Morphological recognition of fungal spore germination by a computer-aided image analysis and its application to antifungal activity evaluation

Oh, Ki‐Bong; Chen, Yuansong; Matsuoka, Hiroaki; Yamamoto, Akira; Kurata, Hiroshi

doi:10.1016/0168-1656(95)00148-4

Cited by 20 publications

(11 citation statements)

References 15 publications

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“…Traditional germination assays, in which germination is evaluated by microscopic observations, are too labor-intensive to be used in screening large compound libraries for discovery of new antifungal agents. While computer-aided image analysis has been used as an alternative to visual evaluation of spores (15), it requires sophisticated equipment and has not been widely applied. In contrast, our spore adhesion assays provide a simple, rapid, and efficient means to evaluate inhibition of spore germination within a few hours and are amenable to high-throughput screening.…”

Section: Discussionmentioning

confidence: 99%

Novel Fungitoxicity Assays for Inhibition of Germination-Associated Adhesion of Botrytis cinerea and Puccinia recondita Spores

Slawecki

Ryan

Young

2002

Appl Environ Microbiol

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Botrytis cinerea and Puccinia recondita spores adhere strongly to polystyrene microtiter plates coincident with germination. We developed assays for inhibition of spore adhesion in 96-well microtiter plates by using sulforhodamine B staining to quantify the adherent spores. In both organisms, fungicides that inhibited germination strongly inhibited spore adhesion, with 50% effective concentrations (EC 50 s) comparable to those for inhibition of germination. In contrast, fungicides that acted after germination in B. cinerea inhibited spore adhesion to microtiter plates only at concentrations much higher than their EC 50 s for inhibition of mycelial growth. Similarly, in P. recondita the ergosterol biosynthesis inhibitors myclobutanil and fenbuconazole acted after germination and did not inhibit spore adhesion. The assays provide a rapid, high-throughput alternative to traditional spore germination assays and may be applicable to other fungi.Various methods have been used to measure the sensitivity of filamentous fungi to antifungal compounds. Measurement of the inhibition of spore germination is one such technique. Since spore germination occurs very rapidly for many fungi, this approach frequently allows a fungitoxic effect to be measured within a few hours rather than one or more days, as is typical for methods based on inhibition of mycelial growth. A major disadvantage of spore germination tests for measuring fungitoxicity is the need for labor-intensive microscopic evaluation to assess germination. This problem has essentially precluded the use of germination assays in large-scale fungicide screening operations designed to discover new antifungal compounds.Germination assays are also very useful for evaluating the mechanism of action of antifungal compounds. For many compounds, spore germination is the growth stage that is most sensitive to inhibition. For example, the strobilurin class of fungicides, which block electron transport at the cytochrome bc 1 complex of the mitochondrial electron transport chain, are extremely potent inhibitors of spore germination but much less active as inhibitors of mycelial growth (19). On the other hand, many fungicides have little or no effect on spore germination but strongly inhibit mycelial growth. Examples of fungicides that typically act after germination in filamentous fungi include antimicrotubule agents, e.g., carbendazim and N-phenylcarbamates, which inhibit nuclear division (22), and inhibitors of ergosterol biosynthesis (4,20). Consequently, comparison of the potency of a compound as an inhibitor of germination with its activity in a mycelial growth assay can provide preliminary information on its mode of action.Botrytis cinerea is the causal agent of grey mold disease on a variety of fruits, vegetables, and field crops (1). Puccinia recondita f. sp. tritici, the causal agent of wheat leaf rust, is one of the most economically important pathogens of wheat (24). Because it is an obligate pathogen, methods for measuring in vitro fungitoxicity based on inhibition of...

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Section: Discussionmentioning

confidence: 99%

Novel Fungitoxicity Assays for Inhibition of Germination-Associated Adhesion of Botrytis cinerea and Puccinia recondita Spores

Slawecki

Ryan

Young

2002

Appl Environ Microbiol

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“…Many researchers have reported that microscopic examination and measurement of absorbance of preheated spores during the early stage of incubation revealed gradual swelling and loss of refractiveness. These morphological changes correspond to the initiation of spore germination and the decrease in absorbance of the spore suspension (Rousseau et al 1972;Al-Khayat et al 1987;Oh et al 1996;Cho et al 1997). The results shown in Fig.…”

