A Semi-Selective agar medium to detect the presence of Xanthomonas axonopodis pv. malvacearum in naturally infected cotton seed

A semi-selective agar medium was developed for detection of Xanthomonas axonopodis pv. malvacearum (Xam) in cotton (Gossypium hirsutum) seed. The basic medium was peptone-sucrose-agar (PSA). Criteria for the semi-selective medium were the typical colony characters of Xam and its pathogenicity on cotton. Several systemic fungicides and antibiotics in different concentrations were tested alone or in combination with others. The final composition of the semi-selective agar medium was established after several attempts in order to inhibit most of the fungal and bacterial saprophytes and favour the development of Xam. It contained PSA + cyclohexamide, cephalexin, pencycuron, triadimenol and tolylfluanid. The bacteria were recovered from naturally infected seeds by the direct plating of 2,000 surface disinfected seeds on the semi-selective medium. The recovery of the pathogen from naturally infected leaf tissues and in dilution plating, on semi-selective medium and on nutrient agar, were comparable. Among the three detection methods tested, the semi-selective medium was found to be the most reliable and quantifiable. Degree of severity of angular leaf spot in the field was not always correlated with the level of infection in the seed. This is the first report of a semi-selective agar medium to detect the presence of Xam in naturally infected cotton seed.

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On the relation of colony variants to the time dependency of colony formation during adaptive mutation of Escherichia coli FC40

Canadian Journal of Microbiology ◽

10.1139/m97-128 ◽

1997 ◽

Vol 43 (9) ◽

pp. 884-886 ◽

Cited By ~ 1

Author(s):

Patricia R. MacLeod ◽

Robert A. MacLeod

Keyword(s):

Escherichia Coli ◽

Carbon Source ◽

Pure Culture ◽

Colony Formation ◽

Agar Medium ◽

Selective Medium ◽

Adaptive Mutation ◽

Time Dependency ◽

Colony Type ◽

Selective Agar

When Escherichia coli FC40 formed adaptive Lac+ revenants on a selective agar medium containing lactose as the carbon source, the colonies which accumulated over several days were of two readily distinguishable types. Colonies of both types appeared both early and late on the plates. Cells of colonies that appeared early and late on the plates, irrespective of the type, when grown in liquid medium and replated, all formed colonies on the selective medium within 48 h. Cells of each colony type gave rise to colonies of both types and attempts to isolate cells of each type in pure culture were unsuccessful. It was concluded that the presence of two colony types in the cultures plated did not contribute to the observed time dependency of colony formation during adaptive mutation. The proportions of the two colony types arising from cultures of the Lac+ revertants varied from culture to culture.Key words: Escherichia coli FC40, variants, adaptive mutation, colony accumulation.

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Development of an Improved Selective Agar Medium for Isolation of Yersinia pestis

Applied and Environmental Microbiology ◽

10.1128/aem.69.10.5787-5792.2003 ◽

2003 ◽

Vol 69 (10) ◽

pp. 5787-5792 ◽

Cited By ~ 37

Author(s):

Raphael Ber ◽

Emanuelle Mamroud ◽

Moshe Aftalion ◽

Avital Tidhar ◽

David Gur ◽

...

Keyword(s):

Yersinia Pestis ◽

Quantitative Evaluation ◽

Fluorescent Protein ◽

Agar Medium ◽

Brain Heart Infusion ◽

Selective Medium ◽

Bacterial Populations ◽

Medium Components ◽

Selective Agar ◽

Green Fluorescent

ABSTRACT Existing media designed for selective isolation of clinically important members of the genus Yersinia were found to be unsatisfactory for the growth and isolation of Yersinia pestis. We report the development of a new selective agar medium (termed BIN) that supports the growth of Y. pestis. The development of the formulation of this medium was based on a fluorescence screening system designed for monitoring bacterial growth on semisolid media, using a green fluorescent protein-expressing strain. High-throughput combinatorial experiments can be conducted for the quantitative evaluation of the effect of different medium components on growth. Generation of fluorescence plots in this system, using microplates, allowed the quantitative evaluation of the growth rate of Y. pestis EV76 cultures in different agar compositions. The final BIN formulation is based on brain heart infusion agar, to which the selective agents irgasan, cholate salts, crystal violet, and nystatin were introduced. It was found that BIN agar is more efficient in supporting colony formation and recovery of Y. pestis than are the conventional semisolid media MacConkey agar and Yersinia-selective agar (cefsulodin-irgasan-novobiocin agar). The advantage of BIN over other media has been also demonstrated in recovering virulent Y. pestis from the mixed bacterial populations found in decaying carcasses of infected mice. The BIN medium is suggested as a selective medium for isolation and recovery of Y. pestis from various backgrounds.

