Search

Abstract: Resistance to conventional antitumour therapies and Hypoxia in patients with advanced solid tumours are two major reasons for the failure of conventional anti-tumour therapies. Therefore, it is important to find a new therapeutic method that can overcome these problems. An attenuated anaerobic bacterium, Clostridium novyi-NT, could target Hypoxic and Necrotic areas of tumours causing tumour lysis and stimulating a host anti-tumour immune response. To the best of our knowledge, the combination of bacterial anti-tumour therapy, chemotherapy, radiotherapy and immunotherapy may promote tumour regression, inhibit metastasis and develop a new strategy for the treatment of solid tumours. However, the possible molecular mechanisms of the combined therapies are still the biggest challenge. This review provides an overview of the history of bacterial cancer therapy and the development of a non-lethal strain of Clostridium novyi. Below is a precise definition of Hypoxic conditions in solid tumour tissue. To understand the anticancer effect of Clostridium novyi-NT spores, possible cell death mechanisms were summarised by the enzyme phospholipase C (nt01cx0979), which is secreted by Clostridium novyi-NT spores after germination in tumour tissue. The function of Clostridium novyi-NT spores in stimulating the host immune system to elicit anti-tumour responses was reviewed. Then, the results of anti-tumour combination therapies based on Clostridium novyi-NT spores were compiled. Identifying the molecular mechanisms of Clostridium novyi-NT in treating tumours and inducing cell death in invasive cancer cells, ultimately leading to tumour regression, may develop promising clinical strategies in the combined treatment of solid tumours.

A new kind of Camellia sinensis-loaded nanocomposite hydrogel based on modified gelatin/iron-metal-organic framework was developed as an antibacterial wound dressing. Gelatin as a biocompatible natural polymer was modified with methacrylate anhydride to produce gelatin methacrylate. Thereafter, acrylic acid and acrylamide were grafted on gelatin methacrylate during an aqueous polymerization process. To enhance the porosity, mechanical strength, and drug loading capability of the hydrogel and reduce its toxicity, iron- based metal-organic framework was incorporated within the hydrogel. To add more functionality to the final wound dressing, Camellia sinensis, an antibacterial herbal drug was loaded on the hydrogel. The structural and chemical properties of prepared nanocomposite hydrogel were investigated by FTIR, XRD, SEM, and TGA techniques. The incorporation of iron-based metal-organic framework within the hydrogel matrix led to an increase in its water absorption value from 400.10 to 547.96 (g/g). The release study of Camellia sinensis (CS) extract from the prepared nanocomposite hydrogel exhibited a sustained release manner. The antibacterial test revealed the nanocomposite hydrogel contain extract has an effective antibacterial function against "Bacillus serous", "Staphylococcus aureus", "Streptococcus mutans"," Escherichia coli", "Klebsiella pneumoniae", and "Pseudomonas aeruginosa" bacteria. Therefore, the synthesized nanocomposite is a good candidate as an antibacterial hydrogel wound dressing. .

Background: Lipase is one of the most well-known and essential biocatalysts in the detergent, food, and pharmaceutical industries. Microbial lipase sources such as yeasts are applicable due to their stability in harsh conditions. Objective: In this study, the effect of temperature, initial pH, and incubation time were investigated to improve the extracellular lipase production by yeast, named Zygoascus hellenicus strain MZ_574439 T. Methods: Strain MZ_574439 T has already been isolated and registered from Iran. In the current project, strain MZ_574439 T with 99% similarity to Z. hellenicus was isolated from water samples. Results: Our findings showed that the isolated strain has a remarkable difference from its close phylogenetic species in the production of lipase and can produce extracellular lipase up to 7.2 U/ml while the Z. hellenicus has no ability of lipase production. The isolated strain was not able to produce other hydrolytic enzymes. The enzyme activity results showed that the best activity for the isolated lipase is pH= 7 and 37 °C. The best stability condition for the enzyme occurs at 50 °C and pH =7. Conclusion: From the current study, it can be concluded that Z. hellenicus produces lipase. The lipase enzyme production was optimized with different physiological conditions. Yeast extract could be a better source for maximum lipase production.

