Characterization of recombinant phytase of Klebsiella sp. and the influence of novel 3-phytase on mineral solubility in broiler diets under an in vitro digestion assay.

Phytate (inositol hexaphosphate) is the major storage form of phosphorus (P) in nature, and phytases catalyze the hydrolysis of P from phytate and the formation of inositol phosphate isomers. In this study, a bacterium that produces phytase was isolated in a phytase screening medium. The bacterium was identified as Klebsiella sp. using phenotypic and molecular techniques. The PhyK phytase gene was successfully amplified from the genome, inserted into the pET-21a (+) vector, and expressed as a recombinant protein in E. Coli BL21. The efficiency of a laboratory phytase (Lab-Ph, PhyK phytase) was determined and compared with a commercial phytase (Com-Ph, Quantum Blue 40P phytase, AB Vista) under an in vitro digestion assay. The native signal peptide effectively facilitated the translocation of the protein to the periplasmic space of E. Coli BL21, resulting in the proper folding of the protein and the manifestation of desirable enzyme activity. The Lab-Ph displayed the temperature and pH optima at 50 °C and 5 respectively. In addition, the Lab-Ph was inactivated at 80 °C. Under an in vitro digestion assay condition, Lab-Ph improved the P solubility coefficient in broiler diets. In comparison, the Com-Ph significantly increased the P solubility coefficient even when compared with the Lab-Ph. In summary, this study has shown that Lab-Ph possesses the necessary biochemical properties to be used in various industrial applications. However, Lab-Ph is extremely sensitive to heat treatment. The Lab-Ph and Com-Ph under an in vitro digestion assay improved the solubility coefficient of P in the broiler diet.

Prevalence of the Most Common Virulence-Associated Genes among Brucella Melitensis Isolates from Human Blood Cultures in Hamadan Province, West of Iran.

Brucellosis is a widespread zoonotic disease causing considerable economic and public health problems. Despite animal vaccination, brucellosis remains endemic in some areas such as Iran, especially in the western Iranian province of Hamadan. We sought to detect some of the most common virulence-associated genes in Brucella isolated from human blood cultures to determine the prevalence of some virulence genes among Brucella isolates. Fifty-seven isolates were studied from patients with a clinical diagnosis of brucellosis who referred to the Infectious Diseases Ward of Sina Hospital in Hamadan Province, Iran, between April 2013 and July 2014. Blood samples were collected for the diagnosis of brucellosis using the BACTEC blood culture system. All of these isolates were confirmed by the bcsp31 Brucella-specific gene. We detected 11 virulence-associated genes of Brucella, namely cßg, virB, znuA, ure, bvfA, omp25, omp31, wbkA, mviN, manA, and manB, which are important for the pathogenesis of this bacterium in the intracellular environment by multiplex PCR. Totally, 149 patients with a clinical diagnosis of brucellosis were enrolled in this study. Fifty-seven (38.3%) patients had positive blood cultures. On biochemical and molecular testing, all of the isolates were Brucella melitensis. Ten of the virulence genes were detected among all of the 57 isolates, but the bvf gene was detected in 53 (93%) isolates. The high prevalence of virulence-associated genes among the Brucella isolates detected in Hamadan Province, Iran, underscores the pathogenicity of this bacterium in this region.

Tissue regeneration therapy by Nano composite scaffolds based on PLGA hydrogel embedded with human dental pulp stem cells: a systematic review.

Tissue regeneration is the procedure of renewal, restoration and growth of injured tissues and defective organs including nerve, bone, tooth, cartilage and blood vessels. Repair process of damaged tissues needs non-invasive methods; so, the scientists have recently focused on alternative treatment pathways. Nano gels based on Poly Lactic-co-Glycolic Acid have been designed for different purposes in medicine. It is a biodegradable and biocompatible polymer composite. Also, human dental pulp stem cells embedded in the Poly Lactic-co-Glycolic Acid scaffold have proliferation ability and differentiation potential. They can differentiate into different cell lineages, including bone, cartilage, nerve, tooth and other tissues. So, this treatment technology can be used for tissue engineering in regenerative medicine. On the other hand, this structure is a promising application for targeted cancer therapy. Therefore, this review studied tissue, especially tooth regeneration based on the new designed Nano composite scaffolds embedded with Poly Lactic-co-Glycolic Acid hydrogel and dental pulp stem cells.

