**3. Strategies for cultured aquatic animals' immunization and immune regulation**

#### **3.1 Aquatic animals' immunity and immune regulation**

Animal congenital immune cells or other nonimmune cells, such as epithelial cells that secrete cytokines, mononuclear cells, macrophages, dendritic cells, and natural killer cells, have many nonspecific pattern recognition receptors, targeting identification and binding of antigen-related molecular patterns on invading pathogens. Complement receptor type 3 (CR3 receptor) on these cells is a receptor for the recognition of β-glucan [14], and when β-glucan binds to CR3 receptor, it triggers a series of signaling cascades to activate transcription factors, which translates cellular transcription into cytokines that trigger inflammatory responses, and incrementally regulates the expression of the major histocompatibility complex (MHC) of the antigen. In turn, other immune cells are activated to achieve immunomodulatory functions [15].

The polysaccharide extracted from the yeast (*Saccharomyces cerevisiae*) was orally administered for 4 weeks in dogs. The expression of total IgA, IgM, and IgG in serum and lacrimal gland was detected, and the expression of IgA in serum was found to be significantly decreased and IgM increased significantly, while IgG did not change significantly; the amount of IgA in the lacrimal gland was also significantly reduced. In the second part, the Bordetella vaccine was injected subcutaneously, and the specific IgA, IgM, and IgG showed the same trend as in the first part. Oral administration of β-glucan to Miguel dog changed the expression of IgA and IgM in serum, and there was no difference in the expression of IgG, indicating that the intestinal mucosal immune response was stimulated through this way. Glucan enters the gut-associated lymphoid tissue from M cells and binds to dentin 1 and TLR-2 on macrophages and dendritic cells, secreting IL-12 and TNF-α and other cytokines, which alter the cytokine microenvironment to stimulate the homologous transformation of B cells, affecting the secretion of immunoglobulins of different isoforms [16]. Dendritic cells are one of the important antigen-presenting cells in the immune system. Lu et al. used a polysaccharide extracted from *Antrodia camphorate* to carry out cell experiments and cocultured it with immature dendritic cells and T cells isolated from healthy human blood to investigate the maturation of dendritic cells and T-cell proliferation. The result showed polysaccharides promote maturation of dendritic cells to stimulate T-cell proliferation and IFN-γ expression [17]. Coculture of polysaccharides with macrophages can promote macrophage secretion of immune-related factors and

cytokine gene expression, such as nitric oxide (NO), tumor necrosis factor-α (TNFα), IL-1β, IL-6, etc., and promote macrophage activity [18].

According to the description of the fish immune system, we believe that fish do have a memory-specific immune function, so the administration of the vaccine should be quite feasible, but it is considered that the vaccine must be applied to the suitable stage and subject that can cause the immune reaction, and also regular additional injections to enhance the memory effect for the immune response is necessary. However, the application of additional injections is a slight inconvenience for the user who works on the breeding aquaculture farms. Therefore, the immunomodulatory substances can be used complementarily to enhance the nonspecific immune function and to resist pathogens quickly in the farmed fish. Currently, we are investing in the research and development of immunomodulatory substances, in order to solve the dilemma of the decline of biological and physiological ability of breeding. In recent years, research on immunomodulatory technology or the development of immunomodulatory products has gradually become a prominent feature in aquaculture disease control and health management strategies. Many studies have found that once the nonspecific immunity and specific immune function of the cultured organisms are effectively improved, the survival rate, growth rate, and disease resistance of the cultured organisms are significantly improved. It is a pity that many immunomodulatory substances incur excessively high production costs or inherent unitability that it was difficult to obtain similar benefits as the research results in farm operations. In order to solve such problems, our research team spent more than 10 years of painstaking efforts to find the best solution in the macromolecular polysaccharides extracted from mushroom. We overcame the bottleneck of poor stability and high production cost of polysaccharide products in the past and made the immunomodulatory additives to be more easily applied in aquaculture.

#### **3.2 Immunomodulatory additives in aquaculture**

Mushroom glucan (MBG) is a kind of natural polymeric substance (polysaccharide), which is an immunomodulatory substance, and therefore does not cause an uncontrolled increase in immunity in fish, but certain drugs, such as levamisole, may cause undesirable side effects.

