ABSTRACT

        Background and Objective: Microalgae are a group of algae that produce biochemical products consisting of a wide range of carbohydrates, lipids and proteins that are commercially valuable. Interest in microalgal cultivation is currently blossoming globally. Species of Dunaliella are found in freshwater, euryhaline habitats of all continents, oceans including the Dead Sea and even the salt lakes of the Antarctic. This study investigates the effect of different salinity levels on β-carotene production by Dunaliella sp.

       Methods: Water samples from a hyper-saline lake (the Maharlu Lake in Shiraz) were cultured in modified Johnson media. The β-carotene content was measured after the samples were treated with different salinities (1, 2 and 3M NaCl).

         Results: The cell count and β-carotene content of Dunaliella sp. samples ranged between 0.46×10⁶ to 2.12×10⁶ cell.mL^-1 and 0.15 to 9.98 pg.cell^-1, respectively. At the end of the experiments, the mean maximum cell content (1.78×10⁶ cell. mL^-1) and the highest mean β-carotene content (7.41 pg. cell^-1) were obtained at 2 and 3M NaCl concentrations, respectively.

       Conclusion: Salinity of the medium might affect the quantity and composition of carotenoids in Dunaliella sp. isolates. Alteration of the culture medium’s salinity to 3M NaCl significantly increases the accumulation of β-carotene and total carotenoids in Dunaliella sp. isolates.

       Keywords: Dunaliella, Microalgae, Maharlu Lake, β-carotene.

ABSTRACT

         Background and Objective: Biofilms are community of bacteria that attach to inanimate surfaces or living tissues via production of extracellular polymers and exopolysaccharide matrix. Microbial biofilms on various surfaces of the hospital environment are considered as a reservoir of infection spread. The present study aimed to evaluate the disinfecting effect of benzalkonium chloride on some bacterial isolates causing nosocomial infections.

       Methods: First, 13 isolates from four bacteria including Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter and Enterobacter were obtained from Microbiology Laboratory of Al-Zahra Hospital in Isfahan, Iran. The samples were transferred to Microbiology Laboratory of Faculty of Veterinary Medicine of Shahrekord University for testing. Evaluation of biofilm formation and determination of minimum inhibitory concentration (MIC) of the disinfectant and effect of the disinfectant on planktonic growth and biofilm formation were performed.

        Results: All bacterial isolates (52 cases) produced biofilm. Mean MIC of benzalkonium chloride for P. aeruginosa, S. aureus, Enterobacter and Acinetobacter was 0.14, 0.2, 0.18, 0.17 g/ml, respectively. Planktonic growth of all four bacteria was inhibited at concentrations of 2MIC, MIC and 1/2MIC. Biofilm was not produced in MIC and 2MIC concentrations, and biofilm formation capability increased by reducing the concentration of benzalkonium chloride.

          Conclusion: The results show that the use of appropriate concentration of benzalkonium chloride can prevent the growth of different bacterial species, but sub-MIC dose of this disinfectant may stimulate biofilm formation.

            Keywords: Biofilm, Benzalkonium Chloride, Pseudomonas Aeruginosa, Staphylococcus Aureus, Enterobacter, Acinetobacter.

ABSTRACT
       Background and Objective: MiRNAs are small RNAs that are expressed in most eukaryotes, and can regulate gene expression by attaching to the 3’ end of target mRNA. MicroRNA-101 (miR-101) post-transcriptional regulation is important for host-virus interactions. In addition, miR-101 has a tumor suppressive role in liver cancer and metastasis, and induces apoptosis in tumor cells. We examined miR-101 expression in patients with chronic hepatitis B, hepatitis B virus (HBV)-associated cirrhosis and healthy individuals.
       Methods: The study was performed on 108 whole blood samples (36 samples from each group) collected in EDTA tubes. RNA was extraction by RNX-plus kit according to the manufacturer’s protocol. Finally, miRNA expression was evaluated using relative real time PCR.
         Results: A 2.4-fold increase was observed in miR-101 expression in patients with chronic hepatitis B, while there was a 3.5-fold increase in miR-101 expression in patients with HBV-associated cirrhosis compared with healthy controls (P=0.003). MiR-101 overexpression in patients with HBV-associated cirrhosis was more notable that in patients with chronic hepatitis B.
         Conclusion: According to the results, evaluating miR-101 expression may predict disease progression from chronic hepatitis B to HBV-associated cirrhosis.
         Keywords: MicroRNAs, Chronic Hepatitis B, Liver Cirrhosis, MiR-101.

