Showing 28 results for Bacteria
Salman Ahmady Asbchin1, Moein Safari, Hosein Moradi, Vahid Sayadi,
Volume 16, Issue 6 (9-2013)
Abstract
Background: The most important pathogen in nosocomial infections are microorganisms in the patient's body. 90 percent of nosocomial infections caused by bacteria. Medlar is an medicinal plant that its therapeutic effects has historically been emphasized. The aim of this study was to evaluate the antibacterial effect of methanolic and ethanolic leaf extract of medlar against bacteria isolated from hospital environment.
Materials and Methods: In this experimental study, the Nosocomial bacteria were obtained from Shahid Mostafa Khomeini hospital, Ilam, Iran. Soxhlet extraction method was used for medlar leaf extract. Disk diffusion method was used to study the effect of antimicrobial and broth microdilution method were used to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC).
Results: Two strains of Pseudomonas aeruginosa, three strain of Staphylococcus aureus and five strains of Escherichia coli were isolated from hospital. The results showed that the methanolic extract of Medlar leaf inhibited the growth of all strains of pseudomonas aeruginosa and four strain of Staphylococcus aureus and also inhibits the growth of all strains of Escherichia coli strains except E4 strain. The maximum antimicrobial activity was against E2 strain that zone diameter around it was 19/67 Millimeters. Quantities of minimum inhibitory concentration for all three strains P1, P2 and P3 and E2, E3, E5, S1, S2 and S3 strains was equals with 125 mg/ml.
Conclusion: Medlar leaf methanolic extract possesses significant antibacterial activity against bacteria causing nosocomial infections and so this extract can be considered in the control of infectious diseases.
Nader Zarinfar, Majid Akbari, Mojtaba Sharafkhah,
Volume 16, Issue 10 (1-2014)
Abstract
Background: According to the studies, Iran’s per capita antibiotic consumption is remarkable. Since the emergence of Antibiotic Resistant Organisms (AROs) is considered a global problem in the community and hospitals, this study aimed to investigate the pattern of antibiotic resistance in Gram-negative bacteria isolated from patients in an academic and a non-academic hospital in Arak, Iran.
Materials and Methods: This descriptive cross-sectional study included all specimens referred to the microbiology laboratory at Amir Al-Momenin Hospital (academic hospital) and Imam Khomeini Hospital (non-academic hospital) in a one-year period from June 2012 to June 2013. The susceptibility of the isolated Gram-negative bacteria against the important antibiotics used in clinical practice was determined using the disk diffusion method.
Results: A total of 846 specimens were collected from patients in the two hospitals where 520 (61.5%) were Gram-negative bacteria, of which 63.3% were E. coli. The prevalence of Gram-negative organisms in the academic and the non-academic hospital was measured 79.8% and 20.2%, respectively (p=0.097). It was also determined that there is a significant difference between the two hospitals in the prevalence of ESBL (Extended-Spectrum Beta-Lactamase) Gram-negative bacteria (p=0.003).
Conclusion: There was a significant difference between the two hospitals in the prevalence of ESBL Gram-negative bacteria. Therefore, conducting regional surveillance programs to examine the patterns of antibiotic resistance is recommended.
Mohamad Javad Mostafapour Rami, Salman Ahmady Asbchin ,
Volume 16, Issue 12 (3-2014)
Abstract
Background: Biosurfactants are amphiphilic biological compounds produced extracellularly by a variety of microorganisms. Because their use in various industries are of a particular importance. The aim of this study was to identify a strain of bacteria of the genus Bacillus Cereus biosurfactant producers and investigate the antibacterial effects of biosurfactant produced.
Materials and Methods: In this study, different samples of oil, water and soil contaminated with oil were prepared. Hemolytic activities, emulsification and measurement of surface tension were used and selected strains were identified by biochemical tests. The nature and effect of antibacterial biosurfactant were evaluated for strain selection.