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Xylose-Lysine-Tergitol 4: An Improved Selective Agar Medium for the Isolation of Salmonella

Poultry Science ◽

10.3382/ps.0702429 ◽

1991 ◽

Vol 70 (12) ◽

pp. 2429-2432 ◽

Cited By ~ 49

Author(s):

RUSSELL G. MILLER ◽

C.R. TATE ◽

E.T. MALLINSON ◽

J.A. SCHERRER

Keyword(s):

Agar Medium ◽

Selective Agar

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Assessment of different selective agar media for enumeration and isolation ofListeriafrom dairy products

Journal of Dairy Research ◽

10.1017/s0022029900033367 ◽

1988 ◽

Vol 55 (4) ◽

pp. 579-583 ◽

Cited By ~ 1

Author(s):

Lucas Dominguez ◽

José Francisco Fernández ◽

Victor Briones ◽

José Luis Blanco ◽

Guillermo Suárez

Keyword(s):

Dairy Products ◽

Agar Medium ◽

Raw Milk ◽

Superior Performance ◽

Direct Plating ◽

Selective Agar ◽

Natural Microflora ◽

Agar Media ◽

The Difference ◽

Better Than

SummaryDifferent selective agar media were compared for the recovery and isolation of five species ofListeriafrom raw milk and cheese. The selective media examined were Beerens medium, MacBride medium and that described by Dominguezet al.(1984) with 6 mg/1 acriflavine, listeria selective agar medium (LSAM), and LSAM with 12 mg/1 acriflavine (LSAM × 2A); a non-selective yeast glucose Lemco agar was included for comparison. When the difference between listeria and the natural microflora of raw milk and cheese was 102cfu/ml, listeria could be isolated by direct plating on all media tested. When it was lower than 103–104cfu/ml, listeria were isolated by direct plating only on LSAM and LSAM × 2A. When the difference was greater than 104cfu/ml, a previous enrichment was necessary to isolate them. LSAM and LSAM × 2A media performed better than the other media tested for isolating listeria by direct plating and improved their isolation from dairy products. This superior performance was evaluated by the ability of these media to support colony formation of different species ofListeriatested, the easy recognition of these colonies from those formed by other microorganisms and by their capacity to inhibit the natural microflora of these foods.

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Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

Toxins ◽

10.3390/toxins10120519 ◽

2018 ◽

Vol 10 (12) ◽

pp. 519 ◽

Cited By ~ 1

Author(s):

Kimiko Yabe ◽

Haruna Ozaki ◽

Takuya Maruyama ◽

Keisuke Hayashi ◽

Yuki Matto ◽

...

Keyword(s):

Culture Medium ◽

Agar Medium ◽

Carbon Sources ◽

Tween 80 ◽

Selective Medium ◽

Selective Detection ◽

Aflatoxigenic Fungi ◽

Aspergillus Nomius ◽

Rhizopus Sp ◽

Triton X

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.

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First Report of Leaf Spot Disease on Schisandra chinensis Caused by Phoma glomerata in China

Plant Disease ◽

10.1094/pdis-09-11-0760 ◽

2012 ◽

Vol 96 (2) ◽

pp. 289-289 ◽

Cited By ~ 2

Author(s):

X. Wang ◽

J. Wang ◽

J. Gao ◽

L. Yang

Keyword(s):

