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Background: Nowadays the molecular methods widely use for rapid identificalion of Myobacterium other than tuberculosis (MOTT). The Myobacterium simiae isolates are cause of majority of hunan pulmonary diseases (compared with other atypical mycobacteria. As sensitivity of primers and digestion patterns for diversified fragments is different, this survey evaluated the three various fragments using the PCR- restriction fragment length polymorphism analysis (PRA) for rapid diagnostic of M. simiae isolates. Patients and methods: Strains taht were identified as M. simiae (17 isolates) by phenotypic (photochromogen and positive niacin) methods were selected for this study. The fragments of the 16S-23S rRNA gene spacer and hsp65 gene were amplified by PCR. Subsequently the amplicons were digested with three restriction enzyme namely AvaII, HphI and HpaII for a 644bp region of hsp65 DNAs, BstEII and HaeIII endonucleases for 439bp region of hsp65 gene (TB11 and TB12 fragment) and HaeIII digestion for 225bp region of 16S-23S rRNA gene spacer. Results: Of 962 culture positive speciments, 17 (1.7%) were identified as M. simiae species; majority of them were multidrug-resistance (12; 70.5%). The overall detection rate by Tb11, Tb12 and SP primers were 82.3% whereas hsp65 primer was 100% (p>0.005). We also found out that the HpaII and HphI enzymes were more specific to distinguish M. simiae species than other restriction enzyme used in this study. Conclusion: The high discriminative power of hsp65 pattern particularly HpaII digestion, provide an exact and cost-effective method for rapid identification of M. simiae strains among registered pulmonary cases. [ABSTRACT FROM AUTHOR]

Background and the purpose of the study: Bifidobacterial strains are excessively sensitive to acidic conditions and this can affect their living ability in the stomach and fermented foods, and as a result, restrict their use as live probiotic cultures. The aim of the present study was to obtain bifidobacterial isolates with augmented tolerance to simulated gastrointestinal condition using cross-protection method. Methods: Individual bifidobacterial strains were treated in acidic environment and also in media containing bile salts and NaC1. Viability of the acid and acid-bile-NaCl tolerant isolates was further examined in simulated gastric and small intestine by subsequent incubation of the probiotic bacteria in the corresponding media for 120 rain. Antipathogenic activities of the adapted isolates were compared with those of the original strains. Results and major conclusion: The acid and acid-bile-NaCl adapted isolates showed improved viabilities significantly (p<0.05) in simulated gastric fluid compared to their parent strains. The levels of reduction in bacterial count (Log cfu/ml) of the acid and acid-bile-NaCl adapted isolates obtained in simulated gastric fluid ranged from 0.64-3.06 and 0.36-2.43 logarithmic units after 120 min of incubation. There was no significant difference between the viability of the acid-bile-NaCl-tolerant isolates and the original strains in simulated small intestinal condition except for Bifidobacterium adolescentis (p<0.05). The presence of 15 ml of supernatants of acid-bile-NaCl-adapted isolates and also those of the initial Bifidobacterium strains inhibited pathogenic bacterial growth for 24 hrs. Probiotic bacteria with improved ability to survive in harsh gastrointestinal environment could be obtained by subsequent treatment of the strains in acid, bile salts and NaCl environments. [ABSTRACT FROM AUTHOR]

Background: Stenotrophomonas maltophilia is an opportunistic bacterium, contributing to different hospital-acquired infections and can be acquired from different hospital setting sources. Epidemiological study of S. maltophilia in the hospital also demonstrates the intrahospital distribution of certain strains of bacteria in healthcare facilities. The aim of the current study was to identify the molecular epidemiology of S. maltophilia isolates from clinical and environmental sources within a hospital., Methods: A total of 400 samples (clinical and environmental) were collected from the different settings of hospital. Following the standard biochemical testing and 23S rRNA genotyping, the molecular typing of S. maltophilia isolates was determined using the multilocus sequence typing (MLST) technique. Also, the frequencies of zot and entF virulence genes among S. maltophilia isolates were examined by PCR technique., Results: Based on the biochemical testes and PCRs targeting 23S rRNA gene, 22 S. maltophilia isolates were identified. The MLST analysis demonstrated that these isolates were assigned to 14 ST, and 6 out of 14 STs were common among clinical and environmental samples. All 22 isolates were identified in the PubMLST database. The PCR screening demonstrated that none of 22 S. maltophilia isolates had zot virulence gene, while the entF gene with the 59% frequency was observed in 13 out of 22 isolates. Among these 13 isolates, 6 STs were common in clinical and environmental isolates., Conclusion: Our study showed the clonal relatedness between clinical and environmental sources of the S. maltophilia isolates in a hospital. Further studies are required to understand the epidemic situation of this pathogen in the clinic and the environment.