Results: In this study, eighty eight bacterial strains were isolated. Among them, 24 strains were hemolytic activity. Among them, 14 strains have emulsification activity more than 70% and finally from among them four strains were able to convey to the surface tension of less than 40 mN/m. On the basis of biochemical tests, a strain selective in this study as B. cereus 43 strain, were identification and selection. The results of investigating the nature biosurfactant determined that the type of lipopeptide. Also, the produced biosurfactant has antibacterial activity against six bacterial infectious. The most sensitive and the most resistant bacteria than the impact of biosurfactant extract, of S. aureus PTCC1112 and of the Proteus mirabilis ATCC 2601 respectively. Also, the results of MIC, MBC showed that MIC extract were effective in a dilution of 63 mg/ml on S. aureus PTCC1112 and S.epidermidis ATCC 2405 and the MBC extract had the greatest effect in a dilution of 125mg/ml on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa PTCC 1074 respectively.
Conclusion: Bacillus Cereus 43 had high potential in reducing the surface tension and biosurfactant extracted had high antibacterial effects. Therefore, Frequency of potential has for applications of biotechnology and the environment.
Jalil Kardan , Hossein Kazemian, Mohammad Mehdi Feizabadi,
Volume 17, Issue 2 (5-2014)
Abstract
Nontuberculous mycobacteria (NTM), also known as atypical mycobacteria or mycobacteria other than tuberculosis are environmental organisms that are normally found in soil and water. Many of the mycobacterial species that have been described in the past decade are involved in human diseases, especially in patients with AIDS and immunocompromised HIV-negative patients. In this study, pathogenicity and clinical significance of new species of mycobacteria were evaluated. A total of 63 new species of non-tuberculosis mycobacteria, recognized in the past ten years (2003-2013), were classified in different Runyon groups. Approximately, 40 isolates were reported to infect human. Of these, 27 (67.5%) were non-chromogenic and 13 (32.5%) were scotochromogenic. The majority of the 40 isolates belong to the slow grower group. Photochromogenic species were not pathogenic to human. The most frequent infections included respiratory infections in elderly people and cervical lymphadenitis in children caused by Mycobacterium kyorinense and Mycobacterium mantenii, respectively. NTM also causes disseminated infections, the most frequent agents of which are M. boenickei, M. houstonense, M. neworleansense, and M. brisbanense in immunocompromised HIV-negative persons. Some of the NTMs, such as Mycobacterium riyadhense, are considered the primary pathogens for human. Considering the progressive spread of HIV co-infected mycobacteria in recent years, accurate identification of these agents’ pathogenicity, drug resistance, and appropriate treatment in epidemic regions, such as Iran, is essential.
Hassan Izanloo, Mohammad Ahmadi Jebelli, Shahram Nazari, Navid Safavi, Hamid Reza Tashayoe, Gharib Majidi, Mohammad Khazaei, Vahid Vaziri Rad, Behnam Vakili, Hussein Aghababaei,
Volume 17, Issue 9 (12-2014)
Abstract
Background: This study aimed to examine the antibacterial effect of Polyamidoamine-G4 dendrimer on Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus.
Materials and Methods: In this experimental study, the antibacterial effects of Polyamidoamine-G4 dendrimer were studied by disc diffusion and micro-dilution method. Different concentrations of Polyamidoamine-G4 inoculated onto blank disks and were placed in Mueller-Hinton agar media. Zone of inhibition was investigated by bacterial inoculation according to the McFarland standard 0.5. Minimum inhibitory concentration and minimum bactericidal concentration of Polyamidoamine-G4 dendrimer were determined by micro-dilution method in nutrient broth culture.
Results: Zone of inhibition in concentration 500 &mug/ml of Polyamidoamine-G4 dendrimers for Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus were 14, 0, 35 and 29mm, respectively. Concerning the Zone of inhibition in gram negative bacteria with gram positive ones was p<0.05 and had significant difference. The minimum inhibitory concentration of Polyamidoamine-G4 dendrimer for Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 1250, 2.5, and 1 &mug/ml, respectively. The minimum bactericidal concentration of Polyamidoamine-G4 dendrimer belonged to Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 2500, 5 and 5 &mug/ml, respectively. Polyamidoamine-G4 dendrimer had not bacteriostatic and bactericidal effects on Enterobacter cloacae.
Conclusion: According to the results, Polyamidoamine-G4 dendrimer can eliminate Escherichia coli, Staphylococcus aureus and Bacillus subtilis effectively. It is suggested in the rest of this study that the probable toxicity of nanostructured compounds examined in drinking water and, economic studies is done for synthesis and their applications in case of prevention of using.