In a case study on eel cultured in fresh water, we have found that MBG can properly regulate the cellular immunity; the head, kidney, and spleen are the most important hematopoietic tissues of eel, and when the fish is infected with bacteria or viruses, blood cells from hematopoietic tissues will suffer damage, its number will also be significantly reduced, and the results show that the polysaccharide applied will significantly activate the hematopoietic system of the eel, effectively increasing the number of leukocytes. After 48 hours of using the MBG, the phagocytic cells with phagocytic ability in the body can be increased by about 4–6 times; experimental observations show that the phagocytosis ability is also significantly increased by the polysaccharide-activated phagocytic cells. Studies have confirmed that after the use of polysaccharides, they can significantly enhance the cellular immune function of eels, so that the fish body can resist pathogen infection, which is effective for improving health and improving disease resistance.

The immune stimulatory effects of immunostimulants like glucan, chitosan, and other polysaccharides have been widely studied in fish and crustaceans and were reviewed by Sakai [19]. When fish received immunomodulatory substance, macrophage undergoes phagocytosis, and the rate of intracellular oxygen consumption also increases at the same time, resulting in a so-called respiratory burst phenomenon, and the reaction of oxygen and NADPH into a reactive oxygen species with bacteriostatic ability via NADPH oxidase such as superoxide anion (O2 <sup>−</sup>) and then

**71**

*Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142*

avoid the invasion of pathogens [20].

will be converted to hydrogen peroxide (H2O2) by superoxide dismutase (SOD). The produced hydrogen peroxide can be transferred to hypochlorous acid (HOCl), etc., by myeloperoxidase. The cells can use these reactive oxygen intermediates (ROIs) to

In the study of cobia (*Rachycentron canadum*) fish, it was found that after treatment with polysaccharides, the leukocyte phagocytosis rate, phagocytic index, superoxide ion yield, and lysozyme-like immune-related index were significantly improved in the 2–4 days after treatment. The activity of superoxide dismutase was highest in 4–8 days, or even up to 30 days, similar to that in the untreated group in the physiological index, thus demonstrating the efficient use of polysaccharide in the culture of cobia. It can effectively stimulate macrophages in a short period of time, improve the immunity of fish, and provide a continuous supply of immune-stimulating activity through the addition of feed, which is very helpful for the defense against disease and disease outbreak stage. And long-term treatment has no adverse effects on the fish. For the spot grouper, which is currently the main cultured seawater economic fish in Taiwan, the research has similar effects, and polysaccharides can be used for a long term and be increased in the treatment with 0.8 g/kg and 1.6 g/kg feed. The effect of phagocytes

and other related nonspecific immune responses also increases significantly.

bursts and enhancing resistance against pathogens [25, 26].

that this will be another culture technology in the near future prospect.

**4. Novel disease screening technology**

In invertebrates' culture industry, the abalone culture process often suffered problems in low rate of attachment and poor resistance to foreign pathogens. In abalone immune system, pattern recognition proteins (PRPs) play an important role in innate immunity by recognizing common epitopes on the surface of invading microorganism. In a study of pathogenic challenge experiment of abalone, the test groups were injected with Vibrio, lipopolysaccharides (LPS), and beta-1,3-glucan, respectively, and then compared to controls. Abalone PRP increase can recognize different pathogen-associated molecular patterns (PAMP) and may activate different genes involved in the defense against these pathogens. It acts as an acute inducible protein that could play an important role in the abalone immune defense mechanism [21]. The shrimp immune system has to be activated by pattern recognition proteins such as lipopolysaccharide, *β*-glucan, and peptidoglycan-binding proteins [22, 23]. Once these proteins are bound to their particular targets, they activate hemocytes to release their contents and trigger different biochemical mechanisms [24]. Immunostimulants increase the immune responses in several shrimp species by promoting phagocytosis, bactericidal activity, proPO activity, and respiratory

