Effect of Green Tea Extract on Vibrio Parahaemolyticus Inhibition in Pacific White Shrimp (Litopenaeus Vannamei) Postlarvae

Available online at www.sciencedirect.com

ScienceDirect Agriculture and Agricultural Science Procedia 11 (2016) 117 – 124

International Conference on Inventions & Innovations for Sustainable Agriculture 2016, ICIISA 2016

Effect of Green Tea Extract on Vibrio parahaemolyticus Inhibition in Pacific White Shrimp (Litopenaeus vannamei) Postlarvae Pawapol Kongchuma,*, Suphavadee Chimtonga, Nantanat Chareansaka, Papimon Subpraserta a

Faculty of Animal Sciences and Agricultural Technology, Silpakorn University, Phetchaburi IT Campus, Cha-am, Phetchaburi 76120, Thailand

Abstract Inhibitory effect of green tea against Vibrio parahaemolyticus was assessed to determine its potential as antibacterial agent for Pacific white shrimp culture. Aqueous extracts obtained by boiling or soaking tea leaves in hot water could inhibit the growth of V. parahaemolyticus. Inhibition zone diameters, carried out by agar well diffusion method with 1x106 CFU.mL-1 of tested bacteria in agar medium, ranged from 14.4 to 16.4 mm. The minimum inhibitory concentration (MIC) determined by broth dilution method during 24-hour incubation was 10% (v/v). G reen tea extract (GTE) was effective on reducing mortality of shrimp postlarvae challenged with V. parahaemolyticus at 104 CFU.mL-1. Survival rate of shrimp reared in water treated with 1 mL.L-1 GTE (80±5.4%) was higher (P<0.05) than that of control (70±2.04%). Total Vibrio counts of whole shrimp, estimated 5 days after the postlarvae were challenged with V. parahaemolyticus at 106 CFU.mL-1, were 6.4x106 and 2.3x106 CFU.g-1 in control and GTE-treated shrimp, respectively. Results of this study suggest that green tea is a promising natural antibacterial agent that can be used for V. parahaemolyticus control during the nursery phase of Pacific white shrimp.

© by Elsevier B.V. This is anB.V. open access article under the CC BY-NC-ND license © 2016 2016 Published The Authors. Published by Elsevier (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Faculty of Animal Sciences and Agricultural Technology, Silpakorn University. Peer-review under responsibility of the Faculty of Animal Sciences and Agricultural Technology, Silpakorn University Keywords: plant extract; natural antibacterial agent; Camellia sinensis; Vibrio infection; shrimp mortality

* Corresponding author. Tel.: +66 32 594037; fax: +66 32 594037. E-mail address: [email protected]

2210-7843 © 2016 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Peer-review under responsibility of the Faculty of Animal Sciences and Agricultural Technology, Silpakorn University doi:10.1016/j.aaspro.2016.12.020