This study aimed to screen alpha-amylase producing microorganisms from honey as a low water activity medium, a suitable source for selecting stable and cost-beneficial bacterial enzyme production systems. Plackett–Burman method was used to select twelve effective factors including pH, inoculum size, temperature, time, corn starch, KH2PO4, peptone, MgSO4, CaCl2, NaCl, glycerin, and yeast extract concentrations on bacterial alpha-amylases production yield. The Box–Behnken method was utilized to optimize the level of selected significant factors. The stability of bacterial alpha-amylases was also determined in low pH and high-temperature conditions. In addition, in silico study was used to create the alpha-amylase structure and study the stability in high-temperature and low water available condition. Among all isolated and characterized microorganisms, Bacillus megaterium produced the highest amount of alpha-amylases. The in silico data showed the enzyme 3D structure similarity to alpha-amylase from Halothermothrix orenii and highly negative charge amino acids on its surface caused the enzyme activity and stability in low water conditions. Based on Box–Behnken results, the temperature 35 °C, pH 6 and starch 40 g/l were determined as the optimum level of significant factors to achieve the highest alpha-amylases unit (101.44 U/ml). This bacterial alpha-amylases enzyme showed stability at pH 5 and a range of temperatures from 40 to 60 °C that indicates this enzyme may possess the potential for using in industrial processes.

Alpha-amylase reputes for starch modification by breaking of 1-4 glycosidic bands and is widely applied in different industrial sectors. Microorganisms express unique alpha-amylases with thermostable and halotolerant characteristics dependent on the microorganism’s intrinsic features. Likewise, genetic engineering methods are applied to produce enzymes with higher stability in contrast to wild types. As there are widespread application of α-amylase in industry, optimization methods like RSM are used to improve the production of the enzyme ex vivo. This study aimed to review the latest researches on the production improvement and stability of α-amylase.

Background : Recently, resistant pathogenic microorganisms have become increasingly wide spread. The search for new natural antibiotics is a viable solution to this problem. For this aim we investigated the antimicrobial ability of Tabrizicola aquatica, the novel bacterium isolated from Qurugol Lake located nearby Tabriz city, Iran. Methods: The antimicrobial properties of Tabrizacola aquatica was investigated using well diffusion test. Tabtizicola aquatica was incubated at 40℃ in shaking incubator at 150 rpm for 14 days. The culture was centrifuged to obtain cell free supernatant, which was sterilized using 0.2 μm filter paper and lyophilized. Microorganisms were lawn and then wells were prepared over the agar plates. About 100 ml of the diluted lyophilized supernatant was added to the wells. The plates then were incubated at 37℃. After 48 hours, antimicrobial activity was defined by measuring the inhibition zone diameter. Results: The bacterial filtrates had considerable antagonistic effect against Escherichia coli, Rhizobium radiobacter, Pseudomonas syringae, Erwinia amylovora, Botrytis cinerea, Neurospora crassa and Fusarium oxysporum. However, the filtrates did not show any inhibitory action on the Aspergillus flavus and Klebsiella pneumonia. The supernatant decreased the growth zone on Streptococcus aureus, Pseudomonas aeruginosa, Shigella flexneri, Xanthomonas camoestris and Bassilus cereos. The result of MIC against pathogens was found for Neurospora crassa in the 50 µg/mL. Conclusion: The results, suggested that Tabrizicola aquatica and similar bacteria can be helpful to control freshwater natural water sources from pathogenic microorganism. Moreover, microbial natural products are still the most promising source of new antibiotics. Our results point out a scope for characterization of the metabolites and could be a candidate in the identification of novel antibiotics.