ABSTRACT
         Background and Objectives: Due to adverse effects of pentavalent  antimonial  treatment of visceral leishmaniasis using herbal medicines has received a lot of attention. In this study, we evaluated inhibitory activity of Pelargonium roseum essential oil on growth of Leishmania infantum promastigotes, and compared it with that of Glucantime.
        Methods: Inhibitory effects of different concentrations (1, 2.5, 5, 10, 25, 50 and 100 µL/ml) of P. roseum essential oil on the growth of L. infantum promastigotes were studied by MTT assay after 24 and 48 hours. All the data were analyzed by one-way analysis of variance. The effect of the essential oil was later compared with that of standard dose of Glucantime.
        Results: After 24 hours, different concentrations of the essential oil had no significant inhibitory effect on promastigotes of L. infantum. After 48 hours, all concentrations except for 1µL/ml showed significant anti-leishmanial activity. In addition, the lowest concentration that had significant inhibitory effect on L. infantum promastigote was 5 µL/ml.
       Conclusion: The essential oil of P. roseum has favorable inhibitory activity on the growth of L. infantum promastigotes after 48 hours. This indicates the therapeutic potential of this plant for treatment of leishmaniasis.
        Keywords: Leishmania infantum, Pelargonium, Promastigote, Meglumine antimoniate.

ABSTRACT
       Background and objectives: Contamination of food products with mycotoxins is a public health problem. The International Agency for Research on Cancer has identified mycotoxins as hepatotoxic and carcinogenic agents to humans (Group 1). The Kurdistan Province is the ninth largest producer of wheat in Iran. We aimed to determine the level of contamination with total aflatoxin (TAF), aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in 66 wheat samples randomly selected from 11 wheat flour factories in spring and summer.
       Methods: The level of toxins was measured by microtiter plate enzyme-linked immunosorbent assay (ELISA) using a microtitre plate ELISA reader and total AF, AFB₁ and OTA commercial kits.
      Results: Overall, the level of TAF and AFB in 16.67% of the samples exceeded the maximum tolerable limit set by the Institute of Standard and Industrial Research of Iran (ISIRI). However, the level of OTA contamination did not exceed the maximum tolerable limit set by the ISIRI. In addition, the level of TAF, AFB₁ and OTA exceeded the maximum tolerable limit set by the EU in 68.18, 90.91 and 36.36% of the samples, respectively. The level of contamination with these mycotoxins differed significantly in spring and summer (P<0.05).
      Conclusion: The level of mycotoxin contamination in wheat samples produced in the Kurdistan Province is alarmingly high and appropriate measures should be taken to eliminate the causes of this issue.
         KEYWORDS: Aflatoxin, Aflatoxin B_1, Ochratoxin A, Wheat, ELISA.