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1. Introduction The Pacific white shrimp, Litopenaeus vannamei (Boone, 1931) is a tropical marine species native to the Eastern Pacific coast of Mexico and Central and South America (FAO undated). It is one of the most important farmed species in Latin America and Asia. The world’s aquaculture production of Pacific white shrimp has increased steadily in the past years from 1.31 million tons in 2004 to over 3 million tons in 2012 (FAO, 2014). Intensification in shrimp aquaculture has resulted in disease outbreaks causing massive mortality of cultured penaeid shrimp. These incidents have been reported from many shrimp producing countries and are considered a major constraint to the shrimp production that have caused significant socio-economic losses in the affected areas (Moss et al., 2012; Kumar et al., 2014). Stentiford et al. (2012) estimated that 60% of losses due to diseases in shrimp aquaculture were caused by viral pathogens with a further 20% by bacterial pathogens. However, bacterial diseases have gained more attention in recent years since the causative agent of the early mortality syndrome (EMS) or acute hepatopancreatic necrosis syndrome (AHPNS), an emerging destructive disease that caused an unusual acute mortality in Pacific white shrimp and black tiger shrimp within approximately 35 days after stocking in growout ponds, has been identified as V. parahaemolyticus (Tran et al., 2013; Joshi et al., 2014). V. parahaemolyticus is a Gram-negative, halophilic bacterium that occurs naturally in marine and estuarine environments (Daniels et al., 2000). It is a major Vibrio spp. that causes vibriosis in aquaculture species and is usually associated with shrimp diseases. V. parahaemolyticus has been reported as the major etiological agent for red disease in black tiger shrimp and had concurrent infections with white spot syndrome virus (Jayasree et al., 2006). The presence of V. parahaemolyticus has been associated with necrosis, slow growth, muscle opacity, anorexia, and mortality of shrimp during nursery rearing (Aguirre-Guzmán et al., 2010). Recently, Zhang et al. (2014) reported that V. parahaemolyticus is a predominant vibrio species identified in the mass mortality of cultured juvenile Chinese shrimp, Fenneropenaeus chinensis. The heavy use of antibiotics for disease treatment in aquatic animals has resulted in the emergence of antibioticresistant pathogens in aquaculture environments making the antibiotic treatment ineffective and this type of incident has been reported from all areas of aquaculture (Immanuel et al., 2004). Moreover, there is a growing concern over the risks of the transfer of resistance determinants to bacteria of land animals and to human pathogens and the presence of antibiotic residues in aquaculture products that constitutes threats to public health (Cabello, 2006; Defoirdt et al., 2007). Thus, alternatives to antibiotic treatment are needed to make aquaculture industry more sustainable and to assure that the produce is safe for human consumption. Over the past few years, many researchers have focused on the application of natural antibacterial compounds, especially plant extracts for the treatment of aquatic animal diseases (Sudheer et al., 2011; Caruana et al., 2012; Chang et al., 2013; Rattanavichai and Cheng, 2014; Talpur, 2014; Acar et al., 2015; Sivagnanavelmurugan et al., 2015; Thanigaivel et al., 2015; Dhayanithi et al., 2015). Among the plant extracts that were studied, green tea, Camellia sinensis has been proved for its antibacterial activity against broad spectrum of Gram-positive and Gramnegative bacteria (Yiannakopoulou, 2012) and V. parahaemolyticus (Toda et al., 1989; Xi et al., 2012). However, the effect of GTE on inhibition of V. parahaemolyticus and reduction of Pacific white shrimp mortality during the nursery phase has not yet been studied. The purpose of this study was to investigate the inhibitory effect of green tea against pathogenic V. parahaemolyticus isolated from farmed Pacific white shrimp for possible use as a natural antibacterial agent in shrimp aquaculture. 2. Materials and Methods 2.1 Bacterial culture preparation V. parahaemolyticus used in this study was isolated from the hepatopancreas of EMS/AHPND-diseased Litopenaeus vannamei collected from shrimp farm in the inner Gulf of Thailand. A pure culture from agar slant was streaked onto tryptic soy agar supplemented with 1% NaCl (TSA-salt) plate and incubated at 37oC for 24 h. A single colony on TSA-salt plate was inoculated into 5 mL tryptic soy broth supplemented with 1% NaCl (TSB-salt) and incubated at 37oC. After 6 h of incubation, one mL of the medium was transferred to 100 mL of TSB-salt and incubated at 37oC for 18 h. The culture was centrifuged (3,000 rpm, 5 min at 5oC) to collect bacterial cells and the cells were resuspended with sterile 1% NaCl solution. Cell concentration (colony-forming unit; CFU) was estimated

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by optical density (OD; 620 nm) and adjusted to 109 CFU.mL-1 for further use according to a relationship previously established between plate counts quantified by spread plate method on thiosulfate-citrate-bile salts-sucrose (TCBS) agar plates and OD. V. parahaemolyticus identification was confirmed by PCR assay using primers for the irgB gene (sense 5’CGATACACACCACGATCCAG-3’, antisense 5’-ATACGGCCGGGGTGATGTTTCT-3’), reagents and thermal cycling conditions as described by Yu et al. (2010). The amplified product was analyzed by agarose gel electrophoresis (2% agarose), stained with ethidium bromide and visualized using a Syngene gel documentation system (Fig. 1).

Fig. 1 PCR product (369 bp) amplified using species-specific primer pair targeted to V. parahaemolyticus irgB gene. Lane 1: 100-bp DNA ladder, Lanes 2-4: V. parahaemolyticus DNA sample.

