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Some bacteria can survive in conditions in which even extremophiles cannot survive. In this study, the conditions of contamination of mine-waste extremophiles with other bacteria was studied on the laboratory scale. At the first step, the acid-producing extremophile bacteria were isolated from mine tailings and characterized using a biochemical protocol. The extremophiles survived at the pH from 0 to 8.5 and temperature from ‒ 70 °C to 90 °C. After the complete growth and isolation of active colonies of the acidophilic bacteria in solid medium, their pollution possibility were examined in the laboratory. The characterization of contaminating microorganisms was performed through polymerase chain reaction (PCR) and 16s rRNA gene sequencing. The polluting bacteria were isolated from the acid-producing bacteria using a nutrient broth liquid medium in a sterilized condition for 1 week, which reached an anaerobic condition after a while. The significant growth of acidophilic bacteria in an anaerobic condition required the 9K medium containing Fe₂(SO₄)₃ and elemental sulphur. The results showed that the contaminating bacteria of extremophiles included Bacillus cereus (strain 1), Bacillus sp. (TS3) and Bacillus oryzaecorticis (WJB138), enduring the anaerobic conditions in a nutrient broth medium.
 

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Background:  Aeromonas spp. can cause diarrhea and various infections in humans. Access to rapid techniques with a high sensitivity and specificity is strongly needed for the identification of Aeromonas species. The aim of this study was to evaluate two different methods including API 20E bacterial identification tests and the molecular detection using PCR primers specific for 16s-rRNA and 23S-rRNA genes sequences for identification of Aeromonas spp. in stool samples from patients with diarrhea. Materials and Methods: One hundred stool samples from diarrheal patients were collected. All isolates were subjected toAPI 20 E strip tests and PCR using specific primers for identification of Aeromonas spp. Results: The API 20E analysis identified 2 (2.2%) isolates as Aeromonas spp. Molecular identification by aero-23S-rRNA gene confirmed the same 2 isolates as identified by the API 20E strips. Conclusion: Both API 20E system and PCR method using Aero 23S-rRNA primer were found to be accurate in identification of Aeromonas spp. isolates with highconfidence.

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  Abstract Background: Streptococcus mutans in the oral cavities sable to produce mutacin (bacteriocin-like substances) with antibiotic properties. The aim of this study was to investigate the frequency and expression of genes encoding mutacins typeI, II, III and IV and also two of 8 genes in a cluster encoding the putative bacteriocins, the designated bsm 283, bsm 299, bsm 423, bsm 1889c, bsm 1892c, bsm 1896, bsm 1906c and bsm 1914, were also screened by PCR and specific primers for each type of mutacin biosynthesis gene and then mutacin activity against the indicator strains determined. Methods : In this study, dental clinic samples were collocated; Streptococcus mutans was detected using biochemical tests and molecular methods (PCR). Frequency of mutacin biosynthesis genes types I, II, III and IV, bsm299 and bsm1899 were measured by PCR, using specific primers for each type of mutacin biosynthesis gene. Furthermore, the antimicrobial spectra of Streptococcus mutans isolates against other indicators, including Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Salmonella typhi, Pseudomonas, Escherichia coli were evaluated using well diffusion, disk diffusion and the minimal inhibitory concentrations (MICs) methods. Results : Out of 56 samples collected from patients referred to Milad Hospital dental clinic on October 2011 and three private dental clinics on November 2011, 24 strains of Streptococcus mutans produced mutacins. 67.52% of the strains had a wide antimicrobial spectrum and 37.5% of 67.5% had a high frequency of genes with more inhibitory activity against, Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis respectively that are more related to putative bacteriocins. The expression frequency of the bsm gene (putative bacteriocins) was higher than that of the characterized mutacins types (I–IV). The lowest dilution rate mutacin was found against Staphylococcus epidermidis (0.0625 unit/mL). Conclusion : These findings suggested that all putative bacteriocins may represent a large repertoire of inhibitory substances produced by Streptococcus mutans. Therefore, the high diversity of mutacin-producing phenotypes, associated with high frequency of expression of the biosynthesis genes screened and wide antimicrobial activity against Staphylococcus epidermidis could be used as safe antimicrobial agents in treatment of superficial infections such as, removing the pimple caused by Staphylococcus epidermidis.

