Exserohilum Rostratum Research Articles

First Report of Leaf Spot Disease Caused by Exserohilum rostratum on Bottle Gourd in India.

First Report of Leaf Spot Disease Caused by Exserohilum rostratum on Bottle Gourd in India.

Isolation and identification of fungal assemblages in the necrotic spots of Bambusa pallida (L.) Voss

Bamboos are the most important plant due to their different uses and good source of income for upliftment of rural economy. Different parts of bamboos are damaged by many harmful bacteria, fungi and other organisms causing huge loss of economy. Diseased leaves of Bambusa pallida were used for isolation of fungal assemblages in symptom sites. A total of 7 fungi were isolated from the cultured medium; these were Lasiodiplodia theobromae, Drechslera rostrata, Curvularia lunata, Fusarium redolens, Sterile sp1, Sterile sp2, and Sterile sp3. Isolated L. theobromae, D. rostrata, C. lunata, F. redolens may be the causal fungi for necrotic spots disease in B. pallida. Colonization rate and isolation rate (%) were observed highest in L. theobromae, C. lunata F. redolens and Sterile sp2. The present finding will be helpful for knowing the causes of damage and relation with leaf spot disease. Further studies needed to be undertaken for finding the mode of colonization to causes diseases.

Multi-locus phylogeny and taxonomy of Exserohilum.

Exserohilum includes a number of plant pathogenic, saprobic and clinically relevant fungi. Some of these species are of great importance in human activities, but the genus has never been revised in a phylogenetic framework. In this study, we revise Exserohilum based on available ex-type cultures from worldwide collections, observation of the holotypes and/or protologues, and additional isolates from diverse substrates and geographical origins. Based on nine nuclear loci, i.e., ITS, LSU, act, tub2, cam, gapdh, his, tef1 and rpb2, as well as phenotypic data, the genus and species boundaries are assessed for Exserohilum. Three species, i.e., E. novae-zelandiae, E. paspali and E. sorghicola, are excluded from the genus and reallocated in Sporidesmiella and Curvularia, respectively, whereas E. heteropogonicola and E. inaequale are confirmed as members of Curvularia. Exserohilum rostratum is revealed as conspecific with species previously described in Exserohilum such as E. antillanum, E. gedarefense, E. leptochloae, E. longirostratum, E. macginnisii and E. prolatum. Additionally, E. curvatum is revealed as synonym of E. holmii, and E. fusiforme of E. oryzicola. A total of 11 Exserohilum phylogenetic species are described, illustrated and discussed, including one novel taxon, E. corniculatum. The placements of 15 other doubtful species are discussed, and E. elongatum is validated.

Antitumor activity of extract and isolated compounds from Drechslera rostrata and Eurotium tonophilum

Total extracts of Drechslera rostrata and Eurotium tonophilum in addition of two isolated compounds from their cultures [di-2-ethylhexyl phthalate (H1) and 1,8-Dihydroxy-3-methoxy-6-methyl-anthraquinone (H2)] were tested for their antitumor activity using four human carcinoma cell lines. Antitumor activity was assessed by performing MTT assay to check the % cell viability. The % viability of HCT-116 (colon carcinoma), HeLa (cervical carcinoma), HEp-2 (larynx carcinoma) and HepG-2 (hepatocellular carcinoma) cells decreased after treatment with Drechslera rostrata and Eurotium tonophilum extracts, these effects were ranged from 059.0± 0.1 to 217.0 ± 0.3 µg/ml on all types of cancer cells. The best activity was recorded for Eurotium tonpholium extract (054.5 ± 0.3, 059.0 ± 0.5 and 059.0 ± 0.1 for HEp-2, Hela, and HepG-2 respectively). The isolated compounds (H1&H2) were found to be responsible about the activities because they recorded the lowest IC50 on tested cell lines with range of 9.5–20.3 μg/ml. Vinblastine sulphate was used as a reference standard and showed in vitro anticancer activity. This study demonstrated that all extracts and isolated compounds have antitumor activity against HCT-116, HeLa, HEp-2 and HepG-2 cells.

