Considerable increase in Poly(3-hydroxybutyrate) production via phbC gene overexpression in Ralstonia eutropha PTCC 1615

Introduction: Poly(3-hydroxybutyrate) (PHB) is a well-known biodegradable polymer produced by some microorganisms and can be a suitable alternative for petrochemical plastics. PHB synthase encoded by phbC gene is the main enzyme in PHB biosynthesis pathway in Ralstonia eutropha. The aim of current study was the transformation of R. eutropha PTCC 1615 with its own phbC gene and evaluation of the overexpression effect on PHB accumulation. Methods: DNA fragment including phbC gene and its promoter and terminator regions, was isolated from R. eutropha PTCC 1615, inserted into pET28a(+) vector, and transferred to the competent bacteria using calcium chloride and heat shock method. The effect of the cloned gene expression on PHB production was investigated with absorption of crotonic acid produced through PHB dehydration. Statistical analyses were carried out by SPSS software. Results: PHB content of cells of the engineered strain was 1.4 times more than that of the native bacteria. This significant difference can be an important finding for improvement of biopolymer production. Conclusion: Overexpression of phbC, the critical gene in PHB biosynthesis pathway, in R. eutropha PTCC 1615 had considerable effect on PHB accumulation

Genetics of immunoglobulin-A vasculitis (Henoch-Schönlein purpura): An updated review

Immunoglobulin-A vasculitis (IgAV) is classically a childhood small-sized blood vessel vasculitis with predominant involvement of the skin. Gastrointestinal and joint manifestations are common in patients diagnosed with this condition. Nephritis, which is more severe in adults, constitutes the most feared complication of this vasculitis. The molecular bases underlying the origin of IgAV have not been completely elucidated. Nevertheless, several pieces of evidence support the claim that genes play a crucial role in the pathogenesis of this disease. The human leukocyte antigen (HLA) region is, until now, the main genetic factor associated with IgAV pathogenesis. Besides a strong association with HLA class II alleles, specifically HLA-DRB1 alleles, HLA class I alleles also seem to influence on the predisposition of this disease. Other gene polymorphisms located outside the HLA region, including those coding cytokines, chemokines, adhesion molecules as well as those related to T-cells, aberrant glycosylation of IgA1, nitric oxide production, neoangiogenesis, renin-angiotensin system and lipid, Pyrin and homocysteine metabolism, may be implicated not only in the predisposition to IgAV but also in its severity. An update of the current knowledge of the genetic component associated with the pathogenesis of IgAV is detailed in this review.Acknowledgements: RL-Mis supported by the Miguel Servet I programme of the Spanish Ministry of Economy and Competitiveness through the grant CP16/ 00033. FG is recipient of a Sara Borrell postdoctoral fellowship from the “Instituto Carlos III de Salud” at the Spanish Ministry of Health (Spain) (CD15/00095). SR-M is supported by funds from the RETICS Program (RIER) (RD16/0012/0009). FDC is supported by the Ramón y Cajal programme of the Spanish Ministry of Economy and Competitiveness through the grant RYC-2014-16458

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Isolation and identification of resistant bacteria from dental clinic and evaluation of biofilm formation by them

Background and Aim: Surface bacterial contamination has been shown to be a potential source of cross-infection. The aim of this study was to identify resistant bacterial isolates in the dental clinic before and after disinfection and evaluation of biofilm formation by them. Materials and Methods: Sampling was performed at a dental clinic in Isfahan, Iran, on 2014. Samples were obtained by using swab and settle plate method. In the firs method, sterile swabs were used to sample of dental instrument and unit chair surface before and after disinfection, then swabs were transferred to TSB media (60 tubes). In the second method, air monitoring was carried out by settling blood agar and nutrient agar plates at the certain distance from the patient for 1 hour (24 plates). Then these samples incubated aerobically for 2 days at 37°C. Isolates were identified to species level with morphological and biochemical features and 16S ribosomal RNA gene sequencing. In addition, the strength of biofilm formation by isolates was measured by using microtiter plate method. Results: Most of these isolates were spore-forming Bacillus species and environmental Staphylococcus species. On the basis of the strength of biofilm formation, the most important identified bacteria were Staphylococcus xylosus and Bacillus safensis. Conclusions: Bacteria that are able to form biofilm, can survive after disinfection of dental instruments and can enhance the risk of infection in dental practice by providing a surface for colonization of pathogens

Study of antagonistic effects of Lactobacillus strains as probiotics on multi drug resistant (MDR) bacteria isolated from urinary tract infections (UTIs)

Objective(s):Urinary tract infection (UTI) caused by bacteria is one of the most frequent infections in human population. Inappropriate use of antibiotics, often leads to appearance of drug resistance in bacteria. However, use of probiotic bacteria has been suggested as a partial replacement. This study was aimed to assess the antagonistic effects of Lactobacillus standard strains against bacteria isolated from UTI infections. Materials and Methods: Among 600 samples; those with ≥10,000 cfu/ml were selected as UTI positive samples. Enterococcus sp., Klebsiella pneumoniae, Enterobacter sp., and Escherichia coli were found the most prevalent UTI causative agents. All isolates were screened for multi drug resistance and subjected to the antimicrobial effects of three Lactobacillus strains by using microplate technique and the MICs amounts were determined. In order to verify the origin of antibiotic resistance of isolates, plasmid curing using ethidium bromide and acridine orange was carried out. Results: No antagonistic activity in Lactobacilli suspension was detected against test on Enterococcus and Enterobacter strains and K. pneumoniae, which were resistant to most antibiotics. However, an inhibitory effect was observed for E. coli which were resistant to 8-9 antibiotics. In addition, L. casei was determined to be the most effective probiotic. Results from replica plating suggested one of the plasmids could be related to the gene responsible for ampicillin resistance. Conclusion: Treatment of E. coli with probiotic suspension was not effective on inhibition of the plasmid carrying hypothetical ampicillin resistant gene. Moreover, the plasmid profiles obtained from probiotic-treated isolates were identical to untreated isolates

