Biogenic nanosilver incorporated reverse osmosis membrane for antibacterial and antifungal activities against selected pathogenic strains: An enhanced eco-friendly water disinfection approach

Reverse osmosis (RO) membranes have been used extensively in water desalination plants, waste water treatment in industries, agricultural farms and drinking water production applications. The objective of this work is to impart antibacterial and antifungal activities to commercially available RO membrane used in water purification systems by incorporating biogenic silver nanoparticles (AgNPs) synthesized using Rosa indica wichuriana hybrid leaf extract. The morphology and surface topography of uncoated and AgNPs-coated RO membrane were studied using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Elemental composition of the AgNPs-coated RO membrane was analyzed by energy-dispersive X-ray spectroscopy (EDAX). The functional groups were identified by Fourier Transform Infrared spectroscopy (FT-IR). Hydrophilicity of the uncoated and AgNPs-coated RO membrane was analyzed using water contact angle measurements. The thermal properties were studied by thermogravimetric analysis (TGA). The AgNPs incorporated RO membrane exhibited good antibacterial and antifungal activities against pathogenic bacterial strains such as E. coli, S. aureus, M. luteus, K. pneumoniae, and P. aeruginosa and fungal strains such as Candida tropicalis, C. krusei, C. glabrata, and C. albicans.

Draft genome of a commonly misdiagnosed multidrug resistant pathogen Candida auris

Background: Candida auris is a multidrug resistant, emerging agent of fungemia in humans. Its actual global distribution remains obscure as the current commercial methods of clinical diagnosis misidentify it as C. haemulonii. Here we report the first draft genome of C. auris to explore the genomic basis of virulence and unique differences that could be employed for differential diagnosis. Results: More than 99.5 % of the C. auris genomic reads did not align to the current whole (or draft) genome sequences of Candida albicans, Candida lusitaniae, Candida glabrata and Saccharomyces cerevisiae; thereby indicating its divergence from the active Candida clade. The genome spans around 12.49 Mb with 8527 predicted genes. Functional annotation revealed that among the sequenced Candida species, it is closest to the hemiascomycete species Clavispora lusitaniae. Comparison with the well-studied species Candida albicans showed that it shares significant virulence attributes with other pathogenic Candida species such as oligopeptide transporters, mannosyl transfersases, secreted proteases and genes involved in biofilm formation. We also identified a plethora of transporters belonging to the ABC and major facilitator superfamily along with known MDR transcription factors which explained its high tolerance to antifungal drugs. Conclusions: Our study emphasizes an urgent need for accurate fungal screening methods such as PCR and electrophoretic karyotyping to ensure proper management of fungemia. Our work highlights the potential genetic mechanisms involved in virulence and pathogenicity of an important emerging human pathogen namely C. auris. Owing to its diversity at the genomic scale; we expect the genome sequence to be a useful resource to map species specific differences that will help develop accurate diagnostic markers and better drug targets.

Sonic hedgehog-responsive lipoxygenases and cyclooxygenase-2 modulate Dectin-1-induced inflammatory cytokines

Immune responses during fungal infections are predominately mediated by 5/15-lipoxygenases (LO)-or cyclooxygenase (COX)-2-catalysed bioactive eicosanoid metabolites like leukotrienes, lipoxins and prostaglandins. Although few host mediators of fungi-triggered eicosanoid production have been established, the molecular mechanism of expression and regulation of 5-LO, 15-LO and COX-2 are not well-defined. Here, we demonstrate that, macrophages infected with representative fungi Candida albicans, Aspergillus flavus or Aspergillus fumigatus or those treated with Curdlan, a selective agonist of pattern recognition receptor for fungi Dectin-1, displays increased expression of 5-LO, 15-LO and COX-2. Interestingly, Dectin-1-responsive Syk pathway activates mTOR-sonic hedgehog (SHH) signaling cascade to stimulate the expression of these lipid metabolizing enzymes. Loss-of-function analysis of the identified intermediaries indicates that while Syk-mTOR-SHH pathway-induced 5-LO and 15-LO suppressed the Dectin-l-responsive pro-inflammatory signature cytokines like TNE-alpha, IL-1 beta and IL-12, Syk-mTOR-SHH-induced COX-2 positively regulated these cytokines. Dectin-1-stimulated IL-6, however, is dependent on 5-LO, 15-LO and COX-2 activity. Together, the current study establishes Dectin-1-arbitrated host mediators that direct the differential regulation of immune responses during fungal infections and thus are potential candidates of therapeutic intervention. (C) 2015 Elsevier Ltd. All rights reserved.

