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Jaglan AB, Vashisth M, Sharma P, Verma R, Virmani N, Bera BC, Vaid RK, Singh RK, Anand T. Phage Mediated Biocontrol: A Promising Green Solution for Sustainable Agriculture. Indian J Microbiol 2024; 64:318-327. [PMID: 39011019 PMCID: PMC11246405 DOI: 10.1007/s12088-024-01204-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 01/06/2024] [Indexed: 07/17/2024] Open
Abstract
In the current scenario of growing world population, limited cultivable land resources, plant diseases, and pandemics are some of the major factors responsible for declining global food security. Along with meeting the food demand, the maintenance of food quality is also required to ensure healthy consumption and marketing. In agricultural fields, pest infestations and bacterial diseases are common causes of crop damage, leading to massive yield losses. Conventionally, antibiotics and several pesticides have been used to manage and control these plant pathogens. However, the overuse of antibiotics and pesticides has led to the emergence of resistant strains of pathogenic bacteria. The bacteriophages are the natural predators of bacteria and are host-specific in their action. Therefore, the use of bacteriophages for the biocontrol of pathogenic bacteria is serving as a sustainable and green solution in crop protection and production. In this review, we have discussed the important plant pathogens and their impact on plant health and yield loss. Further, we have abridged the role of bacteriophages in the protection of crops from bacterial disease by discussing various greenhouse and field trials. Finally, we have discussed the impact of bacteriophages on the plant microbiome, phage resistance, and legal challenges in the registration and commercial production of bacteriophage-based biopesticides. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-024-01204-x.
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Affiliation(s)
- Anu Bala Jaglan
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
- Department of Zoology and Aquaculture, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana 125004 India
| | - Medhavi Vashisth
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
| | - Priya Sharma
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
| | - Ravikant Verma
- Department of Zoology and Aquaculture, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana 125004 India
| | - Nitin Virmani
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
| | - Bidhan C Bera
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
| | - Rajesh K Vaid
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
| | - Raj K Singh
- Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122 India
| | - Taruna Anand
- ICAR - National Research Centre on Equines, Hisar, Haryana 125001 India
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Wang Y, Xuan G, Lin H, Fei Z, Wang J. Phage resistance of Salmonella enterica obtained by transposon Tn5-mediated SefR gene silent mutation. J Basic Microbiol 2023; 63:530-541. [PMID: 37032321 DOI: 10.1002/jobm.202200532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 02/05/2023] [Accepted: 03/12/2023] [Indexed: 04/11/2023]
Abstract
Salmonella enterica contamination is a primary cause of global food poisoning. Using phages as bactericidal alternatives to antibiotics could confront the issue of drug resistance. However, the problem of phage resistance, especially mutant strains with multiple phage resistance, is a critical barrier to the practical application of phages. In this study, a library of EZ-Tn5 transposable mutants of susceptible host S. enterica B3-6 was constructed. After the infestation pressure of a broad-spectrum phage TP1, a mutant strain with resistance to eight phages was obtained. Analysis of the genome resequencing results revealed that the SefR gene was disrupted in the mutant strain. The mutant strain displayed a reduced adsorption rate of 42% and a significant decrease in swimming and swarming motility, as well as a significantly reduced expression of the flagellar-related FliL and FliO genes to 17% and 36%, respectively. An uninterrupted form of the SefR gene was cloned into vector pET-21a (+) and used for complementation of the mutant strain. The complemented mutant exhibited similar adsorption and motility as the wild-type control. These results suggest that the disrupted flagellar-mediated SefR gene causes an adsorption inhibition, which is responsible for the phage-resistant phenotype of the S. enterica transposition mutant.
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Affiliation(s)
- Yinfeng Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China
| | - Guanhua Xuan
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China
| | - Hong Lin
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China
| | - Zhenhong Fei
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China
| | - Jingxue Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China
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Zhang M, Qian J, Xu X, Ahmed T, Yang Y, Yan C, Elsharkawy MM, Hassan MM, Alorabi JA, Chen J, Li B. Resistance of Xanthomonas oryzae pv. oryzae to Lytic Phage X2 by Spontaneous Mutation of Lipopolysaccharide Synthesis-Related Glycosyltransferase. Viruses 2022; 14:1088. [PMID: 35632829 PMCID: PMC9143033 DOI: 10.3390/v14051088] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/14/2022] [Accepted: 05/17/2022] [Indexed: 02/01/2023] Open
Abstract
Phage therapy is a promising biocontrol management on plant diseases caused by bacterial pathogens due to its specificity, efficiency and environmental friendliness. The emergence of natural phage-resistant bacteria hinders the application of phage therapy. Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of the devastating bacterial leaf blight disease of rice. Here, we obtained a spontaneous mutant C2R of an Xoo strain C2 showing strong resistance to the lytic phage X2. Analysis of the C2R genome found that the CDS2289 gene encoding glycosyltransferase acquired a frameshift mutation at the 180th nucleotide site, which also leads to a premature stop mutation at the 142nd amino acid. This mutation confers the inhibition of phage adsorption through the changes in lipopolysaccharide production and structure and bacterial surface morphology. Interestingly, glycosyltransferase-deficient C2R and an insertional mutant k2289 also showed reduced virulence, suggesting the trade-off costs of phage resistance. In summary, this study highlights the role of glycosyltransferase in interactions among pathogenic bacteria, phages and plant hosts, which provide insights into balanced coevolution from environmental perspectives.
