with the mobile element IS26, which plays an important role in the spread of resistance genes. pN260-1 did not possess the mcr-9 expression regulative gene qseBC. Both plasmids were transferable into other bacterial species via conjugation. This is the first study to report not only a bla and bla co-encoding plasmid, but also the co-harbouring of another plasmid carrying mcr-9 and bla in Enterobacter cloacae complex. The development of advanced resistance via IS26-mediated insertion and the co-harbouring of resistance plasmids highlights the need to monitor for resistance genes in CPE.This is the first study to report not only a blaIMP-1 and blaGES-5 co-encoding plasmid, but also the co-harbouring of another plasmid carrying mcr-9 and blaCTX-M-9 in Enterobacter cloacae complex. The development of advanced resistance via IS26-mediated insertion and the co-harbouring of resistance plasmids highlights the need to monitor for resistance genes in CPE.Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. Cell-of-origin classification in DLBCL has identified activated B cell (ABC) and germinal center B cell (GCB) as two major subtypes. Patients with the ABC subtype show reduced overall survival with standard therapies. Development of a quantitative RT-PCR-based lymphoma cell-of-origin (LCOO) assay to determine ABC, GCB, and unclassifiable subtypes in formalin-fixed, paraffin-embedded tissue (FFPET) DLBCL samples is reported. The LCOO classifier was trained on two DLBCL cohorts with validation performed by using an analytical grade assay in an independent cohort of 60 FFPET DLBCL samples. In the validation cohort, LCOO classification was 88.1%, 84.7%, and 84.7% concordant with microarray, immunohistochemistry (Hans classification), and Lymphoma Subtyping Test, respectively. Importantly, LCOO and Lymphoma Subtyping Test assays commonly assigned subtypes in 17 (94.4%) of 18 ABC samples and 34 (89.5%) of 38 GCB DLBCL samples from this cohort. Progression-free survival and overall survival of ABC and GCB subtypes, as classified by all platforms, were not significantly different in the validation cohort. LCOO classification using publicly available microarray gene expression from two independent data sets (414 fresh frozen and 474 FFPET DLBCL biopsies) revealed a significantly worse outcome for the ABC subtype compared with that of the GCB subtype. Thus, a sensitive, reproducible, LCOO assay developed on an easy to standardize quantitative RT-PCR platform may be an important clinical tool for DLBCL cell-of-origin classification.