Section: Discussionmentioning

confidence: 99%

GERMINATION AND SUBSEQUENT INACTIVATION OFBACILLUS SUBTILISSPORES BY PULSED ELECTRIC FIELD TREATMENT

Shin

Lee

Cho³

et al. 2010

Journal of Food Processing and Preservation

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The use of high‐intensity pulsed electric field (PEF) as a nonthermal method for triggering spore germination was investigated. Spores suspended in 0.01% NaCl solution (ca. 108cells/mL) were treated with an exponential‐decay pulse (20–50 kV/cm) at selected temperatures. The inactivation resulting from the direct effect of PEF treatment was less than 0.5 log cycles, even with a relatively high electric field intensity of 40 kV/cm. Most of the surviving PEF‐treated spores germinated after inoculation into selected germination media (0.85% NaCl solution, nutrient broth [NB], or tryptic soy broth [TSB]) and subsequent incubation at 37C for 40 min. The extent of germination increased with the treatment temperature and electric field intensity. More than 98% of surviving spores in TSB germinated during incubation after PEF treatment with an electric field strength of 40 kV/cm for 1,000 µs at 50C. The rate of germination in nutrient‐rich TSB medium was higher than that in NB. PRACTICAL APPLICATIONS High‐intensity pulsed electric field (PEF) treatments have been studied recently as an alternative method of conventional thermal sterilization. High‐intensity PEF inactivation of microorganisms can be carried out at ambient temperature with a short treatment time of seconds or less without inducing a significant temperature increase. Considerable research has been conducted on the inactivation of microbial cells using PEF. However, a major obstacle to the application of PEF as a technology for the preservation of foods and pharmaceuticals is that it is inefficient at inactivating bacterial spores. Bacterial spores are also resistant to inactivation by adverse physical and chemical agents. Methods to overcome this problem have been studied extensively with the aim of establishing reliable sterilization procedures for the food and pharmaceutical industries.

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“…In Oh et al (1996), a binary-class classification system is developed to distinguish the activity of fungi spores. In this work, microscopic videos are first converted into individual images (frames), then image segmentation, four shape features and morphological decision values are applied.…”

Section: Overview Of MM Classificationmentioning

confidence: 99%

“…Beneficial AMs can help farmers to increase the agricultural yields, for Shabtai et al (1996), Ronen et al (2002) IM 1998 Gerlach SR et al Gerlach et al (1998) IM 2001 Lee MS et al Lee et al (2001) IM 2002 Lomander A et al Lomander et al (2002) IM 2002 Park JP et al Park et al (2002) IM 2007 Lecault V et al Lecault et al (2007) IM 2011 Yu B et al Yu et al (2011) MM 1992 Reichl U et al Reichl et al (1992) MM 1994 Pichon D et al Pichon et al (1994) MM 1996 Oh B et al Oh et al (1996) MM 1997 Tamura S et al Tamura et al (1997) MM 1998 Veropoulos K et al Veropoulos et al (1998) MM 1998 Wit P et al Wit and Busscher (1998) MM 1999 Kay JW et al Kay et al (1999) MM 2000 Khutlang R et al Khutlang et al (2009Khutlang et al ( , 2010a MM 2011 Rulaningtyas R et al Rulaningtyas et al (2011) MM 2011 Pangilinan C et al Pangilinan et al (2011) MM 2011-2012Osman MK et al Osman et al (2011a, b, 2012 MM 2012 Chang J et al Chang et al (2012b) MM 2012-2016 Priya E et al Priya et al (2012), Srinivasan (2015a, b, 2016) Culverhouse et al (1994Culverhouse et al ( , 1996Culverhouse et al ( , 2000Culverhouse et al ( , 2003Culverhouse et al ( , 2006a WM 1995 Thiel S et al Thiel and Davies (1995), …”

Section: Application Domain Introductionmentioning

confidence: 99%

A survey for the applications of content-based microscopic image analysis in microorganism classification domains

Wang

2017

Artif Intell Rev

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Microorganisms such as protozoa and bacteria play very important roles in many practical domains, like agriculture, industry and medicine. To explore functions of different categories of microorganisms is a fundamental work in biological studies, which can assist biologists and related scientists to get to know more properties, habits and characteristics of these tiny but obbligato living beings. However, taxonomy of microorganisms (microorganism classification) is traditionally investigated through morphological, chemical or physical analysis, which is time and money consuming. In order to overcome this, since the 1970s innovative content-based microscopic image analysis (CBMIA) approaches are introduced to microbiological fields. CBMIA methods classify microorganisms into different categories using multiple artificial intelligence approaches, such as machine vision, pattern recognition and machine learning algorithms. Furthermore, because CBMIA approaches are semior full-automatic computer-based methods, they are very efficient and labour cost saving, supporting a technical feasibility for microorganism classification in our current big data age. In this article, we review the development history of microorganism classification using CBMIA approaches with two crossed pipelines. In the first pipeline, all related works are grouped by their corresponding microorganism application domains. By this pipeline, it is easy for microbiologists to have an insight into each special application domain and find their interested applied CBMIA techniques. In the second pipeline, the related works in each application domain are reviewed by time periods. Using this pipeline, computer scientists can see the dynamic of technological development clearly and keep up with the future devel-

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Morphological recognition of fungal spore germination by a computer-aided image analysis and its application to antifungal activity evaluation

Cited by 20 publications

References 15 publications

Novel Fungitoxicity Assays for Inhibition of Germination-Associated Adhesion of Botrytis cinerea and Puccinia recondita Spores

Novel Fungitoxicity Assays for Inhibition of Germination-Associated Adhesion of Botrytis cinerea and Puccinia recondita Spores

GERMINATION AND SUBSEQUENT INACTIVATION OFBACILLUS SUBTILISSPORES BY PULSED ELECTRIC FIELD TREATMENT

A survey for the applications of content-based microscopic image analysis in microorganism classification domains

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