Synthesis and application of layered nanomaterials are known as emerging field in nanotechnology. Inorganic layered nanomaterials with nanometer scale, high aspect ratios, and large-surface area generate various scientific and technological interests in several potential areas of application such as separation technology, medical sciences, chromatography drug delivery, and catalysis. In this research, naproxen was opted as a unique model of the drug to intercalate into three-dimensional layered double hydroxide (LDH) nanostructures by calcination–reconstruction method. The designed-naproxen nanostructures were synthesized and used as novel drug nanocarriers. The synthesized nanomaterial characteristics were confirmed by FTIR, XRD, and SEM. The results of antibacterial activity indicated that homemade nanostructure can inhibit bacterial growth. Furthermore, MTT assay analysis showed that synthesized-nanostructure in physiological concentration has not cytotoxicity on C2C12 myoblast cells in vitro. Subsequent to intercalation with naproxen according to calcination–reconstruction method, the basal spacing of LDH increased to 2.62 nm from primary 0.77 nm in diameter, which confirms successful intercalation of naproxen into inserted layer of LDH by bridging interaction. Also, in-vitro drug release tests in PBS (pH 7.4) showed constant release profile for naproxen. Consequently, due to the facile and low-cost fabrication of three-dimensional LDH nanostructure, it can be considered as a potential alternative for traditional and high cost drug delivery.

Background Multi-drug resistant bacteria hazards to the health of humans could be an agent in the destruction of human generation. Natural products of Bacillus species are the main source to access progressive antibiotics that can be a good candidate for the discovery of novel antibiotics. Wild honey as a valuable food has been used in medicine with antimicrobial effects. Objective Bacillus strains isolated from wild honey were evaluated for the potential antimicrobial activity against human and plant bacterial and fungal pathogens. Methods Three bacterial isolates were identified as strain Khuz-1 (98.27% similarity with Bacillus safensis subsp. Safensis strain FO-36bT), strain Khuz-2 (99.18% similarity with Bacillus rugosus strain SPB7T), and strain Khuz-3 (99.78% similarity with Bacillus velezensis strain CR-502 T) by 16S rRNA gene sequences. The strains were characterized by their ability to inhibit the growth of human and phytopathogenic fungi. Results The results indicated that B. rugosus strain Khuz-2 inhibited the growth of phytopathogenic and human fungal more effective than other ones. It seems that the strain Khuz-2 has a suitable antimicrobial and antifungal potential as a good candidate for further pharmaceutical research. Conclusion Based on the results of GC–MS, Pyrrolo [1,2-a] pyrazine-1,4-dion, hexahydro-3-(2-methylpropyle) (PPDHM) was the major compound for all strains which have a various pharmacological effect. Isolation and identification of beneficial bacteria from natural sources can play an important role in future pharmaceutical and industrial applications.

Protease is a kind of enzyme with different applications in medicine and industry. The limitation of the enzymes in industry is lack of tolerance for harsh conditions (high temperature, pH, and low water condition). This study intends to evaluate in silico study and screen the alkaline serine protease producing bacteria from honey and optimize the production of low water active alkaline serine protease. Plackett–Burman method was applied to improve effective factors on protease production, including pH, inoculum size, temperature, time, soybean protein, KH2PO4, MgSO4, CaCl2, NaCl, Glycerin and glucose concentration. Further, the Box–Behnken method was used to optimize the significant level of selected factors. Besides, in silico study was utilized to create the enzyme structure and investigate the stability in harsh conditions. The results showed that the highest protease production belongs to Bacillus sp. Khoz1 closed Bacillus safensis, Also temperature, glucose and soybean protein concentration were three significant factors for protease production and the optimized level for them were 35 °C, 0.5 g/l, and 38.32 g/l, respectively. The microorganism was able to produce protease until 98.36 U/ml and it was 98.68% similar to B. safensis. The stability of microbial alkaline serine protease was also determined in high pH and temperature conditions. The best stable condition for isolated protease was pH 9 and temperature at 50 °C. The in silico data showed that this protease has similar 3D structure to Bacillus subtilis Subtilisin E and highly charge amino acids on its surface were that caused this enzyme still activate and stable in low water condition.

