• IMMUNE NETWORK
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• 제15권1호
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• pp.27-36
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• 2015

In the present study, we investigated the protection conferred by a live attenuated Salmonella enterica serovar Typhimurium (ST) strain against Salmonella Typhimurium, Salmonella Gallinarum (SG), and Salmonella Enteritidis (SE) infection in layer chickens. Birds were orally primed with the attenuated ST strain at 7 days of age and then boosted at 4 weeks post prime immunization (PPI). Sequential monitoring of plasma IgG and mucosal secretory IgA (sIgA) levels revealed that inoculation with ST induced a significant antibody response to antigens against ST, SE, and SG. Moreover, significant lymphoproliferative responses to the 3 Salmonella serovars were observed in the immunized group. We also investigated protection against virulent ST, SE, and SG strain challenge. Upon virulent SG challenge, the immunized group showed significantly reduced mortality compared to the non-immunized group. The reduced persistence of the virulent ST and SE challenge strains in the liver, spleen, and cecal tissues of the immunized group suggests that immunization with the attenuated ST strain may not only protect against ST infection but can also confer cross protection against SE and SG infection.

• 한국임상수의학회지
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• 제15권1호
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• pp.46-55
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• 1998

This study was performed to verify the effect of modified live virus vaccine against canine parvovirus (CPV) infection. Serum hemagglutination inhibition (Hl) test, histopathological and immunohistochemical techniques and polymerase chain reaction were used. The results were as follows: 1. During the experimental terms after vaccination, serum Hl titer was stable. Geometric mean titer (GMT) after the 1st vaccination was 280. After virulent CPV was challenged, GMT was 1,306. 2. After challenge by virulent CPV, the vaccinated group was not shown clinical signs and gross and histopathological findings. 3. After challenge by virulent CPV, the vaccinated group was not detected viral antigens in the small intestine immunohistochemically. 4. After challenge by violent CPV, the vaccinated group was not shown virus shedding in feces. In conclusions the overall results confirmed that modified live virus vaccine was effective on prevention of canine parvovirus infection.

• 생명과학회지
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• 제20권9호
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• pp.1294-1298
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• 2010

흰반점바이러스(WSSV)는 새우양식산업에 막대한 경제적 손실을 일으키는 가장 치명적인 바이러스성 질병 원인체 중 하나이다. 본 연구는 인위적인 실험모델로서 WSSV에 대한 자주새우(Crangon affinis)의 감수성을 확인하고자 실험을 수행하였다. WSSV가 희석된 수조 내에서 침지법으로 감염된 새우는 감염 후 7일째에 100% 누적폐사율을 보여 자주새우가 WSSV에 대해 매우 높은 감수성을 갖고 있음을 확인하였다. 또한 재조합단백질인 rVP466에 대한 항혈청의 중화효과를 확인하기 위해 항혈청과 반응시킨 바이러스액($1{\times}10^4$ 배로 희석된 WSSV)을 이용하여 침지법으로 자주새우에 대해 공격실험(challenge test)을 수행하였다. 실험 결과, WSSV로 challenge한 감염대조구(positive control)의 새우들은 감염 후 5일째에 100% 폐사하였으며, WSSV와 rVP466 항혈청을 1:0.01, 1:0.1, 1:1로 혼합한 액으로 challenge한 새우들은 감염 후 14일째에 각각 100%, 68.8%, 68.8%의 누적폐사율을 보였다. 따라서 본 연구 결과는 연안서식종인 자주새우가 양식장으로부터 배출된 WSSV에 의해 자연상태에서 감염 될 수 있는 가능성과 함께 항혈청에 대한 중화효과를 나타냄으로써 겨울철 저수온기에 WSSV 감염을 위한 대체 실험생물로서의 유용성을 확인하였다.

• 대한수의학회지
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• 제58권1호
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• pp.39-43
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• 2018

The efficacy of using a bacteriophage (phage) to control Flavobacterium psychrophilum (F. psychrophilum) infection of ayu (Plecoglossus altivelis altivelis) was evaluated in this study. Intramuscular challenge failed to induce sufficient infection levels; therefore, a newly designed net-scratch challenge method was also used to induce bacterial infection. Administration of phage PFpW-3 in F. psychrophilum-infected ayu showed notable protective effects, increased survival rates and mean times to death. Additionally, the fate of inoculated bacteria and phage in ayu were investigated. Our results suggest that the phage PFpW-3 could be considered an alternative biocontrol agent against F. psychrophilum infections in ayu culture.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.69-74
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• 2013

Leishmania tropica is one of the causative agents of leishmaniasis in humans. Routes of infection have been reported to be an important variable for some species of Leishmania parasites. The role of this variable is not clear for L. tropica infection. The aim of this study was to explore the effects of route of L. tropica infection on the disease outcome and immunologic parameters in BALB/c mice. Two routes were used; subcutaneous in the footpad and intradermal in the ear. Mice were challenged by Leishmani major, after establishment of the L. tropica infection, to evaluate the level of protective immunity. Immune responses were assayed at week 1 and week 4 after challenge. The subcutaneous route in the footpad in comparison to the intradermal route in the ear induced significantly more protective immunity against L. major challenge, including higher delayed-type hypersensitivity responses, more rapid lesion resolution, lower parasite loads, and lower levels of IL-10. Our data showed that the route of infection in BALB/c model of L. tropica infection is an important variable and should be considered in developing an appropriate experimental model for L. tropica infections.

