97 research outputs found

    Evaluation of Metallo-β-Lactamase-Production and Carriage of bla-<sub>VIM</sub> Genes in Pseudomonas aeruginosa Isolated from Burn Wound Infections in Isfahan

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    Background: Metallo-β-lactamase-production among Gram-negative bacteria, including Pseudomonas aeruginosa, has become a challenge for treatment of infections due to these resistant bacteria. Objectives: The aim of the current study was to evaluate the metallo-β-lactamase-production and carriage of bla-VIM genes among carbapenem-resistant P. aeruginosa isolated from burn wound infections. Patients and Methods: A cross-sectional study was conducted from September 2014 to July 2015. One hundred and fifty P. aeruginosa isolates were recovered from 600 patients with burn wound infections treated at Imam-Musa-Kazem Hospital in Isfahan city, Iran. Carbapenem-resistant P. aeruginosa isolates were screened by disk diffusion using CLSI guidelines. Metallo-β-lactamase-producing P. aeruginosa isolates were identified using an imipenem-EDTA double disk synergy test (EDTA-IMP DDST). For detection of MBL genes including bla-VIM-1 and bla-VIM-2, polymerase chain reaction (PCR) methods and sequencing were used. Results: Among the 150 P. aeruginosa isolates, 144 (96%) were resistant to imipenem by the disk diffusion method, all of which were identified as metallo-β-lactamase-producing P. aeruginosa isolates by EDTA-IMP DDST. Twenty-seven (18%) and 8 (5.5%) MBL-producing P. aeruginosa isolates harbored bla-VIM-1 and bla-VIM-2 genes, respectively. Conclusions: Our findings showed a high occurrence of metallo-β-lactamase production among P. aeruginosa isolates in burn patient infections in our region. Also, there are P. aeruginosa isolates carrying the bla-VIM-1 and bla-VIM-2 genes in Isfahan province

    Ability of biofilm production and molecular analysis of spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus

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    Objective: This study aimed to evaluate the phenotypic and genotypic characterization of biofilm formation and spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus. Result: This cross-sectional study was performed on 146 Staphylococcus aureus isolates from hospitalized patients in Isfahan Province Hospitals. MRSA isolates were confirmed using disk diffusion test with oxacillin disk and amplification of mecA gene by PCR assays. Ability of biofilm production was evaluated targeting the icaA and icaD genes. Of 146 Staphylococcus aureus isolates, 24 (16.4) carried mecA genes and identified as MRSA strains. Strong ability of biofilm production was seen among 76.02 (111/146) S. aureus isolates and 87.5 (21/24) MRSA strains, respectively. Also, 75.0 (18/24) MRSA isolates carried icaA and icaD was not detected in these strains. Analysis of spa gene showed 70.83 (17/24) MRSA strains were spa positive. From which 14 and 3 strains identified with one band (150, 270, 300, 360, 400 bp) and two bands (150-300 bp), respectively. According to data obtained, the prevalence of MRSA isolates from Isfahan Province Hospitals is relatively high and a remarkable percentage of them show strong power in biofilm production. Also analysis of spa gene showed a fairly large diversity among MRSA strains. © 2020 The Author(s)

    Rapid detection of pathogenic bacteria in whole blood samples using 23S rRNA PCR assays

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    Purpose: Bloodstream infections are a general cause of death among hospitalized patients. Rapid diagnosis and timely treatment can reduce mortality. The aim of this investigation was to evaluate the 23S rRNA PCR assays as a rapid detection method for diagnose of sepsis in patients with suspected bacteremia. Methods: A cross-sectional study was conducted at Shahid Beheshti University Hospital in Kashan from November 2017 to December 2018. The blood samples of 265 patients with suspected bacteremia were studied by blood culture and 23S rRNA PCR techniques. The results were analyzed using SPSS version 16 and Chi-square test. Results: Eighty (30.2) blood samples of 265 suspected patients, were identified as positive by PCR assays, whereas 27 (10.2) were identified as positive by the blood culture technique. The statistical analysis showed a significant association between the results of PCR assays and blood culture and factors such as prior antibiotic use and underlying diseases (P <0.05). Also a significant correlation was observed between laboratory and clinical criteria and the results of both PCR assays and blood culture (P < 0.05). Conclusion: The 23S rRNA PCR method is a rapid and sensitive technique specially for diagnosing sepsis among patients in whom bacteremia is difficult to diagnose with culture method including neonates and patients who have taken antibiotics before microbial culture. © 2019 Firoozeh et al. All rights reserved