Newly designed nanoparticle-drug delivery systems against Staphylococcus aureus infection: a systematic review.

A nanoparticle-drug delivery system against Staphylococcus aureus, especially Methicillin-resistant staphylococcus aureus, has been recently proposed as an alternative pathway therapy. Methicillin-resistant staphylococcus aureus is resistance to many antibiotics, making it a a threat to human life, especially for older and immunocompromised people. Treatment of Multidrug-resistant staphylococcus aureus is considered an urgent need. A variety of kinds of nanoparticle-drug delivery systems with different compositions, and biological properties have been extensively investigated against Staphylococcus aureus. This review summarizes the novel nanoparticle-drug delivery systems against Staphylococcus aureus. These nanoparticle-drug delivery systems could reduce antibiotic resistance and minimize side effects of the antibiotics. Also, they can deliver a high concentration of the drugs and eliminate the bacteria in a specific and targeted site of infection. Despite these benefits of nanoparticle-drug delivery systems, the cytotoxicity, stress oxidative, genotoxicity, and inflammation that may occur in vivo and in vitro should not be ignored. Therefore, we need a better knowledge of the pharmacological properties and safety concerns of nanoparticle-drug delivery systems. The limitations of each nanoparticle-drug delivery system with high therapeutic potential have to be considered for further design.

Solid lipid nanoparticles and their application in the treatment of bacterial infectious diseases.

Nano pharmacology is considered an effective, safe, and applicable approach for drug delivery applications. Solid lipid nanoparticle (SLNs) colloids contain biocompatible lipids which are capable of encapsulating and maintaining hydrophilic or hydrophobic drugs in the solid matrix followed by releasing the drug in a sustained manner in the target site. SLNs have more promising potential than other drug delivery systems for various purposes. Nowadays, the SLNs are used as a carrier for antibiotics, chemotherapeutic drugs, nucleic acids, herbal compounds, etc. The SLNs have been widely applied in biomedicine because of their non-toxicity, biocompatibility, and simple production procedures. In this review, the complications related to the optimization, preparation process, routes of transplantation, uptake and delivery system, and release of the loaded drug along with the advantages of SLNs as therapeutic agents were discussed.

Prognostic biomarkers and molecular pathways mediating Helicobacter pylori-induced gastric cancer: a network-biology approach.

Cancer of the stomach is the second most frequent cancer-related death worldwide. The survival rate of patients with gastric cancer (GC) remains fragile. There is a requirement to discover biomarkers for prognosis approaches. Helicobacter pylori in the stomach is closely associated with the progression of GC. We identified the genes associated with poor/favorable prognosis in H. pylori-induced GC. Multivariate statistical analysis was applied on the Gene Expression Omnibus (GEO) dataset GSE54397 to identify differentially expressed miRNAs (DEMs) in gastric tissues with H. pylori-induced cancer compared with the H. pylori-positive with non-cancerous tissue. A protein interaction map (PIM) was built and subjected to DEMs targets. The enriched pathways and biological processes within the PIM were identified based on substantial clusters. Thereafter, the most critical genes in the PIM were illustrated, and their prognostic impact in GC was investigated. Considering p-value less than 0.01 and |Log2 fold change| as >1, five microRNAs demonstrated significant changes among the two groups. Gene functional analysis revealed that the ubiquitination system, neddylation pathway, and ciliary process are primarily involved in H. pylori-induced GC. Survival analysis illustrated that the overexpression of DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, and TXNIP was associated with poor prognosis, while increased MRPS5 expression was related to a favorable prognosis in GC patients. DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, TXNIP, and MRPS5 may be considered prognostic biomarkers for H. pylori-induced GC. However, experimental validation is necessary in the future.

Approaches to determine the efficiency of novel 3-phytase from Klebsiella pneumoniae and commercial phytase in broilers from 1 to 14 d of age.