The use of immersion, injection, and feeding with polysaccharides to improve the nonspecific immune response for aquaculture organisms has become popular. This polysaccharide efficacy was found in the administration with freshwater carp, catfish, trout, eel, tilapia, or seawater salmon, flounder, grouper, cobia, etc. Finally, although the effects of polysaccharide function on aquatic animal-specific immunity are not directly stimulated and promoted, in other animal experiments, it has been found that the use of polysaccharides as an adjuvant for animal vaccines can increase the vaccine potency, stimulating the production of antibodies. The vaccine of fish has also been widely studied in recent years. With the aid of polysaccharides, it is believed that more research and certification are needed. Therefore, it is hoped

The Raman spectrometer (RS) is an instrument that measures the Raman scattering light spectrum. Raman scattered light was discovered by Indian scientists in 1928. Unlike the general laser scattered light, the wavelength of Raman scattered

#### *Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142*

*Emerging Technologies, Environment and Research for Sustainable Aquaculture*

α), IL-1β, IL-6, etc., and promote macrophage activity [18].

**3.2 Immunomodulatory additives in aquaculture**

may cause undesirable side effects.

cytokine gene expression, such as nitric oxide (NO), tumor necrosis factor-α (TNF-

According to the description of the fish immune system, we believe that fish do have a memory-specific immune function, so the administration of the vaccine should be quite feasible, but it is considered that the vaccine must be applied to the suitable stage and subject that can cause the immune reaction, and also regular additional injections to enhance the memory effect for the immune response is necessary. However, the application of additional injections is a slight inconvenience for the user who works on the breeding aquaculture farms. Therefore, the immunomodulatory substances can be used complementarily to enhance the nonspecific immune function and to resist pathogens quickly in the farmed fish. Currently, we are investing in the research and development of immunomodulatory substances, in order to solve the dilemma of the decline of biological and physiological ability of breeding. In recent years, research on immunomodulatory technology or the development of immunomodulatory products has gradually become a prominent feature in aquaculture disease control and health management strategies. Many studies have found that once the nonspecific immunity and specific immune function of the cultured organisms are effectively improved, the survival rate, growth rate, and disease resistance of the cultured organisms are significantly improved. It is a pity that many immunomodulatory substances incur excessively high production costs or inherent unitability that it was difficult to obtain similar benefits as the research results in farm operations. In order to solve such problems, our research team spent more than 10 years of painstaking efforts to find the best solution in the macromolecular polysaccharides extracted from mushroom. We overcame the bottleneck of poor stability and high production cost of polysaccharide products in the past and made the immunomodulatory additives to be more easily applied in aquaculture.

Mushroom glucan (MBG) is a kind of natural polymeric substance (polysaccharide), which is an immunomodulatory substance, and therefore does not cause an uncontrolled increase in immunity in fish, but certain drugs, such as levamisole,

In a case study on eel cultured in fresh water, we have found that MBG can properly regulate the cellular immunity; the head, kidney, and spleen are the most important hematopoietic tissues of eel, and when the fish is infected with bacteria or viruses, blood cells from hematopoietic tissues will suffer damage, its number will also be significantly reduced, and the results show that the polysaccharide applied will significantly activate the hematopoietic system of the eel, effectively increasing the number of leukocytes. After 48 hours of using the MBG, the phagocytic cells with phagocytic ability in the body can be increased by about 4–6 times; experimental observations show that the phagocytosis ability is also significantly increased by the polysaccharide-activated phagocytic cells. Studies have confirmed that after the use of polysaccharides, they can significantly enhance the cellular immune function of eels, so that the fish body can resist pathogen infection, which

The immune stimulatory effects of immunostimulants like glucan, chitosan, and other polysaccharides have been widely studied in fish and crustaceans and were reviewed by Sakai [19]. When fish received immunomodulatory substance, macrophage undergoes phagocytosis, and the rate of intracellular oxygen consumption also increases at the same time, resulting in a so-called respiratory burst phenomenon, and the reaction of oxygen and NADPH into a reactive oxygen species with

<sup>−</sup>) and then

is effective for improving health and improving disease resistance.

bacteriostatic ability via NADPH oxidase such as superoxide anion (O2

**70**

will be converted to hydrogen peroxide (H2O2) by superoxide dismutase (SOD). The produced hydrogen peroxide can be transferred to hypochlorous acid (HOCl), etc., by myeloperoxidase. The cells can use these reactive oxygen intermediates (ROIs) to avoid the invasion of pathogens [20].

