Advances in Detecting Cystic Echinococcosis in Intermediate Hosts and New Diagnostic Tools: A Literature Review.

Cystic echinococcosis (CE) is a zoonotic disease affecting humans and animals. Despite a lack of clarity about many details of parasite-intermediate host interactions, the nature of the immune responses triggered by hydatid infection has revealed new perspectives. This study discusses the latest advances in elucidating the immunologic mechanism of echinococcosis and its detection and potential approaches to enhance serodiagnosis accuracy. Moreover, nanobiosensors have been evaluated according to their potential to improve treatment efficiency and aid in an early diagnosis of cystic echinococcosis. The serum of an intermediate host can diagnose CE by analyzing antibodies induced by Echinococcus granulosus. Among the most notable features of this method are its noninvasive ability and high sensitivity, both of which make it an excellent tool for clinical diagnosis. Several serological tests, including ELISAs and immunoblotting, can detect these antibodies to assess the disease's state and determine the treatment outcome. A thorough understanding of what cross-reactivity means and the stage of the disease are crucial to interpreting serological results. Nanobiosensors have also proven better than conventional biosensors in detecting hydatid cysts. Additionally, they are highly sensitive and versatile when detecting specific biomarkers, improving diagnostic accuracy. These immunomodulatory molecules, induced by E. granulosus, are a good candidate for diagnosing cystic echinococcosis because they alter intermediate host immune responses. Hydatid cyst detection is also enhanced through nanobiosensors, which provide better accuracy.

Effect of new methionine-based ionic liquid on the CDR1 and CDR2 gene expression on sensitive and resistant strains of Candida albicans.

Background and Objectives: Previous researchers showed the antimicrobial ability of ionic liquids (ILs) on different infective agents. ILs can dissolve organic components, especially DNA molecules. Among synthesized eight binary ILs mixtures, we have chosen ([Met-HCl] [PyS]) IL for determining the antifungal ability of IL against Candida albicans cells. Materials and Methods: Well diffusion assay, chrome agar and Germ tube tests were used to detect the Candida samples. PCR, real-time-PCR, and flow cytometry tests were performed to determine the IL's rate of toxic ability. Results: Well diffusion assay revealed the diameters of the growth inhibition zones were the largest in IL with methionine and Proline amino acids. Minimum inhibitory concentration (MIC) and the Minimum fungicidal concentration (MFC) tests showed that they inhibited the growth of the C. albicans at a range from 250 µg/ml for sensitivity and 400 µg/ml for resistance, MIC average of all samples were 341.62 ± 4.153 µg/ml. IL reduced the expression of CDR1 and CDR2 the genes encoded by the major protein of ABC system transporter by 2.1 (P= 0.009) and 1.2 fold (P= 0.693), revealed by PCR and real time-PCR. In the flow cytometry test, there were increasing dead cells after treating with the ([Met-HCl] [PyS]) even in the most resistant strain. Conclusion: The novel IL was effective against the most clinical and standard C. albicans.

Antimicrobial and anti-biofilm effects of carotenoid pigment extracted from Rhodotorula glutinis strain on food-borne bacteria.

Background and Objectives: Carotenoid pigments are among the most important pigments and have many applications in various food, cosmetics, hygiene industries and biotechnology. These pigments are produced by plants and microorganisms including Rhodotorula spp. This research intended to study the antimicrobial and antibiofilm effects of the carotenoid pigment from Rhodotorula glutinis on food spoilage bacteria (Staphylococcus aureus and Salmonella Typhimurium). Materials and Methods: The R. glutinis was isolated from milk samples of cows with mastitis and ITS sequence-based typing was performed on them. After extracting the pigment from R. glutinis, its purity was examined using thin-layer chromatography. Following that, the broth microdilution method was used to evaluate antimicrobial effects of the pigment and MtP assay and subsequently scanning electron microscopy were used to assess the antibiofilm effects. In addition, the sub-MIC effects of the pigment on expression of quorum-sensing (QS) genes in S. Typhimurium isolates (sdiA and luxS) and S. aureus isolates (hld) were studied. Finally, the degree of toxicity of the pigment was analyzed using the MTT assay. Results: ITS sequence analysis of R. glutinis revealed that the recently separated isolates exhibited strong differences with the strains recorded in NCBI database in genetic structure. The pigment produced by R. glutinis had strong antimicrobial effects and its mean MIC against S. Typhimurium isolates (17.0 µl.ml-1) was higher than the mean MIC against the S. aureus isolates (4.1 µl.ml-1). Electron microscope images and real-time observations indicated that the sub-MIC values of the pigment suppressed biofilm formation by suppressing expression of QS genes. In addition, the mentioned pigment at high MIC concentrations did not have toxic effects on Vero cells. Conclusion: This research suggests that R. glutinis pigment is effective in destroying the planktonic form of food spoilage bacteria and degrading food spoilage biofilm-forming bacteria. Moreover, considering the low toxicity level of R. glutinis pigment for eukaryotic cells, we can suggest its use as a natural antibacterial preservative in various food materials.