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Affiliation(s)
- Muchen Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (M.Z.); (J.Q.); (X.X.); (T.A.)
| | - Jiahui Qian
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (M.Z.); (J.Q.); (X.X.); (T.A.)
| | - Xinyan Xu
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (M.Z.); (J.Q.); (X.X.); (T.A.)
| | - Temoor Ahmed
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (M.Z.); (J.Q.); (X.X.); (T.A.)
| | - Yong Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
| | - Chenqi Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
- Institute of Biotechnology, Ningbo Academy of Agricultural Sciences, Ningbo 315040, China
| | - Mohsen Mohamed Elsharkawy
- Agricultural Botany Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt;
| | - Mohamed M. Hassan
- Department of Biology, College of Science, Taif University, Taif P.O. Box 21974, Saudi Arabia; (M.M.H.); (J.A.A.)
| | - Jamal A. Alorabi
- Department of Biology, College of Science, Taif University, Taif P.O. Box 21974, Saudi Arabia; (M.M.H.); (J.A.A.)
| | - Jianping Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Virology, Ningbo University, Ningbo 315211, China
| | - Bin Li
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (M.Z.); (J.Q.); (X.X.); (T.A.)
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Vishakha K, Das S, Das SK, Banerjee S, Ganguli A. Antibacterial, anti-biofilm, and anti-virulence potential of tea tree oil against leaf blight pathogen Xanthomonas oryzae pv. oryzae instigates disease suppression. Braz J Microbiol 2022; 53:19-32. [PMID: 35001350 PMCID: PMC8882498 DOI: 10.1007/s42770-021-00657-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 10/21/2021] [Indexed: 01/12/2023] Open
Abstract
Bacterial leaf blight (BLB) disease, caused by Xanthomonas oryzae pv. oryzae (Xoo), causes major annual economic losses around the world. Inorganic copper compounds and antibiotics are conventionally used to control BLB disease. They often cause environmental pollution, contributing to adverse effects on human health. Therefore, research is now leading to the search for alternative control methods. Tea tree oil (TTO) is obtained from a traditional medicinal plant, Melaleuca alternifolia, with antibacterial properties. In this study, we found that TTO showed antibacterial activity against Xoo with a minimum inhibitory concentration (MIC) of 18 mg/ml. These antagonistic activities were not limited only to planktonic cells, as further studies have shown that TTO effectively eradicated sessile cells of Xoo in both initial and mature biofilms. Furthermore, it was also observed that TTO reduced various key virulence properties of Xoo, such as swimming, swarming motility, and the production of extracellular polymeric substances, xanthomonadin, and exoenzymes. TTO triggered ROS generation with cell membrane damage as an antibacterial mode of action against Xoo. The in silico study revealed that 1,8-cineole of TTO was effectively bound to two essential proteins, phosphoglucomutase and peptide deformylase, responsible for the synthesis of EPS and bacterial survival, respectively. These antibacterial and anti-virulence activities of TTO against Xoo were further confirmed by an ex vivo virulence assay where TTO significantly reduced the lesion length caused by Xoo on rice leaves. All these data concluded that TTO could be a safe, environment-friendly alternative approach for the comprehensive management of BLB disease.
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Affiliation(s)
- Kumari Vishakha
- Department of Microbiology, Techno India University, West Bengal EM-4 Sector V, Kolkata, West Bengal, 700091, India
| | - Shatabdi Das
- Department of Microbiology, Techno India University, West Bengal EM-4 Sector V, Kolkata, West Bengal, 700091, India
| | - Sudip Kumar Das
- Department of Microbiology, Techno India University, West Bengal EM-4 Sector V, Kolkata, West Bengal, 700091, India
| | - Satarupa Banerjee
- Department of Microbiology, Techno India University, West Bengal EM-4 Sector V, Kolkata, West Bengal, 700091, India
| | - Arnab Ganguli
- Department of Microbiology, Techno India University, West Bengal EM-4 Sector V, Kolkata, West Bengal, 700091, India.