An Endophytic Fungus, Talaromyces radicus, Isolated from Catharanthus roseus, Produces Vincristine and Vinblastine, Which Induce Apoptotic Cell Death

Endophytic fungi isolated from Catharanthus roseus were screened for the production of vincristine and vinblastine. Twenty-two endophytic fungi isolated from various tissues of C. roseus were characterized taxonomically by sequence analysis of the internal transcribed spacer (ITS) region of rDNA and grouped into 10 genera: Alternaria, Aspergillus, Chaetomium, Colletotrichum, Dothideomycetes, Eutypella, Eutypa, Flavodon, Fusarium and Talaromyces. The antiproliferative activity of these fungi was assayed in HeLa cells using the MTT assay. The fungal isolates Eutypella sp-CrP14, obtained from stem tissues, and Talaromyces radicus-CrP20, obtained from leaf tissues, showed the strongest antiproliferative activity, with IC50 values of 13.5 mu g/ml and 20 mu g/ml, respectively. All 22 endophytic fungi were screened for the presence of the gene encoding tryptophan decarboxylase (TDC), the key enzyme in the terpenoid indole alkaloid biosynthetic pathway, though this gene could only be amplified from T. radicus-CrP20 (NCBI GenBank accession number KC920846). The production of vincristine and vinblastine by T. radicus-CrP20 was confirmed and optimized in nine different liquid media. Good yields of vincristine (670 mu g/l) in modified M2 medium and of vinblastine (70 mu g/l) in potato dextrose broth medium were obtained. The cytotoxic activity of partially purified fungal vincristine was evaluated in different human cancer cell lines, with HeLa cells showing maximum susceptibility. The apoptosis-inducing activity of vincristine derived from this fungus was established through cell cycle analysis, loss of mitochondrial membrane potential and DNA fragmentation patterns.

Targeting human telomeric G-quadruplex DNA with curcumin and its synthesized analogues under molecular crowding conditions

The formation of telomeric G-quadruplexes has been shown to inhibit telomerase activity. Indeed, a number of small molecules capable of p-stacking with G-tetrads have shown the ability to inhibit telomerase activity through the stabilization of G-quadruplexes. Curcumin displays a wide spectrum of medicinal properties ranging from anti-bacterial, anti-viral, anti-protozoal, anti-fungal and anti-inflammatory to anti-cancer activity. We have investigated the interactions of curcumin and its structural analogues with the human telomeric sequence AG(3)(T(2)AG(3))(3) under molecular crowding conditions. Experimental studies indicated the existence of a AG(3)(T(2)AG(3))(3)/curcumin complex with binding affinity of 0.72 x 10(6) M-1 under molecular crowding conditions. The results from UV-visible absorption spectroscopy, a fluorescent TO displacement assay, circular dichroism and molecular docking studies, imply that curcumin and their analogues interact with G-quadruplex DNA via groove binding. While other analogs of curcumin studied here bind to G-quadruplexes in a qualitatively similar manner their affinities are relatively lower in comparison to curcumin. The Knoevenagel condensate, a methoxy-benzylidene derivative of curcumin, also exhibited significant binding to G-quadruplex DNA, although with two times decreased affinity. Our study establishes the potential of curcumin as a promising natural product for G-quadruplex specific ligands.

Targeting human telomeric G-quadruplex DNA with curcumin and its synthesized analogues under molecular crowding conditions

The formation of telomeric G-quadruplexes has been shown to inhibit telomerase activity. Indeed, a number of small molecules capable of p-stacking with G-tetrads have shown the ability to inhibit telomerase activity through the stabilization of G-quadruplexes. Curcumin displays a wide spectrum of medicinal properties ranging from anti-bacterial, anti-viral, anti-protozoal, anti-fungal and anti-inflammatory to anti-cancer activity. We have investigated the interactions of curcumin and its structural analogues with the human telomeric sequence AG(3)(T(2)AG(3))(3) under molecular crowding conditions. Experimental studies indicated the existence of a AG(3)(T(2)AG(3))(3)/curcumin complex with binding affinity of 0.72 x 10(6) M-1 under molecular crowding conditions. The results from UV-visible absorption spectroscopy, a fluorescent TO displacement assay, circular dichroism and molecular docking studies, imply that curcumin and their analogues interact with G-quadruplex DNA via groove binding. While other analogs of curcumin studied here bind to G-quadruplexes in a qualitatively similar manner their affinities are relatively lower in comparison to curcumin. The Knoevenagel condensate, a methoxy-benzylidene derivative of curcumin, also exhibited significant binding to G-quadruplex DNA, although with two times decreased affinity. Our study establishes the potential of curcumin as a promising natural product for G-quadruplex specific ligands.