2.2 Green tea extract preparation Dried green tea leaves used in this study were obtained from a local market and the aqueous extract was prepared by hot water extraction. The three different preparation methods used were as follows: (1) boiling tea leaves (5 g) in 100 mL distilled water for 10 min; (2) soaking tea leaves (10 g) in 100 mL of boiling distilled water and kept in water bath (70oC) for 15 min; and (3) soaking tea leaves (10 g) in 100 mL of boiling distilled water and kept in water bath (70oC) for 30 min. The extracts were filtered using Whatman #1 filter paper and the volumes of filtrate were adjusted to 100 mL and used for further experimental work. 2.3 Experimental animal Pacific white shrimp postlarvae (PL) 12 were obtained from a local hatchery in Kui Buri District, Prachuap Khiri Khan Province, Thailand. Upon arrival, shrimp larvae were stocked in a 300-L polyethylene tank containing 200 L of continuously aerated artificial seawater and maintained under laboratory conditions (29.5±1.5oC, 15 ppt salinity) for 7 days prior to the start of the experiment. During the acclimation period, shrimp were fed a commercial diet (45% protein) 3 times a day and approximately 10% of the rearing water was changed daily. 2.4 Effects of GTE on inhibition of V. parahaemolyticus in culture medium The bactericidal effect of green tea against V. parahaemolyticus was performed according to Xi et al. (2012). One hundred L of 109 CFU.mL-1 of V. parahaemolyticus culture suspension was added to 100 mL warm (45oC) TSA-salt to attain a density of 106 CFU.mL-1 in the medium. The medium was then poured into petri dishes (25 mL) and allowed to solidify at room temperature. Wells (5 mm in diameter) were made on the TSA-salt plates using a sterile glass dropper. One hundred L of GTE obtained from each extraction method was added to the wells in triplicate and the agar plates were incubated at 37oC for 20 h. The efficiency of extract on inhibition of bacterial growth was determined by measuring the diameter of clear zones to the nearest mm. 2.5 Determination of minimum inhibitory concentration (MIC) of GTE MIC of GTE was determined based on a micro-well dilution method (Zgoda and Porter, 2001; Karaman et al., 2003) with some modifications. Aqueous extract obtained by boiling method as previously described was filtered using Acrodisc syringe filters. The filtrate was then diluted and dispensed to each well of a 96-well microplate

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containing 100 μL of 2X Nutrient Broth (NB) with 1% NaCl and 1% the starter culture of V. parahaemolyticus to obtain a final volume of 200 μL mixture with 10%, 5%, 1%, 0.1% (v/v) GTE and control (5 replicates each). At each concentration, 3 wells of uninoculated mixture was used as a negative control. The mixture was incubated at 37°C in SPECTROstar Nano microplate reader and the OD at wave length 620 nm was measured hourly up to 24 hours to determine the lowest extract concentration that fully inhibit the growth of V. parahaemolyticus. 2.6 Effects of GTE on reducing mortality of V. parahaemolyticus-challenged shrimp The GTE prepared by boiling method was tested for its efficiency in bacterial control by determining the survival of Pacific white shrimp that were challenged with V. parahaemolyticus. After acclimation to laboratory conditions, PL19 shrimp were randomly allocated into 8 glass aquaria filled with 15 L of 15 ppt artificial seawater at a density of 40 shrimp per tank (~2.7 shrimp.L-1) and aeration was supplied by aquarium air pump. Four aquaria were assigned to a control group (normal culture medium) and the other 4 aquaria were assigned to a group receiving GTE at 1 mL.L-1 of rearing water on the second day, then at 0.1 mL.L-1 after water exchange on the following days. Twenty-four hours after stocking, experimental shrimp in each aquarium were challenged with V. parahaemolyticus at a predetermined density of 104 CFU.mL-1. Shrimp in both groups were fed commercial diet during acclimation and bacterial inoculation. GTE was added in rearing water 24 hours after bacterial inoculation. During the 15-day trial, shrimp were fed to satiation 3 times a day and 10% of rearing water was renewed daily and water quality (pH, temperature) was monitored twice a day. At the end of experiment, the survival rate of shrimp in each aquarium was assessed. 2.7 Effects of GTE on Vibrio load Thirty shrimp (PL19) were stocked in each of 2 15-L plastic containers containing 10 L of continuously aerated artificial seawater (15 ppt). V. parahaemolyticus was inoculated into rearing water at a density of 106 CFU.mL-1. Twenty-four hours after exposure, the shrimp in one container were treated with GTE in the same way as the trial on shrimp survival. Five days after inoculation, 5-6 shrimp from each container were collected and washed with sterile 1% NaCl solution for seconds. The whole body was used for bacterial load determination due to the small size of experimental shrimp. Tissue samples (0.1 g) from each group were homogenized and serially diluted up to 10-3 dilution, and the vibrio loads were determined by plate count method on TCBS agar plates. Bacterial colonies were counted after incubation at 37oC for 24 h and the bacterial load was calculated as follows: Bacterial count (CFU.g-1) = 2.8 Data analysis Diameters of inhibition zones among extraction methods were subjected to one-way analysis of variance (ANOVA). Treatment means were compared using a least significant difference (LSD) test at significance level (α) of 0.05. Shrimp survival rates in bacterial challenge test were compared using the Student's t-test. 3. Results 3.1 Effects of GTE on inhibition of V. parahaemolyticus in culture medium Agar well diffusion test showed that GTE from all preparation methods could inhibit the growth of V. parahaemolyticus. The inhibition zone diameters observed were 16.33 mm, 14.33 mm and 15.66 mm for the extracts prepared by 10-min boiling, 15-min soaking and 30-min soaking, respectively. Analysis of variance did not reveal any significant differences in diameters of inhibition zone among preparation methods. 3.2 Minimum inhibitory concentrations of GTE Green tea aqueous extract could inhibit the growth of V. parahaemolyticus with the MIC value of 10%. The OD of mixtures with different extract concentrations measured at each time point after subtracting the internal control’s OD during 24-h period and the log-phase growth (at 8-h time point) are shown in Fig. 2 and Fig. 3. The result showed that the growth of V. parahaemolyticus was completely inhibited in the NB medium with 10% tea extract whereas the medium containing extract at 5%, 1% and 0.1% concentration could inhibit the bacterial growth by 77.1%, 39.6% and 12.5%, respectively.

