Showing 142 results for Ph
Azizollah Ebrahimi, Younes Daryalal, Mohamadreza Mahzounieh, Sharareh Lotfalian,
Volume 12, Issue 4 (7-2018)
Abstract
ABSTRACT
Background and Objectives: Silver nanoparticles (AgNPs) have physical and surface properties that could threaten human and environmental health. AgNPs are classified as ‘very toxic’ to eukaryotic organisms and are less toxic to bacteria. The aim of the present study was to study the effects of different sub-minimum inhibitory concentrations (MICs) of AgNPs on some virulence factors of Staphylococcus aureus as a pathogenic bacterial model.
Methods: Tube double serial dilution method was used to determine MIC of AgNPs against standard strain and ten field isolates of S. aureus. Tube cultures of isolates in LB broth were supplemented with different concentrations of AgNPs and were incubated at 37 °C with constant shaking under aerobic conditions. Samples from each tube were streaked on blood agar plates and assay for hemolysins, coagulase and DNase production were performed.
Results: The MIC of AgNPs against all examined isolates was determined as 50 µg/mL. The results showed that 1/2, 1/4 and 1/8 MIC of AgNPs had no negative effect on DNase and coagulase production but inhibited alpha- and beta-hemolysin production in most isolates (64-91%). In addition, production of delta-hemolysin was inhibited by 1/2 MIC of AgNPs.
Conclusion: The effects of sub-MIC of AgNPs on bacterial growth appear at 4-8 hours post-exposure and then the bacteria follow a normal growth trend. This toxic effect may affect ecosystems species.
Keywords: Silver particles, Minimum inhibitory concentration, Virulence factors, Staphylococcus aureus.
Semira Kheiri, Mahdieh Safarzad, Mohammad Shariati, Hoda Sohrabi ,
Volume 12, Issue 5 (9-2018)
Abstract
ABSTRACT
Background and Objectives: Non-synonymous single nucleotide polymorphisms are typical genetic variations that may potentially affect the structure or function of expressed proteins, and therefore could be involved in complex disorders. A computational-based analysis has been done to evaluate the phenotypic effect of non-synonymous single nucleotide polymorphisms in the gene encoding the human hypoxanthine-guanine phosphoribosyltransferase (HGPRT-1). HGPRT-1 is an enzyme involved in purine recycling pathway and its deficiency is associated with several human genetic disorders.
Methods: We provide a list of all amino acid replacements in the human HGPRT-1 from the dbSNP, Uniprot and dbEST databases. Sorting intolerant from tolerant (SIFT) and PolyPhen softwares were also used in our study.
Results: Of 94 amino acid substitutions, rs 267606863 was predicted to be the most deleterious. Substitutions of S110L and S104A in flexible loop and D194N, D201Y, H204R, Y195C, F199V and H204D in hood domain were predicted as functionally damaging.
Conclusion: It could be concluded that these intolerant changes may lie within a functional region of the protein and may affect the stability and folding of HGPRT-1. These variants could be used for future functional and molecular epidemiology studies of HGPRT-1-related disorders.
Keywords: Polymorphism, Single Nucleotide, Amino acid substitution, Hypoxanthine Phosphoribosyltransferase.
Ameneh Arab, Alireza Mohebbi, Hamid Afshar, Abdolvahab Moradi,
Volume 12, Issue 5 (9-2018)
Abstract
ABSTRACT
Background and Objectives: Psychiatric disorders such as schizophrenia and bipolar disorder pose a high burden among the general population. Etiological factor(s) of such disorders remain unknown. Borna disease virus (BDV) is a neurotropic virus that has been suggested as an etiological agent for psychiatric disorders. Therefore, we aimed to investigate the prevalence of BDV among patients with schizophrenia and bipolar disorder.
Methods: Peripheral blood mononuclear cells (PBMCs) of schizophrenic (n=75) and bipolar (n=55) patients and healthy blood donors (n=125) were extracted form whole blood samples. RNA was extracted from PBMCs and the presence of BDV P40 RNA was assessed by reverse transcription-polymerase chain reaction.
