Study of fungal colonization of wheat kernels in Syria with a focus on Fusarium species

Wheat is one of the main crops in Mediterranean countries, and its cultivation has an important role in the Syrian economy. In Syria, Fusarium head blight (FHB) has not been reported so far. Mycological analysis of 48 samples of wheat kernels collected from cultivation areas with different climatic conditions were performed in 2009 and 2010. Fungal isolates were identified at the genus level morphologically; Fusarium species were characterized morphologically and by species-specific PCR. The most frequent fungal genera found were Alternaria spp. and Cladosporium spp., with frequencies of 24.7% and 8.1%, respectively, while the frequency of Fusarium spp. was 1.5% of kernels. Most frequent Fusarium species were F. tricinctum (30% of all Fusarium isolates), F. culmorum (18%), F. equiseti (14%) and F. graminearum (13%). The mycotoxin production potential of selected Fusarium isolates was assessed by HPLC-MS analysis of rice cultures; chemotyping by PCR was carried out for comparison. All six F. graminearum strains tested produced small amounts (<3 mg/kg) of nivalenol (NIV). All ten F. culmorum strains tested produced large amounts of trichothecenes (>100 mg/kg); four strains produced NIV and six strains produced deoxynivalenol (DON) and 3-acetyl-deoxynivalenol (3Ac-DON). PCR chemotyping lead to an oversimplified picture, because all 3Ac-DON chemotype strains produced more DON than 3Ac-DON; furthermore, the strongest NIV producers produced significant amounts of DON. All tested strains of F. culmorum, F. graminearum, F. pseudograminearum (two strains) and most F. equiseti strains (five of six strains) produced zearalenone. Grains of durum wheat were more frequently colonized by Fusarium spp. than grains of soft wheat. Incidence of Fusarium spp. in irrigated fields was higher than in rainfed fields. The incidence of Fusarium strains producing mycotoxins raises concerns about the risk of Fusarium head blight to Syria and its consequences for public healt

Determination of deoxynivalenol and nivalenol producing chemotypes of Fusarium graminearum isolated from durum wheat in different Italian regions

Durum wheat production in Italy is economically of great importance. Fusarium graminearum is the main fusarium head blight (FHB) causal agent in wheat, reducing both yield and grain quality. F. graminearum produces several mycotoxins and, among trichothecenes, deoxynivalenol (DON) and nivalenol (NIV) are the most studied for their toxicity towards humans and animals. DON-producing isolates can be further distinguished on the basis of the predominant acetyl-DON derivative in 3-acetyldeoxynivalenol (3-ADON) or 15acetyldeoxynivalenol (15-ADON). In order to evaluate possible mycotoxin contamination risks in food, it is very important to know which chemotype is the prevalent in a F. graminearum population. F. graminearum sensu stricto strains were collected from symptomatic durum wheat heads and grains of several naturally infected fields located mostly in Emilia – Romagna, The Marche, Lazio, Tuscany and Umbria. A multiplex PCR in the region of genes Tri12, located in the terminal gene cluster of trichothecenes, was used to characterize 187 single-spore isolates of F. graminearum as NIV, 3-ADON and 15-ADON chemotypes. All the three chemotypes were present in the F. graminearum population studied. The most frequent chemotype was 15-ADON (83.4%), followed by 3-ADON (10.7%) and NIV (5.9%). NIV-producing isolates were found only in Emilia-Romagna (3.5%), Umbria (33.3%) and The Marche (5.7%)

Lattice-Based Blind Signatures, Revisited

We observe that all previously known lattice-based blind signature schemes contain subtle flaws in their security proofs (e.g., Rückert, ASIACRYPT \u2708) or can be attacked (e.g., BLAZE by Alkadri et al., FC \u2720). Motivated by this, we revisit the problem of constructing blind signatures from standard lattice assumptions. We propose a new three-round lattice-based blind signature scheme whose security can be proved, in the random oracle model, from the standard SIS assumption. Our starting point is a modified version of the (insecure) BLAZE scheme, which itself is based Lyubashevsky\u27s three-round identification scheme combined with a new aborting technique to reduce the correctness error. Our proof builds upon and extends the recent modular framework for blind signatures of Hauck, Kiltz, and Loss (EUROCRYPT \u2719). It also introduces several new techniques to overcome the additional challenges posed by the correctness error which is inherent to all lattice-based constructions. While our construction is mostly of theoretical interest, we believe it to be an important stepping stone for future works in this area

Fusarium population in syrian wheat seeds.

