Concentration vs. Optical Density of ESKAPEE Bacteria: A Method to Determine the Optimum Measurement Wavelength.

Optical density measurement has been used for decades to determine the microorganism concentration and more rarely for mammalian cells. Although this measurement can be carried out at any wavelength, studies report a limited number of measurement wavelengths, mainly around 600 nm, and no consensus seems to be emerging to propose an objective method for determining the optimum measurement wavelength for each microorganism. In this article, we propose a method for analyzing the absorbance spectra of ESKAPEE bacteria and determining the optimum measurement wavelength for each of them.

Absorption/Attenuation Spectral Description of ESKAPEE Bacteria: Application to Seeder-Free Culture Monitoring, Mammalian T-Cell and Bacteria Mixture Analysis and Contamination Description.

Despite numerous innovations, measuring bacteria concentrations on a routine basis is still time consuming and ensuring accurate measurements requires careful handling. Furthermore, it often requires sampling small volumes of bacteria suspensions which might be poorly representative of the real bacteria concentration. In this paper, we propose a spectroscopy measurement method based on a description of the absorption/attenuation spectra of ESKAPEE bacteria.

Absorption Spectra Description for T-Cell Concentrations Determination and Simultaneous Measurements of Species during Co-Cultures.

Advanced Therapy Medicinal Products are promising drugs for patients in therapeutic impasses. Their complex fabrication process implies regular quality controls to monitor cell concentration. Among the different methods available, optical techniques offer several advantages.

Molecular characterization of blaNDM-1 in a sequence type 235 Pseudomonas aeruginosa isolate from France.

An NDM-1 carbapenemase-producing Pseudomonas aeruginosa isolate was recovered from a patient hospitalized in France after a previous hospitalization in Serbia. Genetic studies revealed that the blaNDM-1 gene was surrounded by insertion sequence ISAba125 and a truncated bleomycin resistance gene. This blaNDM-1 region was a part of the variable region of a new complex class 1 integron bearing IS common region 1 (ISCR1).

Complexity of resistance mechanisms to imipenem in intensive care unit strains of Pseudomonas aeruginosa.

Background: Pseudomonas aeruginosa can become resistant to carbapenems by both intrinsic (mutation-driven) and transferable (β-lactamase-based) mechanisms. Knowledge of the prevalence of these various mechanisms is important in intensive care units (ICUs) in order to define optimal prevention and therapeutic strategies.

Methods: A total of 109 imipenem-non-susceptible (MIC >4 mg/L) strains of P.