Showing 45 results for Bacterial
A R Abdolahi,
Volume 3, Issue 2 (10-2009)
Abstract
Abstract Background and objectives: A Nosocomial infection is one of the Leading problems causing high mortality among hospitalized patients. This study aimed at confirming the concurrence of Nosocomial infections with microorganisms spreading in the air of hospital wards. Material and Methods: This study was conducted in 2009 at ValieAsr Hospital in Tehran, Iran. The Samples were taken from the air of different sections of the hospital both actively (with Quick-Tak, 30) and passively. After that, the samples were investigated for bacerial and fungal contamination and the results were compared with the results of Laboratory Studies of patients in different wards. Results: The Bone Marrow Transplant (BMT) ward shows the least fungal and microbial contamination whiles the Intensive Care Unit (ICU) the highest. The fungi are essentially Cladosporium and penicillium while the most well-Known organisms are Micrococcus and Staphylococcus epidermidis. Stenotrophomonas is seen in both blood and air culture in thorax surgery ward. Also, the concurrence of Staphylococcus epidermidis in the samples of the air and patients is considerable. Conclusion: There isn’t concurrence between the Nosocomial caused organism, apart from Stenotrophomonas and Staphylococcus epidermidis, and microorganisms isolated from patients. Because the bacterial and fungal organisms are in the air of Hospital, it is a necessity to install proper ventilation system. Keywords: Air Bacterial Contamination, Hospital, Nosocomial Infection
Mousazade Moghadam M, Babavalian H, Mirnejad R, Shakeri F,
Volume 6, Issue 1 (4-2012)
Abstract
Abstract
Background and objectives: Genomic DNA extraction of bacterial cells is of processes performed normally in most biological laboratories therefore, various methods have been offered, manually and kit, which may be time consuming and costly. In this paper, genomic DNA extraction of Staphylococcus aureus was investigated using some laundry detergent brands available in Iran to achieve a rapid and cost effective method.
Material and Methods: five-enzyme Taj brand, three-enzyme Saftlan brand ,and Darya and Pak brands without enzyme were used in the concentrations of 10, 20, 40, 80 mg/L. Afterwards, in order to evaluate the efficiency of extracted DNA in downstream processing, PCR test was performed for femA gene in the genome of Staphylococcus aureus.
Results: DNA extraction using different concentrations of the brands show that extracted DNA using 40 mg/L Saftlan and Taj brand powders have the best results according concentration (µg/ml) and purity (A260/A280) parameters. These parameters are 387.5 1.88 (Taj), 254.1 2.80 (Softlan), 396.6 1.95 (Manual) and 423.3 2.2 (Kit), respectively. Afterward, the PCR test results by show that DNA extraction using laundry detergents has no effect on its efficiency in order to be used in downstream processes.
Conclusion: These results indicate that the proper concentrations of laundry detergents can be used to extract genomic DNA with similar efficiency to kit and manual extraction methods.
Key words: Bacterial genome, DNA extraction, laundry powder, PCR, Staphylococcus aureus
Saadatmand M M (msc), Yazdanshenas M E (phd), Rezaei-Zarchi S (phd), Yousefi-Telori B (bsc), Negahdary M (msc),
Volume 6, Issue 1 (4-2012)
Abstract
Abstract Background and objectives: In this research, the formation of chitosan-TiO2 nanocomposite and its antibacterial effect on Escherichia coli and staphylococcus aureus was investigated Material and Methods: to study the results, we used Scanning electron microscopy (SEM) and transition electron microscopy (TEM) images, infrared (IR) spectroscopy and ultraviolet-visible. Optical Density (OD) was also measured by spectrophotometer then the effect of this nano composite, in the vicinity of aforementioned bacteria, on the sterilized gauze in solid Muller Hinton Agar and TSB liquid mediums was assessed Results: The mentioned nanocomposite was formed with the composition of 4mg/ml Chitosan concentration and 2% titanium dioxide concentration. Finally, we observed that this nanocomposite near 100% could prevent bacterial growth and in the presence of this material did not grow any bacteria. Conclusion: chitosan-Tio2 Nanocomposite can be useful on culture medium and sterilized gauze to control pathologic bacteria. Key words: nanocomposite, nanochitosan, titanium dioxide, antibacterial, sterilized gauze
