STATEMENT REGARDING SEQUENCE LISTING

The Sequence Listing associated with this application is provided in text format in lieu of a paper copy, and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is 200187_471USPC_SEQUENCE_LISTING.txt. The text file is 2.7 KB, was created on Sep. 3, 2020, and is being submitted electronically via EFS-Web.

TECHNICAL FIELD

The present disclosure relates to aLactobacillus plantarumCJLP17 strain having acid resistance, bile resistance, and an immune-enhancing activity. Specifically, the present disclosure relates to a composition, a feed additive, and a functional food, which include theLactobacillus plantarumCJLP17 strain and a culture thereof.

BACKGROUND ART

In the current livestock industry, livestock are killed due to highly contagious viral diseases, and this often leads to economic damage to farms. In particular, in the swine industry, infectious diseases caused by viruses and germs, such as the four major chronic wasting diseases (i.e., porcine respiratory disease complex, postweaning multisystemic wasting syndrome, porcine reproductive and respiratory syndrome, and porcine epidemic diarrhea), have caused huge economic losses.

Among them, porcine epidemic diarrhea is a porcine digestive disease caused by the infection of porcine epidemic diarrhea virus (PEDV), a member of the coronavirus family. The virus proliferates in the villi of the small intestine and large intestine and causes acute enteritis, vomiting, and watery diarrhea in pigs of all ages, especially in piglets. In particular, the damage is severe mainly in winter, from November to April, and it is known that the mortality rate of pre-weaning piglets within 1 week of birth is about 50%, and in severe cases, the mortality rate can reach almost 100% due to extreme dehydration.

The PED virus was first recognized in Europe in 1971 (Oldham J., Letter to the editor.Pig Farming,1972, 10:72-73), and Gla-type PEDV CV777 was further detected and isolated in Belgium in 1976 (Pensaert M B et al., A new coronavirus-like particle associated with diarrhea in swine.Arch Virol.,1978, 58:243-247). The virus spread throughout Europe in the 1980s, and outbreaks occurred in East Asian countries including China, Korea, Japan, Taiwan, etc. in the 1990s. Further, G2b-type PEDV, which is more virulent than the Gla-type, first emerged in China in 2010. This new type of PEDV has spread to North America (the United States and Canada) as well as to Southeast Asia and Europe, causing severe damage (Song D. et al., Porcine epidemic diarrhoea virus: a comprehensive review of molecular epidemiology, diagnosis, and vaccines,Virus Genes,2012, 44:167-175). In 2013, the damage was estimated to be about 2.2 trillion won due to the loss of productivity in the US swine industry. In Korea, it is reported that PEDV outbreaks occur annually in 20% to 40% of pig farms, causing 6% of the total pigs to be killed. It is also reported that the infection rate of the vehicles entering and leaving slaughterhouses reaches about 60% (Korea Rural Economic Institute, Korea Swine Veterinary Association).

Thus far, the only way to fundamentally prevent the G2b-type PED virus has been thorough sterilization. Many farms use an artificial infection method or an inoculation of the existing Gla-type PEDV vaccine to prevent damage caused by viral diseases, but there is a limitation in preventing the G2b-type PEDV infection. In order to overcome such problems, the development of agents for prevention and treatment of PED virus (vaccines, etc.) and treatment (IgY, essential oil, organic acid, probiotics, etc.) is actively underway. In particular, a method of enhancing immunity using a functional material that stimulates the immune system in vivo while having an antiviral effect has recently been studied.

Immunity is generally divided into innate immunity and adaptive immunity. Innate immunity is a system that instantly defends pathogen infection from the first line, acting directly on invaders (antigens) or inducing adaptive immunity. Adaptive immunity is a more complex and precise system that recognizes and removes invaders, or acts as a memory for the corresponding invaders, thereby providing more permanent immune functions compared to the innate immunity. Dendritic cells (DCs), macrophages, and natural killer cells, which are antigen-presenting cells related to innate immunity, directly serve innate immune functions and possess receptors that assist in activation of various types of T cells, thereby secreting cytokines. Adaptive immunity is a secondary defense system against antigens that have entered the body, and is a specific immune response carried out by B lymphocytes and T lymphocytes. The immune responses controlled by antigen-activated T cells include a cytotoxic T cell response, a helper T cell response, etc. Naive CD4 T cells, which act as precursors to these T cells, secrete interleukin-12 (IL-12) and induce a cytotoxic T lymphocyte (CTL) response that eradicates intracellular pathogens, or secrete interleukin-4 (IL-4) and thereby induce a response that specifically eradicates extracellular pathogens (antibody secretion of B cells). In addition, the above-enumerated immune cells respond in an appropriate manner to invaders that have entered the body through an elaborate and complex process, by secreting TGF-beta (beta transforming growth factor) to suppress excessive immune responses such as an inflammatory reaction, stimulating the production of antibodies by transforming B cells into plasma cells in response to the secretion of TGF-beta and interleukin-6 (IL-6), or inducing an immune response (Th17) to eradicate false autoimmunity and extracellular pathogens.

DISCLOSURE

Technical Problem

Under these circumstances, the present inventors have completed the present disclosure by isolating and identifying a novel microorganism capable of activating the immune system while exhibiting an inhibitory activity against the above-mentioned virus, and confirming its activity.

Technical Solution

It is one object of the present disclosure to provide aLactobacillus plantarumCJLP17 strain deposited under accession No. KCCM12249P, having acid resistance, bile resistance, and an immune-enhancing activity.

It is another object of the present disclosure to provide a composition including theLactobacillus plantarumCJLP17 strain or a culture thereof.

It is still another object of the present disclosure to provide a feed additive including theLactobacillus plantarumCJLP17 strain or a culture thereof.

It is yet another object of the present disclosure to provide a functional food including theLactobacillus plantarumCJLP17 strain or a culture thereof.

Advantageous Effects

TheLactobacillus plantarumCJLP17 strain of the present disclosure has excellent acid resistance and bile resistance, and can thus be provided as a probiotic. The CJLP17 strain activates immune cells in vivo and thereby allows for regulation of immune functions, and particularly exhibits an excellent inhibitory activity against porcine epidemic diarrhea virus. In addition, it can be found that when livestock is orally administered with theLactobacillus plantarumCJLP17 strain of the present disclosure, it not only significantly reduces the diarrhea incidence rate through the immunomodulatory effect, but also shows an effect of improving average daily gain (ADG). Accordingly, the present disclosure can provide a novelLactobacillus plantarumCJLP17 strain having an antiviral activity against PEDV, an immune-enhancing activity, and an effect of improving average daily gain and reducing diarrhea incidence rate in livestock, and thus, the strain can be effectively used for a pharmaceutical composition, a food composition, or a feed composition.