This study aimed to evaluate the effects of a laboratory 3-phytase (the expression of the phyK gene, Lab-Phy) and a commercial 6-phytase (Quantum Blue 40 P, Com-Phy) alone and in combination (corn-soy-based diets) in broilers. A total of 400, day-old Ross 308 male broilers were randomly assigned to 5 treatments with 10 replicate cages (8 chicks/cage) for a 14-day trial. Experimental treatments included the positive control (0.95% Ca and 0.48% nonphytate phosphorus (nPP), PC), negative control (0.90% Ca and 0.22% nPP, NC), and NC which was supplemented with Lab-Phy 250 FTU/kg and Com-Phy 250 FTU/kg alone or in combination of Lab-Phy 125 FTU/kg and Com-Phy 125 FTU/kg. The inclusion of Lab-Phy in the NC diet significantly improved the P and Ca content in the tibia compared to the NC group. Moreover, the inclusion of Com-Phy alone and in combination with Lab-Phy in the NC diet significantly increased the P and Ca content in the tibia compared to the Lab-Phy. The mRNA expression of NaPi-IIb was upregulated in the duodenum by the reduction of nPP and downregulated by the inclusion of any phytase, whereas other nutrient transporters were not influenced by the reduction of nPP or the addition of phytase in the small intestine mucosa. Broilers receiving the NC diet obtained the lowest body weight (BW) and body weight gain (BWG) at 8 to 14 and 1 to 14 d of age. The NC group showed the lowest villi height and surface area, Newcastle disease (ND) antibody titer, and digestibility of nutrients compared to the PC group at 14 d of age. Supplementing the NC diet with the Lab-Phy and Com-Phy individually, or in combination tended to improve BW, BWG, tibia characteristics, villi characteristics, ND, and retained CP and P, and apparent ileal digestibility of CP, P, methionine, and threonine. The present research indicated that the studied traits by the combination of phytases were slightly better than the average of the 2 individually, suggesting there might be some value in combining the laboratory and commercial phytases.

The effects of combination therapy by solid lipid nanoparticle and dental stem cells on different degenerative diseases.

Stem cells have multiple therapeutic applications, as well as solid lipid nanoparticles. Solid lipid nanoparticle has appeared as a field of nano lipid technology with various potential applications in drug delivery, clinical medicine and research. Besides, the stem cells have a high proliferation rate and could differentiate into a variety of tissues. Stem cells derived from human dental pulp tissue differ from other sources of mesenchymal stem cells due to their embryonic neural crest source and neurotrophic potential. These consist of both dental pulp stem cells from dental pulp tissues of human permanent teeth and stem cells from human exfoliated deciduous teeth. With the emergence of stem cell banks, stem cells are considering for tissue engineering with respect to therapies attitude and regenerative medicine. The present study aimed to evaluate the advantages and disadvantages of the solid lipid nanoparticle and stem cells combination therapy in different therapeutic applications. The solid lipid nanoparticles have anticancer activity against tumors, induce neural differentiation in pluripotent stem cells, and regulate the mesenchymal stem cells. They also have immunomodulatory effects on human mesenchymal stem cells, the gene transfection efficiency, osteogenic differentiation and bone regeneration. But, the crucial health hazards related to stem cell transplantation such as immune rejection reactions and the interaction with other tissues and the effect of solid lipid nanoparticles must not be neglected. Overall, more experiments need to approve the synergism and antagonism effects of the stem cells and solid lipid nanoparticle combination therapy on different degenerative diseases.

The Effect of Helicobacter pylori Infection on Overweight: A Systematic Review and Meta-Analysis.

Background: The association between Helicobacter pylori infection and overweight, as one of the most common health issues, remains controversial. In this study, we systematically reviewed the effect of H. pylori infection and overweight to get a reliable answer. Methods: We used the Preferred Reporting Items for the Systematic Review and Meta-Analysis statement. We searched the association between H. pylori and overweight infection in international databases including Medline, Web of knowledge and Scopus, without any limitations of language, publication type, and publication status in search step of this systematic review from 2000 to 2020. We surveyed the title, abstract and full text of each research studies, and we used Newcastle-Ottawa quality for assessing the quality of each paper. A random effects model was used to calculate the pooled odd ratio with 95% confidence intervals. Results: Fifteen papers were eligible for this review. The selected studies reported different Odd Ratio between overweight and H. pylori infection but Odds Ratio (95% confidence interval) in our systematic and meta-analysis study was estimated at 1.42 (95% CI; 1.12, 1.81) and it was statistically significant (P: 0.003). Conclusion: H. pylori infection is significantly associated with overweight, therefore, the eradication of H. pylori infection is suggested because this infectious might be resulted in overweight.

