Aspergilli and their aflatoxins contamination of poultry and animal feedstuff samples in western region of Saudi Arabia

Aspergillus and their aflatoxins contaminations were studied in sixty poultry and animal feedstuff samples collected from the western region (Jeddah, Makkah and Taif cities) from Saudi Arabia. Fourteen species of Aspergillus were isolated and identified in the present investigation using Potato Dextrose Agar (PDA) at 27ºC. The identification of isolated Aspergillus was confirmed by using internal transcribed spacer (ITS) region sequencing for representative species (194 species) of the collected Aspergillus sp. were sequenced and the obtained sequence results were deposited in Gene Bank under accession numbers. The sequence results indicated to the full correspondence between the molecular identification of the isolated fungi and the morphological identification. Moisture content was considered indicator for the number of Aspergillus isolated, therefore, Aspergillus and their aflatoxins were isolated in high counts from Jeddah and Taif according to the moisture content. Therefore, A. flavus was the most common species (59.78%), followed by A. niger (21.59%). The co-occurrence of Aspergillus species ranged from one species to 6 species per sample. The frequencies of occurrence for most afltoxigenic species isolated from studied samples ranged from 2 to 56%. Aspergillus flavus contaminated the majority of investigated feedstuff samples and the co-occurrence of more than one aflatoxigenic species was reported in many samples

Natural occurrence of Alternaria toxins in pomegranate fruit and the influence of some technological processing on their levels in juice

Alternaria species produce several mycotoxins that are of particular health concern. The natural occurrence of three Alternaria toxins; alternariol (AOH), alternariol methyl ether (AME), and tenuazonic acid (TA) in pomegranate fruit was considered. A. alternata and A. tenuissima were identified by analysis of partial sequence of ITS-region. All studied strains produced high quantities of AOH in vitro on rice. A. tenuissima produces high quantities of AME and TA compared with A. alternata. In rotten tissues AME was the highest determined toxin with frequency percentage of 95.6%, followed by AOH and TA. All toxins were detected in the healthy tissues surrounding the infected tissues but at low levels. No visible changes were noted in Alternaria toxins after pasteurization of pomegranate juice, but they appeared after clarification. In conclusion, pasteurization and/or clarification are not sufficient to reduce Alternaria toxins in juice. The removal of the rotten parts does not ensure excluding Alternaria toxins

Detoxification of toxic phorbol esters from Malaysian Jatropha curcas Linn. kernel by Trichoderma spp. and endophytic fungi

The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05) removed PEs with percentage losses of 96.9%–99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%–92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%–96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs

Genetic heterogeneity of CTX-M type extended-spectrum ß-lactamase producing Escherichia coli strains from diverse sources in Saudi Arabia

Background: The rise of CTX-M extended spectrum β-lactamase (ESBLs)-producing E. coli in non-human sources is a growing concern of public health. Understanding the extent of public health risk attributed to CTX-M type ESBLs-producing strains from different sources is critical for effective control.Objective: This study focuses on detection and molecular typing of CTX-M type ESBL-producing E. coli isolated from various sources in Taif, Western Saudi Arabia. Material and Methods: A total of 24 E. coli ESBLs-producing isolates from multiple sources were assessed for the presence of CTX-M groups gene by PCR, and subsequently their clonal relatedness by random amplifid of polymorphic DNA (RAPD) analysis. Isolates were selected according to a resistance phenotype consistent with production of ESBL-type beta-lactamase using double disk diffusion method.Results: A CTX-M gene was detected in all 24 isolates. RAPD typing of E. coli isolates bearing CTX-M gene showed 24 patterns verifid into two major clusters (A, B) and three sub-clusters (A1 – A3). Phylogenetic analysis indicating a degree of similarity among clustering isolates from human, sheep and raw milk origins. Identical profie was observed between three isolates obtained from pet bird and chicken

Species diversity of Trichoderma in Poland

In the present study, we reinvestigate the diversity of Trichoderma in Poland utilizing a combination of morphological and molecular/phylogenetic methods. A total of 170 isolates were collected from six different substrata at 49 sites in Poland. These were divided among 14 taxa as follows: 110 of 170 Trichoderma isolates were identified to the species level by the analysis of their ITS1, ITS2 rDNA sequences as: T. harzianum (43 isolates), T. aggressivum (35), T. citrinoviride (11), T. hamatum (9), T. virens (6), T. longibrachiatum (4), T. polysporum (1), and T. tomentosum (1); 60 isolates belonging to the Viride clade were identified based on a fragment of the translation-elongation factor 1-alpha (tef1) gene as: T. atroviride (20 isolates), T. gamsii (2), T. koningii (17), T. viridescens (13), T. viride (7), and T. koningiopsis (1). Identifications were made using the BLAST interface in TrichOKEY and TrichoBLAST (http://www.isth.info). The most diverse substrata were soil (nine species per 22 isolates) and decaying wood (nine species per 75 isolates). The most abundant species (25%) isolated from all substrata was T. harzianum

Assimilation of alternative sulfur sources in fungi

Fungi are well known for their metabolic versatility, whether it is the degradation of complex organic substrates or the biosynthesis of intricate secondary metabolites. The vast majority of studies concerning fungal metabolic pathways for sulfur assimilation have focused on conventional sources of sulfur such as inorganic sulfur ions and sulfur-containing biomolecules. Less is known about the metabolic pathways involved in the assimilation of so-called “alternative” sulfur sources such as sulfides, sulfoxides, sulfones, sulfonates, sulfate esters and sulfamates. This review summarizes our current knowledge regarding the structural diversity of sulfur compounds assimilated by fungi as well as the biochemistry and genetics of metabolic pathways involved in this process. Shared sequence homology between bacterial and fungal sulfur assimilation genes have lead to the identification of several candidate genes in fungi while other enzyme activities and pathways so far appear to be specific to the fungal kingdom. Increased knowledge of how fungi catabolize this group of compounds will ultimately contribute to a more complete understanding of sulfur cycling in nature as well as the environmental fate of sulfur-containing xenobiotics