Naked-Eye Detection of Morphine by Au@Ag Nanoparticles-Based Colorimetric Chemosensors.

In this study, we report a novel and facile colorimetric assay based on silver citrate-coated Au@Ag nanoparticles (Au@AgNPs) as a chemosensor for the naked-eye detection of morphine (MOR). The developed optical sensing approach relied on the aggregation of Au@Ag NPs upon exposure to morphine, which led to an evident color variation from light-yellow to brown. Au@Ag NPs have been prepared by two different protocols, using high- and low-power ultrasonic irradiation. The sonochemical method was essential for the sensing properties of the resulting nanoparticles. This facile sensing method has several advantages including excellent stability, selectivity, prompt detection, and cost-effectiveness.

Molecular study and antifungal susceptibility profile of Trichophyton rubrum and Trichophyton mentagrophytes strains isolated from lesions of humans and cattle.

Background and Objectives: Monitoring of contagious diseases is important to advance our knowledge of their epidemiology and to enable more impressive investigation and prevention efforts. This study aimed to examine antifungal drug susceptibility and molecular analysis of clinical isolates of Trichophyton rubrum and Trichophyton mentagrophytes in humans and cattle. Materials and Methods: A total of 400 patients and 500 cattle were evaluated in this study. Dermatophytosis was confirmed in cases by direct microscopy and culture methods. Antifungal drug susceptibility profiles, MIC50, and MIC90 of isolates were determined using the broth microdilution method. Multiplex-PCR, RAPD PCR, and sequencing methods were used for the genetic analysis of virulence genes and the ITS1 and ITS2 regions, respectively. Results: A total of 175 patients and 120 cattle were diagnosed with dermatophytosis. Dermatophytes showed a remarkable rate (30%) of terbinafine resistance. T. mentagrophytes showed lower susceptibility than T. rubrum (MIC50 =16 µg/mL). Strains harboring Mep1, Mep2, and Mep4 genes had the highest frequency among all genotypes. A RAPD-PCR dendrogram divided T. mentagrophytes and T. rubrum strains into three and six groups, respectively. Conclusion: A notable rate of resistance to terbinafine in isolated dermatophytes was reported in this study. Examination of RAPD-PCR results showed that T. rubrum strains had higher genetic diversity than T. mentagrophytes. Genetic monitoring of dermatophytes must be considered an important factor in providing fungal infection prevention and treatment approaches.

Effect of fluconazole and terbinafine nanoparticles on the treatment of dermatophytosis induced by Trichophyton mentagrophytes in guinea pig.

BACKGROUND AND OBJECTIVES: Dermatophytosis induced by Trichophyton mentagrophytes is a major human and animal fungal contamination. Antifungals like terbinafine and fluconazole are widely used to treat dermatophytosis; nevertheless, the prevalence of drug resistance has increased. Hence, novel curative strategies are needed. In the present study, we compared the efficacies of conventional and nanoform of antifungals agents in guinea pig model of dermatophytosis. MATERIALS AND METHODS: Guinea pigs (n=36) were injected (the posterior dorsal portion) with Trichophyton mentagrophytes conidia. The guinea pigs were divided into 6 groups (positive control, negative control, fluconazole 0.5% treated group, nano-fluconazole treated group, terbinafine 1% treated group, and nano-terbinafine treated group), then were scored both clinically (redness and lesion intensity) and mycologically (microscopy and culture) until day 40 of inoculation. The treatment started 5 days after the inoculation and continued until day 40 of inoculation. RESULTS: Assessment of the mean score of clinical lesions in groups treated with nano-drug forms of fluconazole and terbinafine on the first day of treatment showed a score of 3 (significant redness with large scaling) and for the conventional form of terbinafine and fluconazole had a score of 4 (ulcer and scar). The decrease in lesion score in nano-drug treated groups was observed between days 15 and 20 and continued until day 40. On day 40, all groups had zero scores except the positive control group. CONCLUSION: This study indicated that nano-drugs are more suitable for the treatment of dermatophytosis and could be considered as future alternatives for the treatment of dermatophytosis.