    Nuclear classical dynamics of H2_2 in intense laser field

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    In the first part of this paper, the different distinguishable pathways and regions of the single and sequential double ionization are determined and discussed. It is shown that there are two distinguishable pathways for the single ionization and four distinct pathways for the sequential double ionization. It is also shown that there are two and three different regions of space which are related to the single and double ionization respectively. In the second part of the paper, the time dependent Schr\"{o}dinger and Newton equations are solved simultaneously for the electrons and the nuclei of H2_2 respectively. The electrons and nuclei dynamics are separated on the base of the adiabatic approximation. The soft-core potential is used to model the electrostatic interaction between the electrons and the nuclei. A variety of wavelengths (390 nm, 532 nm and 780 nm) and intensities (5×10145\times10^{14} Wcm2Wcm^{-2} and 5×1015 5\times10^{15} Wcm2Wcm^{-2}) of the ultrashort intense laser pulses with a sinus second order envelope function are used. The behaviour of the time dependent classical nuclear dynamics in the absence and present of the laser field are investigated and compared. In the absence of the laser field, there are three distinct sections for the nuclear dynamics on the electronic ground state energy curve. The bond hardening phenomenon does not appear in this classical nuclear dynamics simulation.Comment: 16 pages, 7 figure

    Molecular characterization of class 1, 2 and 3 integrons in clinical multi-drug resistant Klebsiella pneumoniae isolates

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    Background: The aim of this study was to characterize class 1,2 and 3 integrons in clinical MDR Klebsiella pneumoniae isolates in Kashan, Iran. Methods: One hundred-eighty one Klebsiella pneumoniae were recovered from clinical specimens during November 2013 to October 2014. Antimicrobial susceptibility patterns were determined by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for detection of MDR strains. Of the 181 Klebsiella pneumoniae, 146 (80.7) of isolates were isolated from nosocomial infected patients and 150 (82.9) identified as MDR isolates. The PCR amplification was used to show presence of class 1, 2 and 3 integrons among MDR strains. The PCR method and sequencing were used for evaluation of cassette content of integrons. Results: Of the MDR K. pneumoniae isolates, 150 (100) and 55 (36.7) carried intI1 and intI2 genes, respectively. None of the MDR Klebsiella pneumoniae isolates carried class 3 integrons. Amplification of conserved segment (CS) of class 1 and class 2 integrons revealed 10 different arrays including: No. cassette; dfrA5, dfrA30; aadA2; aadA2, dfrA12; dfrA17, aadA5, aadA4; dfrA5, dfrA30, aadA2; dfrA5, dfrA30, aadA2, dfrA12, dfrA5, dfrA30, dfrA17, aadA5, aadA4; aadA2, aadA2, dfrA12; dfrA5, dfrA30, aadA2, aadA2, dfrA12 and 4 arrays including: No. cassette; aadA1; dfrA1-sat1; aadA1, dfrA1-sat1, respectively. Conclusions: The finding of present study revealed a high prevalence of integrons especially class 1 among MDR K. pneumoniae isolates from nosocomial infections in Kashan, which led to rapid extension of MDR strains. © 2019 The Author(s)

    Diagnosis of bacteremia in patients with suspected septicemia using polymerase chain reaction method

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    Background: Sepsis or blood stream infection is a clinical lethal syndrome with severe systemic inflammatory response to infection, if not treated quickly, is associated with dangerous consequences and high morbidity and mortality. The traditional and conventional method for identification of sepsis is blood culture method which is so time-consuming and long that it eliminates the possibility of rapid treatment. Although, new molecular methods, due to their high sensitivity, specificity, and speed, lead to the rapid and accurate and exact detection of bacterial sepsis within only a few hours. The aim of this study was diagnosis of bacteremia in patients with suspected sepsis using amplification of 23S rRNA gene by polymerase chain reaction (PCR). Methods: This cross-sectional study was performed in two clinical and analytical steps at Shahid Beheshti University Hospital in Kashan City, Iran, in twelve months from November 2016 to December 2017. The blood samples of two hundred and fifty-six patients with suspected sepsis admitted to Shahid Beheshti Hospital were studied by PCR method using specific primers of 23S rRNA gene of the bacteria. Results: The finding of molecular assays using PCR showed that of 256 blood samples that were collected from patients with clinical signs and symptoms of sepsis, 80 (30.2) diagnosed with bacteremia. Of these patients diagnosed with sepsis, 46 out of 80 (57.5) were male while 34 out of 80 (42.5) were female. The most PCR positive results were obtained among patients with diabetes and bedsore as underlying diseases (21.3). Statistical analysis showed that there was a significant correlation between results of molecular methods by PCR assays and history of antibiotic use. Conclusion: Overall, the results of the present study showed that the molecular methods such as polymerase chain reaction using universal 23S rRNA primers is an appropriated test for diagnosis of bacteremia in blood samples of patients with suspected sepsis. © 2020 Tehran University of Medical Sciences. All rights reserved