ABSTRACT
         Background and Objectives: Elevated blood lipid levels are correlated with risk of cardiovascular disease, especially in overweight individuals. The beneficial effect of strength training on lipid profile has been well documented. However, the effect of strength training with flow blood restriction has not been established. The purpose of this study was to compare the effect of eight weeks of strength training with and without blood flow restriction on some of the cardiovascular risk factors in overweight females.
         Methods: In this study, 28 overweight females aged 18 to 24 years were randomly assigned into three groups of blood flow restriction strength training (BFRT), traditional strength training (TRT) and control. Participants in the BFRT group performed eight weeks of strength training three sessions per week at 30% of 1-repetetion maximum, while participants in the TRT group performed the training at 65-80% of 1-repetetion maximum. Cardiovascular variables, systolic blood pressure and diastolic blood pressure were measured before and after the exercise training. Data was analyzed using descriptive statistics, paired t-test and one-way analysis of variance.
          Results: Triglyceride level decreased significantly in the BFRT (p=0.022) and TRT (p=0.038) groups compared with the control group. Moreover, there were no significant differences in the body mass, waist-to-hip ratio, body mass index, high-density lipoprotein, low-density lipoprotein, and cholesterol levels between the study groups (P≥0.05).
           Conclusion: Our findings suggest that the BFRT and TRT may not be suitable for preventing or even reversing the physiological changes induced by obesity.
         Keywords: Resistance Training, Lipids, lipoprotein, overweight.

ABSTRACT
           Background and Objectives: Local cheese made from raw milk is one of the most commonly consumed dairy products in the world. Mycotoxin contamination of foodstuff and its transmission to consumers are extremely important public health issues. The purpose of this survey was to determine the level of aflatoxin M1 (AFM1) residues in Koupeh cheese, a traditional fermented Iranian cheese produced in spring and summer.
           Methods: We randomly collected 48 local cheese samples produced in Mahabad (northwest of Iran) during spring and summer. The level of AFM1 was measured by enzyme-linked immunosorbant assay using commercial kits and a microplate reader.
           Results: All samples contained measurable amounts of AFM1. Cow milk cheese samples contained higher level of AFM1 compared to sheep milk cheese samples. The level of AFM1 in the samples from both animals was lower in summer. There was no significant difference between the mean level of AFM1 in summer and spring. Moreover, 33.3% of cow milk cheese samples collected in spring and 16.6% of the samples collected in summer contained toxin levels higher than the maximum allowed concentration set by the European Commission (250 ng/Kg) and by the Institute of Standards and Industrial Research of Iran (200 ng/Kg).
           Conclusion: The results of this study show that the level of AFM1in Koupeh cheese is influenced by the livestock type and production season, in a way that the level of contamination is higher in spring.
           Keywords: Cheese, Cultured Milk Products, Aflatoxin M1, ELISA.

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.

ABSTRACT
             Background and Objectives: Efflux-based systems may play a role in resistance to fluoroquinolones in Gram-negative pathogenic bacteria. Extracts of some medicinal plants contain molecules that can act as efflux pumps inhibitors. In this study, we aimed to evaluate antibacterial activities of ethanolic and chloroform extracts of Cinnamomum zeylanicum and their possible synergistic activity with ciprofloxacin against some Gram-negative pathogenic bacteria. We also analyzed the extracts for presence of efflux pump inhibitors against the examined bacteria.
             Methods:  Powdered dried leaves and branches of C. zeylanicum were extracted with ethanol (85%) and chloroform by the maceration method. Minimum inhibitory concentrations of the extracts alone or combined with ciprofloxacin and phenylalanine-arginine β-naphthylamide (an efflux pump inhibitor) were determined against Pseudomonas aeruginosa, Acinetobacter bummani, Escherichia coli and Salmonella enteritidis using the double serial microdilution method.
             Results: The extracts of C. zeylanicum inhibited the growth of all studied bacteria. Synergistic effects were noted between the extracts and ciprofloxacin against all tested bacteria other than P. aeruginosa. Ciprofloxacin efflux pumps in E. coli, S. enteritiditis and A. baumannii were inhibited by the extracts of C. zeylanicum.
             Conclusion: The extracts of C. zeylanicum could be used as ciprofloxacin-potentiating agents against some Gram-negative pathogens.
             Keywords: Anti-bacterial agents, Cinnamomum zeylanicum, Bacterial pathogens, Efflux pumps.