The fungal meningitis outbreak five years later: what have we learned about Exserohilum rostratum?

ABSTRACTIntroduction: On 18 September 2012, United States health officials began to react to a large outbreak of fungal meningitis traceable to methylprednisolone from a compounding pharmacy in Framingham, Massachusetts. Although the index case was attributed to the opportunistic mold Aspergillus fumigatus, all subsequent cases were due to the dematiaceous mold Exserohilum rostratum, which had previously been an uncommon cause of disease in humans.Areas covered: In this paper, the authors examine recent advances in the diagnosis and treatment of Exserohilum infection and provide updates on how the innate and acquire immune responses enable clearance of human fungal pathogens.Expert commentary: The fungal meningitis outbreak of 2012 stretched across 20 states and resulted in 753 cases of central nervous system infection and 64 deaths. In this paper, the authors examine how the outbreak prompted investigators to develop novel diagnostic and therapeutic options that have advanced the study of human fungal pathogens and will benefit patients who are susceptible to invasive mycoses.

Alpha-glucosidase and alpha-amylase inhibiting thiodiketopiperazines from the endophytic fungus Setosphaeria rostrata isolated from the medicinal plant Costus speciosus in Sri Lanka

Three new thiodiketopiperazine derivatives, rostratazine A (1), rostratazine B (2) and rostratazine C (3) along with exserohilone (4) and boydine A (5) were isolated and identified from the laboratory culture of Setosphaeria rostrata, an endophytic fungus obtained from the fresh asymptomatic leaf tissues of the medicinal plant Costus speciosus from Sri Lanka. The structures of compounds 1–3 were elucidated on the basis of detailed interpretation of 1D- and 2D- NMR data and comparison to known compounds. Compounds 1–5 were subjected to α-glucosidase inhibitory and porcine pancreatic alpha amylase inhibitory assays and 4 showed alpha–glucosidase inhibitory activity while 2 showed porcine pancreatic alpha amylase inhibitory activity.

ISOLATION AND CHARACTERIZATION OF NATURAL HERBICIDAL COMPOUND FROM Drechslera rostrata

ABSTRACT In agriculture, weeds have inevitable importance because of reducing the crop growth and also affecting food quality. Although, synthetic herbicides are available to combat these weeds but during recent years there is a trend of using ecofriendly herbicides extracted from natural resources. Present investigation is a continuity of the research, which reported a natural herbicidal compound named as Ophiobolin A from a fungus, Drechslera rostrata. The fungus was incubated in a growth medium of known composition (minimal medium) up to 28 days and its metabolites were extracted with organic solvents. The compound showing bioactivity was purified with the help of Reversed Phase High Performance Liquid Chromatography (RPHPLC) and identified with the help of Spectroscopic techniques viz. Mass Spectroscopy (MS) (LRESIMS and HRESIMS) and Nuclear Magnetic Resonance Spectroscopy (NMR). The purified compound caused death of superficial leaf cells of Chenopodium album, a noxious weed of wheat. Present investigation concludes that the identified compound could be used as structural analogue alternative to synthetic herbicides to synthesize natural herbicides.

Identification of Newer Antimicrobial Agents: A Study of Invitro Antibacterial and Antifungal Activities of Leaf extracts of Medicinal Plant <i>Aerva lanata</i> (L.) Juss. ex Schult