Background: Bacteria are one of the important sources of producing enzymes. The aim of this study was to the isolate the halophilic bacteria producing amylase, lipase and pectinase from saline soil of the center of Iran. Methods: In this study, soil samples were collected from Dagh Biarjmand and Haj Aligholi in Semnan province. At first, isolated halophilic bacteria were cultured and screened for producing of hydrolytic enzymes including amylase, lipase and pectinase using enzyme-specific media. The enzymatic activities of isolates were recognized by induction of growth inhibition zone and/or precipitation around colonies after addition of related indicators. Afterward, enzyme positive isolates were identifies using the 16S rRNA sequencing. Results: Out of 7 bacterial isolates, 4 bacteria with amylase activity, 6 bacteria with lipase activity and 3 bacteria with pectinase activity were recognized and identified. Results showed that 2 isolates with the ability of producing all three types of enzymes belong to Bacillus genus using molecular identification methods. Furthermore, the halophilic bacteria producing amylase and pectinase were belonging to Bacillus and Halobacillus genera. Besides, bacteria producing lipase belonged to Bacillus and Virgibacillus genera. Conclusion: The Bacillus bacteria isolated from the soil can produce all three amylase, pectinase and lipase enzymes.

Environmental bacteria have an important role in the removal and improvement of metals from polluted area. Metal–microbe interactions as a form of detoxification of metal have been developed. In this study, we investigated the ability of Tabrizicola aquatica RCRI19T, a novel environmental bacterium isolated from deepwater from Qurugol Lake nearby Tabriz city, Iran, to Fe(III)-reduction as an electron acceptor in minimal essential elements condition. Subsequently, bioabsorption behaviour of heavy metals (Ni2+, Co2+, pb2+) by strain RCRI19T has been demonstrated. Our results showed that strain RCRI19T can reduce 20mM ferric-citrate particularly in anaerobic condition, and a positive correlation was observed between bacterial growth and iron (II) production. Owing to its iron reduction rate, T. aquatica RCRI19T may contribute to iron mineral transformation and element cycling in deepwater of the lake. We further observed that the dead biomass of strain RCRI19T absorbs of heavy metals (Ni2+, Co2+ and Pb2+) from aqueous solution. The optimum conditions of biosorption are in pH = 4 for Ni2+, Pb2+ and pH = 5 for Co2+. The equilibrium experimental data fitted both of Freundlich and Langmuir isotherms and displayed monolayer adsorption. Two kinetic models, namely pseudo-first-order and pseudo-second-order were used to describe the kinetics of heavy metal ion biosorption on T. aquatica. Pseudo second order was the best of the other kinetic.

Background: Halophilic bacteria are potent organisms in production of novel bioactive antimicrobial compounds which might be considered in drug innovation and control of plant pathogens. Salt deserts in Semnan province are of the most permanent hypersaline areas in the North of Iran. Despite the importance of these areas, there is no scientific report regarding the biodiversity and potency of their halophilic bacteria. Thus, aforementioned areas were selected to detect the halophilic bacteria. Methods: Here, seven strains were isolated and cultured on their molecular and biochemical properties were characterized. To determine the antibiotic potency of the isolates, agar well diffusion method was conducted. Phylogenetic analysis was done to reveal the isolates relationship with previously known strains. Results: As a result, growth of the strains in the medium containing 5 to 20% (w/v) NaCl determined that the majority of the isolates were moderately halophile. Catalase activity of all strains was positive. The results represented that D6A, Dar and D8B have antimicrobial effects against different plant and human pathogens. Phylogenic tree analysis also showed that two strains of D6A and Dar are belonged to Bacillus subtilis and D8B is belonged to Virgibacillus olivae. The bacteria extracts were evaluated for their antifungal and antibacterial activities on human and Plant pathogenic strains. The MIC of the extract B. subtilis against was found active against human pathogenic fungi and Plant pathogenic bacteria and fungi, ranging from 12.5 to 25 µg/mL. Conclusion: This study highlights the therapeutic and prophylactic potential of B. subtilis extracts as antibacterial and antifungal agents.