In the study of cobia (*Rachycentron canadum*) fish, it was found that after treatment with polysaccharides, the leukocyte phagocytosis rate, phagocytic index, superoxide ion yield, and lysozyme-like immune-related index were significantly improved in the 2–4 days after treatment. The activity of superoxide dismutase was highest in 4–8 days, or even up to 30 days, similar to that in the untreated group in the physiological index, thus demonstrating the efficient use of polysaccharide in the culture of cobia. It can effectively stimulate macrophages in a short period of time, improve the immunity of fish, and provide a continuous supply of immune-stimulating activity through the addition of feed, which is very helpful for the defense against disease and disease outbreak stage. And long-term treatment has no adverse effects on the fish. For the spot grouper, which is currently the main cultured seawater economic fish in Taiwan, the research has similar effects, and polysaccharides can be used for a long term and be increased in the treatment with 0.8 g/kg and 1.6 g/kg feed. The effect of phagocytes and other related nonspecific immune responses also increases significantly.

In invertebrates' culture industry, the abalone culture process often suffered problems in low rate of attachment and poor resistance to foreign pathogens. In abalone immune system, pattern recognition proteins (PRPs) play an important role in innate immunity by recognizing common epitopes on the surface of invading microorganism. In a study of pathogenic challenge experiment of abalone, the test groups were injected with Vibrio, lipopolysaccharides (LPS), and beta-1,3-glucan, respectively, and then compared to controls. Abalone PRP increase can recognize different pathogen-associated molecular patterns (PAMP) and may activate different genes involved in the defense against these pathogens. It acts as an acute inducible protein that could play an important role in the abalone immune defense mechanism [21].

The shrimp immune system has to be activated by pattern recognition proteins such as lipopolysaccharide, *β*-glucan, and peptidoglycan-binding proteins [22, 23]. Once these proteins are bound to their particular targets, they activate hemocytes to release their contents and trigger different biochemical mechanisms [24]. Immunostimulants increase the immune responses in several shrimp species by promoting phagocytosis, bactericidal activity, proPO activity, and respiratory bursts and enhancing resistance against pathogens [25, 26].

The use of immersion, injection, and feeding with polysaccharides to improve the nonspecific immune response for aquaculture organisms has become popular. This polysaccharide efficacy was found in the administration with freshwater carp, catfish, trout, eel, tilapia, or seawater salmon, flounder, grouper, cobia, etc. Finally, although the effects of polysaccharide function on aquatic animal-specific immunity are not directly stimulated and promoted, in other animal experiments, it has been found that the use of polysaccharides as an adjuvant for animal vaccines can increase the vaccine potency, stimulating the production of antibodies. The vaccine of fish has also been widely studied in recent years. With the aid of polysaccharides, it is believed that more research and certification are needed. Therefore, it is hoped that this will be another culture technology in the near future prospect.

#### **4. Novel disease screening technology**

The Raman spectrometer (RS) is an instrument that measures the Raman scattering light spectrum. Raman scattered light was discovered by Indian scientists in 1928. Unlike the general laser scattered light, the wavelength of Raman scattered

light is slightly different from the wavelength of the original incident light. The reason for the difference is that the collision occurs after the molecules are hit by photons. Increasing or reducing photon energy causes the effects of these changes due to molecular bonding and structure [27]. Therefore, this technology is widely used in the detection of high molecular polymers, nanomaterials, electrochemistry, semiconductors, thin films, mineralogy, carbides, etc.

Surface-enhanced Raman scattering (SERS) has been proven to be highly sensitive for trace chemical detection. The power of SERS detection is the labelfree detection capabilities, due to the highly specific Raman scattering fingerprint spectrum (RSFS) and combined with the high sensitivity. SERS has been used to detect a wide range of targets including bio- and nonbiomaterials (DNA, proteins, pesticides, and metabolites). RSFS is a narrow band signal with highly specific characteristic to imply that it can be used to detect multiple analytes simultaneously. Therefore, SERS may finally realize its potential as a highly sensitive and specific analytical technique for trace chemical and biomolecule detection [28].