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Fig. 2 Growth of V. parahaemolyticus in Nutrient Broth with different GTE concentrations in 24-hour period.

Fig. 3 Growth of V. parahaemolyticus at different concentrations of GTE at 8-hour time point. The error bars indicate the standard deviation among five replicates.

3.3 Effects of GTE on reducing mortality of V. parahaemolyticus-challenged shrimp GTE prepared by boiling method and applied by adding to rearing water was effective in reducing mortality of bacterial-challenged postlarvae. The number of shrimp survived after 15-day exposure to V. parahaemolyticus in the control group and the GTE-treated group were 28±0.82 and 32±2.16, respectively. The survival rate of GTE-treated group (80±5.40%) was higher (P<0.05) than that of the control group (70±2.04%). 3.4 Effects of GTE on Vibrio load Vibrio load at day 5 post-challenge in the tissue of shrimp treated with GTE tended to be lower than that of shrimp reared in water without GTE (Table 1). Survival rates of shrimp 5 days after challenge with 106 CFU.mL-1 V. parahaemolyticus in GTE-treated group and control were 50% and 26.6%, respectively. Table 1. Vibrio load in tissue of L. vannamei postlarvae at day 5 after the challenge. Trials Control group GTE-treated group

Green colonies 2.3 x 106 0.8 x 106

Vibrio load (CFU.g-1) Yellow colonies 4.1 x 106 1.5 x 106

Total colonies 6.4 x 106 2.3 x 106

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4. Discussions Extracts from plants have great potential as antimicrobial compounds against microorganisms that can be used for treatment of infectious diseases caused by resistant pathogens (Al Akeel et al., 2014) and green tea has been reported for its beneficial effects, especially antibacterial activity against a wide range of pathogenic bacteria (Toda et al., 1989; Xi et al., 2012; Yiannakopoulou, 2012). The inhibitory effect as revealed by the agar well diffusion test in this study proved that green tea had antibacterial activity against V. parahaemolyticus. The zones of inhibition varied among preparation methods but were not significantly different, indicating that the intensities of active antibacterial compounds contained in extracts were not much different among preparation methods. Xi et al. (2012) reported that zones of inhibition of GTE against V. parahaemolyticus ranged from 10 to 13 mm depending on tea products. These authors also found that the yields of total phenolic contents (TPC) in the extract increased significantly from 4.08 to 4.85 g.L-1 as the extraction time increased from 5 to 15 min. In this study, the soaking time was extended to 30 min. However, the diameter of inhibition zone observed (15.66 mm) was not statistically different from those formed by 15-min soaking (14.33 mm) and 10-min boiling (16.33 mm) extracts. As a result of well diffusion assay, it is concluded that tea extract can either be prepared by boiling and soaking tea leaves in hot water. However, the amount of tea leaves used in boiling method was half that of the amount used in soaking methods, therefore, extract preparation by boiling is more economical and recommended. Antibacterial properties of plant extracts against bacteria have been evaluated extensively (Bussmann et al., 2010; Hutton et al., 2012) and the MIC concentrations varied among plant species. In this study, as shown in Fig. 2 and Fig. 3, inhibitory effect of GTE on V. parahaemolyticus was strong in medium containing 10% extract which the growth was inhibited completely while 5% extract could partially inhibit bacterial growth. It is likely that tea extract at a low concentration (1%) retarded the growth of V. parahaemolyticus as evidenced by the lower cell intensity in log phase when compared to the control. This result offers an opportunity for the utilization of green tea in shrimp cultivation by continuously applying the extract at low concentrations to control bacteria in culture tanks. As the results of laboratory tests revealed that green tea exhibited an inhibitory effect on V. parahaemolyticus, it is also important to evaluate its protective potential in shrimp. In this study, the authors examined the effect of GTE on reductions of mortality and bacterial loads in shrimp challenged with V. parahaemolyticus. Adding tea extract into rearing water could reduce the mortality of experimental shrimp about 10% compared to the control group. The effect of GTE administration on the survival of experimental animals agrees with that reported by Abdel-Tawwab et al. (2010). These authors found that the survival of tilapia challenged with Aeromonas hydrophila increased when fish received green tea enriched diets, suggesting that green tea is a promising antibacterial agent. However, in the present study the extract was applied by adding to water. Thus, it would be useful to evaluate the effect of varying levels of GTE in the diet as well as in the rearing water on the survival of shrimp. The results obtained will help in determining the optimum level of extract for practical application in the culture of Pacific white shrimp. The trial to determine bacterial load was conducted by challenging shrimp postlarvae with a higher bacterial density (106 CFU.mL-1) due to the bacterial count in the experiment which shrimp were challenged with 104 CFU.mL-1 was lower than accepted range of countable colonies (25-250 CFU/plate). In this trial, it was found that the mortality of shrimp reared in normal water (73.4%) was higher than shrimp reared in GTE-treated water (50%). The bacterial counts in shrimp that survived the challenge elucidated that adding GTE to the culture water could help reduce bacterial load. However, additional experiments are needed to confirm this observation. Aside from its antibacterial effects against several pathogenic bacteria tested in vitro and in vivo as were reported by several studies, green tea also stimulated immune response and could help battle infection. Harikrishnan et al. (2011) reported that a green tea-supplemented diet enhanced non-specific immune responses and resistance to V. carchariae of kelp grouper, Epinephelus bruneus. It is, therefore, possible that the lower mortalities and vibrio loads observed in shrimp receiving GTE in this study were due to its antibacterial activity and immunostimulant properties. The results of this study illustrated that green tea has a potential for use as antibacterial substance in V. parahaemolyticus control during the nursery phase of Pacific white shrimp. It is also possible that the extract can be utilized for the treatment of infectious diseases caused by Vibrio spp. in penaeid shrimps. However, further studies are needed to assess the antibacterial efficiency for specific pathogens in certain shrimp species.