Cancer is a serious debilitating disease and one of the most common causes of death. In recent decades the high risk of various cancers enforced scientists to discover novel prevention and treatment methods to diminish the mortality of this terrifying disease. Accordingly, its prevention can be possible in near future. Based on epidemiological evidence, there is a clear link between pathogenic fungal infections and cancer development. This association is often seen in people with weakened immune systems such as the elderly and people with acquired immunodeficiency (AIDS). Carcinoma in these people is first seen chronically and then acutely. Although the different genetic and environmental risk factors are involved in carcinogenesis, one of the most important risk factors is fungal species and infections associating with cancers etiology. Now it is known that microbial infection is responsible for initiating 2.2 million new cancer cases. In this way, many recent studies have focused on investigating the role and mechanism of fungal infections in diverse cancers occurrence. This review provides a comprehensive framework of the latest clinical findings and the association of fungal infections with versatile cancers including esophageal, gastric, colorectal, lung, cervical, skin, and ovarian cancer.

Background: magnetic nanocomposites with a core-shell nanostructure has huge applications in different sciences especially in the release of the drugs, because of their exclusive physical and chemical properties. In this research, magnetic@layered double hydroxide multicore@shell nanostructure was synthesized by the facile experimentand is used as novel drug nanocarrier.Methods: Magnetic nanospheres were synthesized by a facile one-step solvothermal route, and in following, layered double hydroxide nanoflakes were prepared on the magnetic nanospheres by coprecipitation experiment. The synthesized nanostructures were characterized by FTIR, XRD, SEM, VSM and TEM, respectively. After intercalation with Ibuprofen and Diclofenac as the anti-inflammatory drugs by using exchange anion experiment, the basal spacing of synthesized layered double hydroxides were compared with brucite nanosheets from 0.48 nm to 2.62 nm and 2.22 nm, respectively. Results: The results indicated Ibuprofen and Diclofenac were successfully intercalated into the interlay space of LDHs by bridging bidentate interaction. Besides, in vitro drug release experiments in pH 7.4, Phosphate-buffered saline (abbreviated PBS) showed the constant release profiles with Ibuprofen and diclofenac as model drugs with different lipophilicity and water solubility and size and steric effect. Conclusions: The Fe3O4@LDH-ibuprofen and Fe3O4@LDH-diclofenac had the advantage of the strong interaction between the carboxyl groups with higher trivalent cations by bridging bidentate, clarity and high thermal stability. We confirm, which Fe3O4@LDH multicore-shell nanostructure will have potential application for constant drug delivery.

Additional file 1: Figure S1. The standard curve of Ibuprofen in phosphate buffer, pH 7.4. Figure S2. The standard curve of Diclofenac sodium in phosphate buffer, pH 7.4. Figure S3. The cumulative release kinetic of Ibuprofen and Diclofenac from Fe3O4@LDH ‎nanostructure in phosphate buffer saline (PBS) at pH = 7.4.

Initiation of cancer is interconnected with different factors like infections. It has been estimated that infections, particularly viruses, participate in about 20% of all cancers. Bacteria as the most common infectious agents are also reported to be emerging players in the establishment of malignant cells. Microbial infections are able to modulate host cell transformation for promoting malignant features through the production of carcinogenic metabolites participating in inflammation responses, disruption of cell metabolism, and integrity and also genomic or epigenetic manipulations. It seems that the best example of the role of bacteria in cancer promotion is Helicobacter pylori infection, which is related to gastric cancer. World Health Organization (WHO) describes bacterium as class I carcinogens. Several bacterial infections have been reported in association with prevalent cancers. In this review, we will summarize the role of known bacterial infections in the initiation of the main common cancers, which show high mortality in the world. Examining the microbiomes in cancer patients is important and necessary to better understand the pathogenesis of this disease and also to plan therapeutic interventions.