F Safarnezhad Tameshkel, Mr Khatami Nejad, A Nasrollahi, P Rahdari, F Gholam Hossein Poor, S Kazemi Afarmejani,, A Rahnavard,
Volume 6, Issue 2 (10-2012)
Abstract
Abstract Background and objectives: Giardiasis is a parasitic infection of small intestine, with a worldwide distribution and the prevalence of Giardia in different parts of the world varies between 1 to 25%. Plants have the vast range of antimicrobial and antifungal activity that can be identified as alternative treatments for bacterial and parasitic pathogens, the same as Giardia. In this study, the methanol extracts of eucalyptus plants, Satureia hortensis and Heracleum glabrescens, on Giardia cysts were studied in vitro. Material and Methods: The cysts were isolated from the feces using a modified Bingham. After counting by Hemusytumetr, they were placed near by 200 mg / ml, 100 mg / ml and 10 mg / ml of the extracts prepared by DMSO for 30 and 60 minutes. Then, the number of dead and live cysts was counted under a microscope. Results: the fatality effect of the extracts in 60 minutes is higher than those of 30 minutes. The methanol extracts of Satureia hortensis, Eucalyptus and Heracleum glabrescens with the dilution of 200 mg/ml in 60 mins have the fatality effect of 84/3%, 63/3% and 44%, respectively. The highest fatality(84.3%) on Giardia cysts is related to Satureia hortensis with the dilution of 200 mg/ml in 60 mins and the Lowest(27%) is related to Heracleum glabrescens with the dilution of 10 mg/ml in 30-minute period. The significant relationship between the plant type and the fatality of methanol extracts is observed. Conclusion: the methanol extracts of Eucalyptus, Heracleum glabrescens and especially Satureia hortensis have anti-parasitic effects in the laboratory conditions. Thus, they can be used in the future, instead of the chemical antiparasitic drugs. Key words: Antibacterial Giardia lamblia cysts, Eucalyptus, Satureia hortensis, Heracleum glabrescens, Tonekabon
F Mashayekhi, F Rajaei,
Volume 6, Issue 2 (10-2012)
Abstract
Abstract
Background and objectives: Meningitis is one of the most common infectious of the central nervous system (CNS), defined as an inflammation of the meninges. LIF is a potent pro-inflammatory factor. Cerebrospinal fluid (CSF) contains the growth factors and cytokines whose concentrations have been changed in most neurological diseases. The aim of this study was to determine the LIF concentration of serum and CSF in the children with bacterial meningitis.
Material and Methods: In this study, the total protein concentration (TPC) and LIF in the serum and CSF of normal subjects and children with bacterial meningitis were measured by enzyme linked immunosorbent assay (ELISA).
Results: the Values of serum TPC for children with meningitis (74.17±7.73 g/L) and controls (73.50±7.28 g/L) are not different significantly (P=0.7), and the TPC in the CSF of children suffering from meningitis and controls are 35±0.03 and 0.34±0.05 g/L, respectively (P=0.65). The concentration of serum LIF for children with meningitis( 253±19.14 ng/ml) is higher than that of controls (49.75±8.97 ng/ml), and also the concentration of LIF in the CSF of the children with meningitis (116.25±8.60 ng/ml ) is significantly higher than that of controls which is 9.04±1.83ng/ml (P<0.001).
Conclusion: The LIF concentration in the CSF and serum may provide additional information in the differential diagnosis of meningitis. It is also concluded that LIF could be significantly involved in the pathophysiology of meningitis.
Key words: Serum, Cerebrospinal fluid, Leukemia inhibitory factor, Children, Bacterial meningitis
S Ahmady- Asbchin, A Nasrolahi Omran, N Jafari, Mj Mostafapour, S.m Kia,
Volume 6, Issue 2 (10-2012)
Abstract
Abstract
Background and Objectives: Concurrent with the development of new chemical drugs and antibiotics, their harmful effects are gradually emerged. Due to lack of harmful effects, herbal medicines have been used in the pharmaceutical industry. The aim of this study was the use of lavender essential oil as an herbal medicine for the replacement of antibiotics and chemicals.
Material and Methods: In this study, the plant essential oil was isolated by drying and distillation method using Clevenger apparatus. The antibacterial effect of this plant was evaluated by using disc diffusion method and successive dilutions. In order to control the standard of the method, antibiotic discs and standard bacterial strains were used.
