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First Report of Gray Leaf Spot of Mango (Mangifera indica) Caused by Pestalotiopsis mangiferae in Taiwan

Ko Y, Yao KS, Chen CY, Lin CH

Plant Dis, 2007 Dec;91(12):1684.
PMID: 30780618 DOI: 10.1094/PDIS-91-12-1684B

Mango (Mangifera indica L.; family Anacardiaceae) is one of the world's most important fruit crops and is widely grown in tropical and subtropical regions. Since 2001, a leaf spot disease was found in mango orchards of Taiwan. Now, the disease was observed throughout (approximately 21,000 ha) Taiwan in moderate to severe form, thus affecting the general health of mango trees and orchards. Initial symptoms were small, yellow-to-brown spots on leaves. Later, the irregularly shaped spots, ranging from a few millimeters to a few centimeters in diameter, turned white to gray and coalesced to form larger gray patches. Lesions had slightly raised dark margins. On mature lesions, numerous black acervuli, measuring 290 to 328 μm in diameter, developed on the gray necrotic areas. Single conidial isolates of the fungus were identified morphologically as Pestalotiopsis mangiferae (Henn.) Steyaert (2,3) and were consistently isolated from the diseased mango leaves on acidified (0.06% lactic acid) potato dextrose agar (PDA) medium incubated at 25 ± 1°C. Initially, the fungus grew (3 mm per day) on PDA as a white, chalky colony that subsequently turned gray after 2 weeks. Acervuli developed in culture after continuous exposure to light for 9 to 12 days at 20 to 30°C. Abundant conidia oozed from the acervulus as a creamy mass. The conidia (17.6 to 25.4 μm long and 4.8 to 7.1 μm wide) were fusiform and usually straight to slightly curved with four septa. Three median cells were olivaceous and larger than the hyaline apical and basal cells. The apical cells bore three (rarely four) cylindrical appendages. Pathogenicity tests were conducted with either 3-day-old mycelial discs or conidial suspension (105 conidia per ml) obtained from 8- to 10-day-old cultures. Four leaves on each of 10 trees were inoculated. Before inoculation, the leaves were washed with a mild detergent, rinsed with tap water, and then surface sterilized with 70% ethanol. Leaves were wounded with a needle and exposed to either a 5-mm mycelial disc or 0.2 ml of the spore suspension. The inoculated areas were wrapped with cotton pads saturated with sterile water and the leaves were covered with polyethylene bags for 3 days to maintain high relative humidity. Wounded leaves inoculated with PDA discs alone served as controls. The symptoms described above were observed on all inoculated leaves, whereas uninoculated leaves remained completely free from symptoms. Reisolation from the inoculated leaves consistently yielded P. mangiferae, thus fulfilling Koch's postulates. Gray leaf spot is a common disease of mangos in the tropics and is widely distributed in Africa and Asia (1-3); however, to our knowledge, this is the first report of gray leaf spot disease affecting mango in Taiwan. References: (1) T. K. Lim and K. C. Khoo. Diseases and Disorders of Mango in Malaysia. Tropical Press. Malaysia, 1985. (2) J. E. M. Mordue. No. 676 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Surrey, England, 1980. (3) R. C. Ploetz et al. Compendium of Tropical Fruit Diseases. The American Phytopathological Society. St. Paul, MN, 1994.
First Report of Fruit Rot of Strawberry Caused by an Alternaria sp. in Taiwan