In-Vitro Activity of Nano Fluconazole and Conventional Fluconazole against Clinically Important Dermatophytes.

BACKGROUND: Dermatophytosis is one of the most common fungal infections in humans. Antifungals such as fluconazole are effectively used for treating dermatophytosis; however, drug resistance was observed in many cases. Therefore, a newer treatment strategy is essential. METHODS: This study (Conducted in the Laboratory of the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran in 2018) evaluated the antifungal susceptibility of nano fluconazole compared to conventional fluconazole on dermatophyte isolates using CLSI M38-A2guidelines. Dermatophyte species isolated from clinical cases of dermatophytosis were identified using PCR sequencing techniques. Zeta potential and size of the nano particles containing fluconazole were measured; scanning electron microscope (SEM) was used to determine nano particle structure. RESULTS: The size of liposomal fluconazole obtained was 88.9 ± 12.14 nm with -20.12 ± 3.8 mV for zeta potential. The encapsulation rate for fluconazole was 75.1± 4.2%. MIC50 for the three tested species was 32, 16, and 8 µg/ml for Trichophyton interdigitale, T. rubrum, and Epidermophyton floccosum isolates, respectively. The corresponding values for nano fluconazole were 8 µg/ml for the three tested species. CONCLUSION: MIC value for nano-fluconazole was lower than conventional fluconazole in all dermatophytes species tested; therefore, nano-fluconazole could inhibit the growth of dermatophytes better than fluconazole at a lower concentration of the drug.

Absence of AfuXpot, the yeast Los1 homologue, limits Aspergillus fumigatus growth under amino acid deprived condition.

In Saccharomyces cerevisiae, los1 encodes a nuclear tRNA exporter. Despite the non-essentiality, the deletion of los1 has been shown to extend replicative life span in yeast. Here, we characterized AfuXpot, the los1 homologue in human pathogen Aspergillus fumigatus and found that it is continuously expressed during fungal growth. Microscopic examination of an AfuXpot-GFP-expressing transformant confirmed the nuclear localization of the fusion protein. The targeted gene deletion affirmed the non-essential role of AfuXpot in hyphal growth and sporulation. However, the growth of the deletion mutant was affected by amino acid, but not glucose, deprivation. The susceptibility of the deletant strain to protein and DNA/RNA synthesis inhibitors was also altered. Using bioinformatics tools, some transcription factor binding sites were predicted in AfuXpot promoter. Expression analyses of potential AfuXpot-interacting genes showed a marked down-regulation of sfp1 and mtr10 homologues in ΔAfuXpot strain. Our data demonstrates some conserved aspects of AfuXpot as a tRNA exporter in A. fumigatus.

Validation of an UHPLC-MS/MS Method for Simultaneous Analysis of 11 Mycotoxins in Wheat Flour Using Immunoaffinity Column.

This study focuses on optimization and validation of an Ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous analysis of 11mycotoxins: Aflatoxins (B1, B2, G1, and G2), Ochratoxin A, Deoxynivalenol, Fumonisins (B1 and B2), Zearalenone, T-2, and HT-2toxin, in wheat matrix. Sample extraction and cleanup procedure is based on a single extraction step using acetonitrile/water/acetic acid mixture (79.5/20/0.5 v/v/v) and rapid clean-up of samples were performed with the Myco6in1+ Immunoaffinity column. Electrospray ionization at positive mode was operated to the simultaneously analysis of selected mycotoxins in a single run time of 15 min. Multiple Reaction Monitoring (MRM) mode was selected for quantification and detection of the mycotoxins. The analysis method was validated for selected mycotoxins at different spike levels (2-150 ngg-1 for AFs, T-2, OTA; 20-1500 ngg-1 for ZER, HT-2 toxin; and 100-1500 ngg-1 for DON and FB1+B2) in wheat. Calibration curves were plotted based on the area of peak analyte in spike samples. Limits of detection (LOD) ranged from 0.7 to 33.3 ngg-1 and limits of quantification (LOQ) ranged from 2 to 100 ngg-1. Recovery values were between 70 and 120% for all the mycotoxins, except for AFG2 (72-123%) and T-2 toxin (77-122%) with good repeatability. The recoveries and repeatabilities were in accordance with the criteria determined by European Union (EU) Recommendation 519/2014.