Results: Based on the results, Proteus mirabilis and Enterococcus faecalis are , respectively , the most sensitive and most resistant bacteria to dilutions of 1, 1/2 and 1/4. Escherichia coli and Enterococcus faecalis, respectively, are the most sensitive and most resistant bacteria to the dilution of 1/8, 1/16, 1/32 and 1/64. MIC and MBC methods also show that all bacteria have the same minimum inhibitory and fatality concentrations except Enterococcus faecalis with minimum inhibitory concentration of 16/1 and minimum concentration fatality of 8/1. Evaluating the results of the disk diffusion method with antibiotic discs, we can observe the better effect of this plant in comparison with gentamicin and streptomycin discs on the growth of five strains of Staphylococcus aureus ATCC1885, Staphylococcus epidermidis ATCC 2405, Enterococcus faecalis ATCC2321, Escherichia coli ATCC 1652 and Proteus mirabilis ATCC 2601.
Conclusion: the essential oil of Lavender can be used instead of chemical drugs to treat bacterial infections.
Keywords: Lavandula, Anti-bacterial effects, Essential oils, Bacterium
R Esmaeili, Ma Amir-Zargar, M Nazari, M Alikhan,
Volume 7, Issue 5 (2-2014)
Abstract
Abstract
Background and Objective: Urinary tract infections and bacteremia are the major problems in renal transplant patients, which are mostly due to immunesuppressive regimens, surgery, and exposure to the germs in hospital. The aim of this study was to determine the prevalence of bacterial agents in the blood and urine samples of kidney transplant candidates.
Material and Methods: In this one-year-long study, thirty-three renal transplant candidates were assessed for urine and blood cultures. One urine and blood samples from each patient before transplantation and three samples after transplantation were collected. The Samples, using standard microbiological methods, were investigated and infectious organisms identified.
Results: In 133 urine samples, Escherichia coli (20.5%), Enterobacter spp. (5.3%), Klebsiella spp. (3 %) and Staphylococcus epidermidis (1.5%) were isolated. In the blood samples, Enterobacter spp. (9.1%), Escherichia coli (6.8%), Staphylococcus epidermidis (3.8%) and Klebsiella spp. (0.8%) were isolated.
Conclusion: The results indicate that urinary tract infection was high in patients with transplanted kidney, and E. coli is the most common cause of this infection.
Keywords: Kidney Transplantation Bacterial infections Urinary Tract and Blood Infections Escherichia Coli
P Torabi, M Azimirad, Z Hasani, M Janmaleki, H Peirovi, M Alebouyeh, Mr Zali,
Volume 8, Issue 1 (4-2014)
Abstract
Abstract
Background and Objective: This study was aimed to determine the extent of bacterial contamination and drug resistance patterns of isolates colonized in colonoscope and endoscope and in relevant personnel.
Material and Methods: A total of 107 samples were obtained from staff of endoscopy and colonoscopy units (SEU and SCU) and gastroenterological imaging equipment. For isolation and identification of the bacteria, swab culture method and biochemical identification test were used, respectively. Antimicrobial resistance profiles, multi-drug resistance (MDR) patterns and phenetic relatedness of these isolates were also analyzed according to standard methods.
Results: Most frequent pathogenic bacteria among the SEU and gastroenterological imaging related equipments were included S. aureus (20.8 % and 0 %) Enterococcus spp. (0 % and 5.4%) Pseudomonas spp. (0% and 13.5 %), and Clostridium difficile (0% and 12.5%). Analysis of resistance phenotypes showed a high frequency of MDR phenotypes among the SEU (82.1%), and also in endoscopes, colonoscopes, and other equipments (20%, 50% and 100%, respectively). Phylotyping of S. epidermidis isolates showed the role of staff in transmission of resistance strains to medical equipments and also circulation of strains with identical resistance phenotype among the studied samples.
Conclusion: High frequency of pathogenic bacteria in colonoscopes, endoscopes and in the staff of endoscopy & colonoscopy units, and also contamination of these instruments with MDR pathogens emphasize the need for proper disinfection of endoscopes and colonoscopes and also instruction of staff in these units.
Key words: Bacterial Contamination Endoscope Colonoscope Antimicrobial Resistance Gastrointestinal Disease.
L Dolatshah, R Ghanbarpour, F Momeni, H Alizade,
Volume 8, Issue 1 (4-2014)
Abstract
Abstract
Background and Objective: This study was aimed to determine the extent of bacterial contamination and drug resistance patterns of isolates colonized in colonoscope and endoscope and in relevant personnel.