• 대한수의학회지
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• 제46권3호
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• pp.185-196
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• 2006

Newcastle disease (ND) is a highly contagious disease of poultry that can cause severe economic losses throughout the world. Vaccination has been used for a long time and proved as one of the most effective method to reduce the economic loss due to ND virus infection, The measurement of antibody titer such as hamagglutination-inhibition (Hl) test with sera has been used as a useful method to evaluate the immunity leve of host. However, Hl test is gradually being replaced by the enzyme linked-immunosorbent assay (ELISA), To evaluate the efficacy of ELISA in the chickens vaccinated with different procedure, present study has been performed. After SPF chicks and commercial broilers were vaccinated with different kinds of live vaccines such as V4, VG/GA and/or Bl at various time, the antibody level has been measured using both HI test and ELISA. Challenge test with velogenic viscerotropic NDV was also performed to measure the protective level of antibody. In the SPF chickens, the mean ELISA titer after vaccination and survival rate after challenge was increased and correlated with days post inoculation. More than 80% of chickens with higher than 1,000 ELISA titer after vaccination were survived after challenge with velogenic ND virus and had good correlation between survival rate and antibody titier. In commercial broiler chickens, most of them at market age had low level of ELISA titer regardless of the number of vaccination, and had a low correlation between survival rate and ELISA titer. However, the ELISA titer of remaining birds after challenge was increased. This result indicated that ELISA titer had good response against velogenic NOV infection compared to Hl titer.

• 미생물과산업
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• 제13권3호
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• pp.3-11
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• 1987

Hepatitis B virus (HBV) is a very serious threat to public health in most of the developing countries of the world. It is estimated that around 300 million people worldwide are chronic carriers of this virus and will transmit the disease both vertically and horizontally. Infection by this virus may cause a wide range of clinical manifestations ranging from an asymptomatic infection to liver cirrhosis.

• Parasites, Hosts and Diseases
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• 제35권4호
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• pp.245-250
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• 1997

마우스에 있어서 쥐와포자충 감염에 대한 면역기전을 해명하기 위하여 이 원충을 최초 및 도전 감염시켜 위점막 비만세포수의 동태를 관찰하였다. ICR계 SPF3주령 마우스에. 그리고 감염 내과 후 분변 내의 오오시스트 음전 후에 두 번에 걸쳐 각각 $2{\;}{\times}{\;}10^6$의 쥐와포자충 (MCR주) 오오시스트를 경구투여하였다 최초 감염 후 5일 및 도전 감염 후 10일 간격으로 희생시켜 위를 적출하여 pH 2.0으로 조정된 Camoy's solution에 5-6시간 고정한 다음 pH 0.3으로 조정된 l% alcian blue에서 2시간. pH 1.0의 0.5% sihnin에서 5분간 염색하여 위점막 비만세포수를 계수하였다. 위점막 비만세포수는 최초 감염 후 15일에서 25일까지 최고치에 이른 다음 30일에 감소하여 그 이후에는 정상으로 복귀하였으며. 도전 감염 후 20-30일에도 역시 증가하였다 최초 감염 후 이 세포의 증가 후에는 분변에 배설되는 오오시스트의 수도 감소하였으며. 도전 감염 후에는 분변에서 오오시스트를 거의 검출할 수 없었다 이러한 사실로 미루어 보아 이 세포는 최초 감염 흡충체 배출. 그리고 도전 감염의 방어기전과 관련이 있다고 생각한다.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.137-143
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• 2021

Most cervical cancers are associated with high-risk human papillomavirus (HPV) infection. Currently, cervical cancer treatment entails surgical removal of the lesion, but treatment of infection and preventing tissue damage are issues that still remain to be addressed. Herbal medicine and biological studies have focused on developing antiviral drugs from natural sources. In this study, we analyzed the potential antiviral effects of Pinus densiflora Sieb. et Zucc. leaf extracts against HPV. The pine needle extracts from each organic solvent were analyzed for antiviral activity. The methylene chloride fraction (PN-MC) showed the highest activity against HPV pseudovirus (PV). The PN-MC extract was more effective before, rather than after treatment, and therefore represents a prophylactic intervention. Mice were pre-treated with PN-MC via genital application or oral administration, followed by a genital or subcutaneous challenge with HPV PV, respectively. The HPV challenge results showed that mice treated via genital application exhibited complete protection against HPV. In conclusion, PN-MC represents a potential topical virucide for HPV infection.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1332-1339
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• 2017

Objective: This study investigated the effects of Bacillus subtilis CSL2 (B. subtilis CSL2) administration before Salmonella challenge on the fecal microbiota and microbial functionality of Hy-line Brown (HLB) laying hens. Methods: Fecal samples were collected from control (CON), Salmonella-infected (SAL) and Salmonella-infected, probiotic-treated (PRO) groups before and after Salmonella challenge for microbiome analysis using 16S rRNA gene pyrosequencing. Results: Infection with Salmonella led to decreased microbial diversity in hen feces; diversity was recovered with Bacillus administration. In addition, Salmonella infection triggered significant alterations in the composition of the fecal microbiota. The abundance of the phylum Firmicutes decreased while that of Proteobacteria, which includes a wide variety of pathogens, increased significantly. Bacillus administration resulted in normal levels of abundance of Firmicutes and Proteobacteria. Analysis of bacterial genera showed that Salmonella challenge decreased the population of Lactobacillus, the most abundant genus, and increased populations of Pseudomonas and Flavobacterium genera by a factor of 3 to 5. On the other hand, Bacillus administration caused the abundance of the Lactobacillus genus to recover to control levels and decreased the population of Pseudomonas significantly. Further analysis of operational taxonomic units revealed a high abundance of genes associated with two-component systems and secretion systems in the SAL group, whereas the PRO group had more genes associated with ribosomes. Conclusion: The results of this study indicate that B. subtilis CSL2 administration can modulate the microbiota in HLB laying hens, potentially acting as a probiotic to protect against Salmonella Gallinarum infection.