Results: The BDV genome was not detected in any of the subjects. Positive family history of disease was significantly more frequent among patients (P=0.0001). There was a significant association between contact with animals and psychiatric illnesses (P<0.05). Moreover, education level differed significantly between the two groups (P<0.05).
Conclusion: The results indicate no evidence of BDV genome among patients with psychiatric disorders. Serological examination for BDV antigens or antibodies could provide further information in this regard. In addition, contact with cats is significantly more prevalent among patients with mental illnesses, which might be due to infection with Toxoplasma gondii.
Keywords: Borna disease virus, Psychiatric disorder, Schizophrenia, Bipolar disorder, Risk factors.
Amir Abbas Barzegari, Masood Hashemzaei, Ali Reza Aslihematti,
Volume 13, Issue 2 (3-2019)
Abstract
ABSTRACT
Background and Objectives: Current medications used for the treatment of burn wounds have some side effects and disadvantages. Oral or topical administration of probiotic bacteria is thought to be useful for treatment of skin disorders. The aim of this study was to evaluate effects of spray-dried Streptococcus thermophilus on healing of second-degree burn wounds.
Methods: After induction of second-degree burn on back of 80 male Wistar rats, the animals were randomly allocated to negative control (no treatment), first vehicle control (treatment with Eucerin), second vehicle control (treatment with skim milk) and experimental (treatment with bacterial ointment) groups. Wound healing rate (percent) and histopathological parameters of wound samples were evaluated on post-burn days 1, 3, 7 and 14.
Results: On days 3 and 7, macroscopic results showed that the healing rate was significantly higher in the experimental group compared to the control groups. Histopathological analysis of wound samples showed increased fibroblastic migration, collagen formation and re-epithelialization in the wounds treated with probiotic bacteria compared with the wounds of control groups.
Conclusion: Our results indicate that the topical use of spray-dried S. thermophilus could be useful for the treatment of burn wounds.
Keywords: Streptococcus thermophilus; Probiotics; Burns; Wound Healing; Rats.
Hoorieh Hoseinpoor , Davoud Esmaeili ,
Volume 13, Issue 3 (5-2019)
Abstract
ABSTRACT
Background and Objectives: In recent years, infections caused by antibiotic-resistant strains of Staphylococcus aureus have become a major health issue. It has been suggested that the extract or essential oil of cinnamon tree has antibacterial properties. In this study, we investigated the antibacterial effects of polyurethane-cinnamon nanofibers against clinical isolates of S. aureus.
Methods: Polyurethane-Cinnamomum zeylanicum nanofiber scaffolds were synthesized. Polyurethane nanofiber and cinnamon polymers were also used to prepare the scaffold under the electrospinning process. Infrared spectroscopy, electron microscopy and mechanical tensile test were utilized to assess the scaffolds. Minimum inhibitory concentration of the nanofiber against the bacteria was determined using the broth dilution method according to the Clinical & Laboratory Standards Institute guidelines.
Results: The results of antibiogram test showed that all tested disks were susceptible to S. aureus. Diameter of growth inhibition zone for polyurethane-cinnamon 10% was 41 mm. Minimum inhibitory concentration of the nanofiber against S. aureus isolates was 0.02 μg/mL.
Conclusion: We demonstrated that the polyurethane-cinnamon nanofiber has favorable antibacterial effects against clinical isolates of S. aureus. It is recommended to conduct further studies on the antibacterial effects of this nanofiber on other bacteria.
Keywords: Staphylococcus aureus, Cinnamon, Nano fiber.
Mohammad Habibi Juybari , Hamidreza Pordeli , Saeid Mikaeili ,
Volume 13, Issue 3 (5-2019)
Abstract
ABSTRACT
Background and Objectives: Schiff base ligands are prepared via the condensation reaction of 1, 10- dimethyl–phenantroline aldehyde derivative with some nitrogen donor ligands, such as benzene ring that have different functional groups (-OH, -SH, -OCH3,-CH2OH, -Br) in acetonitrile. Recent studies suggest that Schiff bases might have antibacterial activity. Therefore, we aimed to synthesize new Schiff base complexes and evaluate their antibacterial activity against a number of Gram-positive and Gram-negative bacteria.
