SignificanceWe present identification of the luciferase and enzymes of the biosynthesis of a eukaryotic luciferin from fungi. Fungi possess a simple bioluminescent system, with luciferin being only two enzymatic steps from well-known metabolic pathways. The expression of genes from the fungal bioluminescent pathway is not toxic to eukaryotic cells, and the luciferase can be easily co-opted to bioimaging applications. With the fungal system being a genetically encodable bioluminescent system from eukaryotes, it is now possible to create artificially bioluminescent eukaryotes by expression of three genes. The fungal bioluminescent system represents an example of molecular evolution of a complex ecological trait and with molecular details reported in the paper, will allow additional research into ecological significance of fungal bioluminescence.

A review of the research conducted during the past 30 years on the distribution, taxonomy, phylogeny, ecology, physiology and bioluminescence mechanisms of luminescent fungi is presented. We recognize 64 species of bioluminescent fungi belonging to at least three distinct evolutionary lineages, termed Omphalotus, Armillaria and mycenoid. An accounting of their currently accepted names, distributions, citations reporting luminescence and whether their mycelium and/or basidiomes emit light are provided. We address the physiological and ecological aspects of fungal bioluminescence and provide data on the mechanisms responsible for bioluminescence in the fungi.

The presence of Helicobacter DNA species has been investigated in the biliary epithelium of patients with biliary diseases. However, conflicting results have been observed that may have been due to the small number of subjects studied, difficulty in obtaining a healthy control group, absence of controlling for confounding factors, or differences among populations. Therefore, we investigated the presence of Helicobacter species by culture and nested PCR of 16S rRNA genes in gallbladder tissue and bile from 46 Brazilian subjects with and 18 without cholelithiasis. The control group was mainly composed of liver donors and of patients who had submitted to cholecystectomy as part of the surgical treatment for morbid obesity. No Helicobacter species were grown from the bile or gallbladder tissues. Helicobacter DNA was detected in the gallbladder tissue and bile from 31.3 and 42.9% of the patients, respectively. In a logistic regression model, cholelithiasis was positively and independently associated with the female gender (P ‫؍‬ 0.02), increasing age (P ‫؍‬ 0.002), and the presence of Helicobacter DNA in the gallbladder tissue (P ‫؍‬ 0.009). The presence of Helicobacter DNA in the bile was not associated with cholelithiasis (P ‫؍‬ 0.8). A significant association between the presence of Helicobacter DNA in the gallbladder epithelium and histological cholecystitis, even after adjusting for gender and age (P ‫؍‬ 0.002), was also observed. The sequences of the 16S rRNA genes were >99% similar to that of Helicobacter pylori. In conclusion, our results support the hypothesis that Helicobacter is associated with the pathogenesis of human cholelithiasis and cholecystitis.

Study of fungal bioluminescence mechanisms generates development of a multicolor enzymatic chemiluminescence system.

The babA2 and cagA genes were investigated in 208 Brazilian Helicobacter pylori strains. A strong association between babA2 and duodenal ulcer or gastric carcinoma was observed, even after adjusting for confounding factors, such as age, gender, and cagA status. cagA-positive strains were also independently associated with H. pylori-related diseases.Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. Although most infected persons remain asymptomatic, 15 to 20% of H. pylori-positive individuals will develop a peptic ulcer, gastric carcinoma, or mucosa-associated lymphoid tissue lymphoma (19). However, it remains unclear why only a minority of infected patients develop the severe associated diseases. This phenomenon may be due to differences in host genetics, environmental factors, and the virulence of bacterial strains.There is now evidence for the existence of different strains of H. pylori with different degrees of virulence (2,3,18). The cytotoxin-associated gene cagA was the first gene found to be differentially present in H. pylori isolates and is considered a marker for the presence of the cag pathogenicity island (4). In addition to other putative virulence properties encoded by the cag pathogenicity island, several genes of the island encode proteins, such as interleukin-8, that enhance the gastric inflammatory response to the infection.A cagA-positive status has been associated with severe clinical outcomes in some Western countries (3,14,18). Conversely, since the majority of H. pylori-infected individuals in Asian countries harbor cagA-positive strains, associations of cagA status and diseases are not observed in Asia (11,20). The recently described blood group antigen-binding adhesin BabA has been shown to mediate adherence of H. pylori to Lewis b (␣-1,3/4-difucosylated) receptors on gastric epithelium (8). Although three bab alleles have been identified (babA1, babA2, and babB), only the babA2 gene product is necessary for Lewis b binding activity (8,16). Studies in Western countries have demonstrated associations between babA2-positive status and duodenal ulcer as well as gastric carcinoma (7). However, in Asian countries, most of the circulating H. pylori strains are babA2 positive, whether or not they were isolated from asymptomatic or diseased patients (9,10,12,20). In addition to these differences between Western and Eastern countries, the prevalence of babA2-positive H. pylori strains also seems to vary among the Western populations, being much lower in patients from Portugal (13) than in those from Germany, the United States, or Colombia (7, 20). Since there are few studies on this subject, specifically evaluating patients with gastric carcinoma, the frequency of babA2 H. pylori strains may vary around the world and because the clinical relevance of babA2-positive strains has not been determined in Brazil, we investigated associations between babA2 and cagA genotypes and different H. pylori infection outcomes, adjusting for confounding factors.H Two ...

No abstract

Summary Bioluminescence, the creation and emission of light by organisms, affords insight into the lives of organisms doing it. Luminous living things are widespread and access diverse mechanisms to generate and control luminescence [1-5]. Among the least studied bioluminescent organisms are phylogenetically rare fungi – only 71 species, all within the ~9000 fungi of the temperate and tropical Agaricales Order - are reported from among ~100,000 described fungal species [6,7]. All require oxygen [8] and energy (NADH or NADPH) for bioluminescence, and are reported to emit green light (λmax 530 nm) continuously, implying a metabolic function for bioluminescence, perhaps as a by-product of oxidative metabolism in lignin degradation. Here, however, we report that bioluminescence from the mycelium of Neonothopanus gardneri is controlled by a temperature compensated circadian clock, the result of cycles in content/activity of the luciferase, reductase, and the luciferin that comprise the luminescent system. Because regulation implies an adaptive function for bioluminescence, a controversial question for more than two millenia [8-15], we examined interactions between luminescent fungi and insects [16]. Prosthetic acrylic resin “mushrooms”, internally illuminated by a green LED emitting light similar to the bioluminescence, attract staphilinid rove beetles (coleopterans) as well as hemipterans (true bugs), dipterans (flies), and hymenopterans (wasps and ants) at numbers far greater than dark control traps. Thus, circadian control may optimize energy use for when bioluminescence is most visible, attracting insects that can in turn help in spore dispersal, thereby benefitting fungi growing under the forest canopy where wind flow is greatly reduced.

The uncertainty about the possible involvement of a luciferase in fungal bioluminescence has not only hindered the understanding of its biochemistry but also delayed the characterization of its constituents. The present report describes how in vitro light emission can be obtained enzymatically from the cold and hot extracts assay using different species of fungi, which also indicates a common mechanism for all these organisms. Kinetic data suggest a consecutive two-step enzymatic mechanism and corroborate the enzymatic proposal of Airth and Foerster. Finally, overlapping of light emission spectra from the fungal bioluminescence and the in vitro assay confirm that this reaction is the same one that occurs in live fungi.