Background: Candidemia is a fatal invasive fungal infection that involves thousands of patients annually and is associated with high mortality rate and economic burden. The incidence of candidemia is increasing due to the use of invasive medical instruments and immunosuppressive drugs. The treatment of infection is problematic because of the increased resistance of clinical strains to antifungal drugs. The aim of the present study was to identify Candida species isolated from candidemia and determination of antifungal susceptibility patterns of clinical isolates., Materials and Methods: Three thousand eight hundred BACTEC bottles suspected to candidemia were evaluated from April 2019 to June 2020. For primary identification, a positive blood culture was subcultured onto the sabouraud glucose agar and CHROMagar™ Candida . For molecular identification, ITS1-5.8SrDNA-ITS2 region was amplified by ITS1 and ITS4 primers and Msp I restriction enzyme was applied to digest polymerase chain reaction amplicons. Minimum inhibitory concentration of seven antifungals was determined against clinical isolates by broth microdilution method in accordance with the Clinical and Laboratory Standards Institute M27-A3 and M27-S4 documents., Results: Forty-six out of 3800 suspected specimens were positive for candidemia (1.2%). The age range of the patients was between 11 days and 89 years, with a median age of 34.8 years. Candida albicans was found to be the most Candida species (58.7%), followed by C. parapsilosis complex (19.6%), C. glabrata complex (8.7%), C. krusei (6.5%), C. famata (4.3%), and C. tropicalis (2.2%). Resistance to amphotericin B, fluconazole, itraconazole, and voriconazole was detected in 13.6%, 11.3%, 6.8%, and 4.5% of clinical isolates, respectively., Conclusion: The incidence of non- albicans Candida species is increasing that must be highlighted. Since resistant Candida strains are found repeatedly, consecutive tracing of the species distribution and in vitro antifungal susceptibility of clinical isolates is recommended for better management of infections., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Journal of Research in Medical Sciences.)

Background and Objectives: In recent decades, enterococcal resistance to antimicrobials has greatly increased. Furthermore, these chemicals include several side effects on the patients. Since no reports are available of the bacteriophages' effects on eukaryotic cells, they can be good solutions for multidrug-resistant bacterial problems. Therefore, the major aim of this study was to isolate bacteriophages from wastewaters on clinical antibiotic-resistant enterococci., Materials and Methods: Clinical bacteria were isolated, then enterococcal isolates were identified using different methods. The antibiotic resistance scheme of the enterococcal isolates was assessed. The bacterial isolates were exposed to wastewater samples containing potential bacteriophages. Technically, isolated bacteriophages were studied by electron microscopy., Results: Isolated bacteria were verified as Enterococcus faecium . Results showed that bacteriophages could easily be isolated from wastewater sources. The isolated bacteriophages were effective on E. faecium as well as Streptococcus dysgalactiae. Furthermore, these bacteriophages were challenged with five other bacteria (ATCC) with no visible effects. In general, the isolated bacteriophages belonged to the Myoviridae, Siphoviridae , and Inoviridae families., Conclusion: Further studies on bacteriophages and their efficacy on enterococcal strains could increase the treatment possibility of enterococcal infections. Due to these bacteriophages' effects on Streptococcus strains, bacteriophages may be used to treat streptococcal infections as well., (Copyright © 2021 The Authors. Published by Tehran University of Medical Sciences.)