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Nakayinga R, Makumi A, Tumuhaise V, Tinzaara W. Xanthomonas bacteriophages: a review of their biology and biocontrol applications in agriculture. BMC Microbiol 2021; 21:291. [PMID: 34696726 PMCID: PMC8543423 DOI: 10.1186/s12866-021-02351-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 10/12/2021] [Indexed: 11/10/2022] Open
Abstract
Phytopathogenic bacteria are economically important because they affect crop yields and threaten the livelihoods of farmers worldwide. The genus Xanthomonas is particularly significant because it is associated with some plant diseases that cause tremendous loss in yields of globally essential crops. Current management practices are ineffective, unsustainable and harmful to natural ecosystems. Bacteriophage (phage) biocontrol for plant disease management has been of particular interest from the early nineteenth century to date. Xanthomonas phage research for plant disease management continues to demonstrate promising results under laboratory and field conditions. AgriPhage has developed phage products for the control of Xanthomonas campestris pv. vesicatoria and Xanthomonas citri subsp. citri. These are causative agents for tomato, pepper spot and speck disease as well as citrus canker disease. Phage-mediated biocontrol is becoming a viable option because phages occur naturally and are safe for disease control and management. Thorough knowledge of biological characteristics of Xanthomonas phages is vital for developing effective biocontrol products. This review covers Xanthomonas phage research highlighting aspects of their ecology, biology and biocontrol applications.
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Affiliation(s)
- Ritah Nakayinga
- Department of Biological Sciences, Faculty of Science, Kyambogo University, P.O. Box 1, Kyambogo, Uganda.
| | - Angela Makumi
- Department of Animal and Human Health, General Biosciences, International Livestock Research Institute, P.O. Box 3070, Nairobi, 00100, Kenya
| | - Venansio Tumuhaise
- Department of Agriculture, Faculty of Vocational Studies, Kyambogo University, P.O. Box 1, Kyambogo, Uganda
| | - William Tinzaara
- Department of Agriculture, Faculty of Vocational Studies, Kyambogo University, P.O. Box 1, Kyambogo, Uganda
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Picchi SC, Granato LM, Franzini MJF, Andrade MO, Takita MA, Machado MA, de Souza AA. Modified Monosaccharides Content of Xanthan Gum Impairs Citrus Canker Disease by Affecting the Epiphytic Lifestyle of Xanthomonas citri subsp. citri. Microorganisms 2021; 9:microorganisms9061176. [PMID: 34072545 PMCID: PMC8229982 DOI: 10.3390/microorganisms9061176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/16/2021] [Accepted: 04/22/2021] [Indexed: 11/16/2022] Open
Abstract
Xanthomonas citri subsp. citri (X. citri) is a plant pathogenic bacterium causing citrus canker disease. The xanA gene encodes a phosphoglucomutase/phosphomannomutase protein that is a key enzyme required for the synthesis of lipopolysaccharides and exopolysaccharides in Xanthomonads. In this work, firstly we isolated a xanA transposon mutant (xanA::Tn5) and analyzed its phenotypes as biofilm formation, xanthan gum production, and pathogenesis on the sweet orange host. Moreover, to confirm the xanA role in the impaired phenotypes we further produced a non-polar deletion mutant (ΔxanA) and performed the complementation of both xanA mutants. In addition, we analyzed the percentages of the xanthan gum monosaccharides produced by X. citri wild-type and xanA mutant. The mutant strain had higher ratios of mannose, galactose, and xylose and lower ratios of rhamnose, glucuronic acid, and glucose than the wild-type strain. Such changes in the saccharide composition led to the reduction of xanthan yield in the xanA deficient strain, affecting also other important features in X. citri, such as biofilm formation and sliding motility. Moreover, we showed that xanA::Tn5 caused no symptoms on host leaves after spraying, a method that mimetics the natural infection condition. These results suggest that xanA plays an important role in the epiphytical stage on the leaves that is essential for the successful interaction with the host, including adaptive advantage for bacterial X. citri survival and host invasion, which culminates in pathogenicity.
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Affiliation(s)
- Simone Cristina Picchi
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
| | - Laís Moreira Granato
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
- Correspondence: (L.M.G.); (A.A.d.S.)
| | - Maria Júlia Festa Franzini
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
| | - Maxuel Oliveira Andrade
- Bioscience National Lab, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083100, Brazil;
| | - Marco Aurélio Takita
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
| | - Marcos Antonio Machado
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
| | - Alessandra Alves de Souza
- Biotechnology Lab, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, São Paulo 1349070, Brazil; (S.C.P.); (M.J.F.F.); (M.A.T.); (M.A.M.)
