• Journal of Veterinary Science
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• v.22 no.3
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• pp.39.18-39.18
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• 2021

Background: Interferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear. Objectives: The purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV). Methods: The effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods. Results: In this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV. Conclusion: Expression of the IFNLR1 gene has an important regulatory role in PRRSV-infected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.782-787
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• 2018

Goose hemorrhagic polyomavirus (GHPV) is not a naturally occurring infection in geese in China; however, GHPV infection has been identified in Pekin ducks, a domestic duck species. Herein, we investigated the prevalence of GHPV in five domestic duck species (Liancheng white ducks, Putian black ducks, Shan Sheldrake, Shaoxing duck, and Jinyun Sheldrake) in China. We determined that the Jinyun Sheldrake duck species could be infected by GHPV with no clinical signs, whereas no infection was identified in the other four duck species. We sequenced the complete genome of the Jinyun Sheldrake origin GHPV. Genomic data comparison suggested that GHPVs share a conserved genomic structure, regardless of the host (duck or geese) or region (Asia or Europe). Jinyun Sheldrake origin GHPV genomic characterization and epidemiological studies will increase our understanding of potential heterologous reservoirs of GHPV.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.283-291
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• 2023

Brucellosis and tuberculosis are major infectious and contagious bacterial diseases in cattle. These diseases are malicious diseases that must be inspected at the slaughterhouse of cattle in accordance with the practice of quarantine in Korea. Furthermore, both diseases lead to abortion, reproductive disorder, and calf disease, causing major difficulty in the breeding of Korean Native cattle (Hanwoo), a representative industrial animal currently being raised in Korea. Co-infections of these diseases intensify clinical symptoms such as abortion and have a particularly significant effect on increasing mortality. Thus, serological tests were performed in Hanwoo, to establish the association of co-infection between brucellosis and tuberculosis in cattle. ELISA and PCR tests were conducted on blood samples collected from a total of 102 cattle in Jeonnam province, Korea, to detect brucellosis and tuberculosis infections. The PCR results revealed that 41 samples tested positive for Brucella abortus (B. abortus) infection (40.20%), and 5 samples tested positive for Mycobacterium bovis (M. bovis) (4.90%) infection confirmed by PCR. Notably, 9.76% (4/41) of the cattle infected with brucellosis also tested positive for tuberculosis. In conclusion, this study highlights the co-infection of brucellosis and tuberculosis among Hanwoo cattle in Jeonnam province, which is expected to contribute to our understanding of disease transmission, pathogenicity, the establishment of future prevention strategies.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.363-370
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• 2014

Campylobacter jejuni is a prevalent foodborne pathogen worldwide. Human infection by C. jejuni primarily arises from contaminated poultry meats. Genes expressed in vivo may play an important role in the pathogenicity of C. jejuni. We applied an immunoscreening method, in vivo-induced antigen technology (IVIAT), to identify in vivo-induced genes during human infection by C. jejuni. An inducible expression library of genomic proteins was constructed from sequenced C. jejuni NCTC 11168 and was then screened using adsorbed, pooled human sera obtained from clinical patients. We successfully identified 24 unique genes expressed in vivo. These genes were implicated in metabolism, molecular biosynthesis, genetic information processing, transport, and other processes. We selected six genes with different functions to compare their expression levels in vivo and in vitro using real-time RT-PCR. The results showed that the selected six genes were significantly upregulated in vivo but not in vitro. In short, these identified in vivo-induced genes may contribute to human infection of C. jejuni, some of which may be meaningful vaccine candidate antigens or diagnosis serologic markers for campylobacteriosis. IVIAT may present a significant and efficient method for understanding the pathogenicity mechanism of Campylobacter and for finding targets for its prevention and control.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1126-1133
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• 2022

This study investigated the contribution of lipoxygenase (LOX) inhibitors, nordihydroguaiaretic acid (NDGA), tetra-O-methyl nordihydroguaiaretic acid (M₄N) and zileuton (ZIL), and thromboxane A2 (TXA₂) inhibitor 4,5-diphenylimidazole (DPI) in the proliferation of Brucella abortus infection. None of the compounds affected the uptake of Brucella into the macrophages. We determined the effect of neutralizing leukotriene B4 (LTB4) receptor and showed that the uptake of the bacteria was inhibited at 30 min post-infection. M₄N treatment attenuated intracellular survival of Brucella at 2 h post-incubation but it was not observed in the succeeding time points. DPI treatment showed reduced survival of Brucella at 24 h post-incubation while blocking LTB4 receptor was observed to have a lower intracellular growth at 48 h post-incubation suggesting different action of the inhibitors in the course of the survival of Brucella within the cells. Reduced proliferation of the bacteria in the spleens of mice was observed in animals treated with ZIL or DPI. Increased serum cytokine level of TNF-α and MCP-1 was observed in mice treated with M₄N or ZIL while a lower IFN-γ level in ZIL-treated mice and a higher IL-12 serum level in DPI-treated mice were observed at 7 d post-infection. At 14 d post-infection, ZIL-treated mice displayed reduced serum level of IL-12 and IL-10. Overall, inhibition of 5-LOX or TXA₂ or a combination therapy promises a potential alternative therapy against B. abortus infection. Furthermore, strong ligands for LTB4 receptor could also be a good candidate for the control of Brucella infection.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.81-85
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• 2011