In the era of presence and spread of infectious diseases caused by microorganisms demonstrating resistance against most antimicrobial agents routinely used in the treatment, there is a serious need of search for potential agents which can be used as antimicrobials. The plant extracts of Aerva lanata were collected and processed using standard procedures. Whatman filter papers were then impregnated with varied concentrations of plant extract and antimicrobial susceptibility testing was performed using Kirby-Bauer disk diffusion method for bacteria. The standard disk diffusion method was used to test antifungal drugs against yeasts, and non-dermatophyte filamentous fungal isolates.The ethanolic extract at a concentration of 600 µg/ mL and 900 µg/ mL showed increased antibacterial activities against Esherichia coli as compared to the standard drug tested at similar concentrations. The chloroform extracts and the ethanol extract revealed increased antibacterial activity against Klebsiella pneumoniae. The chloroform solvent extract showed similar antifungal activities as the standard drug against Candida albicans, and the H2O extract showed greater antifungal activity against Drechslera halodes as compared to the control drug tested. Antibacterial and antifungal properties of leaf extracts of Aerva lanata plant in comparison with the control drugs revealed either similar or increased activities signifying their potential for future candidates as antimicrobial agents.

Bioprospecting of antimicrobial activity of extracts of endophytic fungi from Bauhinia guianensis

Antibiotic resistance results in higher medical costs, prolonged hospital stays and increased mortality and is rising to dangerously high levels in all parts of the world. Therefore, this study aims to search for new antimicrobial agents through bioprospecting of extracts of endophytic fungi from Bauhinia guianensis, a typical Amazonian plant used in combating infections. Seventeen (17) fungi were isolated and as result the methanolic extract of the fungus Exserohilum rostratum showed good activity against the bacteria tested. The polyketide monocerin was isolated by the chromatographic technique, identified by NMR and MS, showing broad antimicrobial spectrum.

First Report on Exserohilum rostratum Pathogenicity Causing Brown Spot to Rice in Brazil

First Report on <i>Exserohilum rostratum</i> Pathogenicity Causing Brown Spot to Rice in Brazil

A First Report of Rubber Tree Leaf Spot Caused by Exserohilum rostratum in China

A First Report of Rubber Tree Leaf Spot Caused by <i>Exserohilum rostratum</i> in China

Morphological and molecular characterization, sexual reproduction, and pathogenicity of Setosphaeria rostrata isolates from rice leaf spot

Setosphaeria rostrata, a common plant pathogen causing leaf spot disease, affects a wide range of plant species, mainly grasses. Fungi were isolated from brown spots on rice leaves throughout Peninsular Malaysia, and 45 isolates were identified as Setosphaeria rostrata. The isolates were then characterized using morphological and molecular approaches. The mating type was determined using PCR amplification of the mating type alleles, and isolates of opposite mating types were crossed to examine sexual reproduction. Based on nuclear ribosomal DNA ITS1-5.8S-ITS2 region (ITS) and beta-tubulin (BT2) sequences, two phylogenetic trees were constructed using the maximum likelihood method; S. rostrata was clustered in one well-supported clade. Pathogenicity tests showed that S. rostrata isolates are pathogenic, suggesting that it is the cause of the symptoms. Mating-type analyses indicated that three isolates carried the MAT1-1 allele, and the other 42 isolates carried MAT1-2. After isolates with opposite mating types were crossed on Sach’s medium and incubated for 3 wk, six crosses produced pseudothecia that contained eight mature ascospores, and 12 other crosses produced numerous pseudothecia with no ascospores. To our knowledge, this is the first report on S. rostrata isolated from leaf spots on rice.

Detection and Identification of Mycobiota Associated with Rice in Three Districts of Iraq

The reduction of yield, quality, and nutritional value of grain cereals by different fungal species is of great concern around the world. A comprehensive investigation was made on fungal mycobiota in rice from three provinces; Baghdad, Al-Najaf and Al-Qadisiyah of Iraq surveyed during the growing season 2014-2015. Fields were selected due to their location near the Euphrates and Tigris Rivers. Mycological analysis indicated that there were a difference rates in disease infection due to various fungal species. Predominant fungal species identified as Bipolaris spicifera, Curvularia lunata, Fusarium spp., Nigrospora oryzae, Exserohilum rostratum, Alternaria spp. and Thanatephorus cucumeris. Confirmation of the associated fungal species was further accomplished by analysis of their ribosomal DNA and internal transcribed spacer region sequences. The present study provides a detailed description of the associated fungal species, which may help in understanding the population dynamics and in developing effective control measures.