- Correspondence: (L.M.G.); (A.A.d.S.)
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Bacteriophage-Mediated Control of Phytopathogenic Xanthomonads: A Promising Green Solution for the Future. Microorganisms 2021; 9:microorganisms9051056. [PMID: 34068401 PMCID: PMC8153558 DOI: 10.3390/microorganisms9051056] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 12/21/2022] Open
Abstract
Xanthomonads, members of the family Xanthomonadaceae, are economically important plant pathogenic bacteria responsible for infections of over 400 plant species. Bacteriophage-based biopesticides can provide an environmentally friendly, effective solution to control these bacteria. Bacteriophage-based biocontrol has important advantages over chemical pesticides, and treatment with these biopesticides is a minor intervention into the microflora. However, bacteriophages’ agricultural application has limitations rooted in these viruses’ biological properties as active substances. These disadvantageous features, together with the complicated registration process of bacteriophage-based biopesticides, means that there are few products available on the market. This review summarizes our knowledge of the Xanthomonas-host plant and bacteriophage-host bacterium interaction’s possible influence on bacteriophage-based biocontrol strategies and provides examples of greenhouse and field trials and products readily available in the EU and the USA. It also details the most important advantages and limitations of the agricultural application of bacteriophages. This paper also investigates the legal background and industrial property right issues of bacteriophage-based biopesticides. When appropriately applied, bacteriophages can provide a promising tool against xanthomonads, a possibility that is untapped. Information presented in this review aims to explore the potential of bacteriophage-based biopesticides in the control of xanthomonads in the future.
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Zandonadi FS, Ferreira SP, Alexandrino AV, Carnielli CM, Artier J, Barcelos MP, Nicolela NCS, Prieto EL, Goto LS, Belasque J, Novo-Mansur MTM. Periplasm-enriched fractions from Xanthomonas citri subsp. citri type A and X. fuscans subsp. aurantifolii type B present distinct proteomic profiles under in vitro pathogenicity induction. PLoS One 2020; 15:e0243867. [PMID: 33338036 PMCID: PMC7748154 DOI: 10.1371/journal.pone.0243867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/29/2020] [Indexed: 12/24/2022] Open
Abstract
The causative agent of Asiatic citrus canker, the Gram-negative bacterium Xanthomonas citri subsp. citri (XAC), produces more severe symptoms and attacks a larger number of citric hosts than Xanthomonas fuscans subsp. aurantifolii XauB and XauC, the causative agents of cancrosis, a milder form of the disease. Here we report a comparative proteomic analysis of periplasmic-enriched fractions of XAC and XauB in XAM-M, a pathogenicity- inducing culture medium, for identification of differential proteins. Proteins were resolved by two-dimensional electrophoresis combined with liquid chromatography-mass spectrometry. Among the 12 proteins identified from the 4 unique spots from XAC in XAM-M (p<0.05) were phosphoglucomutase (PGM), enolase, xylose isomerase (XI), transglycosylase, NAD(P)H-dependent glycerol 3-phosphate dehydrogenase, succinyl-CoA synthetase β subunit, 6-phosphogluconate dehydrogenase, and conserved hypothetical proteins XAC0901 and XAC0223; most of them were not detected as differential for XAC when both bacteria were grown in NB medium, a pathogenicity non-inducing medium. XauB showed a very different profile from XAC in XAM-M, presenting 29 unique spots containing proteins related to a great diversity of metabolic pathways. Preponderant expression of PGM and XI in XAC was validated by Western Blot analysis in the periplasmic-enriched fractions of both bacteria. This work shows remarkable differences between the periplasmic-enriched proteomes of XAC and XauB, bacteria that cause symptoms with distinct degrees of severity during citrus infection. The results suggest that some proteins identified in XAC can have an important role in XAC pathogenicity.
