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Background: Existence of extended spectrum B-lactamase (ESBL) genes plays an important role in spreading B-lactam antibiotic resistance in the producing strains of these enzymes. The resistance of gram-negative bacteria, such as Pseudomonas aeruginosa, to different antimicrobial agents, especially B-lactam and carbapenem, has increasingly been reported. This study was conducted to determine the prevalence of TEM-1 beta-lactamases in Pseudomonas aeruginosa isolates through Duplex PCR. Materials and Methods: In this descriptive-analytic study, 175 Pseudomonas aeruginosa isolates collected from burn patients were subjected to bacteriological tests. The samples were cultured and identified according to standard methods. Then the frequency of ESBL producing strains was determined via the combined disk method. Using boiling method, DNA was extracted and examined for the existence of TEM-1 gene by Duplex PCR. Results: Out of the 175 Pseudomonas aeruginosa isolates, 66 (37.7%) were ESBL positive, 15.15% of which were positive for TEM-1 B-lactamases resistance gene. Conclusion: Noticing the increasing rate of the ESBLs producing strains, using the appropriate treatment protocol based on the antibiogram pattern of the strains is highly recommended.

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Background: Pseudomonas aeruginosa is a human opportunistic pathogen which is considered one of the agents causing nosocamial infection. Recent studies have reported increased resistance of Pseudomonas aeruginosa to imipenem. The aim of this study was to determine resistance to antipseudomonal antibiotics including imipenem in Pseudomonas aeruginosa strains. Materials and Methods: In this cross-sectional study, 100 Pseudomonas aeruginosa strains obtained from clinical samples of patients in hospitals in Arak, Iran, were identified and isolated through microbiological methods, including Gram staining, oxidase test, Indol test, and oxidative-fermentative test. Then antibiotic susceptibility test was performed for imipenem, meropenem, gentamicin, amikacin, ciprofloxacin, and ceftazidime by disk diffusion method according to NCCLS (National Committee for Clinical Laboratory Standards) .Minimum inhibitory concentration (MIC) was done for determining imipenem-resistant strains Results: Antibiotic susceptibility test showed that resistance rates to imipenem, meropenem, gentamicin, amikacin, ciprofloxacin, and ceftazidime were 35%, 35%, 14%, 9%, 23% and 15%, respectively. Also, MIC test showed that 30 strains were resistant to imipenem, 27 to ceftazidime, 35 to cefepime, and 35 to ciprofloxacin. Conclusion: The results of this study indicated a high rate of antibiotics resistant of Pseudomonas aeroginosa strains to different antibiotic groups. Therefore, new and more effective methods should be found for controlling Pseudomonas infections and preventing the outbreak of its antibiotic-resistant strains.

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Background: Differentiation of M. tuberculosis complex organisms were assigned to one of three genotypic groups based on the combinations of polymorphisms at katG codon 463 and gyrA codon 95. Early identification of strains belonging to any particular group is very important. This study was planned to identify major genetic groups of clinically isolated Mycobacterium tuberculosis. Materials and Methods: In this cross sectional study 33 sputum samples were collected from tuberculosis patients of the Markazi province. DNA purification from isolated samples was performed by Chelex 100. Identification of isolates was confirmed by detection of katG gene and the mutation in KatG463 by using PCR method and RFLP respectively. Finally 620-bp of katG gene and 194-bp of gyrA gene purified from PCR product were sequenced. Results: Amplification of 620-bp fragment of katG gene was a good way to confirm the detection of bacteria as a molecular approach. Results of sequencing codon GyrA95 in combination by results of PCR-RFLP determined type of the major genetic group (MGG). Therefore it showed that among the 33 Mycobacterium tuberculosis isolates 12 samples were MGG 1, 15 Samples were MGG2 and 6 samples were MGG 3. Results revealed that MGG 2 was dominant form of M. tuberculosis strains of Markazi province by frequency of 45.5%. Conclusion: Based on the results of this study MGG2 occurrence was more frequent among clinical strains in Markazi province that its accordance with susceptibility of these strains to conventional antibiotics is notable. In this study, three applicable benefits from the test as: MGG typing, molecular detection of M. tuberculosis and bacterial resistance to Isoniazid were proven.