Methods: Schiff base ligands and their complexes were characterized by mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy. The in vitro antibacterial activity of the Schiff base ligands and metal ions against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the broth dilution method.
Results: All synthesized Schiff bases exhibited favorable antibacterial activity against the tested microorganism, but the antibacterial effect of compounds 3OH and 3SH was more significant than that of other compounds.
Conclusion: Compound 3EOH has favorable antibacterial activity against the tested bacteria.
Keywords: Schiff bases, antibacterial effect, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa.
Abolfazl Khandandel , Hami Kaboosi , Ailar Jamalli , Fatemeh Peyravii Ghadikolaii ,
Volume 13, Issue 4 (7-2019)
Abstract
Background and Objectives:
Staphylococcus aureus is a common cause of nosocomial infections. The ability of
S. aureus to form biofilm and acquire antimicrobial resistance has made this organism a major health problem. In this study, we investigate the biofilm-forming ability of
S. aureus isolates from clinical samples.
Methods: Sixty
S. aureus isolates from clinical specimens were collected from the 5th Azar Hospital of Gorgan (Iran) in 2018. The isolates were identified using conventional methods including Gram staining and biochemical tests (catalase and coagulase). Biofilm formation by
S. aureus isolates was evaluated using a microplate-based method.
Results: Of 60
S. aureus isolates, 47 (78.3%) strains were identified as biofilm-forming and 13 (21.7%) strains were non-biofilm-forming.
Conclusion: The high prevalence of biofilm-producing
S. aureus isolates in the 5
th Azar hospital of Gorgan could pose a major health challenge with serious consequences for hospitalized patients. Therefore, it is crucial to disinfect and sterilize hospital surfaces and equipment effectively to minimize the risk of contamination and spread of bacteria in the hospital settings.
Keywords: Biofilms,
Staphylococcus aureus, sample.
Fereshteh Keyghobadi, Nader Bahramifar, Elahe Gharekhani, Seyyedeh Marzieh Kia,
Volume 13, Issue 5 (9-2019)
Abstract
ABSTRACT
Background and Objectives: In this study, nanosilica modified with HS-SiO2 thiol groups was utilized as adsorbent for solid phase extraction, as a fast and reliable method of preconcentration and separation of very small quantities of selenium ions from water and blood samples.
Methods: The samples included four natural water samples and one biological sample (blood serum) prepared in volumes of 25, 100, 200, 300, 400 and 500 ml. The samples were analyzed by solid phase microextraction, using thiolated-nanosilica (as adsorbent), ultraviolet-visible spectrophotometry and atomic absorption spectroscopy.
Results: Optimized conditions for preconcentration of a 25 ml 0.2 mg/l selenium solution were pH 5, 40 mg of adsorbent, sample-adsorbent mixing time of 15 minutes and 5 ml of 2N sulfuric acid as detergent. The volume limit and concentration factor were 400 and 80, respectively. Limit of detection and relative standard deviation of the method were 0.46 μg/l and 0.9%, respectively.
Conclusion: This study is the first to successfully utilize thiolated nanosilica for measuring low selenium levels. Thiolation of the absorbent increases selenium adsorption by thiolated-silica compared to SiO2.
Keywords: Solid phase extraction, Selenium, Preconcentration, Nano, UV-visible spectrophotometry.
Mohammad Tabatabaei, Aslam Dehvari, Bita Geramizadeh, Mohammad Hadi Niakan,
Volume 14, Issue 1 (1-2020)
Abstract
ABSTRACT
Background and Objective: Bilophlia spp. are gram-negative, pleomorphic rod, obligate anaerobe, oxidase-negative, catalase-positive and non-motile bacteria. B. wadsworthia is type species of genus Bilophila with the additional characteristic of urea hydrolysis. B. wadsworthia can be found in a variety of anaerobe infections, particularly appendicitis and intra-abdominal infection that are considered as important opportunistic pathogens.
Methods: This study was designed to identify Bilophila spp. in clinical specimens by culture and PCR. We examined 91 DNA samples extracted from infected appendix tissues with specific primers.
Results: Data showed that Bilophila spp. DNA existence in 53.85% (n=49) provided appendiceal tissue.
