Background: Bacterial burn infections are one of the serious infections and since their treatment with antibiotics is very difficult, infection control in such wounds is very important. Therefore, methods should be sought to enhance the effects of antibiotics and also reduce the resistance to them. It seems that probiotics have antimicrobial features and are effective in wound healing. Objectives: The current study aimed at evaluating and comparing the antimicrobial effects of antibiotics and probiotics, as well as their combination on bacterial burn infections. Methods: Thirty clinically resistant Pseudomonas aeruginosa species isolated from hospitalized patients with burn wounds were collected. Antibacterial activity of five antibiotics and 11 probiotic strains, and also their combination were evaluated by disk diffusion method. One-way ANOVA and Tukey post hoc test were used for data analysis. Results: It was found that the effect of inhibitory zone in combination use of tetracycline + a probiotic strain was more than using the antibiotic and probiotic alone. Also, the current study found that among the probiotics, Lactobacillus plantarum 299v had the highest effect, although not significant, on resistant P. aeruginosa. The current study explained that the inhibitory effect of L. plantarum 299v was significantly higher than that of ciprofloxacin (P = 0.009). In addition, antibacterial activity of gentamicin + L. salivarius (ES1) was significantly higher compared with that of gentamicin + L. routeri (P = 0.01). Conclusions: The current study explained that probiotics had a useful potential inhibitory effect on the growth of the pathogens. The study showed that in most cases, inhibitory zones of probiotics were greater than those of antibiotics as well as combination of antibiotic + probiotic. But, there was an exception in tetracycline, which had synergistic effect with probiotics. Conversely, in the cases of imipenem and chloramphenicol, addition of probiotics had antagonistic effects. Further studies are needed to describe different results. Therefore, it seems that the type of antibiotics and probiotics are important to create the synergistic or antagonistic effects.

Although not fully recognized, the neurotoxic effects of silver nanoparticles (Ag-NPs) are thought to occur through induction of oxidative stress and apoptosis. To investigate the exact underlying molecular mechanism, we aimed to explore the apoptotic effects of intraperitoneal injection of Ag-NPs and investigated the possible attributed changes in the mRNA expression of Bcl-2 and Bax genes in the rat hippocampus. Two in vivo sets of experiments, one to demonstrate apoptosis and the other to assess gene expression, were conducted on male Wistar rats. In each set, the first group, acting as control, received saline and the other three groups received Ag-NP at doses of 100, 200, and 400 ppm for five successive days. Ten days after the last injection, hippocampal tissue of the first set of rats was assessed for apoptosis using terminal deoxynucleotidyl transferase-mediated deoxy uridine triphosphate nick-end labeling staining. In the second set of experiments, mRNA expression of Bcl-2 and Bax genes was evaluated using real-time polymerase chain reaction. Ag-NP treatment was shown to induce apoptosis in a dose-dependent manner. Furthermore, Ag-NP reduced mRNA level of Bcl-2 in the rat hippocampal cells at all investigated doses compared to the control group ( p < 0.001). The mRNA level of Bax, on the other hand, was increased in these cells. The increase was significant compared to the control group at the doses of 200 ppm ( p < 0.05) and 400 ppm ( p < 0.001). Our results show that Ag-NPs reduce Bcl-2 and increase Bax genes expression, resulting in increased Bax/Bcl-2 ratios in rat hippocampal cells. This altered gene expression induces cell apoptosis and contributes to the neurotoxicity of Ag-NPs.

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Background: Nanobacteria-like structures (NLSs) or calcifying nanoscale particles (CNPs) are novel ambiguous entities. As their names imply, they are tiny creatures (100 to 500 nanometers). Compared to ordinary bacteria, they can exhibit some unbelievable properties such as resistance to conventional antibacterial procedures. Form a scale point of view, these microorganisms are much smaller than ordinary bacteria and are preserved from the outer environment by their rigid apatite shell. The above-mentioned protective properties of nanobacteria are responsible for a dangerous in vivo calcification procedure causing pathological infectious diseases. Objectives:The main goal of this study was to identify and isolate the nanobacteria from patients with atherosclerosis. Methods: Human vascular tissues were assessed for the presence of NLSs in atherosclerotic plaques at Sina Hospital, Tehran, Iran. All 40 samples obtained from patients as the wastes of surgery showed crystallization in vitro after about 10 days. Crystallization was seen also in filtered media. The precipitates of media were investigated by scanning electron microscopy (SEM). Results:NLSs were seen in all samples by SEM. After confirming the NLSs presence, they were characterized by TEM, XRD, and SEM/EDAX. Conclusions:The NLSs are observed in patients with atherosclerosis.