Background: The aim of the study was to suggest a high specific and sensitive blood biomarker for early GC diagnosis., Methods: the expression data of miRNAs and mRNAs were collected from the blood samples of the GC patients based on literature mining. Bioinformatics tools and databases (PANTHER, TargetScan, miRTarBase, miRDB, STRING, and Cytoscape) were used to predict the regulatory relationship. Subsequently, expression level of the selected miRNA was evaluated in the blood samples of gastritis patients to recognize the common miRNA between the GC and gastritis patients., Results: Analysis of 40 target genes by MCODE (installed in Cytoscape software) indicated 4 hub genes (WWP1, SKP2, KLHL42, and FBXO11) as a significant cluster in the PPI network related to miR-21, with Node Score Cutoff: 0.2, Degree Cutoff: 2 and K-Core: 2. In addition, the miRNA RT-qPCR results showed that, the expression level of miR-21 was significantly higher in gastritis group compared to the healthy group (p< 0.05)., Conclusion: the present study clearly demonstrated the increasing level of blood miR-21 among the gastritis patients infected by H. pylori . Therefore, the altered miRNAs, especially overexpression of onco-miRs, may identify a potential link between miRNAs and pathogenesis of the H. pylori -related complications.

Introduction: Oxalobacter formigenes, as a gram-negative anaerobic bacterium, metabolizes oxalate in the intestine by the enzymes oxalyl-CoA decarboxylase (OXC) and formyl-CoA transferase (FRC). Therefore, not only the presence of the bacterium but also microbial load may affect intestinal absorption and urinary exertion. We evaluated the relationship between Oxalobacter formigenes load and the formation of calcium oxalate urolithiasis using quantitative molecular methods., Methods: By clinical manifestation and stone analysis, we selected the urine and stool specimens of 73 patients with calcium oxalate urolithiasis. First, the gene regions of the two genes FRC and OXC in Oxalobacter formigenes were selected utilizing bioinformatics and specific primers designed for these regions. Following DNA extraction from stool specimens by specific primers of each gene, PCR was carried out and positive samples were sequenced. Then, qPCR was applied to determine the effective load of Oxalobacter. Also, biochemical tests were performed to measure the excretion rate of oxalate in urine specimens., Results: In addition to oxalobacter identification by PCR, the load of bacteria was quantitatively assessed using qPCR by specific primers for both FRC and OXC gene regions. A significant negative relationship had found between the formation of calcium oxalate urolithiasis and the presence of Oxalobacter formigenes in patients with kidney stone disease. The mean excretion of oxalate and citrate in urolithiasis cases were 22.93 and 552.106 mg/24h, respectively., Conclusion: The presence of Oxalobacter formigenes can highly inhibit the generation of calcium oxalate urolithiasis. Furthermore, molecular techniques are more effective than other methods such as culture for the isolation of this bacterium.

Objectives: Anti-tumor effects of Lactobacilli as normal flora have been described. In a previous study, we identified a protein isolated from the bacterium Lactobacillus casei ATCC 39392 in acidic pH conditions named metallopeptidase. Therefore, we decided to evaluate the effect of the recombinant plasmid coding metallopeptidase protein on the inhibition, proliferation, or apoptosis of the colorectal and breast cancer cell lines., Materials and Methods: Identified metallopeptidase gene of L. casei under the specific colon cancer promoter was transferred to the Human SW480 and MDA-MB231 cells. Cell viability was evaluated in these two cancer cell lines via MTT assay, apoptotic changes, and expression level of p53 and MAP2K1 genes in comparison with healthy blood cells as a control group., Results: Viability of SW480 and MDA-MB231 cells was identified at 25% and 7%, respectively. An increase in apoptotic cell death in the SW480 cell line was observed as revealed by Tunnel staining. The expression assay of TP53 and MAP2K1 genes showed that MPL protein altered gene expression in a cell type-specific manner. Tunnel analyses showed that the pronounced cytotoxic effect of pEGFP-C2/MPL plasmid on SW480 cells was mediated through apoptosis., Conclusion: These results suggest that endogenous recombinant MPL under colon specific promoter inhibits the proliferation of SW480 colorectal cancer cells by increase in MAP2K1 and P53 activation. L. casei metallopeptidase under the same circumstances could not affect the growth rate and viability of MDA-MB231 breast cancer cells in vitro .

Mycobacterium tuberculosis has infected more than two billion individuals worldwide, of whom 5%-10% have clinically active disease and 90%-95% remain in the latent stage with a reservoir of viable bacteria in the macrophages for extended periods of time. The tubercle bacilli at this stage are usually called dormant, non-viable, and/or non-culturable microorganisms. The patients with latent bacilli will not have clinical pictures and are not infectious. The infections in about 2%-23% of the patients with latent status become reactivated for various reasons such as cancer, human immunodeficiency virus infection, diabetes, and/or aging. Many studies have examined the mechanisms involved in the latent state of Mycobacterium and showed that latency modified the expression of many genes. Therefore, several mechanisms will change in this bacterium. Hence, this study aimed to briefly examine the genes involved in the latent state as well as the changes that are caused by Mycobacterium tuberculosis. The study also evaluated the relationship between the functions of these genes.

