27 research outputs found

    Evaluation of Neurofibromatosis Gene Expression in Non-Hereditary Breast Cancer

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    Background: Breast cancer is the most common cause of death in women. Studies have shown that changes in neurofibromatosis gene expression can cause breast cancer. The aim of this study was to investigate the change of neurofibromatosis type 1 gene expression in non-hereditary breast cancer using real time PCR. Materials and Methods: In this study, 160 tissue samples were collected from patients following ethical principles. After lysis of tissues, extraction of RNA and synthesis of cDNA was performed. The amount of gene expression changes was investigated. Results: The results showed that the level of NF1 gene expression was dependent on the stages of the disease and as the stages progress, the level of expression of this gene showed a significant decrease. Conclusion: The use of gene biomarkers can help to diagnose and treat diseases faster. Along with examining other candidate genes, using NF1 gene expression analysis in breast cancer patients can be a suitable option for diagnosing the stages of disease progression

    Bacteriorhodopsin and its Mutants allude a breakthrough impending to artificial retina construction and strategies for curing blindness

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           Bacteriorhodopsin, a model system in nanobiotechnology, is a light-sensitive protein found in the archaean Halobacterium salinarum and a very identical protein to visual Rhodopsin. The modification of biological function of BR and its versatile properties is valuable for technical applications including the artificial retina. These photoactive elements of native and particular mutants of bacteriorhodopsin make protein films, used in artificial retinal implants, to treat some retinal diseases and disorders. The two major reasons of retinal photoreceptor cell deterioration are Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). As in vitro culture of Halobacterium is very difficult, and isolation procedure is much time consuming and usually inefficient, so genetic construction of protein is essential. Here, we have produced two types of bacteriorhodopsin, a native and a mutant BR (D85E) and studied their opto-electric responses with respect to wavelength and absorption properties. They are prerequisite for designing artificial retina (sensors) based on biomolecules. Therefore, the new promising technology soon will conceivably eradicate the blindness

    Antipseudomonal activity of Artemisia quettensis Podlech essential oil and its synergy with imipenem

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    Context: The problems associated with hospital infections caused by Pseudomonas aeruginosa, and the emergence of new and the re-emergence of old infectious diseases have become increasingly evident. Therefore, medicinal plants take precedence over the development of new antibacterial agents. The combination effects of antibiotics and plant compounds might be an appropriate solution for microbial resistance and useful method for assessment of synergistic interactions for inhibition of bacterial growth. This study is an experimental design for the discovery and finding of natural and harmless compounds for the treatment of infectious diseases. Aim: To determine the antibacterial potency of Artemisia quettensis essential oil, and in combination with imipenem, to inhibit the growth of Pseudomonas aeruginosa. Methods: The essential oil was obtained through hydrodistillation from aerial parts of the plant and analysis using GC and GC-MS. To demonstrate the in vitro antibacterial activity of the essential oil against Pseudomonas aeruginosa (ATCC 27853) disc diffusion assay was used, either alone or in combination with a standard antibiotic. Results: The most dominant components were homoadamantane (9.38%), Camphor (7.91%) and Eugenol (10.46%). The oil and antibiotic showed high antibacterial activity against Pseudomonas aeruginosa with minimal inhibitory concentration (MIC) 0.5 µL/mL and 16 µg/mL and minimal bactericidal concentration (MBC) 4 µL/mL and 32 µL/mL, respectively. The synergistic effect of the oil and antibiotic showed MIC 0.2 µL/mL and 4 µg/mL and MBC 2 µL/mL and 8 µL/mL, respectively. This study showed that Artemisia quettensis oil has significant antibacterial activity against Pseudomonas aeruginosa infections. Conclusions: The essential oil exhibited synergism with imipenem displaying the ability to enhance the activity of this compound and it may be useful in the fight against emerging microbial drug resistance

    Evaluation the cytotoxic effect of cytotoxin-producing Klebsiella oxytoca isolates on the HEp-2 cell line by MTT assay

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    Background: The cytotoxic effects on epithelial cells of the human are not observed in other strains of Klebsiella spp and are only observed in K. oxytoca strains. MTT assay was used to evaluate cytotoxic activity. In this study, colorimetric method was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. Materials and methods: In this study, we collected a total of 75 K. oxytoca strains isolate and we detected the production of toxins and their cytotoxic effects on HEp-2 cells. Colorimetric method such as MTT assay was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. Results: Nine isolates had cytotoxic effects on HEp-2 cells. The results of MTT assay showed that the isolated strains were different from the control stain in terms of toxinogenicity and cytotoxic effects on HEp-2 cells at the studied dilutions (1:3, 1:6, 1:12, 1:24, 1:48, and 1:96). Conclusions: In the current study, Percentage of Hep-2 surviving cells exposed to 1:3, 1:6, 1:12, 1:24, 1:48, and 1:96 supernatant dilutions of cytotoxin-producing Klebsiella oxytoca isolates was different

