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
Hamidreza Baghani Aval; Mehran Ekrami Toroghi; Faezeh Haghighi; Yaser Tabarraie
Volume 25, Issue 5 , November and December 2018, , Pages 687-693
Abstract
Background: Urinary tract infection is the most common infectious diseases and increasing resistance to antimicrobial agents in bacteria is a major problem around the world in treatment of urinary infections. This study was conducted to identify causative agents of urinary tract infection and to determine ...
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Background: Urinary tract infection is the most common infectious diseases and increasing resistance to antimicrobial agents in bacteria is a major problem around the world in treatment of urinary infections. This study was conducted to identify causative agents of urinary tract infection and to determine their susceptibility to antibiotics in hospitalized and out patients referred to the Vase’ee Hospital in Sabzevar.Methods: This descriptive cross-sectional study was performed on 256 individuals hospitalized and out patients older than eighteen age in the Sabzevar Vase’ee hospital. Identification of bacteria was performed using biochemical tests and their susceptibility was determined by disk diffusion method. The data were analyzed using t-test, Chi-square and Fisher’s exact test with percentage error 5%.Results: Of 256 patients, 59.7 % and 40.3% were female and male, respectively. The most frequently isolated pathogen were Escherichia coli (50.8%), Klebsiella (17.6%), Coagulase-Negative Staphylococci (15/62%), Enterobacter (7.8%). E. coli as most common pathogen of urinary tract infections showed the most resistance to ampicillin and the least resistance to Imipenem indicated. In total, regardless of the type of bacteria, the highest resistance was against amoxicillin and the lowest resistance was against Imipenem.Conclusion: Considering the frequency of urinary tract infections and in order to prevent serious complication, a survey of regional resistance pattern and timely treatment can control development of resistant bacteria.
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.
Fereshteh Javadian; Zahra Sepehri; Mansour Amraee; Zohreh Kiani; Maryam Shahraki Mojahed; Zahra Shahi; Sepideh Pourghasemi Fetideh
Volume 22, Issue 4 , September and October 2015, , Pages 565-570
Abstract
Background and Purpose: The present study was carried out to determine the potential antibacterial agent of ethanolic extract of Hibiscus Sabdariffa against Klebsiella Pneumonia isolation of urinary tract infections. Methods and Materials:The leaf H. Sabdariffa was properly dried and pulverized ...
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Background and Purpose: The present study was carried out to determine the potential antibacterial agent of ethanolic extract of Hibiscus Sabdariffa against Klebsiella Pneumonia isolation of urinary tract infections. Methods and Materials:The leaf H. Sabdariffa was properly dried and pulverized into a coarse powder as described by Hanafy. Twenty grams of grinded powders from each plant were soaked in 60 ml of ethanol (95 %v/v) plus water, separately for one day with occasionally shaking. After one day of dissolving, materials were filtered through a Whatman no. 1 filter paper .Then the filtrates were evaporated using rotary evaporator. At last, 0.97 g of dried extract was obtained and then stored at40C in an air tight screw-cap tube. Isolation of bacteria : All 12 K. Pneumoniae were isolated from urine culture of hospitalized patients (Amir Al-Momenin Hospital, Zabol, south-eastern Iran), whom suffered from urinary tract infections during the years 2010- 2011. Isolated bacteria were identified by Gram's stain and standard biochemical tests. Sensitive strains to several antibiotics were evaluated by the disk diffusion method with standard Kirby - Bauer. Results: Results showed Klebsiella Pneumoniae isolates resistant to the antibiotics Erythromycin (75%) , Cefixime (3/58%) and Ceftazidime (3/33%). The results showed that the ethanol extract of Hibiscus tea with 10 ml / mg and l5 mg/m density have maximum inhibitory against Klebsiella Pneumonia samples and only one strain of K. Pneumoniae is inhibited in concentration 1/25. Discussion: It seems that H.Sabdariffa extracts could inhibit the growth of all of the mentioned bacteria. We noticed that the bactericidal effect of H.Sabdariffa extract was less than its bacteriostatic effects.
Fakhri Haghi; Marziyeh Bayat; Habib Zeighami
Volume 21, Issue 1 , March and April 2015, , Pages 61-68
Abstract
Background: Enteropathogenic E. coli (EPEC) is the predominant cause of infant diarrhea worldwide and represents a major endemic health threat to children living in developing countries. The increase in antibiotic resistance in pathogenic bacteria, especially in children, is considered as one of the ...
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Background: Enteropathogenic E. coli (EPEC) is the predominant cause of infant diarrhea worldwide and represents a major endemic health threat to children living in developing countries. The increase in antibiotic resistance in pathogenic bacteria, especially in children, is considered as one of the world's health problems. The aim of this study was to evaluate the antibiotic resistance and multi-drug resistance in EPEC which isolated from children with diarrhea admitted to the hospital in Zanjan.
Materials and Methods: In this cross sectional study, 450 stool specimens were collected from children with diarrhea
Ziba Foladvand; Zohreh Kiani; Fereshteh Javadian; Mehran Hesaraki; Aliakbar Nasiri; Zahra Sepehri
Volume 21, Issue 6 , January and February 2015, , Pages 1019-1027
Abstract
Background and Purpose: Development of antibiotic resistance among pathogenic bacteria motivates attempts to search for newer antimicrobial agents. In this research study, antibacterial effect of plant extract of M. communis , z.multiflora and Allium sativum on biofilm formation by strains of Staphylococcus ...
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Background and Purpose: Development of antibiotic resistance among pathogenic bacteria motivates attempts to search for newer antimicrobial agents. In this research study, antibacterial effect of plant extract of M. communis , z.multiflora and Allium sativum on biofilm formation by strains of Staphylococcus aureus resistant to the antibiotic were investigated.
Methods and Materials: 17 samples were separated from nose and throat of hospital and non-hospital personnels. The effect of extracts on biofilm formation by S.aureus and its resistant respect to the antibiotic were determined using a microplate 96 .
Results: Effect of antibacterial extracts used at different concentrations showed that, despite the relative resistance of most strains at concentrations used, the maximum sensitivity was at concentrations of 1.25, 2.5 and 5 mg/ml of extracts and concentration of 10 mg/ml of the extract was considered as MBC. Bacterial growth was observed only at 24 hours and no biofilm was observed at any of the extracts.
Conclusion : Results showed that plant extracts can reduce biofilm formation by Staphylococcus aureus and, therefore, they can play an important role in reducing disease.