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Affiliation(s)
- Flávia S. Zandonadi
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Sílvia P. Ferreira
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - André V. Alexandrino
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Carolina M. Carnielli
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Juliana Artier
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Mariana P. Barcelos
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Nicole C. S. Nicolela
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Evandro L. Prieto
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - Leandro S. Goto
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
| | - José Belasque
- Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, USP, Piracicaba, São Paulo, Brazil
| | - Maria Teresa Marques Novo-Mansur
- Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, São Paulo, Brazil
- * E-mail:
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Holtappels D, Kerremans A, Busschots Y, Van Vaerenbergh J, Maes M, Lavigne R, Wagemans J. Preparing for the KIL: Receptor Analysis of Pseudomonas syringae pv. porri Phages and Their Impact on Bacterial Virulence. Int J Mol Sci 2020; 21:ijms21082930. [PMID: 32331264 PMCID: PMC7216180 DOI: 10.3390/ijms21082930] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/16/2020] [Accepted: 04/19/2020] [Indexed: 12/20/2022] Open
Abstract
The prevalence of Pseudomonas syringae pv. porri (Pspo) in Belgium continues to increase and sustainable treatments for this pathogen remain unavailable. A potentially attractive biocontrol strategy would be the application of bacteriophages. The ideal application strategy of phages in an agricultural setting remains unclear, especially in a field-based production such as for leek plants in Flanders. Therefore, more insight in bacteria–phage interaction is required, along with the evaluation of different application strategies. In this study, we further characterized the infection strategy of two Pspo phages, KIL3b and KIL5. We found that both phages recognize lipopolysaccharide (LPS) moieties on the surface of the bacterium. LPS is an important pathogenicity factor of Pspo. Our data also suggest that KIL5 requires an additional protein in the bacterial cytoplasmatic membrane to efficiently infect its host. Virulence tests showed that this protein also contributes to Pspo virulence. Furthermore, a cocktail of both phages was applied in a seed bioassay. A combination of KIL3b and KIL5 reduced the bacterial concentration 100-fold. However, in vitro Pspo resistance against phage infection developed quite rapidly. However, the impact of this phage resistance might be mitigated as is suggested by the fact that those resistance mutations preferably occur in genes involved in LPS metabolism, and that the virulence of those mutants is possibly reduced. Our data suggest that the phage cocktail has promising potential to lower the prevalence of Pspo and to be integrated in a pest management strategy. Targeted research is needed to further explore the applicability of the phages in combination with other disease control strategies.
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Affiliation(s)
- Dominique Holtappels
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21 box 2462, 3001 Heverlee, Belgium; (D.H.); (A.K.); (Y.B.); (R.L.)
| | - Alison Kerremans
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21 box 2462, 3001 Heverlee, Belgium; (D.H.); (A.K.); (Y.B.); (R.L.)
| | - Yoni Busschots
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21 box 2462, 3001 Heverlee, Belgium; (D.H.); (A.K.); (Y.B.); (R.L.)
| | - Johan Van Vaerenbergh
- Department of Crop Protection, Institute for Agricultural and Fisheries Research, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium;
| | - Martine Maes
- Independent Researcher, Willem Tellstraat 20, 9000 Ghent, Belgium;
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21 box 2462, 3001 Heverlee, Belgium; (D.H.); (A.K.); (Y.B.); (R.L.)
| | - Jeroen Wagemans
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 21 box 2462, 3001 Heverlee, Belgium; (D.H.); (A.K.); (Y.B.); (R.L.)
- Correspondence:
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10
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Biological and molecular characterization of a bacteriophage infecting Xanthomonas campestris pv. campestris, isolated from brassica fields. Arch Virol 2019; 164:1857-1862. [PMID: 31065851 DOI: 10.1007/s00705-019-04263-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 03/29/2019] [Indexed: 11/27/2022]
Abstract
Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot of crucifers. Here, we report a virus that infects Xcc isolated from brassica fields in Brazil. Morphological, molecular and phylogenetic analysis indicated that the isolated virus is a new member of the genus Pbunavirus, family Myoviridae, and we propose the name "Xanthomonas virus XC 2" for this virus. The isolated virus has a narrow host range, infecting only Xcc isolates, and it did not infect unrelated bacteria. These results indicate that the isolated bacteriophage is highly specific for Xcc and may be a potential agent for biological control.
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11
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Sahu SK, Zheng P, Yao N. Niclosamide Blocks Rice Leaf Blight by Inhibiting Biofilm Formation of Xanthomonas oryzae. FRONTIERS IN PLANT SCIENCE 2018; 9:408. [PMID: 29651297 PMCID: PMC5884940 DOI: 10.3389/fpls.2018.00408] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/14/2018] [Indexed: 05/05/2023]
Abstract
Rice (Oryza sativa) is the leading source of nutrition for more than half of the world's population, and by far it is the most important commercial food crop. But, its growth and production are significantly hampered by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) which causes leaf blight disease. Earlier studies have reported the antibacterial ability of FDA-approved niclosamide drug against Xoo. However, the underlying mechanism by which niclosamide blocks the growth of Xoo remained elusive. In the present study, by employing the microbiological, microscopical, molecular, bioinformatics and analytical tools we found that niclosamide can directly inhibit the growth of the Xoo by hampering the biofilm formation and the production of xanthomonadin and exopolysaccharide substances (EPS) required for relentless growth and virulence of Xoo. Interestingly, niclosamide was found to specifically suppress the growth of Xoo without affecting other bacteria like Escherichia coli. Our electron microscopic observations disclosed that niclosamide disrupts the membrane permeability of Xoo and causes the release of intracellular components. Similarly, the molecular docking analysis disclosed the molecular interaction of niclosamide with the biofilm, virulence and quorum sensing related proteins, which was further substantiated by relative gene expression analysis where niclosamide was found to significantly downregulate the expression of these key regulatory genes. In addition, considerable changes in chemical structures were detected by Fourier Transform Infrared Spectroscopy (FTIR) in response to niclosamide treatment. Overall, our findings advocate the utilization of niclosamide as a safe and potent alternative antibacterial compound to control bacterial blight disease in rice.