Conclusion: The pathological and molecular examination of infected appendiceal tissues revealed that B. wadsworthia is able to act as the primary cause of significant lesions in the appendicle tissues.
Key words: Bilophila spp., Appendectomy, Appendicle specimens, PCR, Nucleotide sequencing
Ommolbanin Younesian, Samareh Younesian, Sara Hosseinzadeh, Hamid Reza Joshaghani,
Volume 14, Issue 1 (1-2020)
Abstract
ABSTRACT
Esophageal cancer (EC) is one of the most common types of cancer, especially in Asia. Esophageal squamous cell cancer (ESCC) is the most important histological subtype of EC, which accounts for 90% of all EC cases worldwide. ESCC is highly prevalent in Turkey, Iran, Kazakhstan and northern and central parts of China. Selenium is an essential micronutrient that is required for cellular functioning and synthesis of several selenoproteins. It also modulates the antioxidant defense system, cell cycle and apoptosis. This article reviews the most important molecular mechanisms of EC and investigates the association between selenium level and incidence of EC in high-risk areas.
Keywords: Esophageal cancer, selenium, selenoprotein.
Ali Asghar Ayatollahi, Abolfazl Khandan Del, Ailar Jamalli, Khashayar Shahin, Ania Ahani Azari,
Volume 14, Issue 1 (1-2020)
Abstract
Background and objectives: Staphylococcus aureus is a frequent cause of hospital- and community-associated infections on a global scale. This organism is responsible for causing an extensive range of diseases and many of them are capable of biofilm formation for their survival. By this method, treatment of them with antibiotics become very difficult and antibiotic resistance is another rising concern.
Material and Methods: The clinical samples were collected and examined for Staphylococcus aureus by microbiological and biochemical tests. Then, the biofilm formation in Staphylococcus aureus isolates was detected by microtiter plate. Using SYBR Green Real-Time PCR, the expression of PSM was determined.
Results: A total of 60 strains of Staphylococcus aureus were isolated from clinical isolates. Of them, 47 strains (78.3%) were identified biofilm producing and the others were considered negative for biofilm formation. After real-time PCR testing to detect PSM, it was determined that 100% of the strains were positive for biofilms and PSM genes. The results of phenotypic and genotypic tests of biofilm were closely related to each other and the expression of PSM B gene was 80%. It was found that 100% of strains were biofilm producing and PSM B gene was present in 78.3% (47 strains) of them.
Conclusion: The prevalence of biofilm production in Staphylococcus aureus strains isolated from clinical samples was high, so it is highly important to monitor the prevalence of these organisms in hospitals and community as well as their antimicrobial resistance.
Naficeh Sadeghi , Mohammad Reza Vafi , Behrooz Jannat , Masoomeh Behzad , Mohammad Reza Oveisi , Mannan Hajimahmoodi ,
Volume 14, Issue 2 (3-2020)
Abstract
Background: Tahini (sesame paste) is a kind of food obtained from sesame seeds. To our knowledge, this is the first study to measure total antioxidant activity and total phenolic compounds in tahini brands available in Iranian market.
Methods: In this study, 111 tahini samples were collected and purchased from the Iranian Market, including 37 commercial brands (three samples for per brand). The ferric reducing ability of plasma (FRAP) method was used to measure total antioxidant activity in each sample. Total phenol contents were measured by the Folin–Ciocalteau method in tahini brands.
Results: Current study showed Mino-dates brand (119.93 µmol/ml ±0.159), Trang-Chocolate brand (56.30 µmol/ml ±0.056), Barsam-coffee (45.13µmol/ml±0.094), and Chocolate-barsam brand (53.23 µmol/ml ±0.112), respectively, have more total antioxidant activity than other brands (p< 0.001). Moreover, Mino-dates brand (2057.33 µmol/ml ±0.094), barsam-coffee (805.51 µmol/ml ±0.041), Chocolate-barsam brand (807.42 µmol/ml ±0.095), and Trang-Chocolate brand (685.75 µmol/ml ±0.086), respectively, have more total phenolic compounds than other brands (p< 0.001).
Conclusion: According to the results of this study, Tahini brands with higher polyphenol contents antioxidant capacity also had higher antioxidant capacity. It can be concluded that Tahini in the Iranian market is one of the most valuable foods in terms of antioxidant activity and total phenolic contents.
