Showing 28 results for Bacteria
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.
