A light shining through darkness: probiotic against COVID-19

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Functional and Structural Characterization of SARS-Cov-2 Spike Protein: An In Silico Study

BACKGROUND፡ Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the global outbreak of coronavirus disease 2019 (Covid-19), which has been considered as a pandemic by WHO. SARS-CoV-2 encodes four major structural proteins, among which spike protein has always been a main target for new vaccine studies. This in silico study aimed to investigate some physicochemical, functional, immunological, and structural features of spike protein using several bioinformatics tools.METHOD: We retrieved all SARS-CoV-2 spike protein sequences from different countries registered in NCBI GenBank. CLC Sequence Viewer was employed to translate and align the sequences, and several programs were utilized to predict B-cell epitopes. Modification sites such as phosphorylation, glycosylation, and disulfide bonds were defined. Secondary and tertiary structures of all sequences were further computed.RESULTS: Some mutations were determined, where only one (D614G) had a high prevalence. The mutations did not impact the B-cell and physicochemical properties of the spike protein. Seven disulfide bonds were specified and also predicted in several N-link glycosylation and phosphorylation sites. The results also indicated that spike protein is a non-allergen.CONCLUSION: In summary, our findings provided a deep understanding of spike protein, which can be valuable for future studies on SARS CoV-2 infections and design of new vaccines

Serological Diagnosis of Helicobacter pylori Infection in Patients With a Polycystic Ovary Syndrome

Background: Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in 4%-6% of women in the reproductive age and is a common cause of infertility. Even though the number of investigations is scarce, studies show that Helicobacter pylori infection may influence reproduction. Objectives: The purpose of this study was to determine and compare the levels of H. pylori specific antibodies IgA, IgG and anti-CagA at both PCOS and non-PCOS women with their spouses using the serological test. Patients and Methods: In this cross-sectional study, 127 women with their spouses (age range, 30 - 60 years) were selected. These patient were referred to infertility center of Shariati Hospital in Tehran, Iran, with a diagnostic criteria of PCOS based on Androgen Excess Society (AES). The specific antibodies of IgA, IgG and anti-CagA were measured using the commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. Results: The positive titers of H. pylori antibodies IgA, IgG and anti-CagA in the PCOS group were 45 (35%), 79 (62%) and 77 (60.5%), respectively, while in non-PCOS group were 38 (30%), 76 (60%) and 50 (39.5%), respectively. The sera positive for IgA, IgG and anti-CagA antibodies in spouses of the non-PCOS group were 38 (30%), 84 (66%) and 79 (62%) respectively, but in spouses of the PCOS group were 51 (40%), 83 (66%) and 48 (38%), respectively. The results showed that H. pylori infection probably did not affect infertility or reproduction. Conclusions: Findings of this study demonstrate no significant difference between levels of H. pylori specific antibodies of IgA, IgG, anti-CagA and the presence of PCOS disorders, and also indicate that serologic testing is a sensitive method for the detection of H. pylori antibodies. The high prevalence of H. pylori positive antibody levels in both PCOS and non-PCOS patients can be probably associated with the high frequency of H. pylori infection

Evaluation of the antibacterial and antibiofilm activity of probiotic bacteria against causative bacterial pathogens of dental caries

The most important factor in tooth decay and periodontal disease is the attachment of oral bacteria, especially streptococci, to different levels of the mouth and teeth. Therefore, by changing the microbial ecology in the mouth using probiotic producing bacteria, we can help prevent tooth decay and periodontal infections. This study aimed to evaluate the antibacterial and antibiofilm activities of probiotic producing Lactobacillus against several streptococci that cause tooth decay. Antimicrobial activity and minimal inhibitory concentration (MIC) of probiotic lactobacilli was determined by disk diffusion method and standard broth microdilution, respectively. Antibiofilm activity was assayed by a microtiter-plate screening method. The five isolates of Lactobacillus strains with probiotic properties include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus fermentum, and Lactobacillus brevis were tested against Streptococcus mutans and Streptococcus sanguinis. Most of tested Lactobacillus strain at concentrations above 125 µg/mL showed antibacterial properties. Also, examination of the MICs showed that probiotic bacteria had greater effects on S. sanguinis. While, the tested probiotic bacteria did not show a significant antibiofilm effect. Our results suggest that lactobacilli with potential probiotic properties can be effective used for eliminating oral streptococcal colonization

A comparison of culture and PCR methods for identification of Aggregatibacter actinomycetemcomitans isolated from acute necrotizing ulcerative gingivitis

Objective: To determine Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) isolated from periodontal patients and healthy subjects using culture and PCR methods. Methods: Duplicate paper point needles were taken from 100 samples (50 healthy subjects and 50 patients), who referred to the specialized dental clinic from Oct. 2015 to Mar. 2016. In laboratory after incubation period and observing the star-shaped colony A. actinomycetemcomitans, the confirmation tests, including gram staining and catalase test were carried out. For PCR, samples were analyzed with genus specific primers. These primers set, amplified a 500 bp fragment. Results: Of the 100 samples, A. actinomycetemcomitans was isolated from 31 patients (31%), (24 isolate of patients, and 7 isolate of healthy subjects) by using a selective Aggregatibacter isolation medium. Using PCR, a total of 49 (49%) samples were found to be positive for A. actinomycetemcomitans (35 isolate of patients, and 14 isolate of healthy subjects). Conclusion: PCR was found to be highly sensitive when genus specific primers were used for diagnosis of A. actinomycetemcomitans in comparison with culture method