In recent years, due to the advancement of CCD and laser, scientists have gradually pulled RS to use in the detection of bioassays and medical drugs [27, 29]. At present, SERS is used to enhance the signals needed for specific analysis. It has been widely used in life science research. Common applications include pharmaceuticals, clinical trials, cellular research, immunology, proteomics research, genetics, genetic engineering, plastic surgery, biomedical materials, environmental engineering, and biosafety. In the field of life science research, SERS is able to identify samples with single cell-level accuracy. In the future, instruments combining Raman spectroscopy and microscopic imaging technology will bring great benefits to the life science community.

With the intensive and increasing breeding scale of pigs in various countries, the problem of pig diseases is becoming more and more complicated, and mixed infections or secondary infections are also increasing. Therefore, the diagnosis and prevention of diseases have increasingly shown their importance. In addition, due to the use of antibiotics and vaccines, the symptoms of bacterial (porcine mycoplasma pneumonia and Streptococcus suis infection) or viral (porcine reproductive and respiratory syndrome and porcine type 2 circovirus infection) infections are atypically present. They also often cause serious economic losses for the livestock industry. If they are diagnosed by relying only on clinical symptoms, it will be difficult to confirm the diagnosis. Additionally, the need to strengthen laboratory diagnosis is currently the primary choice. Therefore, it is necessary to develop a nonintrusive real-time image monitoring system. In our laboratory, we tried to characterize and evaluate a SERS-based diagnostic system for the detection and identification of bacteria in the gnotobiotic mice for rapid detection of two common kinds of bacteria in rodent (*Staphylococcus aureus* and *Pseudomonas aeruginosa*)

#### **Figure 3.**

*SERS-based detection system and pig sample collections. (A) the SERS-based detection system. (B) Sample collections from the traditional pig farms.*

**73**

**Figure 4.**

*SERS spectra obtained with (A)* Mycoplasma hyopneumoniae*, (B)* Streptococcus suis*, (C) Staphylococcus aureus, and (D) Pseudomonas aeruginosa. Bacteria recovered from pooled swine urine: (E) swine urine, (F) M. hyopneumoniae, and (G)* S. suis*. Bacteria recovered from pooled swine serum: (H) swine serum, (I) M. hyopneumoniae, (J)* S. suis*, (K) M. hyopneumoniae, and* S. suis*. Bacteria recovered from pooled swine feces: (L) swine feces, (M) M. hyopneumoniae, (N)* S. suis*, (O) M. hyopneumoniae*, *and* S. suis*. Colonization of gnotobiotic mice with the known bacterial strain: 0 day (feces specimens) (P) S. aureus, (Q ) P. aeruginosa, (R) S. aureus*, *and P. aeruginosa. 7 days after colonization (feces specimens) (S) S. aureus, (T) P. aeruginosa, (U) S. aureus*, *and P. aeruginosa. 0 day (serum specimens) (V) without colonization. 7 days after colonization (serum specimens) (W) S. aureus, (X)* P. *aeruginosa, (Y) S. aureus*, *and P. aeruginosa. Arrows indicate the highly* 

*specific peaks of Raman scattering fingerprint spectrum for pathogens.*

*Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142* *Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142*

*Emerging Technologies, Environment and Research for Sustainable Aquaculture*

semiconductors, thin films, mineralogy, carbides, etc.

light is slightly different from the wavelength of the original incident light. The reason for the difference is that the collision occurs after the molecules are hit by photons. Increasing or reducing photon energy causes the effects of these changes due to molecular bonding and structure [27]. Therefore, this technology is widely used in the detection of high molecular polymers, nanomaterials, electrochemistry,

Surface-enhanced Raman scattering (SERS) has been proven to be highly sensitive for trace chemical detection. The power of SERS detection is the labelfree detection capabilities, due to the highly specific Raman scattering fingerprint spectrum (RSFS) and combined with the high sensitivity. SERS has been used to detect a wide range of targets including bio- and nonbiomaterials (DNA, proteins, pesticides, and metabolites). RSFS is a narrow band signal with highly specific characteristic to imply that it can be used to detect multiple analytes simultaneously. Therefore, SERS may finally realize its potential as a highly sensitive and specific analytical technique for trace chemical and biomolecule