Somayeh Jahani, Masoud Salehi, Amin Shakiba, Aliasghar Moradipour, Forouzan Forouzandeh,
Volume 18, Issue 5 (8-2015)
Abstract
Background: Ferula assa-foetida is one of the common medicines that was used as antiseptic with a view to traditional uses, it can be used as a safe and effective drug to treat diseases particularly resistant bacterial infections. This study aims to product gelatin nano- capsules containing Ferula assa-foetida essential oil and investigate their antioxidant and antibacterial activities.
Materials and Methods: This experimental study was performed on gelatin nano-capsules containing Ferula assa-foetida essential oil (FAO) (2, 4, 6 and 8% w/w), glycerol (25% w/w) as plasticizer and glutaraldehyde as cross-linker. The morphology, antioxidant and antibacterial activities and operation of the nano-capsules were assessed according to American Standards by Scanning Electron Microscopy, ABTS, and microbiological tests.
Results: Gelatin nano-capsules exhibited low antioxidant and antibacterial activities while gelatin nano-capsules incorporated with FAO exhibited excellent antioxidant and antibacterial. The highest rates of these effects were seen merged with 8% of FAO.
Conclusion: Gelatin nano-capsules merged with FAO have excellent physical form, as well as they are an appropriate antioxidant and antibacterial that have been considered to produce antoxidant and antibacterial drugs.
Hasan Izanloo, Shahram Nazari, Mohammad Ahmadi Jebelli, Soodabeh Alizadeh Matboo, Hamid Reza Tashauoei, Behnam Vakili, Mohammad Rajabi, Hosein Aghababaei, Gharib Majidi,
Volume 18, Issue 6 (9-2015)
Abstract
Background: Dendrimers are a subset of branched structures that have certain structural order. The aim of this study was to investigate the performance of Polypropylenimine-G2 (PPI-G2) dendrimers in removal of Escherichia coli, Proteus mirabilis, Bacillus subtilis and Staphylococcus aureus from aqueous solution .
Materials and Methods: In this experimental study , initially dilution of 103 CFU/ml was prepared from each strain of bacteria . Then , different concentrations of dendrimers (0.5, 5, 50 and 500 µg/ml) was added to water . In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 40, 50 and 60 min) and were cultured on nutrient agar medium . Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted .
Results: By the increasment of dendrimer concentration and contact time , the number of bacteria in aqueous solution decreased. In times of 40 , 50 and 60 minutes, and the concentrations of 50 and 500 µg/ml, all kinds of bacteria in aqueous solution were removed . 0.5 µg/ml of dendrimer concentration had not effect in reducing the number of Escherichia coli and Proteus mirabilis . The effect of dendrimer on gram-negative bacteria was weaker than gram-positive bacteria.
Conclusion: Results of this study indicated that PP I -G2 dendrimer is able to remove Escherichia coli , Proteus mirabilis , Staphylococcus aureus and Bacillus subtilis in aqueous solution. However, using dendrimers can be considered as a new approach for drinking water disinfection but it requires further wide range studies.
Begher Seyedalipour, Ali Hasani, Mohammad Ali Ebrahimzadeh, Mojtaba Mohseni,
Volume 18, Issue 11 (2-2016)
Abstract
Background: Lamiaceae family has about 200 genuses and 4000 species. The majority of species of the family have essence that was used for nutritional, cosmetic and pharmaceutical industry. The aim of this study was to investigate the chemical composition of essential oil from aerial parts of Bollota platyloma and antibacterial activity of it.
Materials and Methods: In this experimental study, study Ballota platyloma, belonging to lamiaceae family and entomic of iran, was collected from Versk region in Mazandaran provinc. Essential oil from aerial parts was obtained by hydro distillation method by using Clevenger apparatus. GC/MS analysis of essential oil was carried out to identify major volatile constituents. Extraction was prepared by maceration method. Antibacterial activity of methanolic extracts against Pseudomonas aeruginosa, Bacillus subtilis, Stapylococcus aureus, Escherichia coli was investigated by disc diffusion method and minimal inhibitory concentration(MIC) method.