Mahtab Nejadaria, Seyed Mojtaba Mortazavi, Mohammad Hasan Kohansal,
Volume 14, Issue 2 (3-2020)
Abstract
ABSTRACT
Background and Objectives: The pentose phosphate pathway is of particular importance for energy supply in red blood cells. Glucose 6-phosphate dehydrogenase is the key enzyme involved in this pathway. The deficiency of this enzyme due to lack of nicotinamide adenine dinucleotide phosphate (NADPH) production in red blood cells leads to oxidation, hemoglobin deposition, red blood cell membrane changes and favism, which causes jaundice and hemolytic anemia in newborns. In this study, we evaluate the frequency of G6PD deficiency in newborns in a hospital in Bam, Iran.
Methods: In this descriptive-analytical cross-sectional study, blood samples were taken from 572 newborns hospitalized at Pasteur hospital of Bam (Iran) in the first half of 2018. Demographic data including gender and blood type were collected. The G6PD enzyme activity was evaluated using qualitative G6PD assay kit (Saba Teb, Iran). Data were analyzed using SPSS software.
Results: Of the 572 cases examined, 52 (9.09%) had G6PD deficiency. Of the affected patients, 34 (65.4%) were male and 18 (34.6%) were female. In addition, the majority (47.7%) of affected patients were with O+ blood group.
Conclusion: A relatively high frequency of G6PD deficient infants was reported in Bam. As expected, the prevalence of this disorder was higher in males than in females. Given the lost cost of screening, we suggest screening for G6PD enzyme activity in all newborns.
Keywords: Favism, Glucose 6-Phosphate Dehydrogenase, NADPH.
Mahboubeh Tajaldini, Firooz Samadi, Ayyoob Khosravi, Azim Ghasemnejad, Jahanbakhsh Asadi,
Volume 14, Issue 2 (3-2020)
Abstract
ABSTRACT
Background and Objectives: Citrus fruits and their constituents especially naringin (NR), a natural predominant flavanone, have a wide range of pharmacological activities without toxicity against cancer cells. The aim of this study was to investigate the anticancer effects of orange peel extract (OPE) and naringin (NR) on esophageal squamous cell carcinoma (ESCC) cells.
Methods: Amount of phenol, flavonoid and antioxidants in OPE was determined using Folin-Ciocalteu procedure, aluminum chloride colorimetric and DPPH assays, respectively. Effects of NR and OPE on viability, wound healing assay and DNA fragmentation using DAPI were investigated. Data were analyzed by ImageJ software and GraphPad Prism 6.0 at significance of 0.05.
Results: Total amount of phenols, flavonoids and 1,1-diphenyl-2-picrylhydrazyl was 2.83, 2.143 and 60.76 g/100g of OPE. Amount of NR in the dried OPE was estimated to be 5.260 (µg/gr) using high-performance liquid chromatography. Treatment of ESCC cells with OPE or NR decreased viability y of cancer cells in a dose-dependent manner. In addition, both OPE and NR were able to decrease cell migration and increase DNA fragmentation.
Conclusion: The findings of our study suggest that OPE and NR have anticancer effects on ESCC cells but the anticancer effects of OPE was better than that of NR alone.
Keywords: Orange peel extract, Naringin, Migration, Esophageal squamous cell carcinoma.
Reihaneh Sabbaghzadeh,
Volume 14, Issue 3 (5-2020)
Abstract
Background and objectives: Polyphenols can exert free radical scavenging effects by naturalizing dangerous reactive oxidants. Formation of reactive oxygen species can cause oxidative damage to human cells, leading to various diseases such as cancer, cardiovascular disease, osteoporosis and degenerative diseases. In this study, we investigated effect of treatment with various concentrations of lead (II) nitrate, a toxic and an
oxidizing agent, on growth and biochemical parameters of alfalfa (
Medicago sativa L.).
