• Cereal and its products can be contaminated with fungi in the field, during drying, processing, transportation and subsequent storage, which may lead to secretion of mycotoxins under favourable condition. The aim of this study was the isolation and identification of some fungi associated with four kinds of Libyan food products of different trademarks. Twenty four (24) samples of couscous, macaroni, wheat flour and rice regularly used for human consumption by Libyan family were collected from local markets in the city of Alzawia, west of Tripoli, Libya. The results reveal isolation of 113 isolates belonging to nine genera: Penicillium, Aspergillus, Fusarium, Paecilomyces, Alternaria, Rhizopus, Mucor, Scopulariopsis and Cladosporum. Approximately 24 species were identified to belong to those isolated genera, several of which are known as main producer of mycotoxins especially A. flavus which are known to produce aflatoxins, Aspergillus niger, Aspergillus carbonarious, Penicillium chrysogenum and Penicillium verrucosum known to produce ochratoxin and Fusarium oxysporum and Fusarium chlamydosporum known to produce fumonisins and trichothecenes. Certainly, the occurrence of such types of mycotoxins can pose a health threatening risk for the consumer of those food items. Presence of these fungi in food products could be due to lack of good agriculture and food manufacturing practices throughout the food chain.
• Key words: Couscous, macaroni, wheat flour, rice, fungi, Libya.

Background

The use of mosquito coils is a common method of protection against mosquito bites and mosquito borne diseases. These coils are widely marketed and used by households in Malaysia to prevent mosquito associated problems.

Objective

To determine the bioefficacy of commercial d-allethrin and d-trans allethrin spatial repellents against the dengue vector Aedes aegypti.

Method

We evaluated the knockdown and mortality effects of spatial repellents containing d-allethrin (0.3% w/w) and d-trans allethrin (0.1% and 0.15% w/w) on Ae. aegypti in a Peet Grady Chamber, relative to a reference product (0.2% w/w d-allethrin).

Results

The spatial repellent containing 0.3% d-allethrin had the shortest knockdown times (KT₅₀ and KT₉₀) and these were significantly different from the other products including the reference coil except the 0.15% d-trans allethrin coil. The spatial repellent containing 0.3% d-allethrin elicited a mortality response of 96%, which was significantly different from the mortality response to the other coils, except for the 0.15% d-trans allethrin formulation.

Conclusions

Spatial repellents containing 0.3% d-allethrin or 0.15% d-trans allethrin had higher efficacies against Ae. aegypti than repellents containing 0.2% w/w d-allethrin or 0.1% d-trans allethrin and their use by households could offer better relief from Ae. aegypti

Abstract

Aims: In the present work, the Libyan wild-growing Thymus capitatus essential oil (EO) was evaluated for its biological properties.

Methods and results: Carvacrol (68.19%) and thymol (12.29%) were found to be the main compounds of the oil. Antioxidant properties, determined by 2,2-diphenylpicrylhydrazyl (DPPH) assay, revealed that IC50 values were 119, 403 and 105 μg ml(-1) for oil, thymol and carvacrol respectively. Microdilution method showed strong antibacterial and especially antifungal potential. Tetrazolium (MTT) colorimetric assay indicated moderate cytotoxicity towards human cell lines MRC-5, HCT 116 and HT-29 (IC50 = 30-150 μg ml(-1)). In adhesion-inhibition assay oil and main compounds reduced adhesion of Escherichia coli and Listeria monocytogenes on colon cells HT-29 (51 and 39% of inhibition against L. monocytogenes and E. coli respectively).

Conclusions: Essential oil of Th. capitatus showed moderate cytotoxic activity, together with excellent antimicrobial effect, in particular against fungi, and significant potential to reduce pathogen colonization in colon.