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Background: The role of the hospital environment as a source of dissemination of pathogens is critical. Environmental surfaces in the Intensive Care Units (ICUs) are suitable for the growth of Gram-negative bacteria that normally circulate between the environment and patients and can cause outbreaks of nosocomial infections. In this study, the prevalence of Gram-negative bacilli in the environment of the ICUs and neonatal ICU (NICU) of hospitals in the city of Qom was evaluated. Materials and Methods: During a 6 month period from November 2012 to April 2013, samples were collected from environmental surfaces of ICUs of four hospitals and NICU of one hospital located in the city of Qom. Sampling was done from equipment, fluids, and surfaces and identification was carried out based on culture and biochemical tests for Gram-negative bacilli. Results: A total of 230 swab samples was collected and 50 colonies of Gram-negative bacilli were isolated from environmental surfaces. Overall, 64% of the isolates belonged to non-fermentative bacteria and 36% of the isolates belonged to Enterobacteriaceae family.  Strains of Pseudomonas aeruginosa and Acinetobacter baumannii complex accounted for the highest rates of environmental isolates. In addition, Klebsiella pneumoniae was isolated from NICU. Conclusion: The high frequency of genus Acinetobacter among Gram negative bacteria isolated from environmental surfaces has a public health impact and Acinetobacter spp. should be considered in the infection control programs in hospitals. Isolation of K. pneumoniae should be regarded as a risk factor for fatal neonatal infections.

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Background: Masske is a traditional Iranian butter made from yoghurt. The first aim of this study was to isolate and identify the nonlactic pathogenic microflora by culture and molecular methods of identification, and the second purpose was to identify genetic similarity of the isolated bacteria in Masske.
Materials and Methods: In order to detect pathogenic dominant indicator microorganisms, a number of 150 bacterial isolates from three Masske samples, which may comprise the repetitive isolates and could grow on appropriate media for Staphylococci and E.coli, were classified into 8 groups according to their phenotypic characterization followed by chemical tests. Then 2approximately similar isolates from each group were chosen (total 18 isolates; we selected 3 isolates from 2 groups of eight), and the sequencing of 16S rRNA gene was done for subsequent analysis.
Results: Among 18 bacterial isolates, Staphylococcus hominis was the most frequently isolated species during the manufacture of Masske as the presence of this bacterium was confirmed in 14 out of 18 samples. Also, the presence of Staphylococcus epidermidis and Escherichia coli was identical across the samples (for each one, 2 out of 18).
Conclusion: Our results based on cultural and molecular methods suggest making some improvements to the hygiene of Masske manufacture due to the high population of minor pathogens.

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One of the important factors which affect lactic starter cultures activity as well as lack of lactic coagulation in milk is antibiotic residues. Lack of lactic coagulation causes a number of problems such as economic loss in dairy industries when they produce fermented milk products specially cheese and yoghurt. In order to recognize such problem, the present study was undertaken to detect antibiotic residues in milk. The results obtain showed, cow milk which contaminated by ointment in a concentration about 100ppm and the cow under treatment by streptomycin (intramuscular injection) up to 72 hours after injection, no lactic coagulation was observed. Hence, the cow under treatment should be kept separate and the milk drawn should never be mixed with other animals until the antibiotic residues reduce to normal range. Above mentioned parameter have different affects on enzymatic coagulation of milk .

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A total of twenty seven bacterial strains were isolated from cankerous tissues of apricot, nectarine, peach, plum, sour cherry and sweet cherry trees in Tehran province and identified as Pseudomonas syringae pv. syringae (Pss), the causal agent of the bacterial canker disease, on the basis of LOPAT (levan production, oxidase test, potato rot, arginine dihydrolase and tobacco hypersensitive reaction) and GATTa's (gelatin liquefaction, aesculin hydrolysis, tyrosinase activity and Na-tartrate utilization) group tests. Pss strains showed slight differences in morphology, phenotypic (biochemical and physiological) characteristics, serological properties, plasmid DNA and cellular protein profiles and antibiogram. They were divided into three distinct groups based on hippurate and formate utilization which was correlated with protein profile in SDS-PAGE (sodium dodecyl sulfatepolyacrylamide gel electrophoresis). The virulence of Pss was significantly associated with the degree of necrosis on immature sweet cherry fruits and the rate of in vitro syringomycin production.

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Background: Emergence of drug-resistant bacteria has highlighted the need to identify new and more efficient antibacterial agents. The aims of this study were to evaluate the antibacterial activity of dill (Anethum graveolens) seeds essential oil and to investigate the effect of cumin (Cuminum cyminum) seeds alcoholic extract on biofilm formation ability of Klebsiella pneumoniae.
Materials and methods: This experimental study was carried out at the Faculty of Medicine of Kurdistan University of Medical Sciences in 2014. Activity of dill seeds essential oil was evaluated based on the inhibition zone diameter and minimum inhibitory concentration (MIC) against some important pathogenic bacteria including: Vibrio cholerae, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, the effect of sub-inhibitory concentrations of cumin seeds alcoholic extract was evaluated on biofilm formation ability of K. pneumoniae. The biofilms were formed on semi-glass lamellas and observed by a scanning electron microscope.
Results: Dill essential oil showed a good to moderate activity against the tested strains. The highest antibacterial activity was observed against S. aureus (inhibition zone of 15 mm and MIC of 0.62 mg.mL^-1) and V. cholerae (inhibition zone of 14 mm and MIC of 0.7 mg..mL^-1). The cumin alcoholic extract had no effect on biofilm formation ability of K. pneumoniae.
Conclusion: The results of this study showed the presence of antimicrobial compounds in dill extract. The cumin alcoholic extract was not able to inhibit biofilm formation ability of K. pneumoniae. Because of the medicinal plants properties, it is valuable to search for promising herbs and novel chemical compounds.