The assessment of anti-tumoral activity of polysaccharide extracted from terrestrial filamentous fungus.

Fungal polysaccharides are well-known for the medicinal properties such as antitumor and immunomodulating effects. Hence, this study evaluated antitumor effects of polysaccharide extracted from Fusarium sp. isolated from soil samples of Karaj district, Alborz, Iran along with its taxonomic study. The filamentous fungus strain FK1 was isolated from the soil sample of Karaj, Iran. The strain was identified based on cultural, morphological and 18 S rRNA gene parameters as Fusarium. Further, the strain Fusarium was cultured in fermented broth of modified (PDB) for 10  days at 25 °C. The polysaccharide of strain FK1 was extracted from the mycelium free supernatant by boiling water method and evaluated for antitoxicity effect on two human cancer cell lines: HeLa cell line and Lymphoblastoid cell line (LCL) by MTT method. Findings revealed that water-extracted from mycelia polysaccharide of strain FK1 had the highest cytotoxicity effect against LCL which is the cause of B lymphocyte cancer, at 50  µg/ml concentration dose (114 ± 1.63) followed by 100  µg/ml (105 ± 0.57) and 10  µg/ml (104 ± 0.57), while it did not have a considerable effect on HeLa cell line. Fusarium could be alternative sources as an antitumor component.

Epithelial mesenchymal transition Transcription Factor (TF): The structure, function and microRNA feedback loop.

Epithelial to mesenchymal transition (EMT) is a phenomenon in which epithelial cells lose their cell to cell adhesion and detach from the base of the membrane. EMT is a fundamental process which occurs during tumor progression and metastasis. Cancer genomics is a complex network which involves a variety of factors such as transcription factors (TFs), coding genes and microRNAs (miRs). Both TFs and miRs are trans-regulatory elements that crosstalk. Due to a wide range of targets, TF-miR interaction provides a feedback or feedforward loop and cross-gene regulation consequently. In this review, we focused on the structure and function of two TF families involved in EMT, zinc finger and ß helix loop helix and p53. Subsequently we analyzed recent findings on TF-miR interaction in EMT.

Citrinin detection by intensified fluorescence signal of a FRET-based immunosensor using magnetic/silica core-shell.

The specific immune-reaction between the anti-citrinin antibody immobilized on the surface of magnetic/silica core-shell (MSCS) and the citrinin-Rho123-BSA conjugate brings the Rho123 fluorophore as an acceptor and the QDs as a donor in close spatial proximity and causes FRET for occurring upon photo-excitation of the QDs. The novelties of this study include: (1) immobilization of the MSCS; (2) large amount of the immobilized QDs, and (3) immobilization of a large amount of Rho123 on the BSA macromolecule. Cd/Te QDs were synthesized by the simultaneous reduction of cadmium chloride and tellurium in the presence of sodium borohydride. Magnetic nanoparticles were synthesized using FeSO4 and FeCl3. The prepared magnetic nanoparticles shelled by silica using tetraethoxysilane in the presence of ammonia. Transmission electron microscopy (TEM) analysis was used for investigating shape and monodispersity of the nanoparticles. EDC/NHS was used as a cross linking agent for immobilization of the QDs, conjugation of citrinin to amino groups of BSA, labeling of BSA with Rho123 and also for immobilization of the amino-functionalized MSCS on the immobilized QDs. Immobilization of the anti-citrinin antibody on the surface of the amino-functionalized MSCS was performed by Schiff-base mechanism. By using these three effective strategies, sensitivity of the designed nanobiosensor was incredibly enhanced as a very low limit of detection (up to 0.1 pM). The feasibility of this technique was tested by the detection of citrinin in the spiked human serum. Results showed that there was a linear correlation between the decreased fluorescence intensity of the Rho123 and increased fluorescence intensity of the QDs with increasing concentration of citrinin in the spiked samples in the range of 1-6 pM. According to obtained results, we conclude that this highly sensitive detection scheme is a easy, quick and impressive method that can be used in optical-based nanosensors.

Evaluation of intrinsic and acquired immune cells infiltration in kidney and spleen of the mice infected with systemic candidiasis and treated with chloroform fraction of Zataria Multiflora Boiss.