International audience; Histidine kinase receptors (HKRs) appear to be a common strategy for model and pathogenic fungi to sense and respond to environmental stresses. In the human pathogen Aspergillus fumigatus, which is responsible for invasive aspergillosis, 13 genes potentially encoding HKRs have been identified. Until now, only three HKRs have been functionally characterized. The aim of this study was to perform the systematic invalidation of A. fumigatus HKR genes and the careful phenotypic characterization of the relevant mutants. This study notably allowed to gain new important insights into the role of HKRs in physiology of A. fumigatus. Actually, we showed that (i) NikA/TcsC could be involved in the cell wall integrity pathway, (ii) Fhk6 and PhkA were involved in the regulation of the "fluffy" developmental program, (iii) PhkB could participate in the regulation of conidiation and (iv) PhkA was implied in the resistance of oxidative stresses.

The present study highlights the fabrication of novel food-grade hydrogel particles based on pectin and starch for probiotic colon delivery. Lactobacillus plantarum ATCC:13643 (L. plantarum) cells were encapsulated in pectin/starch hydrogels by extrusion method. Four batches were formulated with different ratios of starch/pectin solutions. Optical and scanning electron microscopy obviously showed the random distribution of L. plantarum throughout the hydrogel network. The viability of encapsulated cells in simulated gastric fluid (SGF) and bile salt solution was significantly higher when compared to nonencapsulated cells. Results demonstrated that encapsulated cells in pectin/starch hydrogels were resistant against adverse conditions of the gastro-intestinal tract and bile salt solution compared to non-encapsulated cells. After sequential exposure to simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) for 2h almost complete death of free cells was observed however the numbers of surviving cells were 5.15 and 6.67 Log CFU/g for pectin and pectin/starch hydrogel, respectively.

The race structure and genotypic diversity of four Leptosphaeria maculans populations isolated from Brassica oleracea (broccoli, cauliflower, cabbage, etc.) in central Mexico (Aguascalientes, Guanajuato and Zacatecas states) were analysed. Race structure was characterized by an unusually low diversity at three locations out of four. Fourteen minisatellite markers revealed a high proportion of repeated multilocus genotypes in these populations, combined with a significant linkage disequilibrium and strong clonal fraction (65‐87%). The occurrence of the mating-type idiomorphs always significantly departed from the 1:1 proportion expected in the case of random mating. Each population thus consists of a few (four to nine) multilocus genotypes which are specific to each location. These data strongly support the hypothesis of exclusive, or a high rate of, clonal multiplication. Comparison of cropping practices between B. oleracea and B. napus indicate that the shift in reproductive behaviour of the fungus is chiefly man-mediated.

Pathogen introductions into novel areas can lead to the emergence of new fungal diseases of plants. Understanding the origin, introduction pathways, possible changes in reproductive system and population size of fungal pathogens is essential in devising an integrated strategy for the control of these diseases. We used minisatellite markers to infer the worldwide invasion history of the fungal plant pathogen Leptosphaeria maculans, which causes stem canker (blackleg) of oilseed and vegetable brassicas. Clustering analyses partitioned genotypes into distinct populations corresponding to major geographic regions, along with two differentiated populations in Western Canada. Comparison of invasion scenarios using Approximate Bayesian Computation suggested an origin of the pathogen in the USA, the region where epidemics were first recorded, and independent introductions from there over the last few decades into Eastern Canada (Ontario), Europe and Australia. The population in Western Canada appeared to be founded from a source in Ontario and the population in Chile resulted from an admixture between multiple sources. A bottleneck was inferred for the introduction into Western Canada but not into Europe, Ontario or Australia. Clonality appeared high in Western Canada, possibly because environmental conditions there were less conducive to sexual reproduction. Leptosphaeria maculans is a model invasive pathogen with contrasting features in different regions: shallow population structure, high genetic variability and regular sexual recombination in some regions, by comparison with reduced genetic variability, high rates of asexual multiplication, strong population structure or admixture in others.

