Sensitivity and specificity of phenoloxidase reactions of 1059 strains and species of Micromycetes cultivated on malt/agar medium

1995 ◽  
Vol 11 (5) ◽  
pp. 497-501 ◽  
Author(s):  
M. Rahouti ◽  
J.-L. Benoit-Guyod ◽  
F. Seigle-Murandi ◽  
P. Guiraud
Keyword(s):  
Sensitivity And Specificity ◽  
Agar Medium ◽  
Malt Agar

scholarly journals First Report of Umbel Browning and Stem Necrosis Caused by Diaporthe angelicae on Carrot in France

Plant Disease ◽  
2014 ◽  
Vol 98 (3) ◽  
pp. 421-421 ◽  
Author(s):  
L. Ménard ◽  
P. E. Brandeis ◽  
P. Simoneau ◽  
P. Poupard ◽  
I. Sérandat ◽  
...  
Keyword(s):  
Seed Production ◽  
White Light ◽  
Agar Medium ◽  
Malt Agar ◽  
Universal Primers ◽  
Conidial Suspension ◽  
First Report ◽  
Daucus Carota L ◽  
Cropping Seasons ◽  
Production Areas

In 2011, carrot (Daucus carota L.) seed production occurred on 2,900 ha, which accounts for approximately 25% of the area devoted to the production of vegetable fine seeds. Since 2007, symptoms of umbel browning have been regularly observed in carrot production areas located in the central region. Initially, triangular necrotic lesions appeared on carrot umbels that later spread to the entire umbels and often progressed to the stems. Diseased umbels became dried prematurely, compromising seed development. The loss in seed production was estimated at approximately 8% of the harvested carrot umbels during the cropping seasons of spring and summer 2007 and 2008 in France. In collaboration with seed companies, diseased carrot stems were collected from seven fields of seed production (eight plants per field) and a fungus was isolated from the tissue. The cultures were grown on malt (2%) agar (1.5%) medium and incubated for 2 weeks at 22°C in darkness. Young fungal colonies were white and a brownish green pigmentation developed when the colonies became older. The same color was observed from the top and on the reverse of the colonies. To induce sporulation, isolates were grown on water agar (1.5%) medium in the presence of carrot stem fragments for 1 week at 22°C in darkness, followed by 1 week at 22°C in white light under a 16-h photoperiod. Pycnidia were produced on stem fragments and contained alpha and beta conidia typical of the genus Diaporthe (2). Alternatively, pycnidia were also obtained on malt agar medium after 2 weeks of culture at 25°C in white light under a 12-h photoperiod. The size of alpha and beta conidia was 6.3 ± 0.5 × 2.3 ± 0.4 μm and 23.3 ± 1.8 × 0.9 ± 0.2 μm, respectively (n = 170). In order to confirm the identification at the genus level and determine the species, DNA was extracted from the mycelium of three representative isolates and the ITS regions of the ribosomal DNA were amplified using universal primers (1). The sequences of the amplified products (GenBank Accession Nos. KF240772 to KF240774) were 100% identical with the ITS sequence of a Diaporthe angelicae isolate deposited in the NCBI database (CBS 111592 isolate, KC343027). To confirm pathogenicity, the three isolates of D. angelicae were inoculated on carrot umbels in the greenhouse. A total of nine plants were inoculated (three plants per isolate). Using a micropipette, 10 μl of a conidial suspension containing alpha and beta conidia (105 conidia mL–1) were deposited at the base of the primary umbel and two secondary umbels, which were wounded before inoculation using a scalpel blade. Seven inoculated plants developed triangular, necrotic lesions that were typical umbel browning. D. angelicae was re-isolated on malt agar medium from the inoculated diseased carrot umbels. To our knowledge, this is the first report of D. angelicae in carrot cultivated for seed production in France. The disease resembles the lesions described in the Netherlands in 1951 on carrot inflorescence caused by Phomopsis dauci (3). In future experiments, it would be crucial to precisely determine if D. angelicae could be transmitted to the seeds. References: (1) M. A. Innis et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (2) J. M. Santos and A. J. L. Philips. Fungal Divers. 34:111, 2009. (3) J. A. von Arx. Eur. J. Plant Pathol. 57:44, 1951.