Material and Methods: A total of 107 samples were obtained from staff of endoscopy and colonoscopy units (SEU and SCU) and gastroenterological imaging equipment. For isolation and identification of the bacteria, swab culture method and biochemical identification test were used, respectively. Antimicrobial resistance profiles, multi-drug resistance (MDR) patterns and phenetic relatedness of these isolates were also analyzed according to standard methods.
Results: Most frequent pathogenic bacteria among the SEU and gastroenterological imaging related equipments were included S. aureus (20.8 % and 0 %) Enterococcus spp. (0 % and 5.4%) Pseudomonas spp. (0% and 13.5 %), and Clostridium difficile (0% and 12.5%). Analysis of resistance phenotypes showed a high frequency of MDR phenotypes among the SEU (82.1%), and also in endoscopes, colonoscopes, and other equipments (20%, 50% and 100%, respectively). Phylotyping of S. epidermidis isolates showed the role of staff in transmission of resistance strains to medical equipments and also circulation of strains with identical resistance phenotype among the studied samples.
Conclusion: High frequency of pathogenic bacteria in colonoscopes, endoscopes and in the staff of endoscopy & colonoscopy units, and also contamination of these instruments with MDR pathogens emphasize the need for proper disinfection of endoscopes and colonoscopes and also instruction of staff in these units.
Key words: Bacterial Contamination Endoscope Colonoscope Antimicrobial Resistance Gastrointestinal Disease.
T Ghelich, M Hashemi Karouei, I Gholampor Azizi,
Volume 8, Issue 2 (7-2014)
Abstract
Abstract Background and Objective: Because of increased resistance to antibiotics, side effects of chemical drugs and importance of medicinal plants, we aimed to assess the antibacterial effects of methanolic extract of the Polygonumbistorta plant on the E. coli (ATCC 15224), Ps. aeruginosa (ATCC 25619), B. subtilis (ATCC 6633) and Stap. Aureus (ATCC 25923). Material and Methods: After preparing the extract, its antibacterial effect was assessed via gel diffusion method, using disk / well diffusion methods to determine MIC and MBC Results: MIC of methanolic extract was 78 µg/ml for E. coli, 63×103 µg/ml for Pseudomonas aeruginosa, 39 µg/ml for Bacillus subtilis and 31×102 µg/ml for Staphylococcus aureus Conclusion: In spite of resistance of gram-negative bacteria to chemical agents, polygonum bistorta methanolic extract could inhibit the growth of E.coli and P. aeruginosa. Key words: Antibacterial, Bistorta, Escherichia Coli, Pseudomonas Aeruginosa
M Javadzadeh, M Najafi, M Rezaei, M Dastoor, Aa Behzadi, A Amiri,
Volume 8, Issue 2 (7-2014)
Abstract
Abstract
Background and Objective: Honey is a healthy and nutritious food that has been used for a long time as a treatment for different diseases. One of the applied properties of honey is its antimicrobial effect, which differs between different types of honey due to variation of phenolic and antioxidant compositions. This study aimed to assess antimicrobial effect of honey on Bacillus cereus, considering its chemical properties.
Material and Methods: Three samples of honey (A1 and A2 of Khorasan Razavi Province and A3 of South Khorasan province (were prepared and studied in terms of chemical parameters .The antibacterial effect of honey was surveyed throughTurbidimeter using spectrometer with incubator time of 2, 4, 6, and 8hrs. the level of turbidity caused by bacterium growth was measured at different times with a wavelength of 600nm.
Results: According to the study, the samples containing higher concentration of polyphenol has more antimicrobial activity. The samples of A2, A3, and A1 had the highest concentration of polyphenol, respectively.
Conclusion: The results indicate the prebiotic effect of honey that can be justified by the presence of fructo-oligosacharids and vitamin B.
Keywords: Honey, Bacillus Cereus, Antibacterial, Turbidimetry.
M Rajabi, R Habibipour, S Vesaghati Ezatpour, S Vesaghati Ezatpour,
Volume 8, Issue 3 (8-2014)
Abstract
Abstract
Background and objective: Antimicrobial and antiviral effects of Alloe Vera and Stachys inflata have been proved. We aimed to investigate the effects of extract of Alloe Vera and Stachys inflate on the growth of some bacteria to take the place of chemical drugs.
Material and Methods: the extracts of both plants were prepared by maceration method different concentrations were prepared using Mueller Hinton agar medium and tested by Disc diffusion. Furthermore, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the Microdilution method.
