Heat Resistance Mediated by a New Plasmid Encoded Clp ATPase, ClpK, as a Possible Novel Mechanism for Nosocomial Persistence of Klebsiella pneumoniae

Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We have characterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fighting nosocomial infections

In vitro anti-biofilm activity of Quercus brantii subsp. persica on human pathogenic bacteria

Background and objectives: Quercus brantii subsp. persica is used in folk medicine to treat infections in Iran. There is not available report on the anti-biofilm activity of Quercus brantii subsp.  persica. The aim of the present study was to investigate the effects of Quercus brantii subsp. persica against bacterial biofilms. Methods: Eighty biofilm producing strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa were collected. Quercus brantii subsp. persica fruits aqueous extraction (QBAE) was prepared though maceration method. Chemical analysis to distinguish the main components of the QBAE was carried out using thin-layer chromatography. The antibacterial effects of QBAE on bacterial isolates were determined by the Kirby-Bauer and broth microdilution methods. The antibiofilm effects of QBAE on bacterial isolates were determined using a microtiter assay. Results: The Quercus brantii subsp. persica exhibited bacterial growth inhibition and bactericidal activity on the majority of the strains at concentrations between 0.2 and 1.2 mg/mL. The average of biofilm formation inhibition by Quercus brantii subsp. persica at a minimum inhibitory concentration MIC50 in Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus strains were 35%, 45%, 57% and 61%, respectively. coumarins, phenols, terpenes and steroids were found in the QBAE by TLC. Conclusion: The results showed that Quercus brantii subsp. persica aqueous extraction was effective against the tested microorganisms and showed anti-biofilm activity which can be a basis for future studies to investigate for new anti-biofilm drugs

Antimicrobial use of reactive oxygen therapy: current insights

Mohammad Yousef Memar,1 Reza Ghotaslou,2 Mohammad Samiei,3 Khosro Adibkia4 1Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 2Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; 3Faculity of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran; 4Research Center for Pharmaceutical Nanotechnology and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran Abstract: Infections caused by drug-resistant pathogens are a global public health problem. The introduction of a new antimicrobial strategy is an unavoidable option for the management of drug-resistant pathogens. Induction of high levels of reactive oxygen species (ROS) by several procedures has been extensively studied for the treatment of infections. In this article, the general aspects of ROS production and the common procedures that exert their antimicrobial effects due to ROS formation are reviewed. ROS generation is the antimicrobial mechanism of nanoparticles, hyperbaric oxygen therapy, medical honey, and photodynamic therapy. In addition, it is an alternative bactericidal mechanism of clinically traditional antibiotics. The development of ROS delivery methods with a desirable selectivity for pathogens without side effects for the host tissue may be a promising approach for the treatment of infections, especially those caused by drug-resistant organisms. Keywords: antibiotic resistance, infections, reactive oxygen specie

Effects of resveratrol on coagulative, fibrinolytic, and inflammatory marker expression and secretion by endothelial cells (human umbilical vein endothelial cells)

: Increasing the prevalence of cardiovascular disease (CVD) has led to an investigation into components that might influence CVD. Accordingly, many recent studies have reported the benefits of resveratrol (RSV). Therefore, this study aimed to scrutinize the direct effect of RSV on human umbilical vein endothelial cells (HUVECs) by detecting coagulative, fibrinolytic, and inflammatory markers. HUVECs were cultured and treated with different concentrations of RSV. The effects of RSV were identified by representative markers of coagulation, fibrinolysis pathway, and inflammation, including von Willebrand factor (VWF), factor VIII, tissue plasminogen activator-1 (t-PA-1), and interleukin-8 (IL-8). The detection process was carried out using real-time PCR (qPCR), flow cytometry, ELISA, and immunocytochemistry (ICC) methods. The present findings demonstrated a significant decrease in VWF, t-PA-1, and IL-8 secretion levels. Furthermore, RSV diminished the activity of factor VIII and mRNA expression levels of VWF and t-PA-1. The ICC results also showed a decrease in the level of intracellular t-PA. Our data revealed the anti-inflammatory, anticoagulation, and antifibrinolytic effect of RSV in cell culture

Resistenz von bei Harnweginfektionen isolierten Enterobacteriaceae gegen Chinolone, Trimethoprim/Sulfamethoyxazol und Aminoglycoside in Azerbaijan, Iran