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Acknowledgements The authors wish to thank Mr. Saichol Preanjit of Sailom Farm for providing shrimp postlarvae used in this study and Mr. Anthony Fisher for his assistance in proofreading. References Abdel-Tawwab, M., Ahmad, M.H., Seden, M.E.A., Sakr, S.F.M., 2010. Use of green tea, Camellia sinensis L., in practical diet for growth and protection of Nile tilapia, Oreochromis niloticus (L.), against Aeromonas hydrophila infection. Journal of the World Aquaculture Society 41, 203–213. Acar, Ü., Kesbiç, O.S., Yılmaz, S., Gültepe, N., Türker, A., 2015. Evaluation of the effects of essential oil extracted from sweet orange peel (Citrus sinensis) on growth rate of tilapia (Oreochromis mossambicus) and possible disease resistance against Streptococcus iniae. Aquaculture 437, 282–286. Aguirre-Guzmán, G., Sánchez-Martínez, J.G., Pérez-Castañeda, R., Palacios-Monzón, A., Trujillo-Rodríguez, T., De La Cruz-Hernández, N.I., 2010. Pathogenicity and infection route of Vibrio parahaemolyticus in American white shrimp, Litopenaeus vannamei. Journal of the World Aquaculture Society 41, 464–470. Al Akeel, R., Al-Sheikh, Y., Mateen, A., Syed, R., Janardhan, K., Gupta, V.C., 2014. Evaluation of antibacterial activity of crude protein extracts from seeds of six different medical plants against standard bacterial strains. Saudi Journal of Biological Sciences 21,147–151. Bussmann, R.W., Malca-García, G., Glenn, A., Sharon, D., Chait, G., Díaz, D., Pourmand, K., Jonat, B., Somogy, S., Guardado, G., Aguirre, C., Chan, R., Meyer, K., Kuhlman, A., Townesmith, A., Effio-Carbajal, J., Frías-Fernandez, F., Benito, M., 2010. Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies. Journal of Ethnopharmacology 132, 101–108. Cabello, F.C., 2006. Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment. Environmental Microbiology 8, 1137–1144. Caruana, S., Yoon, G.H., Freeman, M.A., Mackie, J.A., Shinn, A.P., 2012. The efficacy of selected plant extracts and bioflavonoids in controlling infections of Saprolegnia australis (Saprolegniales; Oomycetes). Aquaculture 358–359, 146–154. Chang, C.-C., Tan, H.-C., Cheng, W., 2013. Effects of dietary administration of water hyacinth (Eichhornia crassipes) extracts on the immune responses and disease resistance of giant freshwater prawn, Macrobrachium rosenbergii. Fish & Shellfish Immunology 35, 92–100. Daniels, N.A., MacKinnon, L., Bishop, R., Altekruse, S., Ray, B., Hammond, R.M., Thompson, S., Wilson, S., Bean, N.H., Griffin, P.M., Slutsker, L., 2000. Vibrio parahaemolyticus infections in the United States, 1973–1998. Journal of Infectious Diseases 181, 1661–1666. Defoirdt, T., Boon, N., Sorgeloos, P., Verstraete, W., Bossier, P., 2007. Alternatives to antibiotics to control bacterial infections: Luminescent vibriosis in aquaculture as an example. Trends in Biotechnology 25, 472–479. Dhayanithi, N.B., Ajith Kumar, T.T., Arockiaraj, J., Balasundaram, C., Harikrishnan, R., 2015. Dietary supplementation of Avicennia marina extract on immune protection and disease resistance in Amphiprion sebae against Vibrio alginolyticus. Fish & Shellfish Immunology 45, 52– 58. FAO, 2014. FAO Yearbook: Fishery and Aquaculture Statistics 2012. Fisheries and Aquaculture Department, Food and Agriculture Organization of the United Nations. http://www.fao.org/3/a-i3740t/index.html. Accessed 12 December 2015. FAO, undated. Penaeus vannamei. Cultured aquatic species information programme. Fisheries and Aquaculture Department, Food and Agriculture Organization of the United Nations. http://www.fao.org/fishery/culturedspecies/Litopenaeus_vannamei/en. Accessed 12 December 2015. Harikrishnan, R., Balasundaram, C., Heo, M.