The therapeutic effects of stem cells from human exfoliated deciduous teeth on clinical diseases: a narrative review study.

INTRODUCTION: Stem cells isolated from human dental pulp tissue are different from other sources of Mesenchymal stem cells because of their embryonic neural crest sources and neuro-trophic potential. These stem cells consist of dental pulp stem cells from human permanent teeth and stem cells from human exfoliated deciduous teeth. AIM: In this study, we survey the advantages and disadvantages of these stem cells with therapies attitude. MAIN TEXT: Stem cells from human exfoliated deciduous teeth with a high proliferation rate could distinguish into a wide types of cells. After stem cell banking appearance, stem cells from human exfoliated deciduous teeth can preserve and use for treatment, especially in regenerative medicine. But the crucial health hazards related to stem cell transplantation, such as immune rejection reactions and the interaction with other tissues, should not be neglected. CONCLUSION: Further experiments are required to approve the impact of these stem cells on different human disorders.

Antibacterial effects of natural compounds on biofilm formation of Streptococcus mutans.

Streptococcus mutans is the main cariogenic pathogen in the oral cavity, considered to contribute toward oral diseases. S. mutans is predominantly entrapped in plaque biofilms. OBJECTIVES: In this study, we surveyed the antibacterial activity of natural compounds in terms of the biofilm production of S. mutans. MATERIAL AND METHODS: We extracted the studies related to natural compounds affected on S. mutans biofilm from different databases. RESULTS: Disruption of S. mutans viability in biofilms by a potent new pharmacological factor could inhibit and remove cavities. Various antibacterial agents are needed to destroy biofilms that remove both pathogens and commensal bacteria, and also exert inhibitory effects on many bacterial species. CONCLUSIONS: An effective therapeutic agent for dental caries has to be capable of removing pathogens and their biofilms. Specific virulence attributes of S. mutans exist; hence, natural compounds that have excellent properties to combat such pathogens need to be selected.

Evaluation of L-arginine supplement on the growth rate, biofilm formation, and antibiotic susceptibility in Streptococcus mutans.

INTRODUCTION: Bacteria associated with dental caries have a high ability to produce organic acids from dietary carbohydrates during growth and metabolism under acidic conditions. In contrast, many symbiotic bacteria produce ammonia through the arginine deiminase (ADS) system, which modulates the pH of the oral cavity. L-Arginine metabolism by ADS is a significant inhibitor in the progression of tooth decay. This study aimed to investigate the effect of L-arginine on growth, biofilm formation, and antibiotic susceptibility in Streptococcus mutans. METHODS: In this study, the effect of L-arginine in different concentrations on the growth rate, antibiotic susceptibility, and inhibition of biofilm formation in S. mutans was investigated. RESULTS: The bacterial exponential growth rate was enhanced by 100 µM L-arginine (P > 0.05). The growth inhibition zone diameter of CAZ, CTR, AMP, and AMC-Clav antibiotics was reduced after 24 h of exposure in the presence of various concentrations of L-arginine specifically at 100 µM. L-Arginine also enhanced biofilm development at 5 and 10 µM concentrations, but reduced it at 50 and 100 µM concentrations. CONCLUSION: According to the results of the present study, optimization of L-arginine concentration and its use as an adjunctive therapy or in combination with mouthwash or varnish is recommended to prevent oral caries.

Characterization of Staphylococcus aureus isolates from pastry samples by rep-PCR and phage typing.