Nature of the "black line" produced between different biological species of the Armillaria mellea complex

1986 ◽  
Vol 64 (11) ◽  
pp. 2588-2590 ◽  
Author(s):  
K. I. Mallett ◽  
Y. Hiratsuka
Keyword(s):  
Light Microscopy ◽  
Agar Medium ◽  
Biological Species ◽  
Malt Agar ◽  
Black Line ◽  
Armillaria Mellea

The zone of antagonism or black line, formed between the confronting margins of different biological species of the Armillaria mellea complex when paired on malt agar medium, was investigated. Light microscopy showed that the black line was composed of melanized hyphal cells from both species and was bordered on either side by the bladderlike cells of the pseudosclerotial plate of each species.

Comparison of malt agar with malt agar plus orthophenylphenol for isolating Armillariamellea and other fungi from conifer roots

1978 ◽  
Vol 8 (3) ◽  
pp. 348-351 ◽  
Author(s):  
R. D. Whitney ◽  
D. T. Myren ◽  
W. E. Britnell
Keyword(s):  
Agar Medium ◽  
Malt Agar ◽  
Fast Growing ◽  
Inhibiting Effect

Armillariamellea isolations from the roots of dead and dying conifer saplings increased by 40% when o-phenylphenol (OPP) was added to malt agar compared with isolations on malt agar alone; they were similar on the two media from the roots of larger, healthy trees. This is attributed largely to the inhibiting effect of the additive on fast-growing Hyphomycetes and other fungi which are far more abundant in the roots of dead or dying saplings than in the roots of healthy older trees. Decay-causing Basidiomycetes other than A. mellea were isolated less frequently, whereas bacteria and yeasts were isolated more frequently, when OPP was added to the malt agar medium. This suggests that the additive must be used with discretion.

OBSERVATIONS ON THE CULTURE AND MAINTENANCE OF A FREE-LIVING AMOEBA

1956 ◽  
Vol 2 (5) ◽  
pp. 511-513
Author(s):  
A. Bakerspigel
Keyword(s):  
Pure Culture ◽  
Agar Medium ◽  
Sole Source ◽  
Malt Agar ◽  
Free Living ◽  
Gram Negative ◽  
Negative Bacillus ◽  
The Past ◽  
Gram Negative Bacillus ◽  
Free Living Amoeba

A free-living amoeba isolated from creek water could be grown at 24 °C. on a solid malt agar medium together with a pure culture of a motile Gram-negative bacillus, isolated from the same sample of water. The bacilli apparently served as the sole source of food for the trophozoites, the malt in the medium being-utilized by the bacilli for their own growth. In addition, the encysted form has been maintained on this medium at 24 °C. for the past 12 months and at 4 °C. for 10 months. Transfers to fresh medium of cysts from such cultures yielded numerous trophozoites after 12 hr. incubation at 24 °C, provided that metabolically active bacilli were present.

Benzoic and salicylic acids isolated from a glycoside of aspen bark and their effect on Hypoxylon pruinatum

1969 ◽  
Vol 47 (8) ◽  
pp. 1295-1301 ◽  
Author(s):  
Martin Hubbes
Keyword(s):  
Salicylic Acid ◽  
Benzoic Acid ◽  
Thin Layer ◽  
Agar Medium ◽  
Synthetic Medium ◽  
Malt Agar ◽  
Inhibition Of Growth ◽  
Total Inhibition ◽  
Layer Chromatography ◽  
Salicylic Acids

Benzoic and salicylic acids, isolated from an unknown glycoside of aspen bark, were identified as the main fungistatic factors of this compound against Hypoxylon pruinatum (Klotzsche) Cke. The identity of the carboxylic acids was established by thin-layer chromatography and ultraviolet and infrared spectrophotometry.On a malt agar medium, benzoic acid inhibited the growth of the fungus at 1 × 10−3 M, whereas salicylic acid at the same concentration stimulated growth. Complete inhibition of growth of the fungus was obtained with benzoic acid at a concentration of 4 × 10−3 M and with salicylic acid at 5 × 10−3 M. Total inhibition was also obtained when both benzoic and salicylic acids, each at a concentration of 2 × 10−3 M, were simultaneously present in the malt agar medium.On a synthetic medium, benzoic acid and glucose, each at a concentration of 1 × 10−3 M, inhibited the growth of the fungus. At this concentration salicylic acid had no effect.When ammonium nitrate was replaced simultaneously by asparagine, alanine, and glutamine, benzoic acid at 2 × 10−3 M, and glucose at 3 × 10−3 M promoted the growth of the fungus. The same growth was also obtained when benzoic acid at 1 × 10−3 M and glucose at 1 × 10−3 M were both added to the medium.

