Pitiose nasal em equino

Pythiosis is a subcutaneous infection caused by aquatic fungi (Pythium insidiosum) which occurs in some animal species, as human beings. This paper describes an Quarter Horse, breed in Pernambuco, Brazil, who had this infection. The horse presented nodular and ulcerated lesions only in nasal mucosa and the diagnosis was made by histopathologic analysis and clinical signals. Based in the histopathologic findings and anamneses information by the owner the authors believed this is an atypical presentation of this infection caused by the contact with water offered at stable.

Combining Plant Pathogenic Fungi and the Leaf-Mining Fly, Hydrellia pakistanae, Increases Damage to Hydrilla

Four fungal species, F71PJ Acremonium sp., F531 Cylindrocarpon sp., F542, Botrytis sp., and F964 Fusarium culmorum [Wm. G. Sm.] Sacc. were recovered from hydrilla [ Hydrilla verticillata (L. f.) Royle] shoots or from soil and water surrounding hydrilla growing in ponds and lakes in Florida and shown to be capable of killing hydrilla in a bioassay. The isolates were tested singly and in combination with the leaf-mining fly, Hydrellia pakistanae (Diptera: Ephydridae), for their capability to kill or severely damage hydrilla in a bioassay.

Nitrogen fixing bacteria, Azotobacter sp. in aquatic sediment

Non-symbiotic, free living, nitrogen fixing bacteria, Azotobacter sp. was estimated in sediments of estuarine, marine, backwater and mangrove environments of Portonovo. Number of colony forming units (CFU) of Azotobacter sp. was less (5 to 27 cells/g of dry sediment). CFU of total heterotrophic bacteria (THB), actinomycetes and fungi were between 4.1x10 super(6) and 4.5x10 super (7), 0.8x10 super(5) and 4.9x10 super(5), 1.1x10 super(5) and 3.8x10 super(5)/g respectively. Mangrove sediments contained more CFU of the above microbial groups.

Agrobacterium tumefasciens-mediated transformation of the aquatic fungus Blastocladiella emersonii

Agrobacterium tumefaciens is widely used for plant DNA transformation and more recently, has also been used to transform yeast, filamentous fungi and even human cells. Using this technique, we developed the first transformation protocol for the saprobic aquatic fungus Blastocladiella emersonii, a Blastocladiomycete localized at the base of fungal phylogenetic tree, which has been shown as a promising and interesting model of study of cellular function and differentiation. We constructed binary T-DNA vectors containing hygromycin phosphotransferase (hph) or enhanced green fluorescent protein (egfp) genes, under the control of Aspergillus nidulans trpC promoter and terminator sequences. 24 h of co-cultivation in induction medium (IM) agar plates, followed by transfer to PYG-agar plates containing cefotaxim to kill Agrobacterium tumefsciens and hygromycin to select transformants, resulted in growth and sporulation of resistant transformants. Genomic DNA from the pool o resistant zoospores were shown to contain T-DNA insertion as evidenced by PCR amplification of hph gene. Using a similar protocol we could also evidence the expression of enhanced green fluorescent protein (EGFP) in zoospores derived from transformed cells. This protocol can also open new perspectives for other non-transformable closely related fungi, like the Chytridiomycete class. (C) 2011 Elsevier Inc. All rights reserved.

An analysis of publications on invasive macrophytes in aquatic ecosystems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative EST analysis provides insights into the basal aquatic fungus Blastocladiella emersonii

Abstract Background Blastocladiella emersonii is an aquatic fungus of the Chytridiomycete class, which is at the base of the fungal phylogenetic tree. In this sense, some ancestral characteristics of fungi and animals or fungi and plants could have been retained in this aquatic fungus and lost in members of late-diverging fungal species. To identify in B. emersonii sequences associated with these ancestral characteristics two approaches were followed: (1) a large-scale comparative analysis between putative unigene sequences (uniseqs) from B. emersonii and three databases constructed ad hoc with fungal proteins, animal proteins and plant unigenes deposited in Genbank, and (2) a pairwise comparison between B. emersonii full-length cDNA sequences and their putative orthologues in the ascomycete Neurospora crassa and the basidiomycete Ustilago maydis. Results Comparative analyses of B. emersonii uniseqs with fungi, animal and plant databases through the two approaches mentioned above produced 166 B. emersonii sequences, which were identified as putatively absent from other fungi or not previously described. Through these approaches we found: (1) possible orthologues of genes previously identified as specific to animals and/or plants, and (2) genes conserved in fungi, but with a large difference in divergence rate in B. emersonii. Among these sequences, we observed cDNAs encoding enzymes from coenzyme B12-dependent propionyl-CoA pathway, a metabolic route not previously described in fungi, and validated their expression in Northern blots. Conclusion Using two different approaches involving comparative sequence analyses, we could identify sequences from the early-diverging fungus B. emersonii previously considered specific to animals or plants, and highly divergent sequences from the same fungus relative to other fungi.

