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Neisseria meningitidis (Nm) is the pathogen carried asymptomatically in the nasopharynx but which under certain conditions can produce meningitis or even multi-organ failure. Experimental induction of meningitis in an animal model is necessary for testing new nanopharmaceutical products. Thus, the aim of the study was to establish the concentration of Nm capable of inducing the disease. We carried out 2 studies where we tested different concentrations of Nm obtained by the nephelometric and spectrophotometric methods. In the first study we included 20 BALB/c mice, and in the second 24. Local and general clinical signs, complete with body temperature values, body weight, hematological, microbiological and histopathological examination were important indicators for the assessment of the establishment of meningitis. The clinical results have pronounced depression in the first 2 days after inoculation, then the general condition will appear. The microbiological and histopathological examination indicated the presence of bacteria at the brain level and specific meningeal lesions only in the case of the second attempt, but the early mortality, requires additional testing of the bacterial concentration that induces meningites in a stable and persistent way so that treatment against the condition can be tested later. [ABSTRACT FROM AUTHOR]

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The emergence of multidrug-resistant (MDR) bacteria, especially related to the capacity to adhere to different abiotic and biotic surfaces, such as wounds, skin or other living surfaces, raised several questions regarding the processes underlying this phenomenon. Bacteria within a biofilm (also referred to as the sessile variant of bacteria) proved to be more resistant to common antimicrobials, therefore current methods to control bacterial growth do not have the same effect on a biofilm as on planktonic bacteria. On one hand quantifying and characterizing bacterial biofilms became necessary for practical purposes, as recommended for example in routine checking of the antimicrobial susceptibility of Pseudomonas spp. clinical isolates that developed biofilms. On the other hand, researchers engaged in finding novel substances which could have an antimicrobial effect on biofilms in different stages of development and needed the most suitable methods to study the formation and dynamic ofbiofilms. Taking into consideration the above mentioned aspects, we aimed at reviewing the state of the art regarding the development of qualitative and quantitative methods for biofilm characterization. [ABSTRACT FROM AUTHOR]

Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely toward not only the efficient design of innovative nanomaterials or nanostructures, but to the improvement of their functionality, we benefit from an important asset in the battle against pathogenic illnesses. Herein, we report a versatile biocompatible plasmonic nanoplatform based on a Whatman paper incorporating positively-charged gold nanospherical particles via the immersion approach. The morphological characterization of the as-engineered-plasmonic paper was examined by SEM (scanning electron microscopy) and HRTEM (high-resolution transmission electron microscopy) investigations, while its surface chemical modification with a synthetic polypeptide, specifically RRWHRWWRR-NH2 (P2), was proved by monitoring the plasmonic response of loaded gold nanospheres and the emission signal of P2 via fluorescence spectroscopy. The as-functionalized plasmonic paper is non-cytotoxic towards BJ fibroblast human cells at bactericidal concentrations. Finally, the antimicrobial activity of the P2-functionalized plasmonic paper on both planktonic bacteria and biofilms was tested against two reference strains: Gram-positive Bacteria, i.e., Staphylococcus aureus and the Gram-negative Bacteria, i.e., Escherichia coli, determining microbial inhibition of up to 100% for planktonic bacteria. In line with the above presented nanoplatform's proper design, followed by their functionalization with active antimicrobial peptides, new roads can be open for determining antibiotic-free treatments against different relevant pathogens. [ABSTRACT FROM AUTHOR]