International audience; Stem canker of oilseed rape (canola, Brassica napus) is associated with a species complex of two closely related fungal species, Leptosphaeria maculans and L. biglobosa. Of these, L. maculans is the most damaging and develops gene-for-gene relationships with the host. Here, a wide scale analysis of the L. maculans - L. biglobosa species complex was performed throughout the American continent (23 locations from Chile to Canada) plus several locations inWestern Australia for comparison purposes, based on a collection of 1132 isolates from infected tissues of a susceptible cultivar. Fungal species were discriminated on the basis of morphological, phytopathological and molecular criteria and showed that L. biglobosa was closely associated with L. maculans in most of the locations. Multiple gene phylogeny using sequences of ITS, actin and b-tubulin confirmed the prevalence of the L. biglobosa ‘canadensis’ sub-clade in Canada, whereas up to three different sub-clades of L. biglobosa were found in Georgia (USA). Race structure of L. maculans was investigated using a combination of pathogenicity tests and PCR amplification of avirulence alleles AvrLm1, AvrLm4 and AvrLm6. Three contrasting situations were observed: (i) race structure in Ontario, Chile and Georgia was related to that of European and Western Australian populations, with a low race diversity; (ii) only one race was found in Mexico, and not found outside of this country; (iii) a large diversity of races was observed in central Canada (Manitoba, Alberta and Saskatchewan) with very specific features including maintenance of avirulence alleles absent from Europe, absence of the AvrLm7 allele common in Europe (or eastern Canada) and wide location-to-location variability.

Fungi are of primary ecological, biotechnological and economic importance. Many fundamental biological processes that are shared by animals and fungi are studied in fungi due to their experimental tractability. Many fungi are pathogens or mutualists and are model systems to analyse effector genes and their mechanisms of diversification. In this study, we report the genome sequence of the phytopathogenic ascomycete Leptosphaeria maculans and characterize its repertoire of protein effectors. The L. maculans genome has an unusual bipartite structure with alternating distinct guanine and cytosine-equilibrated and adenine and thymine (AT)-rich blocks of homogenous nucleotide composition. The AT-rich blocks comprise one-third of the genome and contain effector genes and families of transposable elements, both of which are affected by repeat-induced point mutation, a fungal-specific genome defence mechanism. This genomic environment for effectors promotes rapid sequence diversification and underpins the evolutionary potential of the fungus to adapt rapidly to novel host-derived constraints., Leptosphaeria maculans is a plant pathogen that causes stem canker of oilseed rape. Rouxel et al. sequence and describe the key features of the L. maculans genome, including partitioning into AT-rich blocks that are enriched in effector genes and transposable elements affected by repeat-induced point mutation.

Broccoli (Brassica oleracea var. italica), cauliflower (B. oleracea var. botrytis), and cabbage (B. oleracea var. capitata) have been grown in central Mexico since 1970, with 21,000 ha cropped in 2001. In contrast, areas grown with oilseed rape (B. napus) are very limited in Mexico (15-mm pale gray lesions with numerous pycnidia, whereas L. biglobosa causes dark and smaller lesions only containing a few pycnidia. Having a similar epidemiology, both species can be present on the same plants at the same time, and symptom confusion can occur as a function of the physiological condition of the plant or expression of plant resistance responses. A total of 209 isolates from symptomatic B. oleracea leaves were collected from three fields in central states of Mexico (58 to 71 isolates per location). All leaves showed similar symptoms, including a 10- to 15-mm tissue collapse with an occasional dark margin. Cotyledons of seven B. napus differentials were inoculated with conidia of all the isolates as described by Dilmaghani et al. (1). Two hundred isolates caused tissue collapse typical of L. maculans. However, nine obtained from white cabbage in a single location in Aguascalientes caused References: (1) A. Dilmaghani et al. Plant Pathol. 58:1044, 2009. (2) E. Koch et al. Mol. Plant-Microbe Interact. 4:341, 1991. (3) E. Mendes-Pereira et al. Mycol Res. 107:1287, 2003. (4) L. Vincenot et al. Phytopathology 98:321, 2008.