Results: Results showed that GC/MS analysis of the essential oil confirms the presence of 24 constituents in Ballota platyloma. The main constituents were Hexadecanoic Acid (40.03%), Germacrene D (26.6%) and Beta Caryophylene (4.76%). The results indicated that methanolic extract of Ballota platyloma possessed antibacterial activity. Among the aforementioned bacteria, the highest antibacterial activity was seen against S. aureus and the lowest activity against P. aeruginosa.
Conclusion: The findings of the present study showed that the major component of oil essential was germacrene-D and methanolic extract from the aerial parts of Ballota platyloma Rech. f. possess anti-bacterial effects. Thus, in order to find the underlying mechanism of this activity, further research should be carried out.
Shahram Nazari, Sajjad Ashkani, Hadi Yousefzadeh, Fazel Agaei, Gharib Majidi, Aziz Kamran, Payman Azghani, Ayyob Rastegar, Zohreh Nazari, Soudabeh Alizadeh Matboo,
Volume 18, Issue 12 (3-2016)
Abstract
Background: Dendrimers are macromolecules with regular three-dimensional structure that have many branches. The aim of this study was to investigate the fficiency of Nano Polyamidoamine–G5 (NPAMAM-G5) dendrimers in removal of Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.
Materials and Methods: In this experimental study, initially, dilution of 103 CFU/ml was prepared from each strain of bacteria. Then, different concentrations of dendrimers (0.025, 0.25, 2.5 and 25 µg/ml) in the ambient temperature (23-25°C) was added to water. In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 50 and 60 min) and were cultured on nutrient agar medium. Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted.
Results: There is a direct relation between antibacterial properties of dendrimers in aqueous solution and increasing the dendrimer concentration and contact time. At a concentration of 25 μg/ml and 60 minutes, all kinds of bacteria except Staphylococcus aureus, and at 30 minutes, E. coli and Klebsiella bacteria, were removed by 100% The concentration of 2.5 μg/ml at 60 minutes of bacteria, Escherichia coli, Klebsiella and Proteus mirabilis, 100% Were removed. All concentrations of dendrimer at different times were reduced bacteria.
Conclusion: Results of this study indicated that NPAMAM–G5 dendrimer is able to remove Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.
Asefeh Dahmardeh Ghalehno, Maryam Ghavidel-Aliabadi, Zeinab Shahmohamadi, Maliheh Mehrshad, Mohammad Ali Amoozegar, Abolghasem Danesh,
Volume 20, Issue 12 (3-2018)
Abstract
Abstract
Background: Today, discovery and production of new antimicrobial drugs has been emphasized due to the growing of antimicrobial resistance. The purpose of this study was to screen out antimicrobial producing bacteria among halophilic or halotolerant Gram-positive endospore-forming bacteria isolated from different areas of Iran.
Materials and Methods: 62 strains were isolated from salin lakes of Iran, endospore-forming ability was evaluated and further identification of strains was done using 16S rRNA gene sequencing. Screening test was performed using two-layer agar diffusion method in which the indicator strains, Bacillus cereus (ATCC 14579) and Escherichia coli, (PTCC 1330) were inoculated in the seed layer. Finally, the production of antimicrobial active agent during a period of 7 days was studied followed by evaluating the effect of base-layer agar concentration on the dissemination of antibacterial metabolite.
Results: Isolates WT6, R4A19 produced an agent(s) which inhibited the growth of both B.cereuse and E.Coli. The inhibition zone against only E.Coli was observed when R4A20 strain had been cultured in the base layer, while four non-bacillus strains (R4S2, LbS2, RF1 and WT19) could inhibit the growth of B.cereuse. The antibacterial compound production of WT6 against Bacillus cereuse and E.Coli reached to its optimumm leved after 3 and 4 days respectively, while R4A20 produced the active substance, optimally, after 5 days. No significant difference effect on diameter of zone inhibition was observed among various base-layer agar concentrations.
Conclusion: Halophile or halotolerant endospore-forming bacteria isolated from different areas of Iran possess a potential to be considered as interesting microorganisms for further antimicrobial research studies.
Asma Toraji, Mahnaz Hadizadeh, Fahimeh Nemati Mansoor,
Volume 21, Issue 1 (4-2018)
Abstract
Abstract
Background: Nanotechnology offers a great chance to treat drug-resistant microbial infections. The purpose of this study was to synthesize amoxicillin-encapsulated polymeric nanoparticles and compare the antibacterial activity of this nanoformulation with pure amoxicillin.