Background and Objectives: The microbial contamination of wastewater is associated with health risks. The aim of this study was to use the autochthonous Bdellovibrio potential to prey Gram-negative pathogenic bacteria as a bio-control agent to treat urban wastewater., Materials and Methods: Thirty-six raw sewage samples were collected for isolation of Bdellovibrio . Double layer plaque assay was used for isolation and the isolates were identified by microscopic examination and molecular analysis. To evaluate the predatory potential for decrease number of Gram-negative pathogenic bacteria, plaque perdition assay, reduction in host cells viability by colony-forming unit (CFU) counting, reduction in optical density (OD) in co-cultures and assay of killing efficiency were carried out. Also, the raw wastewater was treated by Bdellovibrio then the reduction in CFU counting and reduction in OD was evaluated., Results: Four strains of Bdellovibrio were isolated and were registered in Gene Bank. Clear plaques were observed after 3-6 days of incubation for all prey cells. The CFU enumerations of all preys were decreased after 48 hrs in co-cultures and raw wastewater. Also, OD was decreased down to 0.2 nm after 48 hrs., Conclusion: These autochthonous Bdellovibrio strains are proposed to use for bio-control of Gram-negative pathogenic bacteria in wastewater and reuse it for irrigation in arid regions., (Copyright© 2020 The Authors.)

Background and Objectives: Lactobacillus casei , an acid-resistant bacterium, has a protective role against the pathogens. So we aimed to determine the proteome of Lactobacillus casei ATCC39392 strain in response to different pHs of 5 and 7 using proteomic analysis., Materials and Methods: Supernatant and bacterial extraction of Lactobacillus casei ATCC39392 adapts at pHs 5 and 7 were isolated using sodium dodecyl sulfate-polyacrylamide gel and two-dimensional gel electrophoresis. The comparison of results showed that 7 protein spots were seen in pH 5 but not in pH 7. Afterward, they were excised and sent for Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) to be identified., Results: Seven different proteins (four secretory and three structural) with different roles in human body health were identified. Prescribed proteins include putative cell wall associated Hydrolase, Glycoside Hydrolase, beta-N-Acetyl hexosaminidase, Histidine Kinase, Chaperonin, metal dependent Hydrolase and Lysozyme., Conclusion: Seven isolated proteins with anti-cancer and digestive impresses are proper subjects in therapy or drug delivery approaches especially oral drug usage for protection against stomach acidic area., (Copyright© 2020 The Authors.)

Objectives: Vaccination is the most effective preventive strategy for influenza disease. As the virus undergoes high antigenic drift, it requires a constant reformulation to obtain high protection., Results: Immunogenicity of a purified chimeric protein containing conserved regions of influenza A/H1N1 viruses including the Hemagglutinin stalk domain, Nucleoprotein, and Matrix protein produced in a prokaryotic system was assessed in vitro and in vivo, alone or in combination with adjuvants by evaluating antibody responses, cytokine production, lymphocyte proliferative assay, and mortality rate after challenge. The animals that received the chimeric protein had specific antibody responses, elicited memory CD4 cells, cytokines of Th1 and Th2 cells and showed 75% protection against influenza virus lethal challenge. The animals injected with the chimeric protein supplemented with Alum showed improved immune responses, but they had 67% protection. In other words, although Alum adjuvant enriched the chimera specific immune responses potently, it could not enhance its protectivity., Conclusion: Regarding the immunogenicity and protectivity of the chimeric protein construct against influenza, findings of the study suggested that the chimeric protein could be considered as a promising influenza vaccine candidate.