In recent years, due to the advancement of CCD and laser, scientists have gradually pulled RS to use in the detection of bioassays and medical drugs [27, 29]. At present, SERS is used to enhance the signals needed for specific analysis. It has been widely used in life science research. Common applications include pharmaceuticals, clinical trials, cellular research, immunology, proteomics research, genetics, genetic engineering, plastic surgery, biomedical materials, environmental engineering, and biosafety. In the field of life science research, SERS is able to identify samples with single cell-level accuracy. In the future, instruments combining Raman spectroscopy and microscopic imaging technology will bring great benefits to the life

With the intensive and increasing breeding scale of pigs in various countries, the problem of pig diseases is becoming more and more complicated, and mixed infections or secondary infections are also increasing. Therefore, the diagnosis and prevention of diseases have increasingly shown their importance. In addition, due to the use of antibiotics and vaccines, the symptoms of bacterial (porcine mycoplasma pneumonia and Streptococcus suis infection) or viral (porcine reproductive and respiratory syndrome and porcine type 2 circovirus infection) infections are atypically present. They also often cause serious economic losses for the livestock industry. If they are diagnosed by relying only on clinical symptoms, it will be difficult to confirm the diagnosis. Additionally, the need to strengthen laboratory diagnosis is currently the primary choice. Therefore, it is necessary to develop a nonintrusive real-time image monitoring system. In our laboratory, we tried to characterize and evaluate a SERS-based diagnostic system for the detection and identification of bacteria in the gnotobiotic mice for rapid detection of two common kinds of bacteria in rodent (*Staphylococcus aureus* and *Pseudomonas aeruginosa*)

**72**

**Figure 3.**

detection [28].

science community.

*collections from the traditional pig farms.*

*SERS-based detection system and pig sample collections. (A) the SERS-based detection system. (B) Sample* 

#### **Figure 4.**

*SERS spectra obtained with (A)* Mycoplasma hyopneumoniae*, (B)* Streptococcus suis*, (C) Staphylococcus aureus, and (D) Pseudomonas aeruginosa. Bacteria recovered from pooled swine urine: (E) swine urine, (F) M. hyopneumoniae, and (G)* S. suis*. Bacteria recovered from pooled swine serum: (H) swine serum, (I) M. hyopneumoniae, (J)* S. suis*, (K) M. hyopneumoniae, and* S. suis*. Bacteria recovered from pooled swine feces: (L) swine feces, (M) M. hyopneumoniae, (N)* S. suis*, (O) M. hyopneumoniae*, *and* S. suis*. Colonization of gnotobiotic mice with the known bacterial strain: 0 day (feces specimens) (P) S. aureus, (Q ) P. aeruginosa, (R) S. aureus*, *and P. aeruginosa. 7 days after colonization (feces specimens) (S) S. aureus, (T) P. aeruginosa, (U) S. aureus*, *and P. aeruginosa. 0 day (serum specimens) (V) without colonization. 7 days after colonization (serum specimens) (W) S. aureus, (X)* P. *aeruginosa, (Y) S. aureus*, *and P. aeruginosa. Arrows indicate the highly specific peaks of Raman scattering fingerprint spectrum for pathogens.*

and two kinds of pathogenic bacteria in swine (Mycoplasma hyopneumoniae and Streptococcus suis). SERS spectra of bacteria recovered from sera, feces, and urine were compared to pure culture bacteria. These results indicated that successful detection, identification, and classification of these bacteria from mice specimens (sera and feces) and swine specimens (sera, feces, and urine) using a SERS-based system were demonstrated. SERS is shown to offer reproducible molecular spectroscopic signatures for analytical applications. The approach may be a new and powerful tool for real-time surveillance of animal bacterial disease pathogens in clinics (**Figures 3** and **4**) [28].

This shift away from traditional aquaculture farming to large-scale intensive methods has resulted in the increasing cases of complex, mixed infections, or secondary infections. The early diagnostic and disease prevention becomes more important for aquaculture farm management. However, antibiotic treatment caused atypical diseases symptoms might be interfered clinical diagnosis. In order to perform accurate pathological diagnosis, we need to combine the strengthening laboratory diagnosis and traditional diagnostics. SERS has recently been shown to be a potentially powerful whole-organism fingerprinting technique and is used for the rapid identification of bacteria. Biosensors based on SERS hold great promise as a platform for sensitive and rapid detection of bacterial pathogens and decrease time of diagnosis [30].