Materials and Methods: Amoxicillin-encapsulated polymeric nanoparticles were prepared using chitosan as a polymer and alginate as cross linking agent. The obtained nanoparticles were characterized by Fourier transform infrared, dynamic light scattering and scanning electron microscopy. The antibacterial effects of the nanoparticles were evaluated using broth microdilution and well diffusion methods against some common bacterial strains involved in hospital-acquired infections.
Results: The drug-encapsulated nanoparticles were found to be spherical in shape with average size of 96 nm. These nanoparticles had a significant antibacterial effect on all tested bacteria, except for Pseudomonas aeruginosa. They also displayed stronger antibacterial activity than the nanocarrier alone or free antibiotic. The highest mean zones of growth inhibition (23.7 mm) for methicillin-sensitive Staphylococcus aureus and the smallest zone (12.5 mm) for the resistant species of this bacterium were determined. MIC of the nanoformulation against these two strains was respectively determined at 1.5 and 48 µg/ml and for Escherichia coli and Pseudomonas aeruginosa at 6.6 and 256 µg/ml.
Conclusion: The results suggest that amoxicillin encapsulation in polymer nanoparticles has the potential to increase its antibacterial activity against bacteria causing nosocomial infections.
Behnoush Sadat Khalili, Javad Hamedi, Setareh Haghighat,
Volume 21, Issue 7 (2-2019)
Abstract
Background and Aim: The widespread use of antibiotics has been led to increased emergence of antibiotic resistant bacteria and high mortality and morbidity rates due to infectious diseases. Pseudomonas aeruginosa is one of the most important causes of nosocomial infections, which shows high resistance to a wide range of antibiotics. So, finding new and effective antimicrobial compounds in order to overcome antibiotic resistant infectious diseases is so critical. Screening of native actinobacteria can be an effective strategy to find novel antimicrobial compounds. The aim of current study was isolation, screening and identification of rare actinobacteria to find the strains which produce antimicrobial compounds against P. aeruginosa.
Material and Methods: Thirty samples of water and sediments were collected from Persian Gulf and Oman Sea and used for isolation of actinobacterial strains. After isolation of actinobacteria, their metabolites were extracted and their anti-P. aeruginosa activities were investigated. Minimum inhibitory concentration (MIC) of the most efficient extract was determined using broth microdilution method. Finally, the most efficient strain was identified.
Ethical Considerations: In this study, all principles of biosafety and bioethics have been considered.
Findngs: Fifty actinobacteria were isolated from water and sediments. Five isolates had considerable antimicrobial activity. MIC value of the most efficient extract against P. aeruginosa was 100 µg/ml. Molecular analysis of 16SrRNA showed that the most effective fermentation broth extract belongs to Micromonospora and has 99.8% similarity to M. chalcea.
Conclusion: The current study revealed that the water of southern Iran and their sediments are promising sources of potent rare Actinobacteria in the production of antimicrobial compounds against P. aeruginosa. |
Ali Iranpoor, Mojtaba Bayani, Mohammad Arjomandzadegan, Afrooz Nakhostin,
Volume 22, Issue 4 (9-2019)
Abstract
Background and Aim Periodontal diseases are among the most prevalent inflammatory diseases caused by oral bacteria. Expansion of oral biofilm causes various diseases such as gingival inflammation and periodontitis. The Satureja plant has various species, all of which are aromatic. This plant is traditionally used for the treatment of some diseases. The present study was conducted to evaluate the effect of Satureja essential oil on periodontal pathogens.
Methods and Materials In this study, we evaluated four pathogens; Enterococcus faecalis, Streptococcus sanguinis, Eikenella corrodens, and Actinomyces viscosus. We also used the disk diffusion test and broth microdilution method to evaluate the antimicrobial effect of Satureja essential oil. Finally, we determined the minimum inhibitory concentration and minimum bactericidal concentration.
Ethical Considerations The Ethics Committee of Arak University of Medical Sciences approved this study (Code: IR.ARAKMU.REC.1397.67).