Ko Y, Chen CY, Yao KS, Liu CW, Maruthasalam S, Lin CH

Plant Dis, 2008 Aug;92(8):1248.
PMID: 30769472 DOI: 10.1094/PDIS-92-8-1248B

In March 2005, a fruit rot disease was found in several commercial strawberry (Fragaria × ananassa Duchesne) fields at Fongyuan, 24.25°N, 120.72°E, in Taichung County in central Taiwan. The disease was rare and was negligible in most cultivated areas. However, disease incidence has increased by 4 to 5% over the last 2 years and causes significant postharvest losses. In storage, symptoms on berries include light brown-to-black, sunken, irregularly shaped lesions. The lesions gradually enlarge and become firm with a dark green-to-black, velvety surface composed of mycelia, conidiophores, and conidia. Twelve single conidial isolates (AF-1 to AF-12) of a fungus were isolated by placing portions of symptomatic fruit from four locations onto acidified potato dextrose agar (PDA) and incubating at 24 ± 1°C. One isolate from each of the four locations, AF-2, 6, 9, and 12, was selected for identification and pathogenicity studies. The fungus was identified as an Alternaria sp. according to the morphological descriptions of A. tenuissima (2,3). Conidiophores were simple or branched, straight or flexuous, septate, pale to light brown, 3.0 to 5.0 μm in diameter, and bore two to six conidia in a chain. Conidia were dark brown, obclavate or oval, and multicellular with seven transverse (in most cases) and numerous longitudinal septa. Conidia were 15.5 to 56.5 μm (average 35.0 μm) long × 6.0 to 15.0 μm (average 11.0 μm) wide at the broadest point. The pathogen was consistently isolated from berries in the field or in storage. Pathogenicity tests were conducted by inoculating 12 surface-sterilized berries with each of the four isolates. Approximately 300 μl of a spore suspension (2 × 105 conidia per ml) was placed at two points on the uninjured surface of each fruit and allowed to dry for 5 min. Control fruits were treated with sterile water. The berries were then enclosed in a plastic bag and incubated at 24 ± 1°C for 2 days. Disease symptoms similar to those described above were observed on 95% of inoculated berries 3 days after inoculation, while no symptoms developed in control berries. Reisolation from the inoculated berries consistently yielded the Alternaria sp. described above. Pathogenicity tests were performed three times. Previously, strawberry fruit rot caused by A. tenuissima was reported from Florida (2) and Malaysia (1), however, to our knowledge, this is the first report of fruit rot of strawberry caused by a species of Alternaria in Taiwan. References: (1) W. D. Cho et al. List of Plant Diseases in Korea. Korean Society of Plant Pathology, 2004. (2) C. M. Howard and E. E. Albregts. Phytopathology 63:938, 1973. (3) R. D. Milholland. Phytopathology 63:1395, 1973.
First Report of Fruit Rot of Loquat Caused by an Alternaria sp. in Taiwan

Ko Y, Liu CW, Chen SS, Chen CY, Yao KS, Maruthasalam S, et al.

Plant Dis, 2010 Apr;94(4):481.
PMID: 30754488 DOI: 10.1094/PDIS-94-4-0481B

During March 2007, a fruit rot disease was observed in several loquat (Eriobotrya japonica (Thunberg) Lindley) fields located in Taichung, Nantou, and Miaoli counties. Loquat is a valuable fruit crop grown predominantly in central Taiwan, and hence, even a minor yield loss by this new disease is economically significant. Symptoms on fruits initially appeared as small lesions (<1 mm) that later developed into light-to-dark brown, circular, larger (7 mm), sunken lesions, indicating invasion of a pathogen into the fruit. Pieces of rotted fruit tissue (1 × 1 × 1 mm) were immersed for 1 min in 3% commercial bleach, followed by 70% ethanol, cultured on potato dextrose agar (PDA), and incubated under constant fluorescent light (185 ± 35 μE·m-2·s-1) at 24°C for 2 days. Three single conidial isolates (AS1 to AS3) were selected and used in morphological and pathogenicity studies. All three isolates were identified as an Alternaria sp. (1-3) and formed abundant, dark brown mycelium when cultured on PDA with light at 24°C. Conidiophores were 60 to 89 × 3 to 5 μm, densely fasciculate, cylindrical, simple or branched, and had distinct conidial scars. Conidia were 12 to 74 × 6 to 14 μm, golden brown, straight or curved, obclavate with beaks measuring half the length of the conidium, and observed in chains of 10 or more spores with four to seven transverse septa and several longitudinal septa. Pathogenicity tests were conducted twice by inoculating eight surface-sterilized wounded or unwounded fruits with each of the three isolates in each experiment. Two cuts (1 × 1 × 1 mm) were made on each fruit 3 cm apart with a sterile scalpel, and a 300-μl spore suspension (2 × 105 conidia per ml) was placed on each wound. Similarly, a 300-μl spore suspension was placed on unwounded fruits and air dried for 5 min. Control fruits were similarly treated with sterile water. Inoculated fruits were enclosed in a plastic bag and kept at 24 ± 1°C. Symptoms of soft rot were observed on 60% (unwounded) and 100% (wounded) of inoculated fruits 5 days after inoculation, while control fruits did not develop disease symptoms. Reisolation from the symptomatic fruits consistently yielded an Alternaria sp. This fungus previously has been reported as the causal agent of fruit rot or black spot of papaya, mango, kiwifruit, pear, and carambola from Australia, India, Malaysia, South Africa, and the United States (1-3). To our knowledge, this is the first report of fruit rot of loquat caused by an Alternaria sp. in Taiwan. To manage this disease, growers may resort to fungicidal sprays followed by bagging of fruits to reduce pre- and postharvest losses. References: (1) A. L. Jones and H. S. Aldwinckle. Compendium of Apple and Pear Diseases. The American Phytopathological Society. St. Paul, MN, 1990. (2) R. C. Ploetz. Diseases of Tropical Fruit Crops. CABI Publishing. Wallingford, Oxfordshire, UK, 2003. (3) R. C. Ploetz et al. Compendium of Tropical Fruit Diseases. The American Phytopathological Society. St. Paul, MN, 1994.
Development of Image-enhanced Endoscopy of the Gastrointestinal Tract: A Review of History and Current Evidences