Background: Antibiotic resistant strains of Pseudomonas aeruginosa are the cause of Gram negative nosocomial infections especially among the immunosuppressed patients. The bacteria contains las I and las R genes that play very important roles in the pathogenesis and mechanisms of aggression. These genes can be influenced by the quorum sensing (QS) system and such mechanism is becoming clinically important worldwide. This study aimed to investigate the preventive effects of green coffee extract (GCE) on the expression of pathogenesis-related genes, las I and las R in P. aeruginosa., Methods: A total of fifty four P. aeruginosa strains were isolated out of 100 clinical samples collected from the infectious wards in different hospitals (Tehran province) using conventional microscopic and biochemical methods. Susceptibility of the isolates to different antibiotics, GCE and chlorogenic acid were elucidated. Multiplex polymerase chain reaction (PCR) and real-time PCR were performed to detect and quantify the expression levels of las I and las R genes. The presence of chlorogenic acid in GCE was confirmed by HPLC., Results: Antibiotic susceptibility tests revealed multidrug resistance among the clinical isolates of those 40 strains were resistant to ciprofloxacin (74.07%), 43 to ceftazidime (79.26%), 29 to amikacin (53.7%), 42 to ampicillin (77.77%), 17 to colistin (31.48%), 40 to gentamicin (74.77%), and 50 to piperacillin (92.59%). PCR outcomes exhibited that the frequency of las I and las R genes were 100% in resistant and sensitive strains isolated from clinical and standard strains of P. aeruginosa (ATCC 15449). Real-time PCR analyses revealed that GCE significantly prevented the expression of las I and las R genes in P. aeruginosa. GCE at concentration level as low as 2.5 mg/mL could prevent the expression of lasI and lasR genes in P. aeruginosa clinical isolates., Conclusion: The presence and expression levels of las I and las R genes in P. aeruginosa isolates were investigated when the bacteria was exposed to GCE. Our results tend to suggest that genes involved in pathogenesis of:Pseudomonas aeruginosa are down regulated by quorum sensing effect of chlorogenic acid and therefore GCE could be useful as an adjuvant in combating multidrug resistance strains of Pseudomonas aeruginosa.

Thermoacidophiles can exist in a state of dormancy both in moderate temperatures and even in cold conditions in heap leaching. Sulphide mineral ores such as chalcopyrite produce sulfuric acid when exposed to the air and water. The produced sulfuric acid leads to the decrease of pH and exothermic reactions in heap leaching causing the temperature to increase up to 55°C and the activation of thermoacidophilic microorganisms. The aim of the present study was to isolate indigenous extreme thermoacidophilic microorganisms at ambient temperature from Sarcheshmeh Copper Complex, to adapt them to the high pulp density of a chalcopyrite concentrate, and to determine their efficiency in chalcopyrite bioleaching in order to recover copper. In this study samples were collected at ambient temperature from Sarcheshmeh Copper Complex in Iran. Mixed samples were inoculated into the culture medium for enrichment of the microorganisms. Pure cultures from these enrichments were obtained by subculture of liquid culture to solid media. Morphological observation was performed under the scanning electron microscope. Isolates were adapted to 30% (w/v) pulp density. For the bioleaching test, the experiments were designed with DX7 software. Bioleaching experiments were carried out in Erlenmeyer flasks and a stirred tank reactor. The highest copper recovery in Erlenmeyer flasks was 39.46% with pulp 15%, inoculums 20%, size particle 90μm and 160rpm. The lowest recovery was 3.81% with pulp 20%, inoculums 20%, size particle 40μm and 140rpm after 28 days. In the reactor, copper recovery was 32.38%. Bioleaching residues were analyzed by the X-ray diffraction (XRD) method. The results showed no jarosite (KFe 3 (SO 4 ) 2 (OH) 6 ) had formed in the bioleaching experiments. It seems that the antagonistic reactions among various species and a great number of planktonic cells in Erlenmeyer flasks and the stirred tank reactor are the reasons for the low recovery of copper in our study., (Copyright © 2018. Publicado por Elsevier España, S.L.U.)

Objectives: Pyocyanin, a blue-green pigment produced by Pseudomonas aeruginosa , interferes with host redox cycles, which can lead to generation of reactive oxygen species and progressive cellular oxidative damage. The aim of this study was to assess the influence of pyocyanin on human pancreatic cancer cell line., Materials and Methods: Polymerase Chain Reaction (PCR) was applied to confirm the existence of a specific pyocyanin producing gene (phzM). The pigment was then characterized by UV-visible, FT-IR, and HPLC analysis. Panc-1 cells were treated by different concentrations of pyocyanin and their cytotoxic effect as well as the induction of apoptosis/necrosis were evaluated by XTT assay and flow cytometry., Results: An overnight pyocyanin treatment resulted in significant cell reduction in a concentration-dependent manner. Inhibition rate of 6 mg.ml-1 pyocyanin (the highest concentration) extracted from clinical and soil isolates of P. aeruginosa were 98.69±0.23 and 89.88±1.86%, respectively, which decreased as the pyocyanin concentration lessened. Pyocyanin could also induce dose-dependent apoptosis/necrosis in Panc-1 cells after 24 hr., Conclusion: We reported, for the first time, cytotoxic effects of pyocyanin against human pancreatic cancer cell line. Considering this effect of the pigment, study on pyocyanin as a potential anti-tumor biodrug requires further studies., Competing Interests: The authors have no conflicts of interest.