Leaf Spot ◽

Sequence Data ◽

Leaf Spot Disease ◽

Infected Leaf ◽

Its Sequence ◽

Schisandra Chinensis ◽

Water Control ◽

First Report ◽

Spot Disease ◽

Leaf Tissues

Schisandra chinensis (Turcz.) Baill is a perennial liana belonging to the Schisandra genus of the family Magnoliaceae, which is cultivated in China as an important medicinal plant. In the summer of 2008, we observed a previously unknown foliar disease on the schisandras in Jingyu and Antu counties and the cities of Ji'an and Hunchun in Jilin Province. Symptoms appeared on the apex, margin, and center of leaves. The infection initially manifested as pale brown, small, necrotic spots on the leaves. Subsequently, these lesions became grayish brown in the center and dark brown with slight protuberances at the margins. Finally, these lesions developed concentric rings with a clear boundary separating them from the healthy tissue, were round to elliptical or irregular in shape, and had a diameter of 3 to 5 mm. In severely infected leaves, these spots eventually covered the entire leaf. Black spots (pycnidia) were produced on the infected leaf tissues in a humid environment. Fungus from infected leaf tissues was isolated on potato dextrose agar. The cultures were initially pale brown and turned dark green with age. Embedded pycnidia were generally formed after 5 days. The pycnidia were agglutinating, globose to subglobose, and measured 60.0 to 212.0 × 33.6 to 268.0 μm. Abundant conidia (4.06 to 7.2 × 1.65 to 3.53 μm) exhibiting zero to three oil droplets were produced by an 8-day-old colony; these conidia were ovoid or ellipsoidal, colorless, and aseptate; they were similar to conidia of Phoma glomerata. The internal transcribed spacer (ITS) sequence of rDNA of the isolated pathogenic strain (PG11; GenBank Accession No. GU724511) had 100% identity to P. glomerata (GenBank Accession No. HM769279). Therefore, the pathogen was identified as P. glomerata (Corda) Wollenw. & Hochapfel on the basis of morphology and ITS sequence data. To validate Koch's postulates, schisandra leaves were spray inoculated with a 2.5 × 105 conidia/ml suspension of the isolated pathogen. An equal number of healthy plants were inoculated with sterile water (control). After inoculation, 10 plants were covered with plastic bags for 3 days and maintained in a growth chamber at 25°C. After 8 days, all inoculated plants showed symptoms identical to those observed on the schisandra leaves infected in the field, whereas the controls did not show any symptoms. Reisolation of the fungi from lesions of inoculated leaves confirmed that the causal agent was P. glomerata. Diseases caused by P. glomerata have been reported on some plants (1,2). However, to our knowledge, this is the first report of leaf spot disease caused by P. glomerata on S. chinensis in China as well as in the world. References: (1) J. S. Chohan et al. Trans. Br. Mycol. Soc. 75:509, 1980. (2) T. Thomidis et al. Eur. J. Plant Pathol. 131:171,2011.

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Direct isolation of atypical thermophilic Campylobacter species from human feces on selective agar medium.

Journal of Clinical Microbiology ◽

10.1128/jcm.27.4.668-670.1989 ◽

1989 ◽

Vol 27 (4) ◽

pp. 668-670 ◽

Cited By ~ 19

Author(s):

S L Walmsley ◽

M A Karmali

Keyword(s):

Agar Medium ◽

Human Feces ◽

Thermophilic Campylobacter ◽

Selective Agar ◽

Campylobacter Species

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A selective medium for the isolation of the acinetobacter genus bacteria

Memórias do Instituto Oswaldo Cruz ◽

10.1590/s0074-02761980000200002 ◽

1980 ◽

Vol 75 (3-4) ◽

pp. 11-21 ◽

Cited By ~ 1

Author(s):

Altair A. Zebral

Keyword(s):

Yeast Extract ◽

Crystal Violet ◽

Sodium Citrate ◽

Agar Medium ◽

Selective Medium ◽

Phenol Red ◽

Gram Positive ◽

Gram Negative ◽

Fermentative Activity

A selective and differencial medium was developed for the isolation of Acinetobacter genus bacteria. This Acinobacter Agar Medium (p.H + 7.4) contains in grams per litre: thiotone, 10; yeast extract, 3; naC1, 5; saccharose, 10; mannitol, 10; sodium citrate, 0.5; sodium desoxycholate, 0.1; crystal violet, 0.00025; phenol red, 0.04 and agar-agar 15. This medium has the advantage of inhibiting the growth of cocci and Gram-positive bacilli, by the use of sodium citrate and sodium desoxycholate associated with the crystal violet; and of differentiating the Gram-negative bacilli from the Enterobacteriaceae, through the fermentative activity upon the saccharose and/or mannitol, contrasting with the complete inactivity of the Acinetobacter genus bacteria over those substances.

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Procedures for Recovery of Stressed and Injured Cells of Yersinia Enterocolitica from Meat and Meat Products

Journal of Food Protection ◽

10.4315/0362-028x-52.5.360 ◽

1989 ◽

Vol 52 (5) ◽

pp. 360-362 ◽

Cited By ~ 3

Author(s):

ZHEKO KOUNEV

Keyword(s):

Yersinia Enterocolitica ◽

Agar Medium ◽

Alkali Treatment ◽

Meat Products ◽

The Other ◽

Step Procedure ◽

Selective Agar ◽

Agar Media ◽

Phosphate Buffered Saline

A new three-step procedure (TSP) for the recovery of Yersinia enterocolitica 0:3 from frozen meat, salted and dried meat products, raw dried meat products, and cooked perishable sausages, has been developed. The TSP is based mainly on enrichment in 0.15 M phosphate-buffered saline at 25°C. In the TSP, selected dilutions of samples are enriched for 1, 2, 3, 4, 24, and 48 h and then plated onto nonselective and selective agar media after or without alkali treatment. Additional enrichment was performed with half of the samples at 25°C for 24 h, and the rest at 4°C for up to 2 wk, followed by alkali treatment and plating on selective agar medium. Recovery of Y. enterocolitica was better using the TSP than the other method used for isolating the organism from meats.

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