Wheat is one of the main crops in Mediterranean countries and Fusarium Head Blight (FHB) is considered an important disease in the Mediterranean basin and worldwide (Stack, 1999; Logrieco et al., 2003). The causal agents are different Fusarium species, responsible for losses in grain quantity and quality as well as mycotoxin accumulation (i.e. deoxynivalenol - DON). Mycotoxin concentration in food and feed is strictly regulated by EU, since high levels are responsible for health hazards to humans and animals (Logrieco et al., 2003). Wheat cultivation (year 2007, 1667732 ha) has an important role in Syrian economy, but there are no published records on the epidemiological and etiological aspects of FHB syndrome. Based on these premises, we performed in vitro analysis on samples of wheat kernels (durum and bread), coming from different Syrian cultivated areas, being the seeds one of the main ways for FHB spread. Four hundred kernels per sample were analyzed following the methodology described by Prodi et al. (2009). All different fungal genera present on the kernels were identified at light microscope according to descriptions by Domsch et al. (1980). The Fusarium species were morphologically identified (Leslie and Summerell, 2006) and for some of them PCR techniques, using specific primers, were applied to confirm the morphological identification. The data obtained revealed that Alternaria and Cladosporium were the most frequent fungal genera isolated in the kernel samples examined while Fusarium spp. were present in low percentage. F. culmorum, F. equiseti-incarnatum complex, F. oxysporum and F. tricinctum were the species found. The strains of F. culmorum, one of the most common worldwide pathogens for FHB, were examined for chemotypes based on the presence of gene for mono- acetylated DON derivatives (3-ADON, 15-ADON) and nivalenol (NIV)

Fusarium verticillioides and F. proliferatum from Syrian wheat grains: fumonisin production

Fusarium species are predominantly found associated with Fusarium head blight in wheat and other small-grain cereals all over the world. F. verticillioides (Fv) and F. proliferatum (Fp), the less frequently encountered species, are less pathogenic but toxigenic. The occurrence of these species in harvested wheat and cereals grains could indicate the presence of fumonisin mycotoxins. The risks of the consumption of fumonisin contaminated grains must not be ignored. In Syria, wheat is the main strategic crop and its two main products, bread and bulgur, are common food stuffs. The average consumption of bread per capita per month is 12.9 Kg. The aim of the study was to detect the presence of fumonisins in Syrian wheat grains and the ability of Fv and Fp in their production. Fourty-eight grain samples of durum and soft wheat were collected from different Syrian areas during years 2009 and 2010. Mycological analysis was performed on four hundred kernels for each sample. All Fusarium isolates were studied morphologically and molecularly, and then screened for their ability in producing mycotoxins in wheat cultivation. Fusarium infected samples were analyzed also for mycotoxin content using HPLC\u2013MS/MS. The data revealed that F. verticillioides and F. proliferatum were present in Syrian wheat grains with frequencies of 10.4% and 8.0%, respectively towards the total of Fusarium population. All the strains were able to produce fumonisins B1, B2, B3 (FB1, FB2, FB3), and 10 % of the grain samples were contaminated with low levels of FB1, FB2

Presence of deoxynivalenol and nivalenol chemotypes of Fusarium culmorum isolated from durum wheat in some Italian regions

Durum wheat production in Italy is economically of great importance. Fusarium Head Blight (FHB) is considered an important worldwide disease on wheat and in Italy it causes serious damages in terms of yields and quality of harvested grains. Fusarium culmorum, one of the main causal agents of FHB, is spread in all the Italian regions, but especially in the center-northern areas. It produces mycotoxins, such as Deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEA), potential health hazards for both humans and animals. In this work, it has been studied a population of F. culmorum strains, isolated from durum wheat grains collected from some Italian regions, mainly Emilia Romagna and Tuscany, but also Basilicata, Umbria and the Marche. A multiplex PCR assay, based on primers derived from the Tri3 and Tri7 genes of the trichothecene gene cluster was used to assign a strain to one of the following trichothecene chemotype profiles: NIV, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON). Almost the totality of the strains belonged to 3-ADON chemotype, only a few to NIV, while 15-ADON chemotype strain was not found. This work allowed us to better understand the presence of F. culmorum chemotypes. Knowledge on the distribution of F. culmorum chemotypes is quite important, on a regional basis, to predict a possible contamination by mycotoxins in food and feed