DNA barcoding and isolation of vertically transmitted ascomycetes in sorghum from Burkina Faso: Epicoccum sorghinum is dominant in seedlings and appears as a common root pathogen

Molecular identification of fungal taxa commonly transmitted through seeds of sorghum in Western Africa is lacking. In the present study, farm-saved seeds, collected from four villages in Northern Burkina Faso, were surface sterilized and the distribution of fungal DNA in seeds and seven-day-old seedlings was analyzed by 18S ribosomal DNA (rDNA) amplicon sequencing. More than 99% of the fungal rDNA was found to originate from ascomycetes. The distribution of ascomycetes at species level was subsequently analyzed by barcoding of ITS2 rDNA. Eighteen Operational Taxonomic Units (OTUs) were identified from seedlings, compared to 29 OTUs from seeds. The top-eight most abundant ascomycete OTUs from seedlings were annotated as: Epicoccum sorghinum, Fusarium thapsinum, four different Curvularia spp., Exserohilum rostratum and Alternaria longissima. These OTUs were also present in amplicons from seed samples collected in Central Burkina Faso confirming a common occurrence. E. sorghinum was highly predominant in seedlings both measured by DNA analysis and by isolation. The dominance of E. sorghinum was particularly strong in roots from poorly growing seedlings. Pathogenicity of E. sorghinum isolates was compared to F. thapsinum by inoculation to seeds in vitro. Both fungal species caused significant inhibition of seedling growth (P<0.001) and Koch’s postulates were fulfilled. Extensive, dark necrosis in roots was a typical symptom of E. sorghinum, whereas wilting of leaves was caused primarily by F. thapsinum. This study provides the first molecular approach to characterize the seedling mycoflora of sorghum in Western Africa and suggests E. sorghinum as a common root pathogen.

Fungal Infections Associated with Contaminated Steroid Injections.

In mid-September 2012, the largest healthcare-associated outbreak in U.S. history began. Before it was over, 751 patients were reported with fungal meningitis, stroke, spinal or paraspinal infection, or peripheral osteoarticular infection, and 64 (8.5%) died. Most patients had undergone epidural injection, and a few osteoarticular injection, of methylprednisolone acetate that had been manufactured at the New England Compounding Center (NECC). The offending pathogen in most cases was Exserohilum rostratum, a brown-black soil organism that previously was a rare cause of human infection. Three lots of methylprednisolone were contaminated with mold at NECC; the mold from unopened bottles of methylprednisolone was identical by whole-genome sequencing to the mold that was isolated from ill patients. Early cases manifested as meningitis, some patients suffered posterior circulation strokes, and later cases were more likely to present with localized infection at the injection site, including epidural abscess or phlegmon, vertebral diskitis or osteomyelitis, and arachnoiditis with intradural involvement of nerve roots. Many patients with spinal or paraspinal infection required surgical intervention. Recommendations for treatment evolved over the first few weeks of the outbreak. Initially, combination therapy with liposomal amphotericin B and voriconazole was recommended for all patients; later, combination therapy was recommended only for those who were most ill, and voriconazole monotherapy was recommended for most patients. Among those patients who continued antifungal therapy for at least 6 months, outcomes for most appeared to be successful, although a few patients remain on therapy.