Background and Objectives: Staphylococcus aureus is one of the most common causes of food poisoning. This study aimed to identify S. aureus isolated from pastries, the virulence factors, antimicrobial resistance patterns, biofilm formation, and then classification based on SCCmec types, phage types, and also Rep types. Materials and Methods: In this study, 370 creamy and dried pastry samples have been randomly collected from different confectioneries in Hamadan city. The S. aureus isolates were identified by conventional microbiological methods and nuc gene amplification. The virulence factors and prophage genes were detected. After that, the biofilm production and antibiotic susceptibility assay of S. aureus isolates were examined. Finally, the isolates were classified by rep-PCR typing. Results: Among 370 samples, 97 creamy (34.64%) and 3 dried (3.33%) pastry samples were contaminated with S. aureus. Antibiotic sensitivity results showed the highest resistance to penicillin (90%) but none of them were MRSA. According to biofilm formation assay, 14 strains (45%) were strongly adhesive. The dominant phage among isolates was SGF, especially SGFa subgroup. About half of the isolates carried SCCmec Types I and III. Analysis of the genetic linkage between isolates by rep-PCR showed ≥80% genetic similarity and also different rep-types of S. aureus isolates. Conclusion: The presence of different prophage encoded virulence factors and antibiotic resistance enable S. aureus strains to produce a broad range of diseases. Thus, consumption of creamy pastries increases the risk of infection with S. aureus and it is a serious warning to the health system.

Designing a novel ELISA method based on CagA, NapA recombinant antigens to increase sensitivity and specificity of Helicobacter pylori whole cell antigen detection.

AIM: In this research, we designed a direct Enzyme Linked Immunoassay method to detect Helicobacter pylori antigens in stool specimens. BACKGROUND: Helicobacter pylori infection as the worldwide problem is related to many gastrointestinal disorders such as gastritis, gastric cancer, non-ulcer disease, peptic ulcer disease and duodenal ulcer. METHODS: We produced and purified recombinant CagA and NapA antigens in Escherichia coli and extracted their antibodies from a panel of positive sera specimens. We designed a novel enzyme linked immunoassay direct method in combination with the whole cell for the qualitative and quantitative detection of Helicobacter pylori antigens in human stool. Assay performance was evaluated by histopathology staining and urease activity. RESULTS: The sensitivity and specificity of assay was determined as 91.7 [95% confidence interval: 89.3-95.6%] and 93.1% [95% CI: 91.2-96.4%], respectively. Novel ELISA exhibits enhanced sensitivity and specificity of Helicobacter pylori detection in comparison with another commercially available kit. CONCLUSION: Combination of the recombinant antigens and whole cell of Helicobacter pylori in immunoassay designing is a new approach about early diagnosis, treatment and fallowing up of the Helicobacter pylori infected patients, especially in peptic cancer cases.

Prevalence of enterotoxin A and B genes in Staphylococcus aureus isolated from clinical samples and healthy carriers in Gorgan City, North of Iran.

BACKGROUND: Infections due to Staphylococcus aureus, a nosocomial and community-acquired pathogen, is a major public health problem. Wide range of diseases caused by S. aureus from mild infections of the skin and soft tissue to life threatening diseases which is due to having several virulence factors such as enzymes, toxins and also enterotoxins. Enterotoxin A (SEA) and enterotoxin B (SEB) are superantigens and gastrointestinal toxins causing food poisoning. The sea and seb genes encode SEA and SEB, respectively. The goal of this study was determine the prevalence of sea and seb genes in S. aureus isolated from patients and healthy carriers in Gorgan city, north of Iran. MATERIALS AND METHODS: 170 isolates of S. aureus (95 from patients and 75 healthy carriers) were collected during 1 year. After identification and purification, DNA extraction was done by phenol - chloroform method. Amplification of sea and seb genes was done by specific primers and polymerase chain reaction method. RESULTS: Among the 170 isolates of S. aureus, 60.6% and 27.1% contained sea and seb genes, respectively. The frequencies of isolates containing sea and seb genes were 58.8% and 61.3%, respectively, in methicillin-resistant Staphylococcus aureus (MRSA) isolates and 23.5% and 28.6%, respectively, in methicillin-sensitive Staphylococcus aureus (MSSA) isolates which were not statistically significant. The frequency of these genes was not related to age, sex and source of isolation in the patients. CONCLUSION: This study showed that a high proportion of S. aureus isolates carried sea gene, whereas the frequency of seb gene in this region was predictable.