Microbiology
Elaheh Tasallot Maraghi; Nasim Kashef; Ahmad Reza Gohari; Zahra Fekrirad
Volume 28, Issue 4 , September and October 2021, , Pages 556-568
Abstract
Introduction: Staphylococcus aureus is one of the most important pathogenic bacteria in humans. Due to the antibiotic resistance, treatment of staphylococcal infections is difficult. Among the alternative treatment options, plants are considered as a rich source of material with antimicrobial activity. ...
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Introduction: Staphylococcus aureus is one of the most important pathogenic bacteria in humans. Due to the antibiotic resistance, treatment of staphylococcal infections is difficult. Among the alternative treatment options, plants are considered as a rich source of material with antimicrobial activity. The aim of this study was to evaluate of the antimicrobial effects of ethyl acetatic, methanolic and water-methanolic extracts from Satureja khuzistanica, Peganum harmala, Satureja sahendica onplanktonic growth and biofilm formation of S. aureus.
Materials and Methods: The extracts were prepared from different parts of plants and the antimicrobial properties of the extracts were determined by disk diffusion and microbroth dilution method. Also, Crystal violet staining assay was used to evaluate the ability to inhibit biofilm formation of S. aureus strains. Disruption of pre-formed biofilms of S. aureus strains were evaluated following exposure to plant extracts in different concentrations (ranging from 3/125 to 400mg/ml).
Results: The highest inhibitory zones were showed by ethyl acetatic extract of Satureja sahendica (28/6±0.6mm). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethyl acetatic extract of S.khuzistanica were 1/562 and 3/125mg/ml, respectively. Besides, methanolic extract of S. khuzistanica was the most effective extract in inhibition of microbial cells attachment to surface (57/89%) and it showed disruption of pre-formed biofilms at the concentration of 50 mg/ml.
Conclusion: The extracts of all mentioned plants had satisfactory antimicrobial effects against the planktonic growth of S. aureus and methanolic extract of S. khuzistanica was effective against biofilm formation of S. aureus.
Microbiology
Mazaher Mazaher Ghorbani; Slaman Ahmady-Asbchin
Volume 25, Issue 4 , September and October 2018, , Pages 591-598
Abstract
Background and Objective: Because of the increasing resistance of pathogenic bacteria to common antibiotics, the new generation of researchers sought antimicrobial agents with plant origin as alternative medicine. Oregano is from Lamiaceae family and coriander is from Apiaceae family and has antimicrobial ...
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Background and Objective: Because of the increasing resistance of pathogenic bacteria to common antibiotics, the new generation of researchers sought antimicrobial agents with plant origin as alternative medicine. Oregano is from Lamiaceae family and coriander is from Apiaceae family and has antimicrobial properties.Materials and Methods: This study aimed to investigate and compare the inhibitory effects of alcoholic extracts of coriander and oregano plants on Staphylococcus aureus, Klebsiella and Salmonella. 1000 ml of alcohol poured round-bottom flask, then the target plant (200-300 g of dried powder of plant) put into envelopes of filter paper and envelopes was placed in a distillation device. After 24-48 hours the obtained alcoholic extract was placed in the oven. DMSO was used to provide different concentrations of ethanol extract.Results: The concentrations of 31/25 and 62/5 mg / ml of alcoholic extract of oregano and concentrations of 62.5 and 125 mg / ml coriander were able to inhibit and kill Staphylococcus aureus and weren`t able to inhibit and kill Salmonella and Klebsiella respectively .Conclusion: Although the clinical application of plant extracts and essences seems valuable due to fewer side effects compared to conventional therapeutic agents, in order to clinical application of plant extracts of oregano and coriander, more research about the mechanism of action of effective components of this plant on the microbial agents is needed.
Microbiology
Hamed Tahmasebi; Mohammad Bokaeian
Volume 24, Issue 5 , September and October 2018, , Pages 367-374
Abstract
Objectives: Disinfectants and antiseptics agents of the past were used for disinfect equipment and surfaces. In some cases, these substances ineffective by a series of specific efflux proteins that are present in bacteria. QqcA / B and smr such as most important genes those can be expression more efflux ...
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Objectives: Disinfectants and antiseptics agents of the past were used for disinfect equipment and surfaces. In some cases, these substances ineffective by a series of specific efflux proteins that are present in bacteria. QqcA / B and smr such as most important genes those can be expression more efflux protein in strain of methicillin-resistant staphylococcus aureus (MRSA). The aim of this study was to investigate the genes qacA / B and smr is MRSA strains.Methods: 89 isolates from various clinical samples were early identified by biochemical test. Initial screening was performed by Cefoxitin disk diffusion (30 µg) and then detection of mecA, smr and qacA/B gens was done by polymerase chain reaction (PCR). Finally, were analyzed results by using chi-square tests and t-test.Results: Out of 89 staphylococcus aureus isolates, 59 isolates were identified methicillin-resistant by initial phenotype test. Among those, 50 isolates (17/56%) have respectively mecA gene, 14 isolates (73/15%) smr gene and 29 isolates (58/32%) qacA / B gene. Using by statistical tests and p.value test, was obtained the relationship between qacA / B and mecA genes.Conclusions: According to the results of the studie of prevalence of genes in Zahedan and high frequency of MRSA strains, should pay more attention to the use of disinfectants agents.