BACKGROUND AND AIMS: Despite the use of antifungal drugs, the visceral candidiasis is associated with a high mortality rate. The aims of this study were an evaluation of intrinsic and acquired immune cells infiltration in kidney and spleen of the mice infected with systemic candidiasis and treated with chloroform fraction of Zataria Multiflora Boiss. MATERIALS AND METHODS: Candida albicans (C. albicans) ATCC10231 clinical standard strain was isolated. C. albicans LD50 was determined. The laboratory animal (BALB/C mouse) infection with the visceral candidiasis was performed. The kidney and spleen tissues were stained with PAS and prepared for confirmation under the microscope. The Zataria Multiflora Boiss (Shiraz thyme) was prepared and the effects on the infected group were assessed. The kidney and spleen mononuclear cells (MNCs) were prepared and the flow cytometry technique was performed for the assessment of Th1, Th17, and Treg cells. RESULTS: The LD50 and LD totals were 1.5 × 108 and 2 × 108 Yeast/0.1 ml, respectively. In mice which had a drug intervention, including chloroform fraction of Zataria Multiflora Boiss, thymol, carvacrol or fluconazole, fungal purification was greater in the spleen than in the kidney. Among those mice without medication intervention, fungal clearance was higher in the kidney. The highest percentage of TH1 cells was in group 1 and then group 4 and in groups 2 and 3 respectively. Moreover, there was a significant difference between groups 4 and 5 and also 6 and 7. The percentage of TH1 cells in the spleen MNCs was higher than that of the kidney cells, which is the difference between the groups except for group 7. The percentage of TH17 cells in the kidney and spleen of all drug-receiving groups exhibited a significant increase compared to groups 6 and 7. The percentage of Treg cells in the kidney and the spleen only in the extract-receiving group had a significant decrease compared to the non-drug receiving group and the other groups receiving group depicted no significant difference in the percentage of Treg cells. CONCLUSION: In addition to the direct effect on the fungus proven in vitro, the extract exhibits immunosuppressive effects, and thus can degrade the fungus through this way. The results demonstrated that the fraction of Zataria Multiflora Boiss can be considered as a powerful alternative to C. albicans therapy along with other therapies.

Effect of long-term exposure of mice to 900 MHz GSM radiation on experimental cutaneous candidiasis.

Mobile phones communicate with base stations using 900 MHz microwaves. The current study was aimed to survey the effects of long-term 900 MHz microwave exposure of mice on experimentally induced cutaneous candidiasis. Forty inbred, male, BALB/c mice were randomly divided into four groups. Cutaneous lesions with Candida albicans were experimentally induced on the lateral-back skin of the 20 mice. One group of the diseased mice were exposed (6 h per day and 7 d per week) to 900 MHz microwave radiation, while the other groups were not exposed. Two unexposed control groups were also included. The skin lesions were regularly monitored and the live candida cell density was enumerated using the colony-forming unit (CFU) assay. The process was repeated after a one week resting interval. One week later, all mice were challenged through intra tail veins using LD90 dose of C. albicans. Mortality of the mice was recorded and the candida load of the kidney homogenates from died animals was counted. 900 MHz microwave exposed mice had 1.5 day and 3.7 day delays on wound healing in stages two. Live Candida inoculated Wave exposed (LCW) mice also showed higher yeast loads in skin lesions at days 5, 7 and 9 post inoculation. Survival analysis of live candida challenged mice showed the radiation exposed group is prone to death induced by systemic infection and candida enumeration from the kidney homogenates showed radiation exposed animals have had significantly higher yeast load in the tissue. In collection, long-term 900 MHz radiation exposure of mice led to longevity of skin wounds and susceptibility of the animals to systemic challenge and higher incidences of microorganisms in internal tissues.

Molecular Identification of Mucor and Lichtheimia Species in Pure Cultures of Zygomycetes.

BACKGROUND: The Mucorales are an important opportunistic fungi that can cause mucormycosis in immunocompromised patients. The fast and precise diagnosis of mucormycosis is very important because, if the diagnosis is not made early enough, dissemination often occurs. It is now well established that molecular methods such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) are feasible and reliable tools for the early and accurate diagnosis of mucormycosis agents. OBJECTIVES: The present study was conducted to evaluate the validity of PCR-RFLP for the identification of Mucorales and some important Mucor and Lichtheimia species in pure cultures of Zygomycetes. MATERIALS AND METHODS: Specific sense and anti-sense primers were used to amplify the Mucorales, Mucor, and Lichtheimia DNA. The PCR products were digested by AfIII, XmnI, and AcII restriction enzymes, and the resultant restriction pattern was analyzed. RESULTS: On the basis of the molecular and morphological data, we identified Mucor plumbeus (10.83%), M. circinelloides (9.17%), Lichtheimia corymbifera (9.17%), M. racemosus (5.83%), M. ramosissimus (3.33%), and L. blakesleeana (0.83%). CONCLUSIONS: It seems that PCR-RFLP is a suitable technique for the identification of Mucorales at the species level.