Results: The effect of Alloe Vera extract was significant on Staphylococcus aureus. MIC and MBC of Aloe Vera extract on Bacillus subtilis were obtained in 230 and 410 mg/ml, respectively, which were 500 and 714 mg/ml for Haemophilus influenza. The extract of gel of Alloe Vera had no effect on Bacillus subtilis. The extract of leaf and gel of Alloe Vera had an inhibitory effect on Haemophilus influenza and Pseudomonads aeraginosa. The extract of Stachys inflata had an inhibitory effect on Haemophilus influenza, but it did not have any on Pseudomonads aeraginosa. The Extract of Stachys inflata had no effect on Bacillus subtilis, while showing significant effect on Staphylococcus. Among antibiotics, Ofloxacin had an effect on Haemophilus influenza. The extract of both plants did not show any effect on Klebsiella pneumonia.
Conclusion: Given the effect of Alloe Vera and Stachys inflata in laboratory conditions, we hope that these extracts will be used instead of chemical substances for making nutritional supplements to control human diseases.
Key words: Alloe Vera, Antibacterial, Stachys Inflata, Extract
Hosseini, Sm, Farhang Ara, E, Yousefi Mashouf, R, Parsavash, S,
Volume 8, Issue 4 (1-2015)
Abstract
Abstract Background and Objective: The prevalence of different bacterial species and antibiotic resistance varies according to geographical conditions. Hence, we aimed to identify the prevalence of bacterial agents isolated from the urine culture and also investigate the antibiotic susceptibility of bacteria. Material and Methods: This cross-sectional study conducted on 7200 urine samples to identify the bacteria causing infections, using differential tests. The antimicrobial susceptibility was performed via disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI). Results: The most common bacteria were Escherichia coli (736 61.1%) and Klebsiella pneumonia (128 10.6%) and Enterococcus faecalis, (88 7.3%). The highest antibiotic susceptibility was related to Ciprofloxacin (174 14.45%) and the lowest to Amoxicillin (795 62.02%). Conclusion: Owing to the lowest resistance, it is recommended that Ciprofloxacin be used as the first line of treatment. In addition, Amoxicillin and Ampicillin should be used the least during primary treatment of urinary tract infections. Keywords: Antibiogram, Bacterial Resistance, Urine Culture
Kashani, L, Okhly, M, Ghaemi, Ea, Behnampour, N., Kashani, E, Okhly, Ho, Fendereski, S., Bazoori, M, Falsafi, L,
Volume 8, Issue 5 (1-2015)
Abstract
Abstract Background and Objective: Along with antibiotics, the use of biological methods to combat bacteria is notably considered. A natural barrier such as amniotic membrane is one of the ways of dealing with bacterial infections. The aim of this study was to determine the antibacterial effect of human amniotic membrane. Materials and Methods: This descriptive study was performed in Dezyani teaching Hospital of Gorgan University of Medical Sciences, Iran. To evaluate the antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli bacteria, 20 amniotic membranes were obtained from postpartum mothers and examined by repeated dilution, diffusion and extraction techniques. Data were collected by observation method and described by mean and standard deviation. Results: The antibacterial activity was found in 15% of the samples against Staphylococcus Aureus and Pseudomonas aeruginosa, while no antibacterial activity was found against E. coli. Given the 15% positive responses, "Diffusion" and "repeated dilution" techniques were more effective in investigating the antibacterial effect of amniotic membrane. Conclusion: The results show the probability of antimicrobial effect of amniotic membrane tissue and it seems that this property can be affected by many factors. Keywords: Amniotic Membrane, Anti-Bacterial Properties, Laboratory Methods
Moshtaghi, H, Parsa, M,
Volume 9, Issue 1 (4-2015)
Abstract
Abstract
Background and Objective: Automated Teller Machine (ATMs) is likely to be contaminated with various microorganisms specially pathogen germs. This may be due to their exposure to dust and their vast dermal contact with multiple users. This study investigated the bacterial contamination on the keyboard of ATMs and drug resistance of the bacteria isolated from them.
Material and Methods: the keyboards of 50 ATMs in Shahrekord city, Iran, were examined from October 2012 to February 2013. The sterile swab sticks moistened with Triptose soy broth were used for sampling. The bacteriological tests used were culture, biochemical test and agar disk diffusion method for antibiogram.