scholarly journals New Chromogenic Agar Medium for the Identification of Candida spp

2002 ◽  
Vol 68 (7) ◽  
pp. 3622-3627 ◽  
Author(s):  
Venitia M. Cooke ◽  
R. J. Miles ◽  
R. G. Price ◽  
G. Midgley ◽  
W. Khamri ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Agar Medium ◽  
Candida Guilliermondii ◽  
Candida Spp ◽  
Candida Kefyr ◽  
Chromogenic Agar ◽  
Colony Color ◽  
Increased Sensitivity ◽  
Candida Lusitaniae ◽  
Precise Assessment

ABSTRACT A new chromogenic agar medium (Candida diagnostic agar [CDA]) for differentiation of Candida spp. is described. This medium is based on Sabouraud dextrose agar (Oxoid CM41) and contains (per liter) 40.0 g of glucose, 10.0 g of mycological peptone, and 15.0 g of agar along with a novel chromogenic glucosaminidase substrate, ammonium 4-{2-[4-(2-acetamido-2-deoxy-β-d-glucopyranosyloxy)-3-methoxyphenyl]-vinyl}-1-(propan-3-yl-oate)-quinolium bromide (0.32 g liter−1). The glucosaminidase substrate in CDA was hydrolyzed by Candida albicans and Candida dubliniensis, yielding white colonies with deep-red spots on a yellow transparent background after 24 to 48 h of incubation at 37°C. Colonies of Candida tropicalis and Candida kefyr were uniformly pink, and colonies of other Candida spp., including Candida glabrata and Candida parapsilosis, were white. CDA was evaluated by using 115 test strains of Candida spp. and other clinically important yeasts and was compared with two commercially available chromogenic agars (Candida ID agar [bioMerieux] and CHROMagar Candida [CHROMagar Company Ltd.]). On all three agars, colonies of C. albicans were not distinguished from colonies of C. dubliniensis. However, for the group containing C. albicans plus C. dubliniensis, both the sensitivity and the specificity of detection when CDA was used were 100%, compared with values of 97.6 and 100%, respectively, with CHROMagar Candida and 100 and 96.8%, respectively, with Candida ID agar. In addition, for the group containing C. tropicalis plus C. kefyr, the sensitivity and specificity of detection when CDA was used were also 100%, compared with 72.7 and 98.1%, respectively, with CHROMagar Candida. Candida ID agar did not differentiate C. tropicalis and C. kefyr strains but did differentiate members of a broader group (C. tropicalis, C. kefyr, Candida lusitaniae plus Candida guilliermondii); the sensitivity and specificity of detection for members of this group were 94.7 and 93.8%, respectively. In addition to the increased sensitivity and/or specificity of Candida detection when CDA was used, differentiation of colony types on CDA (red spotted, pink, or no color) was unambiguous and did not require precise assessment of colony color.

scholarly journals The studies on ash dying (Fraxinus excelsior L.) in the Włoszczowa Forest Unit stands

2012 ◽  
Vol 58 (2) ◽  
pp. 429-440 ◽  
Author(s):  
Tadeusz Kowalski ◽  
Agata Łukomska
Keyword(s):  
Alternaria Alternata ◽  
Agar Medium ◽  
Fraxinus Excelsior ◽  
Malt Agar ◽  
Tree Age ◽  
Frequency Of Occurrence ◽  
Disease Symptoms ◽  
Cylindrocarpon Destructans ◽  
Fusarium Lateritium ◽  
Identification Of Fungi