Abstract: The essential oils obtained by hydrodistillation from the aerial parts of Artemisia judaica L., Artemisia herbaalba Asso. and Artemisia arborescens L. (cultivated) from Libya, were analyzed by GC and GC-MS. The antimicrobial properties were determined using the broth microdilution method against eight bacterial species: Bacillus cereus (clinical isolate), Micrococcus flavus (ATCC10240), Listeria monocytogenes (NCTC7973), Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC35210), Pseudomonas aeruginosa (ATCC27853), Salmonella typhimurium (ATCC13311), Enterobacter cloacae (human isolates) and eight fungal species: Aspergillus niger (ATCC6275), A. ochraceus (ATCC12066), A. versicolor (ATCC11730), A. fumigatus (ATCC1022), Penicillium ochrochloron (ATCC9112), P. funiculosum (ATCC10509), Trichoderma viride (IAM5061) and Candida albicans (human isolate). The major constituents of A. arborescens oil were sesquiterpene hydrocarbons (47.4%). Oxygenated monoterpenes were the dominant constituents in the A. judaica and A. herba-alba oils (54.2% and 77.3%, respectively). Camphor (24.7%) and chamazulene (20.9%) were the major components in the essential oil of A. arborescens, chrysanthenone (20.8%), cis-chrysanthenyl acetate (17.6%) and cis-thujone (13.6%) dominated in the A. herba-alba oil, and the major constituents in the A. judaica oil were piperitone (30.21%) and cis-chrysanthenol (9.1%). The best antimicrobial activity was obtained for A. judaica oil and the lowest effect was noticed in A. arborescens oil. The effect of the tested oils was higher against Gram (+) than Gram (-) bacteria. All three oils showed the best antibacterial activity against Listeria monocytogenes and the lowest against Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, compared to streptomycin and ampicillin. All three oils showed better antifungal activities than ketoconazole, except A. arborescens oil against Aspergillus niger. Keywords: Artemisia judaica; Artemisia herba-alba; Artemisia arborescens; essential oils; antimicrobial activity

Mosquito coils are insecticides commonly used for protection against mosquitoes due to their toxic effects on mosquito populations. These effects on mosquitoes could induce the expression of metabolic enzymes in exposed populations as a counteractive measure. Cytochrome P450 family 4 (CYP4) are metabolic enzymes associated with a wide range of biological activities including insecticide resistance. In this study, the efficacies of three commercial mosquito coils with different pyrethroid active ingredients were assessed and their potential to induce the expression of CYP4 genes in Aedes albopictus analyzed by real-time quantitative PCR. Coils containing 0.3 % d-allethrin and 0.005 % metofluthrin exacted profound toxic effects on Ae. albopictus, inducing high mortalities (≥90 %) compared to the 0.2 % d-allethrin reference coil. CYP4H42 and CYP4H43 expressions were significantly higher in 0.3 % d-allethrin treated mosquitoes compared to the other treated populations. Short-term (KT50) exposure to mosquito coils induced significantly higher expression of both genes in 0.005 % metofluthrin exposed mosquitoes. These results suggest the evaluated products provided better protection than the reference coil; however, they also induced the expression of metabolic genes which could impact negatively on personal protection against mosquito.

Aromatic plant species of genus Thymus are important medicinal plants, highly recommended due to a range of therapeutic properties of their essential oils, commonly known as thyme oil: antirheumatic, antiseptic, antispasmodic, antimicrobial, cardiac, carminative, diuretic and expectorant. The oil is also beneficial in boosting the immune system and helps to fight colds, flu, infectious diseases and chills. It is proved to be a urinary antiseptic, being very helpful for cystitis and urethritis. Scientific validation of traditional uses, and phytochemical and bioactivity evaluation of essential oils from Thymus serpyllum, Thymus algeriensis and Thymus vulgaris were performed.

GC/MS analysis revealed thymol as a major component of T. algeriensis, T. vulgaris and T. serpyllum, with its contribution to the oil 56.0%, 48.9% and 38.5%, respectively. All three essential oils (EOs) exhibited a significant antimicrobial activity against all

Abstract- Botryodiplodia sp. AUMC 9468 was isolated in pure culture from canker on Ficus benjamina, on side of Ibraheemia bank stream at Assiut governorate, Egypt. The analysis of growth condition suggested the trees were stressed induced by light, nutrient and medium factors. This report is the first for Botryodiplodia canker on F. benjamina in Egypt. The pathogenicity test were resulted on that the fungus was introduced with the trees, penetrated through bark wounds, and incubated under conditions stressful to the well-being of the tree.