Results: All the samples were found to be contaminated with Coagulase negative staphylococci (57.54%), Bacillus species (21.92%), Staphylococcus aureus (19.18%) and coliform bacteria (1.36%). The resistance of Staphylococcus aureus was 92.8% to penicillin, 85.7% to amoxicilin، 71.4% to ampicillin, 57.1% to nytrofuran, 50% to tetracycline, 42.8% to erythromycin, 42.8% to gentamycin, 14.2 % to ciprofloxacin, 7.1% to trimethoprim and sulfamtuksazul. All species were susceptible to, ofloxacine, chloramphenicol, clindamycin, tobramycin, vancomycin and cefotaxime.
Conclusion: given the presence of pathogens on ATMs and their role in transferring the contamination, we recommend considering personal hygiene and periodically disinfecting the keyboards to reduce contamination.
Keywords: ATMs, Bacterial Contamination, Antibiogram
Gharahjeh, S, Nowzari, A, Azarhoush, R, Fuladi Nejad, M, Nematollahi, N, Aryaei, M, Mohammadi, R,
Volume 9, Issue 2 (7-2015)
Abstract
Background and Objective: Neonatal sepsis is a remarkable factor in mortality, morbidity, neonatal and perinatal complications. Group B Streptococcus (GBS) is the primary cause of invasive disease in infants and pregnant women. This study aimed to determine the relationship between antimicrobial resistance of the bacteria colonized in the vagina and rectum of pregnant women and early neonatal infection.
Material and Methods: In this prospective study conducted on 282 pregnant women, bacterial sensitivity to ampicillin, cefazolin, erythromycin, vancomycin, gentamicin, amikacin was measured. Furthermore, the relationship between rectal and vaginal colonization of mothers and early neonatal sepsis was evaluated.
Results: Of 98 positive rectal cultures, 49 (50%) were Gram-positive cocci and 49 (50%) E.coli. of 143 positive vaginal cultures, 136 (95.1%) were Gram-positive cocci, 7 (4.9%) were E.coli and two were positive GBS. We could find definitive neonatal sepsis. Significant correlation was found between a history of urinary tract infection and the mother's positive rectal culture (P =0. 03).
Conclusion: Clinical sepsis in neonates is correlated with positive rectal culture (P =0. 001) and the positive E.coli vaginal cultures is associated with suspected neonatal sepsis (P =0.007). Gram-positive cocci were resistance to ampicillin and gentamicin, and E.coli was resistant to ampicillin, erythromycin and vancomycin. Because of resistance to ampicillin, we recommend cefazolin due to its sensitivity to organisms and safety in pregnancy.
Hashemi, M, Amin Zare, M, Naghibi, S, Raeisi, M, Hasanzad Azar, H,
Volume 9, Issue 3 (9-2015)
Abstract
Abstract
Background and Objective: The aim of this study was to evaluate chemical composition, antibacterial and antifungal effect and antioxidant property of Salvia officinalis, Mentha piperita and Mentha Longifolia.
Material and Methods: At first, chemical analysis of essential oils was determined using GC/MS. Then the antibacterial and antifungal effect of tested essential oils on L. monocytogenes, S. aureus, S. typhimurium and E. coli and two fungal strains including A. niger and A. flavus were determined using disk diffusion agar and broth microdilution methods. The antioxidant property of essential oils was evaluated using DPPH assay.
Results: Linalool (14.38%), l. menthone (19.03%) and δ-terpinene (21.78%) were the major components of Salvia officinalis, Mentha piperita and Mentha Longifolia, respectively. all tested essential oils had antibacterial effect on foodborne pathogens, which was comparable with tetracycline’s effect. In addition, all essences had appropriate antioxidant potential compared with BHT.
Conclusion: based on the results, Salvia officinalis, Mentha piperita and Mentha Longifolia can be introduced as appropriate natural preservatives.
Keywords: Salvia officinalis; Mentha piperita; Mentha Longifolia, Antibacterial Agents.
Behzad Ghasemi, Mohsen Najimi, Hamid Beyzaei, Abbas Jamshidian,
Volume 9, Issue 4 (10-2015)
Abstract
Abstract
Background and Objectives: Antibiotic resistance in bacteria has actuated researchers toward evaluating many new antibacterial compounds of which are the thiazoles. In this research the inhibitory effects of novel thiazole derivatives were unraveled on Staphylococcus aureus, Streptococcus agalactiae, Pseudomonas aeruginosa and Klebsiella pneumoniae and oxothiazole liver toxicity effects were assessed on mice.