    Dietary differences between elderly Iranians living in Sweden and Iran a cross-sectional comparative study

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    <p>Abstract</p> <p>Background</p> <p>During the last decades, global migration has increased and many immigrant groups have a higher prevalence than the native born population of several cardiovascular disease risk factors, including poor dietary habits. However, it is uncertain if dietary habits in immigrant populations reflect dietary habits in their country of origin or if the current diet is a consequence of the migration and possible change of dietary habits. The aim of this study was to examine possible dietary differences between elderly Iranians living in Stockholm, Sweden with elderly Iranians living in Tehran, Iran, taking into account sex, age, marital status, and education.</p> <p>Methods</p> <p>Dietary intakes were assessed by semi - quantitative food frequency questionnaire in a cross-sectional study of 121 Iranians living in Stockholm and 52 Iranians living in Tehran, aged 60-80. Differences in dietary habits between the two groups was analysed by bootstrapped regression analyses with 1000 replications.</p> <p>Results</p> <p>Iranians living in Sweden had significantly higher intake of protein, total fat, fiber than Iranians living in Iran, but lower consumption of carbohydrates. The observed differences in intake of macronutrients were reflected in consumed amount of all food items, which were higher among Iranians living in Iran with the exception of bread and grain consumption which was lower.</p> <p>Conclusions</p> <p>There are general differences in dietary habits between Iranians living in Iran and Iranians living in Sweden. Parts of observed differences in dietary habits may reflect a favourable adoption process to the Swedish dietary habits after migration. Meanwhile other differences are point of concern in light of the high prevalence of overweight, among Iranians living in Sweden and can have unfavourable impact in particular in the context of cardiovascular health.</p

    Virulence genes and antimicrobial resistance pattern in uropathogenic Escherichia coli isolated from hospitalized patients in Kashan, Iran

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    Background: Urinary tract infection (UTI) is one of the most prevalent infectious diseases. Uropathogenic Escherichia coli (UPEC), as the most important cause of UTI, are associated with a number of virulence factors. Objectives: The current study aimed to investigate the virulence associated determinants as well as their patterns of antibiotic resistance in UPEC isolated from hospitalized patients with UTI. Materials and Methods: A total of 150 E. coli isolates were collected from patients with UTI from December 2012 to June 2013 in Kashan, Iran. Antimicrobial susceptibility screening of 12 antibiotics was determined using disk diffusion method. Polymerase Chain Reaction (PCR) assay was used to detect virulence-related genes in UPEC strains. The purified PCR products were sequenced. Results: Of the total 150 UPEC isolates, 111 (74) were multidrug-resistant. High resistance was observed against ampicillin (81.3), nalidixic acid (71.3), cotrimoxazole (64.7) and ciprofloxacin (61.3), respectively. Eighty-four out of the 150 isolates showed resistance against the extended spectrum cephalosporins. Totally, virulence genes were detected in 126 (84) UPEC isolates .The PCR results identified the traT gene in (74), PAIs markers in (61.3) and the pap gene in (16.6) of the isolates. Conclusions: The traT gene and PAI markers were highly prevalent among UPEC strains isolated from patients in Kashan, Iran; therefore these determinants could be used as targets for prophylactic interventions. Also there was a high level of resistance against the antibiotics commonly used for urinary tract infection treatment. To reach better therapeutic outcomes, treatment regimens have to be modified. © 2015, Ahvaz Jundishapur University of Medical Sciences

    Detection of plasmid-mediated qnr genes among the quinolone-resistant Escherichia coli isolates in Iran

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    Introduction: Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. Methodology: A total of 140 Escherichia coli isolates were collected between March and October 2012 from urinary tract infections in Khorram Abad, Iran. All isolates were tested for quinoloe resistance using the disk diffusion method. Also, all quinolone-resistant isolates were screened for the presence of the qnrA and qnrB genes by polymerase chain reaction. Minimum inhibitory concentrations (MICs) of ciprofloxacin for the qnr-positive isolates were determined. Results: One hundred sixteen (82.8) of 140 Escherichia coli isolates were nalidixic acid-resistant; among them, 14 (12.1) and 9 (7.8) were qnrA and qnrB-positive, respectively. Two quinolone-resistant isolates harbored both qnrA and qnrB. Among 63 ciprofloxacin-resistant isolates, 14 (22.2) and 9 (14.3) were found to carry qnrA and qnrB genes, respectively. The ciprofloxacin MIC range was 0.25-512 μg/mL for 23 qnr-positive Escherichia coli isolates, 18 of which had MICs values of 4-512 μg/mL. Conclusion: Our study shows that the frequency of plasmid-mediated quinolone resistance genes among E. coli isolates in Iran is high. © 2014 Firoozeh et al
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