Seroprevalence of Helicobacter Pylori Infection in Iranian Adolescents: the CASPIAN- III Study

Background: Helicobacter pylori (H.pylori) is a common bacterial infection, with considerably high morbidity and mortality worldwide. This bacterium represents a key factor in the etiology of various chronic infections ranging from gastritis, peptic ulcer disease to gastric cancer; but the prevalence has large variations in different communities. The aim of this study was to estimate the prevalence H. pylori infection in a nationally representative sample of Iranian adolescents.Materials and Methods: In this cross-sectional study, serum samples of 882 Iranian adolescents, aged 10-18 years, were examined for seroprevalence of H.pylori. They were randomly selected from the samples obtained in the third survey of a national surveillance program (the CASPIAN III study). Seroprevalence of H. pylori was examined by detection of H. pylori immunoglobulinA (IgA), immunoglobulinG (IgG) and immunoglobulinM (IgM) in sera by using Enzyme Linked Immunosorbant Assay (ELISA).Results: The study participants had a mean age of 14.82 + 2.77 years. Overall, 51.7% of students were boys and 61.52% were urban residents.  The H. pylori IGM and IGA seropositivity had no significant association with demographic characteristics (p>0.05). The H. pylori IgG seropositivity were significantly different in boys and girls (69.7%, 95% confidence interval [CI] = 66.7-72.7 vs. 76.3%, 95%CI= 73.5-79. 1, respectively, P=0.03).Conclusion: The seroprevalence of H. pylori IgG in Iranian adolescents is high, and girls had greater risk of H. pylori IgG seropositivity compared to boys. Preventive strategies and health education are recommended to reduce the prevalence of this infection in Iranian adolescent

Immunogenicity and safety of RAZI recombinant spike protein vaccine (RCP) as a booster dose after priming with BBIBP-CorV: a parallel two groups, randomized, double blind trial

Abstract Background The immunity induced by primary vaccination is effective against COVID-19; however, booster vaccines are needed to maintain vaccine-induced immunity and improve protection against emerging variants. Heterologous boosting is believed to result in more robust immune responses. This study investigated the safety and immunogenicity of the Razi Cov Pars vaccine (RCP) as a heterologous booster dose in people primed with Beijing Bio-Institute of Biological Products Coronavirus Vaccine (BBIBP-CorV). Methods We conducted a randomized, double-blind, active-controlled trial in adults aged 18 and over primarily vaccinated with BBIBP-CorV, an inactivated SARS-CoV-2 vaccine. Eligible participants were randomly assigned (1:1) to receive a booster dose of RCP or BBIBP-CorV vaccines. The primary outcome was neutralizing antibody activity measured by a conventional virus neutralization test (cVNT). The secondary efficacy outcomes included specific IgG antibodies against SARS-CoV-2 spike (S1 and receptor-binding domain, RBD) antigens and cell-mediated immunity. We measured humoral antibody responses at 2 weeks (in all participants) and 3 and 6 months (a subgroup of 101 participants) after the booster dose injection. The secondary safety outcomes were solicited and unsolicited immediate, local, and systemic adverse reactions. Results We recruited 483 eligible participants between December 7, 2021, and January 13, 2022. The mean age was 51.9 years, and 68.1% were men. Neutralizing antibody titers increased about 3 (geometric mean fold increase, GMFI = 2.77, 95% CI 2.26–3.39) and 21 (GMFI = 21.51, 95% CI 16.35–28.32) times compared to the baseline in the BBIBP-CorV and the RCP vaccine groups. Geometric mean ratios (GMR) and 95% CI for serum neutralizing antibody titers for RCP compared with BBIBP-CorV on days 14, 90, and 180 were 6.81 (5.32–8.72), 1.77 (1.15–2.72), and 2.37 (1.62–3.47) respectively. We observed a similar pattern for specific antibody responses against S1 and RBD. We detected a rise in gamma interferon (IFN-γ), tumor necrosis factor (TNF-α), and interleukin 2 (IL-2) following stimulation with S antigen, particularly in the RCP group, and the flow cytometry examination showed an increase in the percentage of CD3 + /CD8 + lymphocytes. RCP and BBIBP-CorV had similar safety profiles; we identified no vaccine-related or unrelated deaths. Conclusions BBIBP-CorV and RCP vaccines as booster doses are safe and provide a strong immune response that is more robust when the RCP vaccine is used. Heterologous vaccines are preferred as booster doses. Trial registration This study was registered with the Iranian Registry of Clinical Trial at www.irct.ir , IRCT20201214049709N4. Registered 29 November 2021