In spite of these capabilities, SERS has been limited to research labs due to stationary equipment and high cost substrates. The instruments combining Raman spectroscopy and microscopic imaging technology will continuously be developed. At present, a highly sensitive and rapid method of SERS combining with electrochemical preconcentration in detecting malachite green in aquaculture water has been established [31]. However, application of SERS in the aquaculture pathogen detections is lacking now. In the future, the application of SERS in the rapid detection for aquaculture pathogens or veterinary medical drugs in the aquaculture farms is very important and needed.

#### **5. Conclusions**

Aquaculture is the fastest-growing food production field. The scientific and business communities are responding to the many challenges and opportunities. The new farming operation of friendly environment will focus on the use of nonecology destructive substances, no antibiotics, and the natural probiotics or novel immunomodulatory substances to match the physiological regulation of cultured organisms and the management of aquaculture. Finally, R&D of the novel pathogen detection technology in the aquaculture is also very important and needed.

#### **Acknowledgements**

The authors thank the Ministry of Science and Technology and the Council of Agriculture, Taiwan, for support.

**75**

**Author details**

Chung-Lun Lu1

Hsinchu, Taiwan

Hsinchu, Taiwan

, Shiu-Nan Chen<sup>2</sup>

\*Address all correspondence to: 1032169@mail.atri.org.tw

provided the original work is properly cited.

and Shao-Wen Hung3

1 Aquatic Technology Laboratories, Agricultural Technology Research Institute,

3 Animal Technology Laboratories, Agricultural Technology Research Institute,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan

\*

*Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142*

## **Conflict of interest**

The authors declare no conflict of interest.

*Application of Novel Technology in Aquaculture DOI: http://dx.doi.org/10.5772/intechopen.90142*

*Emerging Technologies, Environment and Research for Sustainable Aquaculture*

clinics (**Figures 3** and **4**) [28].

sis [30].

important and needed.

**5. Conclusions**

and needed.

**Acknowledgements**

**Conflict of interest**

Agriculture, Taiwan, for support.

The authors declare no conflict of interest.

and two kinds of pathogenic bacteria in swine (Mycoplasma hyopneumoniae and Streptococcus suis). SERS spectra of bacteria recovered from sera, feces, and urine were compared to pure culture bacteria. These results indicated that successful detection, identification, and classification of these bacteria from mice specimens (sera and feces) and swine specimens (sera, feces, and urine) using a SERS-based system were demonstrated. SERS is shown to offer reproducible molecular spectroscopic signatures for analytical applications. The approach may be a new and powerful tool for real-time surveillance of animal bacterial disease pathogens in

This shift away from traditional aquaculture farming to large-scale intensive methods has resulted in the increasing cases of complex, mixed infections, or secondary infections. The early diagnostic and disease prevention becomes more important for aquaculture farm management. However, antibiotic treatment caused atypical diseases symptoms might be interfered clinical diagnosis. In order to perform accurate pathological diagnosis, we need to combine the strengthening laboratory diagnosis and traditional diagnostics. SERS has recently been shown to be a potentially powerful whole-organism fingerprinting technique and is used for the rapid identification of bacteria. Biosensors based on SERS hold great promise as a platform for sensitive and rapid detection of bacterial pathogens and decrease time of diagno-

In spite of these capabilities, SERS has been limited to research labs due to stationary equipment and high cost substrates. The instruments combining Raman spectroscopy and microscopic imaging technology will continuously be developed. At present, a highly sensitive and rapid method of SERS combining with electrochemical preconcentration in detecting malachite green in aquaculture water has been established [31]. However, application of SERS in the aquaculture pathogen detections is lacking now. In the future, the application of SERS in the rapid detection for aquaculture pathogens or veterinary medical drugs in the aquaculture farms is very

Aquaculture is the fastest-growing food production field. The scientific and business communities are responding to the many challenges and opportunities. The new farming operation of friendly environment will focus on the use of nonecology destructive substances, no antibiotics, and the natural probiotics or novel immunomodulatory substances to match the physiological regulation of cultured organisms and the management of aquaculture. Finally, R&D of the novel pathogen detection technology in the aquaculture is also very important

The authors thank the Ministry of Science and Technology and the Council of

**74**