2,4-D and Mycoleptodiscus terrestris for control of Eurasian Watermilfoil

Growth chamber studies were conducted to evaluate the impact of an indigenous fungal pathogen, Mycoleptodiscus terrestris (Gerd.) Ostazeski, and the herbicide 2,4-D applied alone and in combination with one another, on the growth of a nuisance submersed plant, Eurasian watermilfoil ( Myriophyllum spicatum L.)(PDF has 6 pages.)

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.

Clinical factors associated with a Candida albicans Germ Tube Antibody positive test in Intensive Care Unit patients

Background: Poor outcomes of invasive candidiasis (IC) are associated with the difficulty in establishing the microbiological diagnosis at an early stage. New scores and laboratory tests have been developed in order to make an early therapeutic intervention in an attempt to reduce the high mortality associated with invasive fungal infections. Candida albicans IFA IgG has been recently commercialized for germ tube antibody detection (CAGTA). This test provides a rapid and simple diagnosis of IC (84.4% sensitivity and 94.7% specificity). The aim of this study is to identify the patients who could be benefited by the use of CAGTA test in critical care setting. Methods: A prospective, cohort, observational multicentre study was carried out in six medical/surgical Intensive care units (ICU) of tertiary-care Spanish hospitals. Candida albicans Germ Tube Antibody test was performed twice a week if predetermined risk factors were present, and serologically demonstrated candidiasis was considered if the testing serum dilution was >= 1: 160 in at least one sample and no other microbiological evidence of invasive candidiasis was found. Results: Fifty-three critically ill non-neutropenic patients (37.7% post surgery) were included. Twenty-two patients (41.5%) had CAGTA-positive results, none of them with positive blood culture for Candida. Neither corrected colonization index nor antifungal treatment had influence on CAGTA results. This finding could corroborate that the CAGTA may be an important biomarker to distinguish between colonization and infection in these patients. The presence of acute renal failure at the beginning of the study was more frequent in CAGTA-negative patients. Previous surgery was statistically more frequent in CAGTA-positive patients. Conclusions: This study identified previous surgery as the principal clinical factor associated with CAGTA-positive results and emphasises the utility of this promising technique, which was not influenced by high Candida colonization or antifungal treatment. Our results suggest that detection of CAGTA may be important for the diagnosis of invasive candidiasis in surgical patients admitted in ICU.

The economic impact of diseases and parasitic problems in freshwater fish production

Diseases and parasitic problems could constitute significant economic losses in fish production if not controlled, thus the need to continue monitoring its prevalence. Based on field studies on feral and intensively raised fish at the Kainji Lake Research Institute Nigeria, some diseases and parasitic problems have been identified. These include; helminthiasis; fungal disease; protozoa which include Myxosoma sp., Myxobolus spp., Henneguya sp., Trichodina sp., Ichthopthrius sp. bacterial mainly Aeromonas sp., Pseudomonas sp., mechanical injuries; death due to unknown causes and economic assessment of myxosporidian infection. Suggestion for disease control in fish production are recommended

The effect of traditional handling, processing and storage methods on the quality of dried fish in small scale fisheries in Nigeria

Most of the fish marketed throughout Nigeria are in either smoked or dried form. The technological requirement for other forms of preservation like chilling and freezing cannot be afforded by the small scale fisher folk. Considerable quantities of fish processed for distant consumer markets are lost at handling, processing, storage and marketing stages. Significant losses occur through infestation by mites, insects, fungal infestation and fragmentation during transportation. This paper attempts to describe the effect of these losses on fish quality and suggests methods of protecting fish from agents of deterioration

Estudo aberto prospectivo de 30 pacientes com onicomicose por Scytalidium spp. tratados com terbinafina oral, ciclopiroxolamina esmalte e onicoabrasão