The increasing prevalence of multidrug-resistant Klebsiella pneumoniae strains isolated from hospitals shows the limitation of recent antibiotics used for bacterial eradication. In this study, 81 K. pneumoniae isolates were collected from three hospitals in Tehran. Antibiotic susceptibility test showed the highest rates of resistance to cefotaxim (85.5%) and ceftazidime (78.3%), and the lowest rates of resistance were detected for colistin (16.9%), streptomycin (16.8%), and chloroamphenicol (21.7%). Eleven different resistance patterns were observed. Sixty-six out of 81 isolates (81.5%) were found to be multidrug resistant (MDR), and 35.8% of them belonged to A3 resistance pattern. 7.4% and 66.7% were KPC enzyme and armA gene positive, respectively. RAPD PCR assay of these bacteria showed 5 clusters, 16 single types, and 14 common types, and there was not any correlation between genetic patterns of the isolates and presence of resistance agents. Simultaneous detection of resistance-creating agents could be an important challenge for combination therapy of MDR K. pneumoniae -caused infections.

Objectives: Pyocyanin is a blue-greenish redox-active pigment, produced by Pseudomonas aeruginosa , with a wide range of biological and biotechnological applications. Pyocyanin biosynthesis is regulated by the quorum-sensing (QS) system in which the expression of QS genes and QS-controlled virulence genes may be affected by serum as a complex medium. In the current study, effects of adult bovine serum (ABS) and fetal bovine serum (FBS) on the production of pyocyanin were examined in order to develop it., Materials and Methods: The presence of pyocyanin-producing specific genes and proteins in clinical and soil isolates of P. aeruginosa was confirmed using PCR and SDS-PAGE. Isolates were inoculated to media containing different concentrations of complement-active/-inactivated ABS or FBS and pyocyanin concentration was measured by spectrophotometry. Extracted pigment was characterized by using UV-Visible spectrophotometry. Titration of ABS antibodies against studied isolates was performed by the tube agglutination test., Results: Adding ABS to P. aeruginosa culture medium decreased pyocyanin production compared to the control, while its production increased in FBS-containing media (113.21±2.581 vs. 55.26±0.827 μg.ml -1 and 126.80±2.036 vs. 30.56±0.382 μg.ml -1 of C 11 and E 8 pyocyanin concentration in the presence of 10% FBS vs. control, respectively)., Conclusion: In this study, due to the presence of inhibitors such as complement proteins and antibodies in ABS samples, the use of FBS devoid of antibodies was effective to increase pyocyanin production in studied isolates.