The studies were carried out in the Włoszczowa Forest Unit, in 9 ash stands differing in respect of age, origin (natural, artificial), site and in the nursery on 3 quarters differing due to a silvicultural method (transplanted and not transplanted) and seedlings age. In each stand an analysis of disease symptoms was carried out on 100 trees (2 - 20 years old stands) or 50 trees (21 - 80 years old stands) growing side by side in central part of the stand, while in the nursery in each block 200 seedlings were analyzed (4 sectors with 50 seedlings each). From the infected seedlings and trees 120 fragments of dead branches, living branches with cankers, and dead roots were taken. Identification of fungi was made on the basis of fructification and over 300 isolations of fungi on malt agar medium. The most frequent disease symptoms in ash stands were: the dead top (34.7% trees), the dying of whole branches (83.5%), the dying of the top of branches (20.1%), the occurrence of healed (36.0%) and unhealed cankers (18.9%) and the slime flux (23.7%) on the trunk, also the chlorosis of leaves (7.5%) and their atrophy (11.2%). Most of the types of disease symptoms appeared irrespectively of the tree age, origin and site, sometimes showing only a difference in the frequency of occurrence. On the seedlings in the nursery the shoot discolouration, healed and unhealed cankers on shoots and necrosis of a part of leaves were recorded most frequently. Disease symptoms occurred more frequently on 4-year-old seedlings in comparison with 3-year-old. In respect of transplanted seedlings the leaves dying was more frequent. Within cankers and on dead tops of shoots the most frequent were: <i>Alternaria alternata</i>, <i>Chalara</i> sp., <i>Cytospora ambiens</i>, <i>Diplodia mutila</i>, <i>Fusarium lateritium</i>, <i>Gloeosporidiella turgida</i>, <i>Phomopsis controversa</i> and <i>Phomopsis scobina</i>. In sparsely found dead roots of living trees appeared mostly: <i>Cryptosporiopsis radicicola</i>, <i>Cylindrocarpon destructans</i> and <i>Phialocephala</i> sp.

Applying Item Response Theory Modeling to Identify Social (Pragmatic) Communication Disorder

2020 ◽  
Vol 63 (6) ◽  
pp. 1916-1932 ◽  
Author(s):  
Haiying Yuan ◽  
Christine Dollaghan
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Sensitivity And Specificity ◽  
Social Communication ◽  
National Database ◽  
Communication Disorder ◽  
Social Communication Questionnaire ◽  
Autism Research ◽  
The Social ◽  
Pragmatic Communication

Purpose No diagnostic tools exist for identifying social (pragmatic) communication disorder (SPCD), a new Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition category for individuals with social communication deficits but not the repetitive, restricted behaviors and interests (RRBIs) that would qualify them for a diagnosis of autism spectrum disorder (ASD). We explored the value of items from a widely used screening measure of ASD for distinguishing SPCD from typical controls (TC; Aim 1) and from ASD (Aim 2). Method We applied item response theory (IRT) modeling to Social Communication Questionnaire–Lifetime ( Rutter, Bailey, & Lord, 2003 ) records available in the National Database for Autism Research. We defined records from putative SPCD ( n = 54), ASD ( n = 278), and TC ( n = 274) groups retrospectively, based on National Database for Autism Research classifications and Autism Diagnostic Interview–Revised responses. After assessing model assumptions, estimating model parameters, and measuring model fit, we identified items in the social communication and RRBI domains that were maximally informative in differentiating the groups. Results IRT modeling identified a set of seven social communication items that distinguished SPCD from TC with sensitivity and specificity > 80%. A set of five RRBI items was less successful in distinguishing SPCD from ASD (sensitivity and specificity < 70%). Conclusion The IRT modeling approach and the Social Communication Questionnaire–Lifetime item sets it identified may be useful in efforts to construct screening and diagnostic measures for SPCD.

IgA-antitissue transglutaminase: Sensitivity and specificity for diagnosing Celiac Disease

2001 ◽  
Vol 120 (5) ◽  
pp. A395-A395
Author(s):  
J WEST ◽  
A LLOYD ◽  
P HILL ◽  
G HOLMES
Keyword(s):  
Celiac Disease ◽  
Sensitivity And Specificity
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