Microbiology
mohammad bokaeian; hamed tahmasebi; Javad adabi; alireza mohammad zadeh; jalal mardaneh
Volume 25, Issue 1 , May and June 2018, , Pages 31-37
Abstract
Background: Bacterial resistants to beta-lactam antibiotics, are steadily expanding. Excessive consumption beta-lactam antibiotics in the treatment of related Staphylococcus aureus infections caused the emergence of beta-lactamase enzymes in strains. Identification and analysis of molecular characteristics ...
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Background: Bacterial resistants to beta-lactam antibiotics, are steadily expanding. Excessive consumption beta-lactam antibiotics in the treatment of related Staphylococcus aureus infections caused the emergence of beta-lactamase enzymes in strains. Identification and analysis of molecular characteristics of these strains can be effective to select on the appropriate antibiotic treatment.Materials and Methods: Initially, the isolates collected from clinical samples were screened by biochemical tests. After the whole Staphylococcus aureus resistance to beta-lactam antibiotics, were evaluated by used of molecular-specific primers.Results: Of 496 isolates obtained from different clinical samples, 147 isolates were identified as S. aureus. The highest resistance to the antibiotics had related to penicillin, Oxacillin, Cefocithin and the lowest resistance antibiotics had related to Vancomycin. From the 147 samples, 143 samples were blaZ genes that allocated to over 97 percent.Conclusion: According to the results of molecular tests, in the Zahedan spread of carrier-lactamase strains is very high. This would be to treat all staphylococcal infections of beta lactam antibiotics are not used as much as possible to the access to early treatment prevented the increase in resistant strains.
MohammadReza Saeedi Asl; Mehdi Hasan shahiyan; Sara Rashid; Hossein Estiri
Volume 21, Issue 1 , March and April 2015, , Pages 7-16
Abstract
Background: Probiotics are beneficial microorganisms that will be health effects, if be used in a sufficient amount. Due to the growing use of industry dairy, rather than traditional products, there is the possibility of losing a lot of probiotic bacteria. It is, therefore, essential to identify the ...
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Background: Probiotics are beneficial microorganisms that will be health effects, if be used in a sufficient amount. Due to the growing use of industry dairy, rather than traditional products, there is the possibility of losing a lot of probiotic bacteria. It is, therefore, essential to identify the bacteria from traditional sources and use them in the production of dairy products. The aim of this study was to screen and identify Enterococci from KAMEH (a traditional dairy product of Sabzevar), and evaluation of their probiotic potential.
Material and Methods: In this study, sampling was carried out from four different villages. For screening, the collected samples were placed in pH 4.5. The remained strains were evaluated in pH 4 and 0.3 % bile salt. Antimicrobial activity of screened strains was analyzed against Salmonella typhimurium and staphylococcus aureus using disc plate method. Finally, the strains were identified by PCR and sequencing techniques.
Results: The results showed that three different species of Enterococci , including E. faecium, E. avium and E. faecalis, exist in KAMEH, which have a strong probiotic potential, such that they can withstand high levels of acid and bile salts . E1 code had most antimicrobial activity.
Conclusion: This study revealed that KAMEH has Enterococci with appropriate probiotic potential, and can be added as a supplement to other dairy products.
B BARATI; M SHIRAZI; M SAADATI; MJ SOLTANPOUR
Volume 14, Issue 2 , July and August 2007, , Pages 117-127
Abstract
Background and purpose: Staphylococcus aureus is a pathogen which can cause food poisoning, under certain conditions though growth in nutrients and producing enterotoxin. Only some strains are capable of producing enterotoxin and causing food poisoning and their presence can be detected by DNA amplification ...
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Background and purpose: Staphylococcus aureus is a pathogen which can cause food poisoning, under certain conditions though growth in nutrients and producing enterotoxin. Only some strains are capable of producing enterotoxin and causing food poisoning and their presence can be detected by DNA amplification and gene sequence specification. Therefore, this research was conducted to detect type e enterotoxin producing staphylococcus aureus.
Methods and Materials: 95 staphylococcus aureus strains were isolated from 150 nasal carriers using sterilized swabs and were confirmed by biochemical tests. Then primers were designed and the PCR was used to amplify amplify the staphylococcal enterotoxin e gene (sec) in order to detect type C enterotoxogenic strains.
Results: DNA amplification fragments of 397 bp for staphylococcal nuclease and those of 271 bp for type e gene were confirmed by enzymatic digestion. Only 9.5% of the isolated strains contained sec gene. Specificity and sensitivity were also evaluated and its sensitivity was found to be 125 cells.
Conclusion: this technique is a rapid, sensitive, specific, inexpensive and different alternative to conventional biochemical and serologic assays and it can be used to detect the agent producing type C staphylococcal enterotoxin.