Methods: The antibacterial effect of thiazole derivatives was evaluated by measuring the halo zone with disk diffusion method and dilution procedure in microplate in order to discriminate the minimum inhibitory concentration (MIC) and the liver toxicity of oxothiazole, also, was discerned by injecting 160 mg/kg, 265 mg/ kg and 350 mg/kg doses to mice as well as scrutinizing the liver histopathology.
Results: Derivatives utilized in experiment had no inhibitory effect on Pseudomonas aeruginosa and Klebsiella pneumoniae, though their inhibitory effect was observed on Staphylococcus aureus and Streptococcus agalactiae. For Staphylococcus aureus and Streptococcus agalactiae the diameters of growth inhibition zone were 8.9-22.3 mm and 16.1-25.6 mm, respectively and MIC of 50-200 and 25-100 µg/ml by order. Additionally, by increasing the injection dose of oxothiazole with 160 mg/ml, 265 mg/ml and 350 mg/ml doses, the hepatitis lesions and liver necrosis were observed in experimental mice.
Discussion: The thiazole derivatives possessed more inhibitory trace on gram positive bacteria than gram negative ones. Furthermore, the likely presence of oxygen link to thiazole ring in tested compounds results in the enhancement of inhibitory potency of these substances. Besides, our results suggest that high doses of oxothiazole cause severe liver damage and rapid death less than 24 hours.
Keywords: Thiazole derivatives, Antibacterial effects, Oxothiazole, Liver toxicity.
Mohammad Mohammaddoost Chakoosari, Mohammad Faezi Ghasemi, Alireza Masiha, Reza Kazemi Darsanaki, Abolfazl Amini,
Volume 9, Issue 5 (11-2015)
Abstract
Abstract
Background and Objective: Probiotics are living microorganisms that have beneficial effects on the health of digestive system. The aim of this study was to evaluate the antimicrobial ability of acidic and neutral supernatants (culture supernatant) of lactic acid bacteria against common bacterial pathogens.
Methods: Four species of lactic acid bacteria (Lactobacillus plantarum PTCC1745, Lactobacillus PTCC1608, Lactobacillus Saki PTCC1712 and Lactobacillus Lactis PTCC1336) were obtained from the microbial collection of Iranian Research Organization for Science and Technology in Lyophilized form. The antimicrobial activity of neutral and acidic supernatants against bacterial pathogens was investigated using the Disk and Well Diffusion Agar methods.
Results: Lactic acid bacteria showed good antimicrobial ability against six pathogenic bacteria with the highest inhibitory effect observed in Lactococcus lactis against E. coli PTCC1399 through well method with an average diameter of 14 mm inhibition zone. In this study, the well diffusion method was far more sensitive compared to the disk method and acidic supernatants showed higher antimicrobial efficiency compared to neutral types.
Conclusion: the Metabolites produced by lactic acid bacteria are able to inhibit the growth of pathogenic bacteria that can be an important and practical solution for the prevention and treatment of infections and ultimately improve human health.
Shirin Sheikholeslami , Seyed Mahdi Rezayat , Reza Hosseini Doust , Hamid Reza Ahmadi Ashtiani ,
Volume 10, Issue 1 (1-2016)
Abstract
Abstract
Background and Objective: The spread of drug resistance in bacteria have prompted researchers to seek suitable alternative for antimicrobial drugs among various medicinal plants and nanoparticles. The aim of this study was to evaluate the effect of silver nanoparticles alone and in combination with methanol extract of Zataria multiflora on five Gram-positive and Gram-negative bacteria.
Methods: Different concentrations of the nanoparticles and extract alone or in combination with each other were tested against the bacteria, using well diffusion method. Three concentration levels (lowest, average and highest) were prepared form the nanoparticles and the extract for the combination, and finally nine different combinations were prepared.
Results: The extract and nanoparticles showed inhibitory effects against all the tested bacteria. The maximum diameter of growth inhibition zone in the presence of the extract and nanoparticles were observed in Streptococcus pyogenes (35.6mm) and methicillin-resistant Staphylococcus aureus (20.6mm), respectively. The maximum diameter of growth inhibition zone for the combination was measured in S. pyogenes (31mm).
Conclusion: The combination of low concentrations of the plant extract and nanoparticles are more effective against bacteria, but the combination of their high concentrations reduce the antibacterial effects in some cases.