Experiment: Marine fungi may benefit from ocean acidification

Recent studies have discussed the consequences of ocean acidification for bacterial processes and diversity. However, the decomposition of complex substrates in marine environments, a key part of the flow of energy in ecosystems, is largely mediated by marine fungi. Although marine fungi have frequently been reported to prefer low pH levels, this group has been neglected in ocean acidification research. We present the first investigation of direct pH effects on marine fungal abundance and community structure. In microcosm experiments repeated in 2 consecutive years, we incubated natural North Sea water for 4 wk at in situ seawater pH (8.10 and 8.26), pH 7.82 and pH 7.67. Fungal abundance was determined by colony forming unit (cfu) counts, and fungal community structure was investigated by the culture-independent fingerprint method Fungal Automated Ribosomal Intergenic Spacer Analysis (F-ARISA). Furthermore, pH at the study site was determined over a yearly cycle. Fungal cfu were on average 9 times higher at pH 7.82 and 34 times higher at pH 7.67 compared to in situ seawater pH, and we observed fungal community shifts predominantly at pH 7.67. Currently, surface seawater pH at Helgoland Roads remains >8.0 throughout the year; thus we cannot exclude that fungal responses may differ in regions regularly experiencing lower pH values. However, our results suggest that under realistic levels of ocean acidification, marine fungi will reach greater importance in marine biogeochemical cycles. The rise of this group of organisms will affect a variety of biotic interactions in the sea.

Unexpected homology between inducible cell wall protein QID74 of filamentous fungi and BR3 salivary protein of the insect Chironomus

A gene, qid74, of mycoparasitic filamentous fungus Trichoderma harzianum and its allies encodes a cell wall protein that is induced by replacing glucose in the culture medium with chitin (simulated mycoparasitism conditions). Because no trace of this gene can be detected in related species such as Gibberella fujikuroi and Saccharomyces cerevisiae, the qid74 gene appears to have arisen de novo within the genus Trichoderma. Qid74 protein, 687 residues long, is now seen as highly conserved tandem repeats of the 59-residue-long unit. This unit itself, however, may have arisen as tandem repeats of the shorter 13-residue-long basic unit. Within the genus Trichoderma, the amino acid sequence of Qid74 proteins has been conserved in toto. The most striking is the fact that Qid74 shares 25.3% sequence identity with the carboxyl-terminal half of the 1,572-residue-long BR3 protein of the dipteran insect Chironomus tentans. BR3 protein is secreted by the salivary gland of each aquatic larva of Chironomus to form a tube to house itself. Furthermore, the consensus sequence derived from these 59-residue-long repeating units resembles those of epidermal growth factor-like domains found in divergent invertebrate and vertebrate proteins as to the positions of critical cysteine residues and homology of residues surrounding these cysteines.

A functional screen identifies lateral transfer of beta-glucuronidase (gus) from bacteria to fungi

Lateral gene transfer (LGT) from prokaryotes to microbial eukaryotes is usually detected by chance through genome-sequencing projects. Here, we explore a different, hypothesis-driven approach. We show that the fitness advantage associated with the transferred gene, typically invoked only in retrospect, can be used to design a functional screen capable of identifying postulated LGT cases. We hypothesized that beta-glucuronidase (gus) genes may be prone to LGT from bacteria to fungi (thought to lack gus) because this would enable fungi to utilize glucuronides in vertebrate urine as a carbon source. Using an enrichment procedure based on a glucose-releasing glucuronide analog (cellobiouronic acid), we isolated two gus(+) ascomycete fungi from soils (Penicillium canescens and Scopulariopsis sp.). A phylogenetic analysis suggested that their gus genes, as well as the gus genes identified in genomic sequences of the ascomycetes Aspergillus nidulans and Gibberella zeae, had been introgressed laterally from high-GC gram(+) bacteria. Two such bacteria (Arthrobacter spp.), isolated together with the gus(+) fungi, appeared to be the descendants of a bacterial donor organism from which gus had been transferred to fungi. This scenario was independently supported by similar substrate affinities of the encoded beta-glucuronidases, the absence of introns from fungal gus genes, and the similarity between the signal peptide-encoding 5' extensions of some fungal gus genes and the Arthrobacter sequences upstream of gus. Differences in the sequences of the fungal 5' extensions suggested at least two separate introgression events after the divergence of the two main Euascomycete classes. We suggest that deposition of glucuronides on soils as a result of the colonization of land by vertebrates may have favored LGT of gus from bacteria to fungi in soils.