Methods: Total phenol content was estimated by the Folin-Ciocalteu method. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable free radical was used for assessment of free radical-scavenging activity. Changes in the activity of catalase and peroxidase as well as in the level of proteins, phenol content and malondialdehyde (as marker of lipid peroxidation) were investigated following treatment with different concentrations (0, 8, 12 and 16 mg/l) of lead nitrate for 21 days. All experiments were done in triplicate. Butylated hydroxytoluene and quercetin were used as standard controls.
Results: Treatment with lead significantly altered the level of total phenolic content, proteins, malondialdehyde and the activity of catalase and peroxidase (P<0.05).
Conclusion: Our results indicate that lead-contaminated soil can significantly alter biochemical and growth parameters of alfalfa.
Zeinab Nazari, Javad Ghaffari, Negar Ghaffari,
Volume 14, Issue 3 (5-2020)
Abstract
Background and Objectives: Human T lymphotropic virus type I (HTLV-I) is a virus of the Retroviridae family, which has infected more than 20 million people around the world. The study aimed to review the prevalence of HTLV infection in pregnant women.
Methods: We searched various databases including PubMed, EMBASE, Scopus, Google Scholar, SID, Magiran and Irandoc using the following keywords: HTLV-1, HTLV-2, Retroviridae, pregnancy, prevalence, incidence, women and female. Abstracts, short/brief reports as well as original and review articles published on HTLV-1 and/or HTLV-2 infection during pregnancy until October 2018 were included in the study.
Results: We found five articles from Iran and 14 articles from other parts of the world on the prevalence of HTLV-1 infection in pregnant women. Prevalence of HTLV-1 and or HTLV-2 was higher in pregnant women than in non-pregnant women in cities of Mashhad and Neyshabur, Razavi Khorasan Province (1.5 to 3.3 %), northeastern Iran, which are endemic areas of Iran for HTLV-1 infection. The incidence rate of HTLV-1 infection was 400-500 per 10,000 pregnant women in endemic areas of Japan. In Brazil, the rate of HTLV-1 infection in pregnant women was estimated to be 1.05%.
Conclusion: The prevalence of HTLV-1 varies among pregnant women depending on residence in endemic or non-endemic areas for HTLV-1. In endemic areas, it is recommended to perform routine screening for HTLV-1 infection in the general population, especially pregnant women.
Fatemeh Fakhri, Abdolhamid Habibi, Mohsen Ghanbarzadeh, Rohollah Ranjbar,
Volume 14, Issue 3 (5-2020)
Abstract
Background and Objectives: It has been shown that low intensity physical activity rarely increases bone density or renewal. Therefore, the purpose of this study was to investigate effects of four weeks of plyometric training with and without vascular occlusion on serum levels of bone alkaline phosphatase (BALP) and C-terminal telopeptide of type I collagen (CTX), as markers of bone formation and bone degeneration in inactive girls.
Methods: This was a semi-experimental study with a pretest-posttest design. The study population consisted 36 inactive female students aged 23.84±1.096 years with a mean body mass index of 22.59±0.52 kg/m2 who were randomly divided into a plyometric training group without blood flow restriction, a plyometric training group with blood flow restriction and a control group. The experimental groups performed four weeks of plyometric training (three sessions per week), while the control group did not perform any exercise. Blood samples were obtained 48 hours before the first training session and 48 hours after the last training session. Measurement of BALP and CTX was carried out using commercial enzyme-linked immunosorbent assay kits. Collected data were analyzed using t-test and one-way analysis of variance. All statistical analyses were performed using SPSS software (version 23) and at significance level of ≤ 0.05.
Results: The level of BALP was significantly higher in the low intensity exercise with blood flow restriction group compared to the control group (P=0.005) and the low intensity exercise group without blood flow restriction (P=0.003). The BALP/CTX ratio, as marker of bone metabolism, increased significantly following low intensity exercise with blood flow restriction compared with the other groups (P<0.05). However, low intensity exercise without blood flow restriction induced no significant change in the studied indices.
Conclusion: Plyometric training with blood flow restriction could be as effective as high intensity training for improving bone metabolism and turnover, particularly in inactive individuals.