-S., 2011. Influence of diet enriched with green tea on innate humoral and cellular immune response of kelp grouper (Epinephelus bruneus) to Vibrio carchariae infection. Fish & Shellfish Immunology 30, 972–979. Hutton, P.G., Durmic, Z., Ghisalberti, E.L., Flematti, G.R., Duncan, R.M., Carson, C.F., Riley, T.V., Vercoe, P.E., 2012. Inhibition of ruminal bacteria involved in lactic acid metabolism by extracts from Australian plants. Animal Feed Science and Technology 176, 170–177. Jayasree, L., Janakiram, P., Madhavi, R., 2006. Characterization of Vibrio spp. associated with diseased shrimp from culture ponds of Andhra Pradesh (India). Journal of the World Aquaculture Society 37, 523–532. Joshi, J., Srisala, J., Truong, V.H., Chen, I.T., Nuangsaeng, B., Suthienkul, O., Lo, C.F., Flegel, T.W., Sritunyalucksana, K., Thitamadee, S., 2014. Variation in Vibrio parahaemolyticus isolates from a single Thai shrimp farm experiencing an outbreak of acute hepatopancreatic necrosis disease (AHPND). Aquaculture 428–429, 297–302. Karaman, İ., Şahin, F., Güllüce, M., Öǧütçü, H., Şengül, M., Adıgüzel, A., 2003. Antimicrobial activity of aqueous and methanol extracts of Juniperus oxycedrus L. Journal of Ethnopharmacology 85, 231–235. Kumar, B.K., Deekshit, V.K., Raj, J.R.M., Rai, P., Shivanagowda, B.M., Karunasagar, I., Karunasagar, I., 2014. Diversity of Vibrio parahaemolyticus associated with disease outbreak among cultured Litopenaeus vannamei (Pacific white shrimp) in India. Aquaculture 433, 247–251. Moss, S.M., Moss, D.R., Arce, S.M., Lightner, D.V., Lotz, J.M., 2012. The role of selective breeding and biosecurity in the prevention of disease in penaeid shrimp aquaculture. Journal of Invertebrate Pathology 110, 247–250. Rattanavichai, W., Cheng, W., 2014. Effects of hot-water extract of banana (Musa acuminata) fruit's peel on the antibacterial activity, and antihypothermal stress, immune responses and disease resistance of the giant freshwater prawn, Macrobrachium rosenbegii. Fish & Shellfish Immunology 39, 326–335. Sivagnanavelmurugan, M., Karthik Ramnath, G., Jude Thaddaeus, B., Palavesam, A., Immanuel, G., 2015. Effect of Sargassum wightii fucoidan on growth and disease resistance to Vibrio parahaemolyticus in Penaeus monodon post-larvae. Aquaculture Nutrition 21, 960–969. Stentiford, G.D., Neil, D.M., Peeler, E.J., Shields, J.D., Small, H.J., Flegel, T.W., Vlak, J.M., Jones, B., Morado, F., Moss, S., Lotz, J., Bartholomay, L., Behringer, D.C., Hauton, C., Lightner, D.V., 2012. Disease will limit future food supply from the global crustacean fishery and aquaculture sectors. Journal of Invertebrate Pathology 110, 141–157. Sudheer, N.S., Philip, R., Singh, I.S.B., 2011. In vivo screening of mangrove plants for anti WSSV activity in Penaeus monodon, and evaluation

