Novel allelic variants of bla carried on IncN and IncC plasmids isolated from clinical cases in Argentina: In vivo emergence of bla.

Objective: The OXA-48-like enzymes have the capacity to hydrolyse carbapenems and are members of class D β-lactamases that are primarily detected in Enterobacterales. The allelic variant bla, which has low hydrolytic activity towards carbapenems, was detected in Argentina in 2011 and has spread successfully since then, giving sporadic origin to novel local variants. The aim of this study was to analyse the phenotypic profile and dissemination strategies of two novel OXA enzymes, bla and bla, located in Escherichia coli M17224 and Klebsiella pneumoniae M21014, respectively, isolated from two paediatric patients.

Novel Pinhole Emitter Chip for Micro Supercritical Fluid Chromatography-Mass Spectrometry with Integrated Dilution-Free Fluidic Back-Pressure Regulation.

We present a novel chip-based device featuring a pinhole emitter for mass spectrometry (MS) coupling with integrated fluidic back-pressure regulation for supercritical mobile phases. This design enables facile coupling of packed capillary columns used for supercritical fluid chromatography (SFC) with atmospheric pressure ionization mass spectrometry. The monolithic microfluidic chips were fabricated using selective laser-induced etching, seamlessly integrating multiple functions, including comb-shaped particle retention structures for column packing and ports for zero-clearance connection with standard fused silica capillaries.

Modular Chip-Based nanoSFC-MS for Ultrafast Separations.

This study presents the development of a miniaturized device for supercritical fluid chromatography coupled with mass spectrometry. The chip-based, modular nanoSFC approach utilizes a particle-packed nanobore column embedded between two monolithically structured glass chips. A microtee in the pre-column section ensures picoliter sample loads onto the column, while a microcross chip structure fluidically controls the column backpressure.

Coupling of droplet-on-demand microfluidcs with ESI/MS to study single-cell catalysis.

Droplet microfluidics provides an efficient method for analysing reactions within the range of nanoliters to picoliters. However, the sensitive, label-free and versatile detection with ESI/MS poses some difficulties. One challenge is the difficult association of droplets with the MS signal in high-throughput droplet analysis.

First report of abdominal sepsis caused by a recently described species: Chimaeribacter arupi.

We present a case of a 34-year-old patient with abdominal sepsis caused by an infrequent species: Chimaeribacter arupi. Genomic analysis confirmed the identification which is difficult to achieve by other methods so far. To our knowledge, this represents the first case of infection by this species reported in Argentina.