Effect of polymer/nanosilver composite packaging on long-term microbiological status of Iranian saffron (Crocus sativus L.).

Crocus sativus L. (saffron) is a valuable plant which is native to Iran. Saffron is the dried stigmata of the flowering part of the plant that is usually contaminated with different bacteria and fungi through production process. Antimicrobial properties of silver nanoparticles are well recognized. To survey the effects of nanosilver packaging on microbiological status of spiked, saffron samples over a six month period were chosen. Saffron samples from five regions of Khorasan province were purchased and de novo frequencies of microbial contaminants were determined using standard procedures. Totally 35 g of saffron was spiked with known numbers of four bacterial and two fungal species and packaged into one gram packets. The packaging materials consisted of polyethylene polymers containing 0, 400, 800, 1200 or 4000 ppm nanosilver (as Ag). Total and differential numbers of spiked microorganisms in the packaged saffrons were enumerated at initial and at six time points of seven, 14, 28, 64, 90 and 180 days. Baird-Parker agar (BP agar), Kenner Fecal (KF), Salmonella-Shigella agar (SS agar), Violet Red Bile Glucose Agar (VRBGA), and Sabouraud Dextrose agar (SD agar) media were used for enumeration of the six spiked microorganisms including Staphylococcus aureus, Enterococcus faecalis, Salmonella Enteritidis, Enterobacter species and Escherichia coli, Fusarium oxysporum and Aspergillus flavus, respectively. Direct antibacterial activity of the composites was also determined. De novo frequencies of microorganisms in five saffron samples were at acceptable levels with dominance of fungi species. Nanosilver embedded packages accelerated the reduction in live microbial numbers in saffron samples and the efficacy was the best in packages containing 4000 ppm nanosilver particles. Nanosilver packaging can significantly reduce microbial burden of saffron.

Effect of long-term exposure to mobile phone radiation on alpha-Int1 gene sequence of Candida albicans.

Over the last decade, communication industries have witnessed a tremendous expansion, while, the biological effects of electromagnetic waves have not been fully elucidated. Current study aimed at evaluating the mutagenic effect of long-term exposure to 900-MHz radiation on alpha-Int1 gene sequences of Candida albicans. A standard 900 MHz radiation generator was used for radiation. 10 ml volumes from a stock suspension of C. albicans were transferred into 10 polystyrene tubes. Five tubes were exposed at 4 °C to a fixed magnitude of radiation with different time periods of 10, 70, 210, 350 and 490 h. The other 5 tubes were kept far enough from radiation. The samples underwent genomic DNA extraction. PCR amplification of alpha-Int1 gene sequence was done using one set of primers. PCR products were resolved using agarose gel electrophoresis and the nucleotide sequences were determined. All samples showed a clear electrophoretic band around 441 bp and further sequencing revealed the amplified DNA segments are related to alpha-Int1 gene of the yeast. No mutations in the gene were seen in radiation exposed samples. Long-term exposure of the yeast to mobile phone radiation under the above mentioned conditions had no mutagenic effect on alpha-Int1 gene sequence.

Highly Sensitive FRET-Based Fluorescence Immunoassay for Detecting of Aflatoxin B1 Using Magnetic/Silica Core-Shell as a Signal Intensifier.