A review of melanized (black) fungal contamination in pharmaceutical products-incidence, drug recall and control measures

The aim of this study was to describe the incidence of contamination of pharmaceutical products by melanized fungi and to consider control measures in relation to bioburden and cleanrooms. This study reviews and analyses pharmaceutical product recalls and offers incidence rates of fungal detection from a typical cleanrooms. The recalls include some serious cases which resulted in the loss of life. Of different types of fungal contamination incidences some of the most damaging have been due to melanized fungi ('black mould'), such as Exserohilum rostratum. The focus of the article is with melanized fungi. The study concludes that, from the review of recent pharmaceutical product recalls, fungal contamination is either increasingly common within cleanroom environments or the accuracy of sampling and the level of reporting has risen. The prevalence of melanized fungi in pharmaceutical facilities rests on specific virulence factors particular to these types of fungi, which are outlined. The article identifies a gap in the way that such fungi are screened for using available cultural methods. The article provides some control strategies, including assessing the suitability of disinfectants and biocides, for reducing the risk of melanized fungal incidences within the pharmaceutical facility. Understanding the fungal risk to pharmaceutical products remains a poorly understood and often overlooked aspect of pharmaceutical microbiology. This article helps to identify this risk and offer some guidance to those involved with pharmaceutical products manufacture in relation to bio-contamination control strategies.

First Report of Exserohilum rostratum as Pathogen of Rice Brown Spot in Malaysia

Leaves with brown spot symptoms were sampled from rice planting areas in the Malaysian peninsula, including Kelantan, Penang, Kedah, Perak, and Selangor, over the planting season from November 2012 to December 2013. The disease was observed on the glumes and leaves of rice plants. Mature lesions were brown with a gray or whitish centre, whereas younger lesions were small, circular, and dark brown or purplish brown. Thirteen isolates were recovered from 100 diseased leaf samples that were plated on PDA medium. The mycelia were white in early stages but after 3 to 4 days, they turned gray or dark gray. Based on morphological characteristics, molecular data (polymerase chain reaction assay and nucleotide sequence analysis) and pathogenicity tests, the causal agent was identified as Exserohilum rostratum [Setosphaeria rostrata]. This is thought to be the first report of E. rostratum as pathogen of rice brown spot in Malaysia.

Filamentous fungi isolated from cases of camel skin lesions

Various filamentous fungi isolated from skin lesions in dromedaries were Candida albicans, Alternaria alternata, Basidiobolus ranarum, Curvularia lunata, Exserohilum rostratum, Absidia corymbifera, Rhizopus oryzae, Aspergillus flavus, A. fumigatus, A.niger, A. terreus, A. versicolor, other aspergilli and Penicillium spp. These fungi were isolated either alone or in association with other diamorphic fungi.

Annularins I and J: New Metabolites Isolated from Endophytic FungusExserohilum rostratum

The paper describes the isolation of ergosterol peroxide, monocerin, annularin I and annularin J compounds of Exserohilum rostratum biomass extracts. Compounds were isolated by silica gel column chromatography in polarity gradient and the structures were determined by nuclear magnetic resonance (NMR) and mass spectrometry (MS) methods. Monocerin, annularin I and annularin J compounds were tested against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis bacteria and showed moderate activity. Annularin I and annularin J compounds are new natural products.

Clinical Response, Outbreak Investigation, and Epidemiology of the Fungal Meningitis Epidemic in the United States: Systematic Review.

We conducted a systematic review of the 2012-2013 multistate fungal meningitis epidemic in the United States from the perspectives of clinical response, outbreak investigation, and epidemiology. Articles focused on clinical response, outbreak investigation, and epidemiology were included, whereas articles focused on compounding pharmacies, legislation and litigation, diagnostics, microbiology, and pathogenesis were excluded. We reviewed 19 articles by use of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework. The source of the fungal meningitis outbreak was traced to the New England Compounding Center in Massachusetts, where injectable methylprednisolone acetate products were contaminated with the predominant pathogen, Exserohilum rostratum. As of October 23, 2013, the final case count stood at 751 patients and 64 deaths, and no additional cases are anticipated. The multisectoral public health response to the fungal meningitis epidemic from the hospitals, clinics, pharmacies, and the public health system at the local, state, and federal levels led to an efficient epidemiological investigation to trace the outbreak source and rapid implementation of multiple response plans. This systematic review reaffirms the effective execution of a multisectoral public health response and efficient delivery of the core functions of public health assessment, policy development, and service assurances to improve population health.