Recently, the quick spreads of broad-spectrum beta-lactams antibiotic resistance in pathogenic strains of bacteria have become a major global health problem. These new emerging resistances cause ineffectiveness of antibiotics and increasing the severity of diseases and treatment costs. Among different and diverse resistance targets, we chose a class A beta lactamase, CTX-M-9, with the aim of identifying new chemical entities to be used for further rational drug design. Based on this purpose, a set of 5000 molecules from the Zinc database have been screened by docking experiments using AutoDock Vina software. The best ranked compound, with respect of the previously proved inhibitor compound 19, was further tested by molecular dynamics (MD) simulation. Our molecular modeling analysis demonstrates that ZINC33264777 has ideal characteristics a potent beta lactamase CTX-M-9 inhibitor. In the free form of beta lactamase, NMR relaxation studies showed the extensive motions near the active site and in the Ω-loop. However, our molecular dynamics studies revealed that in the compound 1: beta lactamase complex, the flexibility of Ω-loop was restricted., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: Antiseptics and disinfectants have been used widely in hospitals and other health care settings to control the growth of microorganisms. However, some disinfectant resistant strains were reported. The objectives of our study were to evaluate correlation between the efflux pump genes, drugs and disinfectant resistant among clinical isolates of E.coli., Methods: A total of 102 of E. coli strains were isolated from urine sample of hospitalized patients. The antibiotic susceptibility was carried out by disc diffusion method. Didecyl di-methyl ammonium chloride (DDDMAC) was used as Quaternary ammonium compound (QAC) disinfectant which was used in Heart Center Hospital. PCR reaction was carried out for detection of qacE and qac∆E efflux pump genes., Result: Almost all the strains had higher resistance to ampicillin, ciproflaxacin, cotrimaxazole and cephalothin. Totally 49% (n: 50) of strains were produced ESBL. Almost all the strains have MIC value between 0.00195 to 0.0078 mg/l for DDDMAC. Correlation between presence of qacE and qac∆E genes and antibiotic resistance was perceived. Presence of qacE and qac∆E genes among strains that have high disinfectant MIC value were 96.9% and 93.7% respectively. In addition, 98% of ESBL producing strains harbored qacE gene and 94% of ESBL producing strains harbored qac∆E gene., Conclusion: Our study indicated that there was a strong correlation between presence of qacE and qac∆E genes with resistance to some antibiotics and growth in media which contain high concentration of disinfectant. In conclusion, other mechanisms also play important role in resistant to antimicrobial agents but the role of efflux pumps in resistant to antimicrobial agents should not be neglected., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: Acinetobacter baumannii plays an important role in some types of nosocomial infections as an opportunist microorganism which increases levels of resistance to antibacterial drugs and disinfectants., Objectives: The aim of this study was to determine the resistance and sensitivity of A. baumannii to different antibiotics and evaluate the minimal inhibitory concentration (MIC) for Ciprofloxacin and Tetracycline; in addition to Surfanios, Citron and Aniosyme DD1 disinfectants, and also to detect the presence of gyrA, parC and tetB gene bands in the isolates., Materials and Methods: In this study, 65 A. baumannii isolates were collected from the hospitalized patients in NIOC hospital (National Iranian Oil Company hospital) of Tehran, Iran during 2010-2011. The pattern of sensitivity to antibiotics was determined using CSLI disk diffusion and MIC methods. Furthermore, resistance of isolates to the common disinfectants (Surfanios Citron and Aniosyme DD1) was determined in different hospital wards. Presence of gyrA, parC and tetB gene bands was also detected by PCR method., Results: Frequency of Acinetobacter resistance to Amikacin, Ciprofloxacin, co-Trimoxazole, Ceftazidime and Ceftriaxone was 100% in the isolates reviewed in this study. The frequency of resistance to Gentamicin and Tetracycline were 86.1% in the isolates. The MIC of Ciprofloxacin in all (100%) of isolates was 32-64 μg/mL which showed the resistance to Ciprofloxacin In 86.1% of cases the Gentamicin and Tetracycline MIC were ≥ 16 μg/mL and in 13.9% of isolates the Gentamicin and Tetracycline MIC were 4 μg/mL, these results showed the resistance and sensitivity to the Gentamicin and Tetracycline, respectively. Additionally, all (100%) of the A. baumannii isolates were resistant to disinfectant concentrations, which were used with the methods recommended by manufacturers (0.5%). In 100% of the isolates parC and gyrA genes bands were detected, and tetB gene was also detected in 86.1% of Tetracycline resistant isolates., Conclusions: Due to the high resistance of A. baumannii isolates to most antibiotics in our study and also its high resistance to the common disinfectants usually used in hospitals, it seems that more attentions should be paid for applying disinfectants. Since most of the isolates were collected from tracheal and sputum samples (46%), it seems that respiratory tract is the most t prevalent site of infection among Acinetobacter infections. Therefore, disinfecting the respiratory tract related equipment and instruments by using proper disinfectants seems to be an appropriate way to prevent these infections.