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Affiliation(s)
| | | | - Nan Yao
- *Correspondence: Sunil Kumar Sahu, Nan Yao,
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12
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Goto LS, Vessoni Alexandrino A, Malvessi Pereira C, Silva Martins C, D'Muniz Pereira H, Brandão-Neto J, Marques Novo-Mansur MT. Structural and functional characterization of the phosphoglucomutase from Xanthomonas citri subsp. citri. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1658-1666. [PMID: 27567706 DOI: 10.1016/j.bbapap.2016.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/17/2016] [Accepted: 08/23/2016] [Indexed: 01/22/2023]
Abstract
Citrus canker, caused by bacteria Xanthomonas citri subsp. citri, can affect all economically important varieties of citrus. Studying Xanthomonas genes related to the invasive capacity may improve the knowledge on how this works and ultimately use the information to avoid the disease. Some annotated genes from Xanthomonas citri subsp. citri published genome are addressed to an interesting class of genes named "pathogenicity, virulence and adaptation". One of them is xanA, which encodes a predicted phosphoglucomutase. Phosphoglucomutases are ubiquitous enzymes among the living kingdoms that play roles in carbohydrate metabolism, catalyzing the reversible conversion of 1- to 6-phosphoglucose. In Xanthomonas, phosphoglucomutase activity is required to synthesize precursors of the pathogenesis-related polysaccharide xanthan. In this work, a characterization of this gene product is presented by structural and functional studies. Molecular cloning was used for heterologous expression and deletion of xanA. A Michaelis-Menten kinetics model was obtained using the recombinant protein. The protein structure was also determined by X-ray diffraction on the recombinant enzyme substrate-free, bound to glucose-1,6-biphosphate and to glucose-1-phosphate. Deletion of xanA was done with a suicide plasmid construct and the obtained mutant was tested for pathogenic capacity. This study is the first describing the properties of the Xanthomonas citri subsp. citri phosphoglucomutase.
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Affiliation(s)
- Leandro Seiji Goto
- Laboratório de Bioquímica e Biologia Molecular Aplicada - LBBMA, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
| | - André Vessoni Alexandrino
- Laboratório de Bioquímica e Biologia Molecular Aplicada - LBBMA, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Camila Malvessi Pereira
- Laboratório de Bioquímica e Biologia Molecular Aplicada - LBBMA, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Carla Silva Martins
- Laboratório de Bioquímica e Biologia Molecular Aplicada - LBBMA, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Humberto D'Muniz Pereira
- Laboratório de Biologia Estrutural, Grupo de Cristalografia, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | - José Brandão-Neto
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Maria Teresa Marques Novo-Mansur
- Laboratório de Bioquímica e Biologia Molecular Aplicada - LBBMA, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil
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13
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Chen CM, Liu JJ, Chou CW, Lai CH, Wu LT. RpA, an extracellular protease similar to the metalloprotease of serralysin family, is required for pathogenicity of Ralstonia pickettii. J Appl Microbiol 2015; 119:1101-11. [DOI: 10.1111/jam.12903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 07/05/2015] [Accepted: 07/07/2015] [Indexed: 11/25/2022]
Affiliation(s)
- C.-M. Chen
- Division of Infectious Disease; Department of Internal Medicine; Tungs' Taichung MetroHarbor Hospital; Taichung Taiwan
| | - J.-J. Liu
- The Institute of Medical Science and Department of Microbiology; China Medical University; Taichung Taiwan
| | - C.-W. Chou
- Department of Cosmeceutics; College of Pharmacy; China Medical University; Taichung Taiwan
| | - C.-H. Lai
- The Institute of Medical Science and Department of Microbiology; China Medical University; Taichung Taiwan
| | - L.-T. Wu
- The Institute of Medical Science and Department of Microbiology; China Medical University; Taichung Taiwan
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14
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Antibacterial Activity and Mechanism of Action of Sulfone Derivatives Containing 1,3,4-Oxadiazole Moieties on Rice Bacterial Leaf Blight. Molecules 2015; 20:11660-75. [PMID: 26114927 PMCID: PMC6332022 DOI: 10.3390/molecules200711660] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/04/2015] [Accepted: 06/12/2015] [Indexed: 02/04/2023] Open
Abstract