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Brazilian peppertree (Schinus terebinthifolius) leaf extract was applied against two strains of the crown gall disease agent (Agrobacterium tumefaciens); strains C58 and AR125. In vitro, we used the agar well diffusion method and the extract was tested in different solvents selected according to their polarity indices, at different concentrations and different incubation temperatures. In vivo, we tested the extract prepared in different solvents on the stems of young tomato plants (cv. Firenze) which were inoculated with the strain C58.The best results were obtained with the extract prepared in hot sterile distilled water and in methanol (0.3 g.ml^-1) incubated at 25 °C and 30 °C. The minimum inhibitory concentration (MIC) was evaluated to be 10^-4 g.ml^-1. In another aspect, to identify the nature of certain substances from S. terebinthifolius leaf extracts, we made a test of fractionation using the Thin Layer Chromatography (TLC) method and phytochemical screening of the crude methanol leaf extract. We noticed the presence of alkaloids and flavonoid compounds which may be responsible for the antibacterial activity. These tests indicated that false pepper leaf extract has an antibiotic effect against Agrobacterium tumefaciens both in vitro and in vivo, which represents a conceptual approach with great promise for future biological control.  

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Aims: Infections by extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae (CPE) are increasing problems in pediatrics and are usually associated with higher hospital costs and mortality rates. The aims of this study were the statistical investigation of the worldwide prevalence and risk factors of ESBL and CPE family members among pediatric population.
Instruments and Methods: From October 1, 1995 to July 27, 2017, some keywords including “ESBLs”, “carbapenemase”, “pediatrics”, “children”, and “risk factor” were searched in the searching databases such as Google Scholar, Embase, Scopus, PubMed, and Web of Science among original research articles. The univariate and multivariate analysis of the collected data was performed by Graph Pad Prism 6.1 software.
Findings: The mean percentage of ESBL production was 20.23±22.31 and the mean percentage of CPE was 1.81±2.77. E. coli (n=991) and K. pneumonia (n=627) were the predominant ESBL-producers. Nephrology (n=5005) and NICU (n=1805) were predominant hospital wards. ESBL-PE had significantly higher prevalence in the infants unit (OR=0.9832, 95% CI=12.271-19.519; p<0.001). Moreover, ICU ward was a significant and independent risk factor for CPE acquisition (OR=0.849, 95% CI=2.211-5.415; p=0.0035). ESBL-PE and CPE were significantly isolated from blood samples (OR=0.9276, 95% CI=1.508-2.433, p<0.0001) and fecal specimens (OR=0.968, 95% CI=2.829-5.133, p<0.0001), respectively.
Conclusion: Most of risk factors between ESBL-PE and CPE are similar including previous hospitalization and prolonged use of antibiotics, cephalosporins, and previous colonization. Other possible potential risk factors that should be considered include presence of catheters and travel history. Detection of risk factors provides useful information for formulation of infection control policy.

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The antibiotic properties of eight cyanobacteria (blue-green algae) species from Anzali Wetland was investigated on several bacterial species through vacuum distillation and simple mechanical methods. The result showed that Anabaena sp., A. variabilis, A. flos-aquae and Aphanizomenonflos-aquaehad negative effect on the growth of Staphylococcus aureusandA. flos-aquaeand A. oscillaroideshad negative effects on the growth of E. coli. The growth of Candida albicans yeast was greatly reduced by Aphanizomenonflos-aquae, A. variabilis, and A. oscillaroides. Among the investigated algae only A. oscillaroides could reduce the growth of Pseudomonassp. 