    Identification of Klebsiella pneumoniae Carbapenemase-producing Klebsiella oxytoca in Clinical Isolates in Tehran Hospitals, Iran by Chromogenic Medium and Molecular Methods

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    Objectives: Production of carbapenemase, especially Klebsiella pneumoniae carbapenemases (KPC), is one of the antibiotic resistance mechanisms of Enterobacteriaceae such as Klebsiella oxytoca. This study aimed to investigate and identify KPC-producing K. oxytoca isolates using molecular and phenotypic methods. Methods: A total of 75 isolates of K. oxytoca were isolated from various clinical samples, and were verified as K. oxytoca after performing standard microbiological tests and using a polymerase chain reaction (PCR) method. An antibiotic susceptibility test was performed using a disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines. CHROMagar KPC chromogenic culture media was used to examine and confirm the production of the carbapenemase enzyme in K. oxytoca isolates; in addition, PCR was used to evaluate the presence of blaKPC gene in K. oxytoca strains. Results: Of a total of 75 K. oxytoca isolates, one multidrug resistant strain was isolated from the urine of a hospitalized woman. This strain was examined to assess its ability to produce carbapenemase enzyme; it produced a colony with a blue metallic color on the CHROMagar KPC chromogenic culture media. In addition, the blaKPC gene was confirmed by PCR. After sequencing, it was confirmed and deposited in GenBank. Conclusion: To date, many cases of KPC-producing Enterobacteriaceae, in particular K. pneumoniae, have been reported in different countries; there are also some reports on the identification of KPC-producing K. oxytoca. Therefore

    Identification of cytotoxin-producing Klebsiella oxytoca strains isolated from clinical samples with cell culture assays

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    BACKGROUND: Klebsiella oxytoca is an opportunistic pathogen which damages intestinal epithelium through producing cytotoxin tilivalline. This toxin plays a role in the pathogenesis of bacteria and is the main virulence factor which leads to antibiotic-associated hemorrhagic colitis progress. MATERIALS AND METHODS: In this study, we collected a total of 75 K. oxytoca strains isolated from the stool, urine, blood, wounds, and sputum and evaluated them in terms of the production of toxins; we detected their cytotoxic effects on HEp-2 cells. RESULTS: Of all the isolates, five K. oxytoca strains isolated from the stool cultures, two strains isolated from the blood cultures, one strains isolated from the wound cultures, and one strains isolated from the urine cultures had cytotoxic effects on HEp-2 cells. The strains isolated from sputum cultures had no cytotoxic effects on HEp-2 cells. CONCLUSIONS: In the current study, the majority of strains isolated from the stool of the patients included cytopathic effects on HEp-2 cells. Copyright © 2017 Elsevier Ltd. All rights reserved

    A New Approach for Designing a Potentially Vaccine Candidate against Urinary Tract Infection by Using Protein Display on Lactobacillus

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    Background: The prevalence of Urinary Tract Infection (UTI) is really high in the world. Escherichia coli is a major agent of UTI. One of the strategies for decreasing UTI infections is vaccine development. As the attachment is a really important stage in colonization and infection, at- tachment inhibition has an applied strategy.  FimH protein is a major factor during bacterial colonization in urinary tract and could be used as a vaccine. Thus, it was considered in this research as a candidate anti- gen. Methods: The sequences of fimH and acmA genes were used for de- signing a synthetic gene. It was cloned to pET23a expression vector and transformed  to E. coli (DE3) Origami.  To confirm the expression  of recombinant  protein,  SDS-PAGE  and western  blotting  methods  were used.  Subsequently,  recombinant  protein  was  purified.  On  the  other hand, Lactobacillus reuteri was cultured and mixed with FimH / AcmA recombinant  protein. The rate of protein localization  on lactobacillus surface was assessed using ELISA method. Results: It was showed that the recombinant protein was expressed in E. coli (DE3) Origami and purified by affinity chromatography. More- over, this protein could be localized on lactobacillus surface by 5 days. Conclusion:  In current study,  a fusion recombinant  protein was pre- pared and displayed on L. reuteri surface. This strain could be used for animal  experiment  as  a  competitor  against  Uropathogenic   E.  coli (UPEC). Using manipulated probiotics strains instead of antibiotic ther- apy could decrease the antibiotic consumption  and reduce multi-drug resistant strains