Results In concentration of 0.1 g/mL of Satureja plant, Actinomyces viscosus, Streptococcus sanguinis, Enterococcus faecalis, and Eikenella corrodens were found to be sensible to resistance. The Satureja essential oil had the highest effect on Eikenella corrodens. Results obtained from the biofilm test showed no biofilm in a concentration of 12.5 mg/mL and higher of Satureja plant.
Conclusion The Satureja plant was found to have an antibacterial and inhibitory effect on biofilm growth and formation in the oral cavity.
Mohammad Saeed Poorsoleiman, Seyed Seyed Ahmad Hosseini, Alireza Etminan, Hamid Abtahi, Ali Koolivand,
Volume 22, Issue 5 (11-2019)
Abstract
Background and Aim The widespread application of crude oil and its products has caused numerous environmental pollutions. This study aimed to isolate, identify, and determine a bacterial strain’s potential of oil degradation isolated form oily sludge.
Methods & Materials After preparing the oily sludge in the sterile containers and cultivating in Bushnell-Haas medium, 24 distinct bacterial colonies were obtained. After performing biochemical and molecular tests, the “Acinetobacter radioresistens strain KA2” with the highest growth rate and crude oil degradation was selected. Then, degradation of various concentrations of crude oil at different PHs (5, 6, 7, 8 and 9), bacterial adherence to hydrocarbons and emulsification index of the selected strain were measured. Total petroleum hydrocarbons were determined by gas chromatography.
Ethical Considerations This study has been approved by the Research Ethics Committee of Islamic Azad University of Kermanshah Branch (code: 19250587962001 ).
Results The results indicated that the removal efficiency of crude oil at concentrations of 1, 2, 3, 4, and 5% were 65.24, 76.14, 53.81, 31.84, and 25.21%, respectively. Crude oil removal at pH values of 5, 6, 7, 8, and 9 was 42.4, 69.16, 65.24, 59.41 and 48.24%, respectively. Bacterial adherence to hydrocarbons and emulsification index of the isolated strain were calculated to be 13.69 and 59.14%.
Conclusion The isolated bacterium is an efficient strain in treating the crude oil and petroleum compounds.
Ramin Fallahzadeh, Kasra Esfahani, Abbas Akhavan Sepahi, Nasrin Kamali, Bijan Bambai,
Volume 22, Issue 5 (11-2019)
Abstract
Background and Aim The flavin reductase DszD enzyme is a key enzyme for providing required reduction potential in the bacterial desulfurization process. Considering the low speed of desulfurization process because of low catalytic power of this enzyme, it is necessary to increase the catalytic power of flavin reductase for industrial use of this enzyme as biocatalyst.
Methods & Materials The three-dimensional structure of the flavin reductase DszD enzyme was predicted by a CPHmodel server and its amino acid sequence was searched in the protein data bank to identify the homologue molecules. Based on the alignment of the amino acid sequence and the model molecules, the key residues at the flavin mononucleotide substrate were identified. The key residue of asparagine at position 77 was replaced with phenylalanine using the site-directed mutagenesis method.
Ethical Considerations This study with research ethics code IR.NIGEB.EC.1398.6.24 A has been approved by research ethics committee at National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
Results The cloning and expression of each of the wild-type and mutant genes were performed separately. The catalytic power of the produced wild-type and mutant enzymes were compared. The catalytic activity measurements showed that the mutant enzyme had a 2.5 fold increase in catalytic power.
Conclusion Replacing phenylalanine with asparagine at position 77 of flavin reductase DszD enzyme leads to an increase in enzyme catalytic power to increase the speed of bacterial desulfurization process.
Seyed Hamed Mirhoseini, Fatemeh Ariyan, Samaneh Mohammadi,
Volume 22, Issue 6 (1-2020)
Abstract
Background and Aim: The assessment of indoor air quality and detection of its microbial pollutants in classrooms is very important because of the presence of children sensitive to these pollutants. The aim of this study was to determine the concentration and characterization of dominant species of biological aerosols and their relationship with environmental factors in two selected primary schools in Arak, Iran.
Methods & Materials: This cross-sectional study was conducted at two primary schools in Arak, Iran in Fall 2018. Indoor air sampling was performed using single-stage Andersen microbial sampler (at flow rate of 28.3 liters/min) containing bacterial and fungal culture media. The effects of suspended Particulate Matter (PM) and environmental parameters (temperature and humidity) on the density of bioaerosols were evaluated.