Ho SH, Uedo N, Aso A, Shimizu S, Saito Y, Yao K, et al.

J Clin Gastroenterol, 2018 04;52(4):295-306.
PMID: 29210900 DOI: 10.1097/MCG.0000000000000960

Endoscopy imaging of the gastrointestinal (GI) tract has evolved tremendously over the last few decades. Key milestones in the development of endoscopy imaging include the use of various dyes for chromoendoscopy, the application of optical magnification in endoscopy, the introduction of high-definition image capturing and display technology and the application of altered illuminating light to achieve vascular and surface enhancement. Aims of this review paper are to summarize the development and evolution of modern endoscopy imaging and in particular, imaged-enhanced endoscopy (IEE), to promote appropriate usage, and to guide future development of good endoscopy practice. A search of PubMed database was performed to identify articles related to IEE of the GI tract. Where appropriate, landmark trials and high-quality meta-analyses and systematic reviews were used in the discussion. In this review, the developments and evolutions in endoscopy imaging and in particular, IEE, were summarized into discernible eras and the literature evidence with regard to the strengths and weaknesses in term of their detection and characterization capability in each of these eras were discussed. It is in the authors' opinion that IEE is capable of fairly good detection and accurate characterization of various GI lesions but such benefits may not be readily reaped by those who are new in the field of luminal endoscopy. Exposure and training in making confident diagnoses using these endoscopy imaging technologies are required in tandem with these new developments in order to fully embrace and adopt the benefits.
Fulltext Utility of a standardized training program for endoscopic diagnosis of early gastrointestinal neoplasia

Chiu PW, Sano Y, Uedo N, Singh R, Ng EKW, Aang TL, et al.

Endosc Int Open, 2019 Apr;7(4):E452-E458.
PMID: 30931377 DOI: 10.1055/a-0854-3525

Background and study aims Image enhanced endoscopy (IEE) allows endoscopists to improve recognition and characterization of gastrointestinal neoplasia. The Asian Novel Bio-Imaging and Intervention Group (ANBIG) conducted a standardized training program in endoscopic diagnosis and treatment of early gastrointestinal cancers in Asia. We embarked on a study to investigate the effect of this module on endoscopic diagnosis of early gastrointestinal neoplasia. Methods This prospectively collected database was from workshops conducted on training for endoscopic diagnosis of early gastrointestinal neoplasia. All workshops were conducted in a standardized format, which included a pretest, a learning phase consisting of didactic lectures, case discussion, and live demonstration followed by a post-test to assess knowledge gained. The pretest and post-training tests were standardized questions addressing four domains, including basic knowledge of imaging and diagnosis of esophageal, gastric, and colonic neoplasia. Results From November 2013 to November 2016, 41 ANBIG workshops were conducted in 13 countries. A total of 1863 delegates and 40 faculty participated in these workshops. Of the delegates, 627 completed both tests. There was a significant improvement after training in all domains of the tests. There was a trend in general lack of knowledge across all domains for delegates from "low" healthcare cost countries before training. All delegates demonstrated significant improvement in knowledge of all domains after the workshop irrespective of whether they were from "high" or "low" healthcare cost per capita countries. Conclusion A standardized teaching program on IEE improved the diagnostic ability and quality of endoscopists in recognizing early gastrointestinal neoplasia in Asia.
An Asian consensus on standards of diagnostic upper endoscopy for neoplasia

Chiu PWY, Uedo N, Singh R, Gotoda T, Ng EKW, Yao K, et al.