Aim: Antibiotic susceptibility patterns help to select appropriate empirical treatments of urinary tract infections (UTIs). This study aimed to investigate antibiotic resistance among Enterobacteriaceae isolated from UTIs in Azerbaijan, Iran.Methods: This study was carried out during 2016 in hospitals located in Tabriz, Urmia, and Khoy. Midstream urine specimens were cultured and identified by the standard methods. Susceptibility testing was carried out using the disk diffusion agar method for cefotaxime, ceftazidime, ceftriaxone, cefoxitin, imipenem, meropenem, ertapenem, cefepime, ampicillin, cefazolin, cefuroxime, aztreonam, nitrofurantoin, and fosfomycin and the agar dilution method for MIC determination of aminoglycosides, quinolones, sulfamethoxazole, and trimethoprim. Results: A total of 219 non-duplicated Enterobacteriaceae were isolated from UTIs. According to the agar dilution assay, the following resistance rates were determined: trimethoprim/sulfamethoxazole (co-trimoxazole) 69.8%, nalidixic acid 68.9%, ciprofloxacin 66.2%, levofloxacin 58.5%, tobramycin 47.9%, kanamycin 39.3%, gentamicin 27.8%, and amikacin 5.5%. High levels of resistance were observed to trimethoprim (78.5%), sulfamethoxazole (88.1%), ampicillin (86.3%), and cephazoline (79.4%). Conclusion: The most effective agents against Enterobacteriaceae were fosfomycin, carbapenems, and amikacin. Quinolones, trimethoprim and sulfamethoxazole are not appropriate for empirical therapy due to high levels of resistance. Amikacin is more effective among aminoglycosides and may be more effective, in complicated cases, when used in combination with fosfomycin and carbapenems.Zielsetzung: Antibiotika-Suszeptibilitätsmuster unterstützen die Auswahl von Antibiotika zur empirischen Behandlung von Harnweginfektionen (HWI). Daher sollte die Antibiotikaresistenz von bei Harnweginfektionen in Azerbaijan isolierten Enterobacteriaceae untersucht werden. Methode: Die Studie wurde in 2016 in Krankenhäusern in Tabriz, Urmia und Khoy durchgeführt. Mittelstrahlurin wurde mittels üblicher Technik kultiviert. Die Resistenztestung wurde für Cefotaxim, Ceftazidim, Ceftriaxon, Cefoxitin, Imipenem, Meropenem, Ertapenem, Cefepim, Ampicillin, Cefazolin, Cefuroxime, Aztreonam, Nitrofurantoin und Fosfomycin mit dem Plättchentest, für Aminoglycoside, Chinolone, Sulfamethoxazol und Trimethoprim im Agardiffusionstest mittels Bestimmung der MHK durchgeführt.Ergebnisse: Bei 219 verschiedenen Enterobacteriaceae spp. wurden folgende Resistenzraten ermittelt: Trimethoprim/Sulfamethoxazol (Cotrimoxazol) 69,8%, Nalidixinsäure 68,9%, Ciprofloxacin 66,2%, Levofloxacin 58,5%, Tobramycin 47,9%, Kanamycin 39,3%, Gentamicin 27,8% und Amikacin 5,5%. Hohe Resistenzraten wurden bei Sulfamethoxazol 88,1%, Ampicillin 86,3%, Cephazolin 79,4% und Trimethoprim 78,5% beobachtet.Schlussfolgerungen: Am wirksamsten erwiesen sich gegen Enterobacteriaceae spp. Fosfomycin, Carbapeneme und Amikacin. Chinolone, Trimethoprim and Sulfamethoxazol sind nicht geeignet zur empirischen Therapie. Unter den Aminoglycosiden ist Amikacin wirksamer und in Kombination mit Fosfomycin und Carbapenemen bei schweren Verlaufsformen möglicherweise noch wirksamer

Resistenz von bei Harnweginfektionen isolierten Enterobacteriaceae gegen Chinolone, Trimethoprim/Sulfamethoyxazol und Aminoglycoside in Azerbaijan, Iran