Ethical Considerations: This study with an ethics code of IR.ARAKMU.REC.1397.76 was approved by the Research Ethics Committee at Arak University of Medical Sciences.
Results: The overall mean density of indoor bacteria and fungi was 448 cfu/m3 and 394 cfu/m3, while the mean density of outdoor bacteria and fungi was 210 cfu/m3 and 127 cfu/m3, respectively. There was a positive correlation between indoor density of airborne bacteria and suspected PM concentrations (PM 10 and PM 2.5), and between PM2.5 concentration and indoor fungal density (P<0.05). Penicillium (40%), Cladosporium (19%) and Aspergillus (16%) were dominant species of fungi, while Staphylococcus (42%), Micrococcus (28%), Bacillus (21%) were the dominant species of bacteria.
Conclusion: The age and type of building and the density of students in a classroom are the main factors in increasing the concentration of bioaerosols.
Elaheh Rezaie, Mojtaba Bayani, Mohamohammad Arjomandzadeganmmad,
Volume 23, Issue 2 (5-2020)
Abstract
Background and Aim: Although there are methods such as the use of mouthwashes to prevent periodontal diseases, these diseases are still the most common oral diseases. Given the side effects of chemical methods, the present study aimed to evaluate the inhibitory and antibacterial effects of peppermint essential oil on periodontal pathogens.
Methods & Materials: Antibacterial effect of the peppermint essential oil by the disk diffusion and Microplate dilution techniques was performed on 4 standard bacteria purchased from the microbial bank of Iran, including Enterococcus Faecalis, Streptococcus Sanguinis, Eikenella corrodens, and Actinomyces Viscosus. The minimum inhibitory concentration and minimum bactericidal concentration of the essential oil were also evaluated. The amount of biofilm formation was obtained by calculating the average biofilm formation in the three wells and comparing it with the optical density of negative control by the Elisa Reader device.
Ethical Considerations: This study was approved by the Research Ethics Committee of Arak University of Medical Sciences with code: IR.ARAKMU.REC.1397.15.
Results: Results of diffusion test showed the inhibitory effect of 0.1 g/mL essential oil on Enterococcus Faecalis and Streptococcus Sanguinis. Pure essential oil of peppermint showed the strongest inhibitory effect on streptococcus sanguinis followed by enterococcus faecalis, actinomyces viscosus and eikenella corrodens.
Conclusion: The peppermint plant has antibacterial and inhibitory effects on the bacteria of enterococcus faecalis, streptococcus sanguinis, eikenella corrodens, and actinomyces viscosus. Therefore, peppermint as a natural and effective antibacterial agent, has a potential application in the prevention of periodontal disease.
Abolfazl Morad, Mehdi Zeinoddini,
Volume 23, Issue 6 (11-2020)
Abstract
Background and Aim: In the microbial contamination of food and water, identifying the trace amounts of contaminating bacteria has always been of researchers’ interest and concern. The most frequent approach to resolve this problem is using culture-based methods to increase and enrich bacteria samples; accordingly, it extends the bacterial detection process to several hours or days. One of the smart strategies to solve this problem is the concentration of bacteria using physical methods. The present study aimed to enrich Vibrio cholerae as the most essential water-polluting germs. Accordingly, we used the filtration method and evaluated its function by culture method and two detection approaches of Adenosine Triphosphate (ATP) and PCR assay.
Methods & Materials: A certain concentration of V. Cholerae was artificially added to a specified volume of sterile water. Then, the bacteria were extracted from the medium and filtered using 0.450 µm separable filters. Finally, the performance of the pre- and post-filtration processes was compared using bacterial cell culture (CFU), ATP, and PCR assay with the specific primers for the ompW gene of V. cholerae.
Ethical Considerations: This article is a meta-analysis with no human or animal sample.
Results: The present research results indicated that the applied method presented high efficiency and recovery performance. In other words, samples provided no positive response before filtration in both methods; however, after filtration in isolated and recovered samples, the presence of bacteria was detected in the ATP and PCR methods.