Keywords- Canker,Ficus benjamina, Botryodiplodia.

Abstract

Desert truffle, Tirmania pinoyi (Maire) Malençon from Libya was chemically characterized in nutritional value, primary and secondary metabolites. Antioxidant (scavenging activity, reducing power and inhibition of lipid peroxidation) and antibacterial activity of its methanolic extract alone and in combination with potassium metabisulfite (E224) were evaluated under in vitro conditions. Furthermore, the effect of the extract on the control of Staphylococcus aureus was examined in a contaminated soup under in situ conditions. T. pinoyi was shown to be rich in carbohydrates (82.60 g/100 g dw) and proteins (8.06 g/100 g dw), being identified four free sugars (rhamnose, fructose, trehalose and mannitol) and three tocopherol isoforms (β-, δ- and γ-tocopherols). Oleic (32.29%), linoleic (29.72%) and palmitic (27.97%) acids were the main fatty acids. p-Hydroxybenzoic (300.65 μg/100 g dw) and cinnamic (8.30 μg/100 g dw) acids were quantified, as also four organic acids: quinic (0.83 g/100 g dw), malic (0.35 g/100 g dw), fumaric (0.05 g/100 g dw) and citric (1.26 g/100 g dw) acids. The methanolic extract of the mushroom showed in vitro antioxidant and antimicrobial activities. Sterilized distillated water containing 0.02% Tween 80 proved to be the most convenient solvent for in situ antimicrobial activity; the extract successfully inhibited the growth of S. aureus in chicken soup in a dose dependent manner.

Cytochrome P450 is a group of heme-containing enzymes. They have been detected in virtually all organisms examined from bacteria to mammals. In insects, P450s are involved in the oxidative metabolism of a large number of exogenous compounds (xenobiotics) from natural or anthropogenic origins (plant allelochemicals and insecticides) and endogenous compounds such as steroid hormones ecdysteroid hormones and pheromones. Thus the P450s have an important role in controlling insect growth, development, and evolutionary adaptation to environments containing potentially toxic compounds. A novel cDNA clone encoding a cytochrome P450 gene has been isolated from the mosquito, Ae. aegypti strain VCRU. The cDNA is 1731 bp in length and has an open reading frame from 277 bp to 1647 bp encoding a protein of 529 aa. The classic heme-binding characteristic motifs of P450s (FXXGXRXCXG, RxxR and EVLR) are present and conserved in this gene. The EVDTFMFEGHDTT motif characteristic of CYP4 family is also found in this new gene. The full length cDNA clone for CYP4H28v2 is 98% identical to CYP4H28 of The Liverpool strain Ae. aegypti. So, we propose that  this is an allele of that gene.

The composition of essential oil isolated from Salvia fruticosa, wild growing in Libya, was analyzed by GC and GC-MS. Forty-five compounds could be identified. The essential oil contained 1,8-cineole (49.34%), camphor (7.53%), β-pinene (7.38%), myrcene (7.38%), α-pinene (5.15%), β-caryophyllene (4.13%) and α-terpineol (3.25). Antioxidant activity was analyzed using the DPP H free radical scavenging method and low antioxidant activity was found (IC50 = 15.53 mg/ml). The oil was also screened for its antimicrobial activity against eight bacteria (four Gram-negative and four Gram-positive) and eight fungi. The essential oil of S. fruticosa showed minimal inhibitory activity (MIC) at 0.125-1.5 mg/ml and bactericidal (MBC) at 0.5-2.0 mg/ml. In addition, it exhibited fungistatic (MIC) at 0.125-1.0 mg/ml and fungicidal effect (MFC) at 0.125-1.5 mg/ml