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The antibacterial and antioxidant activities of methanol and acetone extracts of three marine algae, including Hypnea hamulosa, Gracilaria corticata and Enteromorpha intestinalis wereinvestigated.Antioxidant activities were determined by means of total antioxidant capacity, total phenolic compounds, DPPH radical scavenging activity and ferric reducing antioxidant power. Antibacterial activity was determined using a paper disc diffusion method against pathogenic bacteria, including Listeria monocytogenes, Escherichia coli and Bacillus subtilis. Acetone extract of E. intestinalis showed the highest antioxidant activity and contained the highest phenolic compounds. The highest percentage of DPPH radical scavenging activity was observed in the methanol extract of H. hamulosa (p<0.05). The highest ferric reducing antioxidant power was observed in the methanol extract of Glacilaria (p<0.05). The strongest inhibition (p<0.05) against L. monocytogenes was shown by the methanol extract of E. intestinalis and the highest inhibition against B. subtilis and E. coli was observed in the acetone extract (p<0.05). In conclusion, E. intestinalis extracts showed favorable antioxidant and antibacterial activity suggesting its application in food and pharmacological industries.

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Research Subject: One of the important methods in the treatment of skin wounds is the use of wound dressings. Recently, the use of polymer-based wound dressings has become increasingly common. The use of natural polymers is very important in wound dressings. The aim of the present study is to design and manufacture a polyvinyl alcohol/aloe vera wound dressing with the capability of healing skin wounds.
Research Approach: The electrospinning method was applied to prepare the samples. Aloe vera gel was first extracted, purified, and powdered by freeze-drying. In all samples, the amount of polyvinyl alcohol and aloe vera powder was fixed at 8 wt.%. This value was selected empirically based on the quality of the produced fibers. Different samples including different amounts of polyvinyl alcohol and aloe vera were produced and their properties including morphology, tensile strength, swelling, degradability, and antimicrobial properties were investigated.
Main Results: The results showed that the dropless random oriented fibers with uniform diameter were produced. The diameter increased with increasing aloe vera contribution, which was attributed to an increase in viscosity due to the presence of aloe vera. With increasing aloe vera contribution in the samples, tensile strength decreased and the elongation percentage increased. The swelling behavior of the specimens was evaluated by measuring the weight of the specimens in a simulated skin environment and the results showed that the presence of aloe vera increased the hydrophilic properties of the specimens. Antimicrobial activity of the samples against two gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa was investigated using the disk diffusion method and it was found that the presence of Aloe vera in the samples brought antimicrobial activity against Pseudomonas aeruginosa. Finally, the findings of this study confirm the feasibility of using polyvinyl alcohol /aloe vera for the production of the electrospun wound dressing.

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The main goal of this study was to evaluate the antimicrobial activity of Ziziphora clinopodioides against some food spoilage and pathogenic bacteria and determine Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Extract of Ziziphora was tested for its growth inhibitory and bactericidal effect on 6 Gram-negetive (Enterobacter aerogenes, Escherichia coil, Klebsiella pneumoniae, Salmonella enteriticlis, Shigella dysenteria and Pseudomonas aeroginosa) and 3 Gram-positive (Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus) species. Minimum inhibitory Concentration (MIC) was determined using dilution method and minimum bactericidal concentration(MBC) was taken from the concentration of the lowest dosed test tube showing no growth on subcultured. All of microorganisms were inhibited by the extract of Ziziphora clinopodioides except Pseudomonas aeroginosa. The MIC and MBC for Gram-negetive bacteria, including Enterobacter aerogenes, Escherichia coil, Klebsiella pneumoniae, Salmonella enteriticlis and Shigella dysenteria were 1000-2000 μg/L. The MIC and MBC for Gram-positive bacteria, including Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus, were 1000-4000 μg/L. Acording to the results of this study, It is applicable to use extract of Ziziphora as the natural preservatives and flavoring agents in food products.

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In or to evaluation the effects of milk total solids on the growth of starter bacteria during fermentation, pastorizied skim milk concentrated to 4 levels of total solids(14,18,23 and 27%) using a vaccume evaporator. Concentrated milk samples inoculated with a yoghurt starter culture (CH1) and incubated at 43°C for 6 hours. At intervals of 1 hour tow samples removed from the incubator and cultured in BGWA medium. The results showed that increasing milk total solids, increased the lag phase time for both of starter bacteria but increased growth coeficiant. The acidity increased and syneresis decreased with increasing total solids. Increasing total solids to 23% had no significant effect on the flavour scores but increasing of them more than this level decreased the flavour scores significantly. The texture scores increased with increasing of total solids.

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Pantoea ananatis is an important pathogen causing bacterial center rot in onion. Isolated strains from onion soft rot bulbs based on morphological characteristics were tested for hypersensitivity reaction on tobacco. Pathogenic strains underwent some biochemical tests which detected the presence of P. ananatis, based on RNA16S sequencing, this result was confirmed. Symptoms were reproduced by inoculating this species to onion leaves and bulbs. This study reports for the first time the presence of P. ananatis bacterium in Morocco causing the bacterial center rot in onion.