Aim: Antibiotic susceptibility patterns help to select appropriate empirical treatments of urinary tract infections (UTIs). This study aimed to investigate antibiotic resistance among Enterobacteriaceae isolated from UTIs in Azerbaijan, Iran.Methods: This study was carried out during 2016 in hospitals located in Tabriz, Urmia, and Khoy. Midstream urine specimens were cultured and identified by the standard methods. Susceptibility testing was carried out using the disk diffusion agar method for cefotaxime, ceftazidime, ceftriaxone, cefoxitin, imipenem, meropenem, ertapenem, cefepime, ampicillin, cefazolin, cefuroxime, aztreonam, nitrofurantoin, and fosfomycin and the agar dilution method for MIC determination of aminoglycosides, quinolones, sulfamethoxazole, and trimethoprim. Results: A total of 219 non-duplicated Enterobacteriaceae were isolated from UTIs. According to the agar dilution assay, the following resistance rates were determined: trimethoprim/sulfamethoxazole (co-trimoxazole) 69.8%, nalidixic acid 68.9%, ciprofloxacin 66.2%, levofloxacin 58.5%, tobramycin 47.9%, kanamycin 39.3%, gentamicin 27.8%, and amikacin 5.5%. High levels of resistance were observed to trimethoprim (78.5%), sulfamethoxazole (88.1%), ampicillin (86.3%), and cephazoline (79.4%). Conclusion: The most effective agents against Enterobacteriaceae were fosfomycin, carbapenems, and amikacin. Quinolones, trimethoprim and sulfamethoxazole are not appropriate for empirical therapy due to high levels of resistance. Amikacin is more effective among aminoglycosides and may be more effective, in complicated cases, when used in combination with fosfomycin and carbapenems.Zielsetzung: Antibiotika-Suszeptibilitätsmuster unterstützen die Auswahl von Antibiotika zur empirischen Behandlung von Harnweginfektionen (HWI). Daher sollte die Antibiotikaresistenz von bei Harnweginfektionen in Azerbaijan isolierten Enterobacteriaceae untersucht werden. Methode: Die Studie wurde in 2016 in Krankenhäusern in Tabriz, Urmia und Khoy durchgeführt. Mittelstrahlurin wurde mittels üblicher Technik kultiviert. Die Resistenztestung wurde für Cefotaxim, Ceftazidim, Ceftriaxon, Cefoxitin, Imipenem, Meropenem, Ertapenem, Cefepim, Ampicillin, Cefazolin, Cefuroxime, Aztreonam, Nitrofurantoin und Fosfomycin mit dem Plättchentest, für Aminoglycoside, Chinolone, Sulfamethoxazol und Trimethoprim im Agardiffusionstest mittels Bestimmung der MHK durchgeführt.Ergebnisse: Bei 219 verschiedenen Enterobacteriaceae spp. wurden folgende Resistenzraten ermittelt: Trimethoprim/Sulfamethoxazol (Cotrimoxazol) 69,8%, Nalidixinsäure 68,9%, Ciprofloxacin 66,2%, Levofloxacin 58,5%, Tobramycin 47,9%, Kanamycin 39,3%, Gentamicin 27,8% und Amikacin 5,5%. Hohe Resistenzraten wurden bei Sulfamethoxazol 88,1%, Ampicillin 86,3%, Cephazolin 79,4% und Trimethoprim 78,5% beobachtet.Schlussfolgerungen: Am wirksamsten erwiesen sich gegen Enterobacteriaceae spp. Fosfomycin, Carbapeneme und Amikacin. Chinolone, Trimethoprim and Sulfamethoxazol sind nicht geeignet zur empirischen Therapie. Unter den Aminoglycosiden ist Amikacin wirksamer und in Kombination mit Fosfomycin und Carbapenemen bei schweren Verlaufsformen möglicherweise noch wirksamer

Effect of siRNA-mediated silencing of p53R2 gene on sensitivity of T-ALL cellsto Daunorubicin

Introduction: p53R2 is a p53-inducible protein that, as one of the subunits of ribonucleotide reductase, plays an important role in providing dNTPs for DNA repair. Although p53R2 is associated with cancer progression, its role in T-cell acute lymphoblastic leukemia (T-ALL) cells is unknown. Therefore, in this study, we evaluated the effect of p53R2 silencing on double-stranded DNA breaks, apoptosis and cell cycle of T-ALL cells treated with Daunorubicin. Methods: Transfection was performed using Polyethyleneimine (PEI). Gene expression was measured using real-time PCR and protein expression was evaluated using Western blotting. Cell metabolic activity and IC50 were calculated using MTT assay, formation of double-stranded DNA breaks was checked using immunohistochemistry for & gamma;H2AX, and cell cycle and apoptosis were evaluated using flow cytometry. Results: We found that p53 silencing synergistically inhibited the growth of T-ALL cells by Daunorubicin. p53R2 siRNA in combination with Daunorubicin but not alone increases the rate of DNA double-strand breaks in T-ALL cells. In addition, p53R2 siRNA significantly increased Daunorubicin-induced apoptosis. p53R2 siRNA also caused a non-significant increase in cells in G2 phase. Conclusion: The results of the present study showed that silencing of p53R2 using siRNA can significantly increase the antitumor effects of Daunorubicin on T-ALL cells. Therefore, p53R2 siRNA has the potential to be used as an adjuvant therapy in combination with Daunorubicin in T-ALL