Networked aquatic microbial observing systems: An overview

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Assessing genetic diversity in cultured aquatic species : the Sydney Rock Oyster (Saccostrea glomerata) stock improvement program as a model

Genetic variation is the resource animal breeders exploit in stock improvement programs. Both the process of selection and husbandry practices employed in aquaculture will erode genetic variation levels overtime, hence the critical resource can be lost and this may compromise future genetic gains in breeding programs. The amount of genetic variation in five lines of Sydney Rock Oyster (SRO) that had been selected for QX (Queensland unknown) disease resistance were examined and compared with that in a wild reference population using seven specific SRO microsatellite loci. The five selected lines had significantly lower levels of genetic diversity than did the wild reference population with allelic diversity declining approximately 80%, but impacts on heterozygosity per locus were less severe. Significant deficiencies in heterozygotes were detected at six of the seven loci in both mass selected lines and the wild reference population. Against this trend however, a significant excess of heterozygotes was recorded at three loci Sgo9, Sgo14 and Sgo21 in three QX disease resistant lines (#2, #5 and #13). All populations were significantly genetic differentiated from each other based on pairwise FST values. A neighbour joining tree based on DA genetic distances showed a clear separation between all culture and wild populations. Results of this study show clearly, that the impacts of the stock improvement program for SRO has significantly eroded natural levels of genetic variation in the culture lines. This could compromise long-term genetic gains and affect sustainability of the SRO breeding program over the long-term.

Systematics of the Ustilago-Sporisorium-Macalpinomyces complex of smut fungi

Smut fungi are important pathogens of grasses, including the cultivated crops maize, sorghum and sugarcane. Typically, smut fungi infect the inflorescence of their host plants. Three genera of smut fungi (Ustilago, Sporisorium and Macalpinomyces) form a complex with overlapping morphological characters, making species placement problematic. For example, the newly described Macalpinomyces mackinlayi possesses a combination of morphological characters such that it cannot be unambiguously accommodated in any of the three genera. Previous attempts to define Ustilago, Sporisorium and Macalpinomyces using morphology and molecular phylogenetics have highlighted the polyphyletic nature of the genera, but have failed to produce a satisfactory taxonomic resolution. A detailed systematic study of 137 smut species in the Ustilago-Sporisorium- Macalpinomyces complex was completed in the current work. Morphological and DNA sequence data from five loci were assessed with maximum likelihood and Bayesian inference to reconstruct a phylogeny of the complex. The phylogenetic hypotheses generated were used to identify morphological synapomorphies, some of which had previously been dismissed as a useful way to delimit the complex. These synapomorphic characters are the basis for a revised taxonomic classification of the Ustilago-Sporisorium-Macalpinomyces complex, which takes into account their morphological diversity and coevolution with their grass hosts. The new classification is based on a redescription of the type genus Sporisorium, and the establishment of four genera, described from newly recognised monophyletic groups, to accommodate species expelled from Sporisorium. Over 150 taxonomic combinations have been proposed as an outcome of this investigation, which makes a rigorous and objective contribution to the fungal systematics of these important plant pathogens.

Neutrophilic, microaerophilic Fe(II)-oxidizing bacteria are ubiquitous in aquatic habitats of a subtropical Australian coastal catchment (ubiquitous FeOB in catchment aquatic habitats)

We examined the abundance and distribution of neutrophilic, microaerophilic Fe(II)-oxidizing bacteria (FeOB) in aquatic habitats of a highly weathered, subtropical coastal catchment where Fe biogeochemistry is of environmental significance. Laboratory cultivation and microscopy indicated that stalked Gallionella and sheathed Leptothrix-like FeOB were present in microbial mats associated with a circumneutral-pH, groundwater seep and streambank surface sediment,whereas unicellular FeOB werewidespread in surface and subsurface waters, including a seep, shallow stream and estuary-adjacent groundwater. Direct Gallionella-specificPCR detected dominant bacterial members related to Sideroxydans paludicola (95% sequence identity, SI) and Gallionella capsiferriformans (96% SI) in the seep microbialmat. TGGE analysis indicated that themost common FeOB in water enrichment cultures were related to S. lithotrophicus (96% SI). The ubiquity of FeOB in Poona catchment aquatic habitats suggests bacterial Fe(II) oxidation is integral to catchment Fe biogeochemistry.