The inhibitory effect of a polysaccharide from kefir on human rotavirus infection in MA-104 cells was investigated. The extracted polysaccharide was separated as fraction I in unbound materials and as fractions II, III, and IV in bound materials. Adding polysaccharide fractions II (4.8 mg/mL), III (5.3 mg/mL), and IV (1.4 mg/mL) inhibited the infection of MA-104 cells by human rotavirus. The 50% inhibitory concentrations (IC 50) were 0.075, 0.083, and 0.022 mg/mL, respectively. Based on these results, the kefir polysaccharide has anti-rotavirus activity. In conclusion, a polysaccharide from kefir had more than a 97% inhibition effect against human rotavirus infection in MA-104 cells.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.125-128
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• 2015

The prevalence and genotype of Toxoplasma gondii infection in dogs in Henan Province, Central China was investigated. A total of 125 blood samples were collected from pet dogs during April to June 2013, and all samples were examined by indirect hemagglutination antibody test (IHA) and nested PCR. The overall T. gondii prevalence in pet dogs was 24.0% (30/125), with 20.8% (26/125) in IHA and 10.4% (13/125) in PCR, respectively. No statistical associations were found between animal gender and age and the prevalence of T. gondii infection. Thirteen positive DNA samples were genotyped using 11 PCR-RFLP markers, including SAG1, (3'+5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Of these, only 2 samples were genotyped with complete data for all loci, and a novel genotype (type III at SAG3 and GRA6 loci, and type I at other loci) was identified. This is the first report of genetic characterization of T. gondii infection in dogs in China.

• Korean Journal of Veterinary Service
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• v.33 no.2
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• pp.97-103
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• 2010

Foot-and-mouth disease (FMD) commonly infects cloven-hoofed livestock animals such as cattle, pig, sheep, and goat and its clinical signs are well-known. Besides livestock, FMD can be transmitted among cloven-hoofed animals in the wild. FMD mostly affects livestock animals in farms, but, wild animals are likely to play a pivotal role in spreading the disease due to their way of free living. In the case of deer, the clinical signs of FMD vary widely from subclinical to severe infections. Thus, in some deer species, it may be hard to verify clinical signs of FMD. A deer may carry the virus up to 11 weeks after exposure, shedding the virus during the period. However, deer is not considered as a typical host for persistent infection like buffalo, cattle or sheep. In Korea, small-scale livestock farms which have less than 10 animals make up 63.6% of the entire livestock farms. Considering raising environment in deer farms, it is assumed that the risk of virus excretion and consequent transmission of FMD among deers is relatively lower than other cloven-hoofed animals. However, Sika deer and Elk which are typical deer species in Korea would manifest mild to subclinical symptoms upon FMD infection. Therefore, laboratory testing is necessary to confirm FMD in these animals because of difficulty in verifying clinical signs and the risk of virus shedding during inapparent infection.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.681-687
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• 2020

Giardia lamblia is a common enteric pathogen associated with diarrheal diseases. There are some reports of G. lamblia infection among different breeds of cattle in recent years worldwide. However, it is yet to know whether cattle in Jiangxi province, southeastern China is infected with G. lamblia. The objectives of the present study were to investigate the prevalence and examine the multilocus genotypes of G. lamblia in cattle in Jiangxi province. A total of 556 fecal samples were collected from 3 cattle breeds (dairy cattle, beef cattle, and buffalo) in Jiangxi province, and the prevalence and genotypes of G. lamblia were determined by the nested PCR amplification of the beta-giardin (bg) gene. A total of 52 samples (9.2%) were positive for G. lamblia. The highest prevalence of G. lamblia was detected in dairy cattle (20.0%), followed by that in beef cattle (6.4%), and meat buffalo (0.9%). Multilocus sequence typing of G. lamblia was performed based on sequences of the bg, triose phosphate isomerase and glutamate dehydrogenase loci, and 22, 42, and 52 samples were amplifiable, respectively, forming 15 MLGs. Moreover, one mixed G. lamblia infection (assemblages A and E) was found in the present study. Altogether, 6 novel assemblage E subtypes (E41*-E46*) were identified for the first time. These results not only provided baseline data for the control of G. lamblia infection in cattle in this southeastern province of China, but also enriched the molecular epidemiological data and genetic diversity of G. lamblia in cattle.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.441-448
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• 2023

Brucellosis is a contagious zoonotic disease that infects millions of people annually with hundreds of millions more being exposed. It is caused by Brucella, a highly infectious bacterial species capable of infecting humans with an estimated dose of 10-100 organisms. Sirtuin 1 (SIRT1) has been reported to contribute to prevention of viral diseases as well as a chronic infection caused by Mycobacterium bovis. Here, we investigated the role of SIRT1 in the establishment of Brucella abortus infection in both in vitro and in vivo systems using the reported SIRT1 activators resveratrol (RES), piceatannol (PIC), and ginsenoside Rg3 (Rg3). In RAW264.7 cells, SIRT1 activators did not alter the adherence of Brucella or Salmonella Typhimurium. However, reduced uptake of Brucella was observed in cells treated with PIC and Rg3, and survival of Brucella within the cells was only observed to decrease in cells that were treated with Rg3, while PIC treatment reduced the intracellular survival of Salmonella. SIRT1 treatment in mice via oral route resulted in augmented Brucella resistance for PIC and Rg3, but not RES. PIC treatment favors Th2 immune response despite reduced serum pro-inflammatory cytokine production, while Rg3-treated mice displayed high IL-12 and IFN-γ serum production. Overall, our findings encourage further investigation into the complete mechanisms of action of the different SIRT1 activators used as well as their potential benefit as an effective alternative approach against intracellular and extracellular pathogens.