In this study, sulfone derivatives containing 1,3,4-oxadiazole moieties indicated good antibacterial activities against rice bacterial leaf blight caused by the pathogen Xanthomonasoryzaepv.pv. oryzae (Xoo). In particular, 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole revealed the best antibacterial activity against Xoo, with a half-maximal effective concentration (EC50) of 9.89 μg/mL, which was better than those of the commercial agents of bismerthiazole (92.61 μg/mL) and thiodiazole copper (121.82 μg/mL). In vivo antibacterial activity tests under greenhouse conditions and field trials demonstrated that 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole was effective in reducing rice bacterial leaf blight. Meanwhile, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole stimulate the increase in superoxide dismutase (SOD) and peroxidase (POD) activities in rice, causing marked enhancement of plant resistance against rice bacterial leaf blight. It could also improve the chlorophyll content and restrain the increase in the malondialdehyde (MDA) content in rice to considerably reduce the amount of damage caused by Xoo. Moreover, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole, at a concentration of 20 μg/mL, could inhibit the production of extracellular polysaccharide (EPS) with an inhibition ratio of 94.52%, and reduce the gene expression levels of gumB, gumG, gumM, and xanA, with inhibition ratios of 94.88%, 68.14%, 86.76%, and 79.21%, respectively.
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15
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Genomic characterization of the intron-containing T7-like phage phiL7 of Xanthomonas campestris. Appl Environ Microbiol 2009; 75:7828-37. [PMID: 19854925 DOI: 10.1128/aem.01214-09] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The lytic phage phiL7, which morphologically belongs to the Siphoviridae family, infects Xanthomonas campestris pv. campestris. Nucleotide sequence analysis has revealed that phiL7 contains a linear double-stranded DNA genome (44,080 bp, 56% G+C) with a 3'-protruding cos site (5'-TTACCGGAC-3') and 59 possible genes. Among the deduced proteins, 32 have homologs with known functions and 18 show no database similarities; moreover, the genes encoding these 18 proteins mostly have varying G+C contents and form clusters dispersed along the genome. Only 39 genes have sequences related (27% to 78%) to those of sequenced genes of X. oryzae pv. oryzae phages, although the genome size and architecture of these Xanthomonas phages are similar. These findings suggest that phiL7 acquired genes by horizontal transfer, followed by evolution via various types of mutations. Major differences were found between phiL7 and the X. oryzae pv. oryzae phages: (i) phiL7 has a group I intron inserted in the DNA polymerase gene, the first such intron observed in Xanthomonas phages; (ii) although infection of phiL7 exerted inhibition to the host RNA polymerase, similar to the situations in X. oryzae pv. oryzae phages Xp10 and Xop411, sequence analysis did not identify a homologue of the Xp10 p7 that controls the shift from host RNA polymerase (RNAP) to viral RNAP during transcription; and (iii) phiL7 lacks the tail fiber protein gene that exhibits domain duplications thought to be important for host range determination in OP1, and sequence analysis suggested that p20 (tail protein III) instead has the potential to play this role.
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Abstract
Plant pathogenic bacteria of the genus Xanthomonas cause a variety of diseases in economically important monocotyledonous and dicotyledonous crop plants worldwide. Successful infection and bacterial multiplication in the host tissue often depend on the virulence factors secreted including adhesins, polysaccharides, LPS and degradative enzymes. One of the key pathogenicity factors is the type III secretion system, which injects effector proteins into the host cell cytosol to manipulate plant cellular processes such as basal defense to the benefit of the pathogen. The coordinated expression of bacterial virulence factors is orchestrated by quorum-sensing pathways, multiple two-component systems and transcriptional regulators such as Clp, Zur, FhrR, HrpX and HpaR. Furthermore, virulence gene expression is post-transcriptionally controlled by the RNA-binding protein RsmA. In this review, we summarize the current knowledge on the infection strategies and regulatory networks controlling secreted virulence factors from Xanthomonas species.
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Affiliation(s)
- Daniela Büttner
- Genetics Department, Institute of Biology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany.
