Nowadays, nanovaccine is considered as an evolving method in the field of vaccination to induce immunity in the human body against various diseases, including bacterial or viral diseases as well as virulent tumors. Nanovaccines are more efficient than traditional vaccines since they could potentially induce both humoral and cellular immune reactions. Various studies have shown that nanoparticles with multiple compounds have been designed as delivery systems or as adjuvants for vaccines. Nanoparticles could function as a drug delivery tool, as an adjuvant to promote antigen processing, and as an immune modulator to induce immune responses. These nanoparticles generate immune responses through activating immune cells as well as through the production of antibody responses. Design engineering of nanoparticles (NPs) used to produce nanovaccines to induce immunity in the human body needs comprehensive information about the ways they interact with the component of immune system. Challenges remain due to the lack of sufficient and comprehensive information about the nanoparticles' mode of action. Several studies have described the interactions between various classes of nanoparticles and the immune system in the field of prevention of bacterial infections. The results of some studies conducted in recent years on the interaction between nanoparticles and biosystems have considerably affected the methods used to design nanoparticles for medical applications. In this review, NPs’ characteristics influencing their interplay with the immune system were discussed in vivo. The information obtained could lead to the development of strategies for rationalizing the design of nanovaccines in order to achieve optimum induction of immune response.

Vibrio cholerae is a major cause of severe diarrhea, which is ecologically flexible, and remains as a major cause of death, especially in developing countries. Consecutive emergence of antibiotic-resistant strains is considered to be as one of the major concerns of the World Health Organization (WHO). Nanoparticles as a new nonantibiotic therapeutic strategy have been widely used in recent years to treat bacterial infections. The present study aimed to investigate the antibacterial and antibiofilm effect of selenium nanoparticles (SeNPs) in vitro against V. cholerae O1 ATCC 14035 strain. SeNPs were prepared and characterized using ultraviolet-visible (UV-Vis) spectroscopy, DLS (dynamic light scattering), zeta potential measurement, and Fourier transform infrared (FTIR) analysis. The concentration of SeNPs was calculated by ICP (inductively coupled plasma) method. Also, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was employed to assess the cytotoxic effect of SeNPs on Caco-2 cells. Antibacterial and antibiofilm activity of SeNPs was determined by broth microdilution and crystal violet assays, respectively. The average particle size of SeNPs was 71.1 nm with zeta potential −32.2 mV. The SEM images supported the uniform spherical morphology of the prepared nanoparticles. The antibiofilm effect of SeNPs was evident at concentrations of 50–200 μg/mL. This study results provided evidence that SeNPs are safe as an antibacterial and antibiofilm agent against V. cholerae O1 ATCC 14035 strain.

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Background: Many factors are involved in the development of SARS-CoV-2 infection in individuals in each region, such as physiological conditions, underlying diseases, and observance of personal protection and hygiene; therefore, this study aimed to investigate factors affecting the incidence of COVID-19 in Bandar Lengeh, Hormozgan province, southern Iran. Materials & Methods: Blood samples and demographic information were collected from suspected COVID-19 patients referring to Shahid Rajaei governmental health centers in Bandar Lengeh city. Hematological, biochemical, and serological tests were performed on the samples. PCR experiment was conducted to confirm SARS-CoV-2 infection. The thorax computed tomography (CT) was performed for all patients. Findings: According to the PCR test results, the prevalence rate of SARS-CoV-2 infection was 26.92% among 130 individuals enrolled in this study. SARS-CoV-2 infection was more prevalent among clerks than in other occupational groups (p=0.017). Increased ESR (erythrocyte sedimentation rate) and decreased WBC (white blood cell), lymphocyte, and platelet counts were evident in COVID-19 patients. Also, the prevalence of COVID-19 infection was higher in patients with blood group A (33.3%) than in patients with other blood groups. The CRP (C-reactive protein) test was positive for 31 patients whose PCR test was positive for SARS-CoV-2. In addition, LDH (lactate dehydrogenase) level was higher in infected individuals compared to other participants (p=0.018). Conclusion:In addition to the PCR test result, the most effective factors for diagnosing COVID-19 patients best on blood tests were as follows: increased CRP, ESR, and LDH levels and decreased WBC, lymphocyte, and platelet counts.