Gut, 2019 02;68(2):186-197.
PMID: 30420400 DOI: 10.1136/gutjnl-2018-317111

BACKGROUND: This is a consensus developed by a group of expert endoscopists aiming to standardise the preparation, process and endoscopic procedural steps for diagnosis of early upper gastrointestinal (GI) cancers.
METHOD: The Delphi method was used to develop consensus statements through identification of clinical questions on diagnostic endoscopy. Three consensus meetings were conducted to consolidate the statements and voting. We conducted a systematic literature search on evidence for each statement. The statements were presented in the second consensus meeting and revised according to comments. The final voting was conducted at the third consensus meeting on the level of evidence and agreement.
RESULTS: Risk stratification should be conducted before endoscopy and high risk endoscopic findings should raise an index of suspicion. The presence of premalignant mucosal changes should be documented and use of sedation is recommended to enhance detection of superficial upper GI neoplasms. The use of antispasmodics and mucolytics enhanced visualisation of the upper GI tract, and systematic endoscopic mapping should be conducted to improve detection. Sufficient examination time and structured training on diagnosis improves detection. Image enhanced endoscopy in addition to white light imaging improves detection of superficial upper GI cancer. Magnifying endoscopy with narrow-band imaging is recommended for characterisation of upper GI superficial neoplasms. Endoscopic characterisation can avoid unnecessary biopsy.
CONCLUSION: This consensus provides guidance for the performance of endoscopic diagnosis and characterisation for early gastric and oesophageal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early upper GI cancers.
Fulltext Narrow-band imaging and white-light endoscopy with optical magnification in the diagnosis of dysplasia in Barrett's esophagus: results of the Asia-Pacific Barrett's Consortium

Singh R, Jayanna M, Wong J, Lim LG, Zhang J, Lv J, et al.

Endosc Int Open, 2015 Feb;3(1):E14-8.
PMID: 26134765 DOI: 10.1055/s-0034-1377610

The advent and utility of new endoscopic imaging modalities for predicting the histology of Barrett's esophagus (BE) in real time with high accuracy appear promising and could potentially obviate the need to perform random biopsies where guidelines are poorly adhered to. We embarked on evaluating the performance characteristics of white-light endoscopy with magnification (WLE-z), narrow-band imaging with magnification (NBI-z) and a combination of both modalities.
Fulltext Development of an E-learning System for the Endoscopic Diagnosis of Early Gastric Cancer: An International Multicenter Randomized Controlled Trial

Yao K, Uedo N, Muto M, Ishikawa H, Cardona HJ, Filho ECC, et al.

EBioMedicine, 2016 Jul;9:140-147.
PMID: 27333048 DOI: 10.1016/j.ebiom.2016.05.016

BACKGROUND: In many countries, gastric cancer is not diagnosed until an advanced stage. An Internet-based e-learning system to improve the ability of endoscopists to diagnose gastric cancer at an early stage was developed and was evaluated for its effectiveness.
METHODS: The study was designed as a randomized controlled trial. After receiving a pre-test, participants were randomly allocated to either an e-learning or non-e-learning group. Only those in the e-learning group gained access to the e-learning system. Two months after the pre-test, both groups received a post-test. The primary endpoint was the difference between the two groups regarding the rate of improvement of their test results.
FINDINGS: 515 endoscopists from 35 countries were assessed for eligibility, and 332 were enrolled in the study, with 166 allocated to each group. Of these, 151 participants in the e-learning group and 144 in the non-e-learning group were included in the analysis. The mean improvement rate (standard deviation) in the e-learning and non-e-learning groups was 1·24 (0·26) and 1·00 (0·16), respectively (P<0·001).
INTERPRETATION: This global study clearly demonstrated the efficacy of an e-learning system to expand knowledge and provide invaluable experience regarding the endoscopic detection of early gastric cancer (R000012039).