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17
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Hagens S, Loessner MJ. Application of bacteriophages for detection and control of foodborne pathogens. Appl Microbiol Biotechnol 2007; 76:513-9. [PMID: 17554535 DOI: 10.1007/s00253-007-1031-8] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 05/11/2007] [Accepted: 05/21/2007] [Indexed: 10/23/2022]
Abstract
The incidence of foodborne infectious diseases is stable or has even increased in many countries. Consequently, our awareness regarding hygiene measures in food production has also increased dramatically over the last decades. However, even today's modern production techniques and intensive food-monitoring programs have not been able to effectively control the problem. At the same time, increased production volumes are distributed to more consumers, and if contaminated, potentially cause mass epidemics. Accordingly, research directed to improve food safety has also been taken forward, also exploring novel methods and technologies. Such an approach is represented by the use of bacteriophage for specific killing of unwanted bacteria. The extreme specificity of phages renders them ideal candidates for applications designed to increase food safety during the production process. Phages are the natural enemies of bacteria, and can be used for biocontrol of bacteria without interfering with the natural microflora or the cultures in fermented products. Moreover, phages or phage-derived proteins can also be used to detect the presence of unwanted pathogens in food or the production environments, which allows quick and specific identification of viable cells. This review intends to briefly summarize and explain the principles and current standing of these approaches.
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Affiliation(s)
- Steven Hagens
- Institute of Food Science and Nutrition, ETH Zurich, Schmelzbergstrasse 7, CH-8092, Zurich, Switzerland
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18
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Wu LT, Chang SY, Yen MR, Yang TC, Tseng YH. Characterization of extended-host-range pseudo-T-even bacteriophage Kpp95 isolated on Klebsiella pneumoniae. Appl Environ Microbiol 2007; 73:2532-40. [PMID: 17337566 PMCID: PMC1855606 DOI: 10.1128/aem.02113-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 02/12/2007] [Indexed: 11/20/2022] Open
Abstract
Kpp95, isolated on Klebsiella pneumoniae, is a bacteriophage with the morphology of T4-type phages and is capable of rapid lysis of host cells. Its double-stranded genomic DNA (ca. 175 kb, estimated by pulsed-field gel electrophoresis) can be cut only by restriction endonucleases with a cleavage site flanked either by A and T or by T, as tested, suggesting that it contains the modified derivative(s) of G and/or C. Over 26 protein bands were visualized upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the virion proteins. N-terminal sequencing indicated that the most abundant band (46 kDa) is the major coat protein (gp23) which has been cleaved from a signal peptide likely with a length similar to that of T4. Phylogenetic analyses based on the sequences of the central region (263 amino acid residues) of gp23 and the full length of gp18 and gp19 placed Kpp95 among the pseudo-T-even subgroup, most closely related to the coliphage JS98. In addition to being able to lyse many extended-spectrum beta-lactamase strains of K. pneumoniae, Kpp95 can lyse Klebsiella oxytoca, Enterobacter agglomerans, and Serratia marcescens cells. Thus, Kpp95 deserves further studies for development as a component of a therapeutic cocktail, owing to its high efficiencies of host lysis plus extended host range.
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Affiliation(s)
- Lii-Tzu Wu
- Institute of Medical Biotechnology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan, Republic of China.
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Rees CED, Dodd CER. Phage for Rapid Detection and Control of Bacterial Pathogens in Food. ADVANCES IN APPLIED MICROBIOLOGY 2006; 59:159-86. [PMID: 16829259 DOI: 10.1016/s0065-2164(06)59006-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Catherine E D Rees
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, United Kingdom
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20
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Hung CH, Yang CF, Yang CY, Tseng YH. Involvement of tonB-exbBD1D2 operon in infection of Xanthomonas campestris phage phi L7. Biochem Biophys Res Commun 2003; 302:878-84. [PMID: 12646254 DOI: 10.1016/s0006-291x(03)00255-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
phi L7 is a lytic bacteriophage infecting Xanthomonas campestris pv. campestris, a Gram-negative bacterium producing xanthan gum and causing black rot in crucifers. A mutant resistant to phi L7 was isolated by Tn5 mutagenesis. Sequence analysis indicated that the gene responsible for the mutation is tonB encoding an inner membrane protein previously shown to be required for iron uptake and pathogenesis. This gene is clustered with three other genes, tonB-exbB-exbD1-exbD2. Results of insertional mutations, DNA and protein sequence analyses, phage sensitivity tests, transfection tests, complementation tests, and phage adsorption assays together with the cellular location of the proteins indicate that TonB, ExbB, and ExbD1 are essential for penetration of phage phi L7. The genome organization, structural features of the tonB-exb region, and transcriptional analyses including Northern hybridization, reporter assays, and primer extension together indicate that the four genes are organized into an operon.
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Affiliation(s)
- Chih-Hsin Hung
- Department of Chemical Engineering, I-Shou University, Kaohsiung 840, Taiwan
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