123

124

Pawapol Kongchum et al. / Agriculture and Agricultural Science Procedia 11 (2016) 117 – 124

of Ceriops tagal as a potential source of antiviral molecules. Aquaculture 311, 36–41. Talpur, A.D., 2014. Mentha piperita (Peppermint) as feed additive enhanced growth performance, survival, immune response and disease resistance of Asian seabass, Lates calcarifer (Bloch) against Vibrio harveyi infection. Aquaculture 420–421, 71–78. Thanigaivel, S., Vijayakumar, S., Gopinath, S., Mukherjee, A., Chandrasekaran, N., Thomas, J., 2015. In vivo and in vitro antimicrobial activity of Azadirachta indica (Lin) against Citrobacter freundii isolated from naturally infected Tilapia (Oreochromis mossambicus). Aquaculture 437, 252–255. Toda, M., Okubo, S., Ohnishi, R., Shimamura, T., 1989. Antibacterial and bactericidal activities of Japanese green tea. Nihon Saikingaku Zasshi 44, 669–72 (in Japanese with English Abstract). Tran L., Nunan, L., Redman, R.M., Mohney, L.L., Pantoja, C.R., Fitzsimmons, K., Lightner, D.V., 2013. Determination of the infectious nature of the agent of acute hepatopancreatic necrosis syndrome affecting penaeid shrimp. Diseases of Aquatic Organisms 105, 45–55. Xi, D., Liu, C., Su, Y.-C., 2012. Effects of green tea extract on reducing Vibrio parahaemolyticus and increasing shelf life of oyster meats. Food Control 25, 368–373. Yiannakopoulou, E.Ch., 2012. Recent patents on antibacterial, antifungal and antiviral properties of tea. Recent Patents on Anti-Infective Drug Discovery 7, 60–65. Yu S., Chen, W., Wang, D., He, X., Zhu, X., Shi, X., 2010. Species-specific PCR detection of the food-borne pathogen Vibrio parahaemolyticus using the irgB gene identified by comparative genomic analysis. FEMS Microbiology Letters 307, 65–71. Zgoda, J.R., Porter, J.R., 2001. A convenient microdilution method for screening natural products against bacteria and fungi. Pharmaceutical Biology 39, 221–225. Zhang, X.-J., Yan, B.-L., Bai, X.-S., Bi, K.-R., Gao, H., Qin, G.-M., 2014. Isolation and characterization of Vibrio parahaemolyticus and Vibrio rotiferianus associated with mass mortality of Chinese shrimp (Fenneropenaeus chinensis). Journal of Shellfish Research 33, 61–68.