Azizollah Ebrahimi, Soheila Rabiaee, Sharareh Lotfalian, Saied Habibian,
Volume 14, Issue 4 (7-2020)
Abstract
ABSTRACT
Background and objectives: Clove (Syzygium aromaticum) essential oil is a food additive with proven antimicrobial and antioxidant properties. Thus, it may be a good candidate for controlling foodborne pathogens, such as Staphylococcus aureus. The aim of the present study was to evaluate effects of sub–minimum inhibitory concentrations (MICs) of clove oil on some virulence factors of S. aureus.
Methods: The standard strain and 12 field isolates of S. aureus were obtained from our microbial collections. The broth tube dilution method was used to determine the MIC of clove oil against the isolates. Sterile 96-well flat bottom polystyrene microtiter plates were used for planktonic growth and biofilm formation assays. Slide coagulase test was used for assaying effect of clove oil on clumping factor production. Production of α- and β-hemolysins was assessed by culture on 5% bovine blood agar.
Results: The results showed that sub-MIC concentrations of clove oil inhibited α- and β-hemolysins and biofilm production and planktonic growth of the examined isolates. However, clumping factor was not affected by sub-MIC concentrations of clove oil.
Conclusion: Our results indicate the favorable inhibitory effects of sub-MIC concentrations of clove oil against growth and biofilm and hemolysins production of S. aureus isolates.
Ezzat Allah Ghaemi, Fahimeh Azadi, Naeme Javid, Hanieh Bagheri,
Volume 14, Issue 4 (7-2020)
Abstract
Background and objectives: Drug resistance in Staphylococcus aureus and Escherichia coli, as severe pathogenic bacteria, has become a health challenge. However, nanoparticles have been introduced as effective candidates for their eradication. In this study, we investigated presence of genes involved in conferring resistance to silver nanoparticles in S. aureus and E. coli isolates and evaluated its association with minimal inhibitory concentration (MIC) of the nanoparticles against these isolates.
Methods: The MIC of silver nanoparticles against 121 clinical isolates of E. coli and 183 S. aureus isolates was assessed by broth microdilution assay. Presence and expression of the silver resistance genes (silE, silR/S) in the isolates were investigated by PCR and real-time PCR, respectively.
Results: The silE gene was found in three (1.6%) S. aureus and four (3%) E. coli isolates. MIC of silver nanoparticles against S. aureus isolates with the silE gene was 1, 2 and 8 µg/ml. Moreover, the MIC of the nanoparticles against silE-positive E. coli isolates was 16 μg/ml in three cases and 8 μg/ml in one case. None of the S. aureus isolates contained the silR/S gene, but presence of both silE and silR/S was confirmed in two E. coli isolates. Real-time PCR showed no sil expression in the isolates containing the resistance genes.
Conclusion: The frequency of the silver resistance genes among S. aureus and E. coli isolates is very low. There is no relationship between presence of the resistance genes and the MIC value of silver nanoparticles.
Somaieh Sabzali, Majid Bouzari,
Volume 14, Issue 4 (7-2020)
Abstract
Background and objectives: are divided into two species: Salmonella enterica and Salmonella Salmonella bongori. S. enterica has more than 2,500 serotypes. Serovars of S. enterica such as Typhimurium, Enteritidis, Paratyphi B, Paratyphi A and Newport are associated with human infections. Approximately 75% of human Salmonella infections have been associated with contaminated food such as eggs, chicken, beef, pork, dairy products, fruits and vegetables. The aim of this study was to determine the frequency of Salmonella strains isolated from various food sources in Isfahan, Iran.
Methods: Forty Salmonella strains were isolated from 450 suspected cases referred to the veterinary reference laboratory of Isfahan Province. The isolates were identified by differential and serotyping tests and then confirmed by PCR. A phylogenic tree was constructed with 34 sequences by neighbor-joining method using the MEGA7 software (version 7.1).
Results: Overall, 10 Salmonella serovars were isolated from 32 chicken meat, three beef and five egg shell samples. S. enterica serovar Ouakum (20%), S. Enteritidis (17.5%) and S. Typhimurium (17.5%) were the most common serovars, while S. enterica serovar Nitra (2.5%) was found as the least prevalent isolate.
Conclusion: In this study, S. Typhimurium species is placed in different clusters along with sequences reported from different parts of the world, indicating that the serovars are circulating all over the world.