Onicomicose é um termo geral usado para definir infecção fúngica da unha. Seus agentes podem ser dermatófitos, leveduras ou fungos filamentosos não dermatófitos - FFNDs. Estes são comumente encontrados na natureza como saprófitas do solo e de restos vegetais e patógenos de plantas e têm sido considerados fungos patógenos primários de lesões cutâneas. Não existe até o momento terapêutica padrão para o tratamento de onicomicoses por Scytalidium spp., sendo escassos os dados na literatura pesquisada. Este trabalho tem como objetivo avaliar e comparar a resposta terapêutica a três abordagens diferentes de tratamento combinado para onicomicose por Scytalidium spp., todos associados à onicoabrasão. Foram selecionados 30 pacientes com diagnóstico de onicomicose provocada por Scytalidium spp., divididos em três grupos de dez, recebendo cada um os seguintes tratamentos, além da onicoabrasão: Grupo I: Terbinafina oral e esmalte de ciclopiroxolamina 8%, duas vezes por semana por 12 meses; Grupos II e III: Esmalte de ciclopiroxolamina 8%, duas e 5 vezes por semana, respectivamente, por 12 meses. Os parâmetros de avaliação da eficácia foram clínico e micológico ao término do tratamento e seis meses após. Foram utilizados os critérios de cura total, cura parcial, falha terapêutica aos 12 meses e recidiva/reinfecção no acompanhamento de seis meses. Vinte e cinto pacientes completaram o estudo. Não houve diferença estatística entre os grupos nos diversos parâmetros utilizados para avaliação da resposta terapêutica. A avaliação do resultado terapêutico mostra que ao final de 12 meses de tratamento apenas um paciente preencheu os critérios para cura total, e que 32% dos pacientes de todos os grupos apresentaram cura parcial. Todos os pacientes que completaram o estudo obtiveram melhora clínica, que se manteve no período de acompanhamento. A presença dos fungos na lâmina ungueal foi constante, mesmo com a melhora clínica. Embora não se possa afirmar qual a melhor forma de intervenção entre as três terapêuticas propostas devido ao pequeno número de pacientes do estudo, deduz-se, deste trabalho, que não houve vantagem na administração de terapia sistêmica concomitante. É possível considerar que a terapia tópica exclusiva, seja duas ou cinco vezes por semana, possa constituir opção mais adequada para o tratamento da onicomicose por Scytalidium spp.

On new or insufficiently-known Chytridinae [Translation from: Archiv fur Protistenkunde 54 168-173 + pl.9, 1926]

This partial translation of a larger paper provides taxonomic descriptions of 5 fungal zoospores species: Olpidium vampyrellae, 0. pseudosporearum, 0. leptophrydis, Rhizophidium leptophrydis and Chytridium lateoperculatum.

Biossorção de tório com emprego de Sargassum filipendula

Com o aumento do rigor para descarte de efluentes contaminado com metais pesados, as pesquisas têm se intensificado na busca de métodos de remoção, que tragam bons resultados de captação dos metais, aliado a um baixo custo. O uso de biomassas como bactérias, fungos e algas marinhas como material adsorvente, tem se apresentado como uma alternativa, principalmente para soluções com baixo teor de metais. Neste trabalho, a alga marinha Sargassum filipendula foi avaliada na sua capacidade de remoção do metal tório de uma solução sintética e do efluente dos laboratórios de análises ambientais do IRD. A cinética desta biossorção foi estudada em regime de batelada e o equilíbrio foi alcançado com 180 min de reação. Dois modelos cinéticos foram utilizados nesta avaliação, um de primeira ordem e um modelo de pseudo segunda ordem, tendo o modelo de segunda ordem apresentado um melhor ajuste dos dados. Na avaliação da capacidade máxima de captação do tório pela biomassa marinha em regime de batelada, foi construída a isoterma que apresentou um perfil crescente na captação alcançando um máximo de 2,59 mol/g. Os modelos de Langmuir e Freundlich foram utilizados para ajustar os dados da isoterma, tendo apresentado maior correlação com os dados o modelo de Langmuir, resultando num valor de captação máxima calculado pelo modelo de 2,92 mol/g. A capacidade de remoção do metal tório da alga Sargassum filipendula também foi avaliada em regime contínuo. Um estudo de altura crítica de leito foi realizado preenchendo-se uma coluna com diferentes massas de alga correspondendo a diferentes alturas de leito. A concentração de tório residual foi quantificada na solução de saída e a menor concentração na saída foi alcançada com 40 cm de leito ou 96 g de biomassa. Após este estudo um sistema contínuo com duas colunas, com 96 g de biomassa cada, e uma bomba peristáltica foi utilizado para o tratamento do efluente real do IRD, contendo não apenas o metal tório, mas outros metais como urânio, cálcio, cromo, ferro, chumbo, etc. Cento e cinco litros de efluente foram tratados numa concentração de 6 mg/L, a concentração do efluente de saída foi de 3,75 mg/L. A caracterização do efluente quanto aos metais presentes foi realizada em ICP-MS, os resultados demonstraram que não houve competição pelos sítios ligantes da biomassa entre o tório e os demais metais. Além disso, alguns metais como cálcio, ferro e magnésio, tiveram um aumento na concentração de saída indicando a presença do mecanismo de troca iônica na biossorção do tório por Sargassum filipendula

Saprolegnia infections of salmonid fish

This paper deals firstly with the identification and characteristics of fungal pathogens that colonize salmonids and then considers the relative importance of the condition of the host fish and the environmental factors which may influence the interaction between pathogen and host.