Objective: Pyocyanine plays an important role in the pathogenesis of Pseudomonas aeruginosa, (P. aeruginosa) and is known to have inhibitory and bactericidal effects. This study has aimed to detect the phenazine biosynthetic operon (phz ABCDEFG) and two phenazine modifying genes (phzM and phzS) by polymerase chain reaction (PCR) and detection of its possible protein bands by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE). The antimicrobial effects of pyocyanine alone and mixed with colloidal silver nanoparticles were studied., Materials and Methods: In this descriptive study, clinical and environmental species of P. aeruginosa were isolated by thioglycollate medium culture and cetrimide agar, respectively. The existence of a phenazine biosynthetic operon and two phenazine modifying genes as well as their protein products were confirmed by PCR and SDS-PAGE, respectively. Pyocyanine was extracted with chloroform and its antimicrobial effects against bacteria such as; Escherichia coli (E. coli), P. aeruginosaand Staphylococcus aureus (S. aureus) bacteria and yeast Candida albicans (C. albicans) were tested using well, spot and disk diffusion methods., Results: In this study, 3 out of 48 clinical strains were unable to produce pyocyanine on cetrimide and Mueller Hinton (MH) agar. Two strains did not have phenazine modifying gene bands. Another strain did not have the possible protein band of the phzM gene. Pyocyanine had antimicrobial effects against the microbial strains, which increased in the presence of silver nanoparticles., Conclusion: According to the results of the present study, some P. aeruginosa strains are unable to produce pyocyanine due to the absence of the phzM or phzS genes. Therefore, these genes have an important role in pyocyanine production in P. aeruginosa. Pyocyanine shows synergistic antimicrobial effects in the presence of silver nanoparticles against microbial strains.

Background and the Purpose of the Study: Bifidobacterial strains are excessively sensitive to acidic conditions and this can affect their living ability in the stomach and fermented foods, and as a result, restrict their use as live probiotic cultures. The aim of the present study was to obtain bifidobacterial isolates with augmented tolerance to simulated gastrointestinal condition using cross-protection method., Methods: Individual bifidobacterial strains were treated in acidic environment and also in media containing bile salts and NaCl. Viability of the acid and acid-bile-NaCl tolerant isolates was further examined in simulated gastric and small intestine by subsequent incubation of the probiotic bacteria in the corresponding media for 120 min. Antipathogenic activities of the adapted isolates were compared with those of the original strains., Results and Major Conclusion: The acid and acid-bile-NaCl adapted isolates showed improved viabilities significantly (p<0.05) in simulated gastric fluid compared to their parent strains. The levels of reduction in bacterial count (Log cfu/ml) of the acid and acid-bile-NaCl adapted isolates obtained in simulated gastric fluid ranged from 0.64-3.06 and 0.36-2.43 logarithmic units after 120 min of incubation. There was no significant difference between the viability of the acid-bile-NaCl-tolerant isolates and the original strains in simulated small intestinal condition except for Bifidobacterium adolescentis (p<0.05). The presence of 15 ml of supernatants of acid-bile-NaCl-adapted isolates and also those of the initial Bifidobacterium strains inhibited pathogenic bacterial growth for 24 hrs. Probiotic bacteria with improved ability to survive in harsh gastrointestinal environment could be obtained by subsequent treatment of the strains in acid, bile salts and NaCl environments.

Background: The aim of this study was to compare invasive and non-invasive strains of Shigella flexneri isolated from Tehran by a 120 kDa protein band by SDS-PAGE, electron microscopy of cell culture and Congo red dye methods., Methods: S. flexneri strains were isolated by standard bacterial methods from fecal specimens of children attending to the 3 children's hospitals. Phenotype analysis for screening virulent of strains of S. flexneri was done on a plate of tryptic soy agar contained 0.003% Congo red dye. Whole membrane protein preparations were used to examine the protein profiles of the inner and outer membrane of these Gram-negative bacteria. The protein mixture was electrophoresed through a polyacrylamide gel. The gel was stained with Coomassie brilliant blue R250 and destained with ethanol and acetic acid. HeLa cell culture was done by two-step preparations: one for light microscopy and the other for electron microscopy., Results: Some of S. flexneri (46%) were Congo red positive colonies. S. flexneri with negative Congo red phenotype could not enter the HeLa cell culture. A 120 kDa protein band was found in 46% of these bacteria which could enter into HeLa cell culture. Pseudopod structures which facilitate bacterial cell-to-cell spread were readily identified by electron microscopy., Discussion: Since the existence of 120-kDa protein band was corresponded to enter of S. flexneri into the HeLa cell culture and correlated with Congo red dye positive, for identification of invasive and non-invasive S. flexneri strains, the use of a 120-kDa protein band by SDS-PAGE or a simple, rapid and very cheap Congo red dye method is recommended. Because, there are some deaths due to Shigella sp. in our country, notification on the isolation of these bacteria in both children hospitals laboratories and private clinical laboratories is important.