Mycotoxigenic Fusarium populatin in Syrian wheat kernels

The genus Fusarium is a widespread phytopathogenic fungi, including several species able to produce high toxic compounds. Fusarium graminearum and F. culmorum (type B trichothecene-producers), F. sporotrichioides, F. poae and F. equiseti (type A) are among the main trichothene-producing Fusarium species. Tricothecenes are potent inhibitors of eukaryotic protein synthesis through ingestion contaminated food and feed (Desjardin, 2006). All the above cited species are common fungal pathogens of cereals, and are causal agents of Fusarium head blight (FHB) in wheat.Wheat cultivation (year 2007, 1667732 ha) has an important role in Syrian economy, but there are no published records on the etiological aspects of FHB and the accumulation of mycotoxins. Based on these premises, we performed in vitro analysis on wheat kernels samples coming from different Syrian cultivated areas. Four hundred kernels per sample were analyzed following the methodology described by Prodi et al. (2009). All different fungal genera were identified at light microscope. The Fusarium species were morphologically identified (Leslie and Summerell, 2006) and qualitative PCR was performed on the genomic DNA of some strains to confirm the morphological identification. The data revealed that Alternaria spp. and Cladosporium spp. were the most frequent fungi (25.0% and 4.0%, respectively), while Fusarium spp. were present in low percentage (1.4%). F. culmorum, F. incarnatum-equiseti species complex (FIESC), Gibberella fujikuroi complex and F. tricinctum were identified. The strains of F. culmorum and FIESC were tested for their ability to produce trichothecenes, moreover, F. culmorum was characterized for chemotypes based on the presence of gene for mono- acetylated DON derivatives (3-ADON, 15-ADON) and nivalenol (NIV). The trichothecenes production gene was present in a large number of FIESC; the chemotype 3-ADON was mainly present (60%) in F. culmorum while 15-ADON was not detected. The first data of F. culmorum Syrian isolates were similar to those of an Italian population, where 3-ADON is the prevalent chemotype (Prodi et al., 2010)

Effects of processing and storage on aflatoxins levels in processed cheese from cheddar and fresh cheese.

Aflatoxins are secondary metabolites produced by some fungi such as Aspergillus parasiticus, A. flavus and A. nomius. They are the most potent carcinogenic compounds produced naturally (IARC, 1993). Aflatoxins M1 is a hydroxylated derivative of aflatoxin B1 which is secreted in the milk from animals fed with a contaminated feed. The dairy products, including cheese, are very suitable for the growth of fungi able to produce aflatoxins. Many controversial results have been published concerning the effects of processing and storage on the level of aflatoxin M1 in dairy products. The effect of manufacturing processes and storage on the level of aflatoxins has been studied, taking into consideration the lack of researches made in Syria about this topic, the climate, the poor storage conditions in a lot of stores. The work had two objectives: 1) isolation and morphological identification of fungi from cheddar and fresh cheese incubated at two different temperatures (4\ub0 and 25\ub0C); 2) determination of B1,B2,G1,G2,M1,M2 aflatoxin levels by HPLC (Sharman et al.,1993) in: a) A. flavus strain isolated from cheddar and fresh cheese; b) cheddar and fresh cheese samples inoculated with isolated A. flavus strain; c) the main components of processed cheese (i.e. inoculated cheese, butter, dry milk); d) processed cheese samples submitted at different treatments based on three parameters: d-1) temperatures of processing - one part of the samples were melted at 90 \ub0C, the other part after melting were transferred to 140\ub0C (UHT); d-2) temperatures of storage 4\ub0 and 25\ub0C; d-3) time of storage 1 and 30 days. The results brought to evidence the presence in the cheddar and fresh cheese samples assayed of a strain of toxigenic A. flavus, that was compared to a toxigenic strain used as reference. The toxin characterized was aflatoxin B1. The level of this toxin was less in the cheese inoculated compared to that of A. flavus strain grown in vitro. In the main components it was found aflatoxin M1. A significant reduction of aflatoxins levels was detected in both types of processed cheeses compared to the mix of the main components. The aflatoxin levels did not statistically differ in the parameters checked: temperatures of processing and storage, time of storage in both cheese, except in the case of M1 in processed cheese from fresh cheese

Natural co-occurrence of mycotoxins in wheat grains from Italy and Syria

This article describes the application of an analytical method for the detection of 25 mycotoxins in wheat grain based on simultaneous extraction using matrix solid-phase dispersion (MSPD) followed by liquid chromatography coupled to tandem mass spectrometry, a hybrid triple quadrupole-linear ion trap mass spectrometer (QTrap®). Information Dependent Acquisition (IDA), an extra confirmation tool for samples that contain the target mycotoxins, was used. The analysis of 40 Syrian and 46 Italian wheat grain samples interestingly showed that Syrian samples were mainly contaminated with ochratoxin A and aflatoxins, whereas Italian samples with deoxynivalenol and 15-acetyldeoxynivalenol. Emerging Fusarium mycotoxins were predominant in Italian samples compared to the Syrian. Among the analysed samples, only one was found containing zeralenone with level above the maximum European recommended concentration (100 ppb). These results confirm that climatic differences between Syria and Italy, both in Mediterranean basin, play a key role in the diversity of fungal genera and mycotoxins in wheat grains