Conclusion: In conclusion, the employed strategy can detect V. cholerae in non-culture and in the shortest time in contaminated water samples.
Rahil Mirzaei, Mehdi Javad Chavosh, Mehdi Rajabnia, Valiollah Arash, Ali Bijiani, Maysam Mirzaie, Mohamad Mehdi Naghibi Sistani,
Volume 24, Issue 1 (3-2021)
Abstract
Background and Aim: There exists increased demineralization risk of enamel adjacent to fixed orthodontic attachments by cariogenic bacterias (e.g., Streptpcoccus mutans, Streptpcoccus sobrinus) and inadequate data about commonly used orthodontic cements. Thus, we evaluated the antibacterial effects of three common domestic and foreign orthodontic cements (Glass ionomer, Zinc phosphate, & polycarboxylate) on two cariogenic pathogens (S. mutans & S. sobrinus).
Methods & Materials: In this laboratory study, after culturing two standard strains of Streptococcus mutans and Subrinus bacteria and concentrating and diluting them, a direct contact test was used to evaluate the antibacterial properties of types of cement. The study groups (n=5) included the following: three types of glass ionomer resilience cement, Hoffman’s zinc phosphate and Hoffman’s polycarboxylate, and three glass ionomer cement, zinc phosphate, and carboxylate from Aria Dent factory in Iran. The acquired data were analyzed using SPSS v. 17.
Ethical Considerations: The present study was approved by Babol University of Medical Sciences (Code: MUBABOL.REC.1391.7).Results: In both types of culture media, containing Streptococcus mutans and Streptococcus subrinus bacteria, there was a significant difference between culture media containing 3 groups of cements respecting bacterial growth inhibition zone (P<0.001). In general, The mean diameter of the inhibition zone was greater in Iranian polycarboxylate, compared to its foreign counterpart (P<0.001).
Results: Regarding to zone of inhibition, there was statistically significant difference between three tested cements in both S.mutans and S.sobrinus culturing media (P<0.001). The mean diameter of inhibition zone was greater for Iranian polycarboxylate compared to its foreign counterpart (P<0.001).
Conclusion: Glass ionomer cement demonstrated better antibacterial effect compared to zinc phosphate and polycarboxylate cements. There was also greater antibacterial effect of three tested cements on S.sobrinus than S.mutans. Iranian polycarboxylate showed stronger inhibition on both mentioned bacterias compared to the foreign one.
Seyyedeh Mahbouube Mousavi, Nooshin Naghsh,
Volume 24, Issue 4 (9-2021)
Abstract
Background and Aim: One of the new technologies in this century is nanotechnology. Nanotechnology is a vast and promising research platform that has opened up a wide range of opportunities in various fields including pharmacy, medicine, electronics and agriculture. One of the applied nanoparticles in the field of nanobiotechnology is silver nanoparticles. One of the most important features of these nanoparticles is the creation of programmed cell death (Apoptosis). This property has created its antiseptic properties against bacteria, fungi, viruses and nematodes. Nanoparticles have better performance against microorganisms due to their high surface-to-volume ratio and higher contact surface. Meanwhile, silver nanoparticles have shown unparalleled antimicrobial activity against a wide range of microorganisms and have recently attracted the attention of many researchers.
Methods & Materials: In this study, a review of all databases, including ISI Web of Science, Scopus, ISC, PubMed, Google Scholar Learners, Noor, related articles were examined.
Ethical Considerations Ethical principles have been observed in writing the article.
Results: The antimicrobial effect of silver nanoparticles depends on the concentration, shape and diameter of the nanoparticles as well as the time of effect and the type of microorganism. The molecular mechanism of these nanoparticles has been through oxidative stress. The mechanism of inhibitory action of silver ions on microorganisms is the loss of DNA replication ability, inactivation of the expression of ribosomal subunit proteins and other bacterial cell proteins and enzymes necessary for ATP production. The effect of silver ions is primarily on the function of membrane-bound enzymes such as key enzymes in the respiratory chain. Thus, similar cellular mechanisms can cause cell death effects in prokaryotes, fungi, and eukaryotes.
Conclusion: The results showed that variables such as type of microorganism, contact time, concentration, shape and diameter of silver nanoparticles had a significant effect on inhibiting microbial growth.