    Cloning and Expression of Nano Body Gene against Enterotoxin B of Staphylococcus Aureus

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    Background & Objectives: Staphylococcus aureus bacteria causes many different diseases by secretion of various enterotoxins. Therefore, it is necessary to develop ways that facilitate the detection of enterotoxins. Nowadays, immunochemical methods which are based on monoclonal antibody technology are used. The heavy chain antibodies that are called VHH or Nano body were found in blood serum of the Camelidae family. The unique properties of this antibody such as their binding to small molecules like toxins make them attractive candidates for the development of immunodiagnostic tests. The present study was done to achieve a VHH molecules against Staphylococcus enterotoxin B. Materials & Methods: Freighting phage library for isolate private Nano bodies against enterotoxin B was done in previous works. Next, pCANTAB 5E vector that consists VHH, extracted from E.coli bacteria strain xl1blue, and after doing PCR process with relative primers, sub cloning in pET21a(+) as an expression vector with cut sites NdeI and XhoI was done. Transformation in E.coli bacteria strain BL21(DE3) was done. Then, the cells effected with IPTG and producing time, and other terms were optimized. Finally, the expression of the protein with SDS-PAGE and western blot techniques was evaluated. Result: For proving cloning of nano body gene in pET21a (+) vector, nucleotide sequence of gene was analyzed, and transforming to E.coli bacteria strain BL21(DE3) was successful. After inspiration, active protein in cell was seen by SDS-PAGE technique and proved by western blot. Conclusion: cloning, sub cloning, and nonabody expression were surveyed in this research. Production of this protein can help to develop new therapeutic methods and produce vaccine against enterotoxin B of Staphylococcus aureu

    Isolation and molecular identification of gamma-radiation resistant-bacteria from soil samples of a radioactive site in South Khorasan province

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    Background and objectives: Radiation resistance has been found widely among bacteria but little is known about the biodiversity of radiation resistant-bacteria in naturally radioactive-contaminated places in Iran. The aim of this study is to identify the radio resistant-bacteria isolated from soil samples in such locations. Materials and Methods: Samples were collected from suspected above sites and cultured on TGY agar and incubated at 300C using serial dilutions. All isolates were treated with gamma-radiation from 0 to 30 kGy doses and then plated on TGY agar medium. A radio-resistant isolate was identified by microbiological methods and verified by 16S rRNA sequencing. Results: From a total of 20 isolates which were recovered from soil samples, one isolate (F1 5kGy) could survive against gamma radiation. Phylogenetic analysis based on 16S rRNA sequencing reconfirmed the conventional identification tests showing that F1 5kG bacterium belonged to Kocuria genus with up to 5000Gy resistance to gamma radiation. Conclusion:The results showed F1 5kG bacterium would be well suited for long-term survival in naturally radioactive-contaminated sites and a suitable candidate for bioremediation of radioactive waste. Moreover, identification of proteins which involved in radio resistancy could add further application of this strain in future studies

    Molecular analysis of exotoxin A associated with antimicrobial resistance of Pseudomonas aeruginosa strains isolated from patients in Tehran hospitals

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    Background and Aim:  Pseudomonas aeruginosa is a unique bacteria that in order to survive in different environments by complex adaptation process can make changes in his virulence genes expression and drug resistance. The aim of this research is the investigation of existence of a logical association between toxA gene and antibiotic resistance in strains possess the gene. Materials and Methods: Antibiogram test by disk diffusion method (Kirby Bauer) was performed according to CLSI protocols. In this study, the existence of toxA gene with the help of polymerase chain reaction (PCR) in 102 clinical isolates from blood samples, wound, urine and trachea was examined. Chi-square test was used to investigate the relationship between exotoxin A and antibiotic resistance. Results: The 81 strains (79.4%) had toxA gene. Frequency of toxA genes in isolated strains from different infections were wound (91.4%), blood (85.7%), trachea (72.7%), and urine (42.1%). Multiple resistance index in strains possess the toxA gene was calculated 75%. Chi 2 test to determine the relationship between drug resistance and gene toxA was significant (P<0.05). Conclusions: The significant chi-square test and an increase in multi-resistant strains possessing the toxA gene, can represent a considerable genetic switch between exotoxin A activity and resistance to antibiotics in the blood, urine, tracheal, wound infections Respectively, which lead to turn genes on of drug resistance regulating in bacteria. The results of this study will be verified by southern blot, analysis of the expression of toxA gene and determine the mechanism of resistance in resistant strains Methods
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