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Background: Enterococcus is known as an important pathogen in Iran like all around the world. The increasing use of vancomycin makes vancomycin-resistant enterococci (VRE) an important nosocomial pathogen. Vancomycin in combination with an aminoglycoside can provide effective treatment for severe enterococcus infections, while resistance to vancomycin antibiotic is increasing in enterococci. In this study, the pattern of antibiotic resistance and prevalence of vancomycin resistance enterococci have been explored. Materials and Methods: In this experimental study, after isolating and identifying 150 strains of enterococci from clinical specimens, the antibiotic resistance pattern of these strains to erythromycin, teicoplanin, vancomycin, ciprofloxacin, tetracycline, gentamicin, co-trimoxazole and linezolid was examined. The MIC test by using micro dilution broth method was performed for the vancomycin resistance enterococci specimens with the vancomycin and teicoplanin antibiotics. Results: Antibiotic susceptibility test showed 14% and 5.3% of the samples were resistant to vancomycin and teicoplanin respectively. Resistant to erythromycin, co-trimoxazole, ciprofloxacin, tetracycline, linezolid and gentamicin were 64, 40, 38.6, 6.6, 0, 38.76 percent respectively. Fourteen samples had high resistance to vancomycin which MIC were ≥ 256 µg/ml. Conclusion: Based on the results of present study, there are vancomycin-resistant enterococci in Arak as well as other parts of the world. The percentage of vancomycin resistance enterococci is high in Arak and appropriate treatment of infections caused by enterococcus is essential

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Background: Multiple sclerosis (MS) is an autoimmune disorder with unknown etiology. Genetic and environmental factors associated with MS susceptibility. Genetic studies show an important role for human leukocyte antigens (HLA) and susceptibility to autoimmune diseases such as MS. There is controversy between the association of HLA alleles with MS susceptibility in various studies. However, with consider the high incidence of MS in Iranian population and limit information about association of HLA and MS, we analyzed HLA alleles in MS patients.

Materials and Methods: In this case-control study, 60 MS patients and 40 normal individuals with the same ethic background and geographic area were analyzed for HLA-DRB and DQB alleles by single specific primer-polymerase chain reaction (SSP-PCR) method.

Results: HLA-DRB1*03 and DQB1*02 alleles frequencies in MS patients were greater than healthy controls. There was no significant difference in frequency of other HLA-DR alleles between the MS patients and normal individuals.

Conclusion: DRB1*03 and DQB1*02 alleles confer increased susceptibility to MS in this population. However, to determine the role of HLA in Iranian MS patients, more studies are needed.

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Background and Aim: Alzheimer's Disease (AD) is a progressive neurodegenerative disease characterized by loss of memory and multiple cognitive impairments.
Materials and Methods: In this study, key terms were searched in reputable Persian and English databases including DOAJ, PubMed, Google Scholar, LISTA (EBSCO), Embase, and Web of Science. Articles focusing on the molecular basis and pathogenesis of the disease, as well as biomarkers for Alzheimer's diagnosis, were reviewed. In this article, we have attempted a comprehensive review not only of the molecular basis of Alzheimer's disease from a molecular medical perspective but also to address numerous molecular diagnostic methods and biomarkers at both clinical and research levels in this disease.
Ethical Considerations: All Ethical principles in writing this article have principles been observed according to the instructions of National Ethics Committee and the COPE regulations
Findings: The results of this review study indicate that the major factors involved in the pathogenesis of Alzheimer's include beta-amyloid peptides, hyperphosphorylation of tau protein, and activation of inflammatory and oxidative stress pathways. Subsequently, this leads to synaptic loss, mitochondrial dysfunction, and proliferation of activated astrocytes and microglia, which are clinically manifested as memory loss in patients."
Conclusion: Although no precise diagnostic method exists for AD, current clinical recommendations for AD diagnosis include assessing tau protein and beta-amyloid (Aβ) peptides in cerebrospinal fluid, magnetic resonance imaging (MRI) for brain volume, and positron emission tomography (PET) scanning for Aβ plaques and/or glucose metabolism in the brain.