BACKGROUND: Recently, some new nanobiosensors using different nanoparticles or microarray systems for detection of mycotoxins have been designed . However, rapid, sensitive and early detection of aflatoxicosis would be very helpful to distinguish high-risk persons. OBJECTIVES: We report a highly sensitive competitive immunoassay using magnetic/silica core shell as a signal intensifier for the determination of aflatoxin B1 using fluorescence resonance energy transfer (FRET) from Cd/Te quantum dots (antiaflatoxin B1 antibody immobilized on the surface of Cd/Te quantum dots) to Rhodamine 123 (Rho 123-labeled aflatoxin B1 bound to albumin). The specific immune-reaction between the anti-aflatoxin B1 antibody on the QDs and the labeledaflatoxin B1 brings the Rho 123 fluorophore (acting as the acceptor) and the QDs (acting as the donor) in close spatial proximity and causes FRET to occur upon photo-excitation of the QDs. Using magnetic/silica core shell to intensify the obtained signal is the novelty of this study. MATERIALS AND METHODS: Cd/Te QDs were synthesized by the simultaneous reduction of cadmium chloride and tellurium in the presence of sodium borohydride under nitrogen atmosphere. Magnetic nanoparticles were synthesized using FeSO4 and FeCl3 (1:2 molar ratio) and ammonia as an oxidizing agent under nitrogen atmosphere. The prepared magnetic nanoparticles shelled by silica using tetraethoxysilane in the presence of ammonia. Nanoparticles synthesis and monodispersity confirmed by TEM. Immobilization of Cd/Te QDs to antibodies and labeling of aflatoxin B1-albumin by Rho 123 were performed by EDC/NHS reaction in reaction mixture buffer, pH 6, at room temperature. RESULTS: By using the magnetic/silica core shell sensitivity of the system changed from 2×10-11 in our previous study to 2×10-12 in this work. The feasibility of the method established by the detection of aflatoxin B1 in spiked human serum. There is a linear relationship between the decreased fluorescence intensity of Rho 123 with increasing concentration of aflatoxin B1 in spiked samples, over the range of 0.01-0.06 µmol.mL-1. CONCLUSIONS: This homogeneous competitive detection scheme is simple, rapid and efficient, and does not require multiple separation steps and excessive washing.

Antibacterial Effect of Garlic Aqueous Extract on Staphylococcus aureus in Hamburger.

BACKGROUND: Using garlic is widespread in Iran and other countries as a medicine and a natural spice. Garlic is a potential inhibitor for food pathogens. Foods contaminated with pathogens pose a potential danger to the consumer's health. The use of garlic can increase the shelf life and decrease the possibilities of food poisoning and spoilage in processed foods. OBJECTIVES: The aim of this study was to investigate the antibacterial effect of garlic aqueous extract on growth of Staphylococcus aureus bacteria. MATERIALS AND METHODS: In this study, the garlic aqueous extract was prepared under sterile conditions and was added in 1, 2, and 3 mL to 100g hamburger samples. A group of samples was prepared to be used as treatment sample, while a group was stored at 4°C and -18°C. The samples were kept in refrigerator for one and two weeks and they were frozen for one, two and three months and then subjected to microbial tests. RESULTS: Statistical evaluation of the first and second week samples indicated a significant growth decreased by all the 1, 2, and 3-mL extracts. In treatment of one, two and three-month samples, the growth of S. aureus was significantly decreased by the 2 and 3-mL extracts. The 1-mL extract was effective in decreasing the growth, and a significant difference was observed in treatments with 2 and 3-mL extracts. However, there was no significant difference between the two and three-month samples, though they were significantly different from the one-month samples. After evaluations, treatment with the 2-mL extract was found to be the best one. CONCLUSIONS: Garlic aqueous extract has antibacterial properties against S. aureus present in hamburger. Moreover, garlic aqueous extract can be used not only as a flavor but also as a natural additive for hamburger. In addition, garlic has antibacterial properties against other Gram-positive and Gram-negative bacteria, which must be investigated in further studies.

Isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings.

BACKGROUND: Invasive fungal infections cause considerable morbidity and mortality in immunocompromised hosts. Pigeon droppings could especially be a potential carrier in the spread of pathogenic yeasts and mold fungi into the environment. The objective of this study was to isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings. MATERIALS AND METHODS: One hundred twenty samples of pigeon droppings were suspended 1:10 in saline solution and then cultured. Identification of C. neoformans was performed on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium and RapID yeast plus system. The identification of candida species was based on micro-morphological analysis on corn meal-Tween 80 agar, RapID yeast plus system and growth in CHROMagar candida. The identification of other fungi was based on macromorphologic, microscopic, biochemical and physiological characteristics. RESULTS: The highest frequency of yeasts and mold fungi were observed in Candida albicans 6.6% and Penicillium spp. 25%. The frequency rate of C. neoformans isolation was 2.5%. CONCLUSION: Several types of fungi are present in pigeon droppings that can spread in environment and transmit to children and elderly as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.