Analysis of the effects of mesoporous silica particles SBA-15 and SBA-16 in Streptococcus pneumoniae transformation process.

Streptococcus pneumoniae are natural competent bacteria which requires the presence of a pheromone-like molecule to do the transformation process. This study verified the influence of mesoporous silica (SBA-15 and SBA-16) on the transformation process in S. pneumoniae using a donor DNA obtained from a mutant strain of this microorganism (Sp360∆luxS). The results showed that mesoporous silica SBA-15 and SBA-16 particles doubled the transformation ratio frequency compared with negative control (without nanoparticles) in using SBA-15 (ratio 1.81 ± 0.04) and SBA-16 (ratio 2.18 ± 0.22). We demonstrated the how mesoporous silica nanoparticles were able to increase the pneumococcus transformations, which could possibly lead to the acquisition of virulence factor genes and resistance of antibiotics.

Haemophilus influenzae porine ompP2 gene transfer mediated by graphene oxide nanoparticles with effects on transformation process and virulence bacterial capacity.

BACKGROUND: H. influenzae is a natural competent bacterium that can uptake DNA from the environment and recombine into bacterial genome. The outbreaks of Brazilian purpuric fever, heavily polluted areas of a different H. influenzae biogroup - aegyptius - as well as gene transference between Neisseria meningitis make the transformation process an important evolutionary factor. This work studied the horizontal transference of the ompP2 gene from a multiresistant strain of H. influenzae 07 (NTHi), under the influence of graphene oxide nanoparticles in order to mimic an atmosphere rich in suspended particles and this way verify if the CFU transformants number was increased. MATERIAL AND METHODS: In this article the gene ompP2 was transformed into different strains of H. influenzae mediated or not by graphene oxide nanoparticles in suspension, followed by the adhesion tests in Hec-1B (human endometrium adenocarcinoma) and A549 (pulmonary epithelial carcinoma) cells lines. The transformation frequency and the adhesion capacity were determined in all the mutants to which the ompP2 gene was transferred and compared to their wild type strains. RESULTS: The nanoparticles increased the transformation ratio of one particular strain isolated from a pneumonia case. The adhesion patterns to A549 and Hec1b cell lines of these mutated bacteria has their capacity increased when compared to the wild type. CONCLUSIONS: Graphene oxide nanoparticles aid the transformation process, helping to increase the number of CFUs, and the mutants generated with the ompP2 gene from a H. influenzae resistant strain not only present a chloramphenicol resistance but also have an increased adherence patterns in A549 and Hec1B cell lines.