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Background: Rodents are recognized as major reservoirs of numerous zoonotic pathogens and are involved in the transmission and maintenance of infectious diseases. Furthermore, despite their importance, diseases transmitted by rodents have been neglected. To date, there have been limited epidemiological studies on rodents, and information regarding their involvement in infectious diseases in the Republic of Korea (ROK) is still scarce. Methodology/Principal findings: We investigated rodent-borne pathogens using nested PCR/RT-PCR from 156 rodents including 151 Apodemus agrarius and 5 Rattus norvegicus from 27 regions in eight provinces across the ROK between March 2019 and November 2020. Spleen, kidney, and blood samples were used to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato group, Coxiella burnetii, Leptospira interrogans, and severe fever with thrombocytopenia syndrome virus (SFTSV). Of the 156 rodents, 73 (46.8%) were infected with Bartonella spp., 25 (16.0%) with C. burnetii, 24 (15.4%) with L. interrogans, 21 (13.5%) with A. phagocytophilum, 9 (5.8%) with SFTSV, and 5 (3.2%) with Borrelia afzelii. Co-infections with two and three pathogens were detected in 33 (21.1%) and 11 rodents (7.1%), respectively. A. phagocytophilum was detected in all regions, showing a widespread occurrence in the ROK. The infection rates of Bartonella spp. were 83.3% for B. grahamii and 16.7% for B. taylorii. Conclusions/Significance: To the best of our knowledge, this is the first report of C. burnetii and SFTSV infections in rodents in the ROK. This study also provides the first description of various rodent-borne pathogens through an extensive epidemiological survey in the ROK. These results suggest that rodents harbor various pathogens that pose a potential threat to public health in the ROK. Our findings provide useful information on the occurrence and distribution of zoonotic pathogens disseminated among rodents and emphasize the urgent need for rapid diagnosis, prevention, and control strategies for these zoonotic diseases. Author summary: Rodents live almost everywhere in the world, adapt to extremely diverse habitats, and transmit various infectious diseases to humans and other animals. All six pathogens were detected in rodents. Our findings demonstrated that 66.7% (104/156) of rodents were infected with at least one pathogen. We also observed differences in the pathogens detected in rodents by province. These results provide evidence that rodents play an important role in the transmission of SFTSV. Although we did not screen for all rodent-borne diseases, these data provide information about emerging rodent-borne diseases disseminated in the ROK and emphasize the risk of occurrence of rodent-borne diseases. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii, a major zoonotic pathogen distributed worldwide, causes severe infections in humans, animals, and birds. However, limited information is available regarding T. gondii infection in livestock in the Republic of Korea (ROK). Herein, we determined the prevalence of T. gondii infection in livestock in the ROK and identified animal species that can potentially transmit T. gondii to humans. B1 gene-targeting nested polymerase chain reaction detected T. gondii DNA in 3.3% (2/61), 2.9% (3/105), 14.1% (11/78), and 15.4% (14/91) of dairy cattle, beef cattle, Boer goats, and Korean native goats, respectively. The prevalence of T. gondii was significantly higher (p = 0.002) in goats than in cattle. The risk of contracting T. gondii infection was significantly higher by 6.18-fold in Korean native goats (95% confidence interval [CI]: 1.72–22.27%, p = 0.005) and by 5.58-fold in Boer goats (95% CI: 1.50–20.76%, p = 0.010) than in beef cattle. Our T. gondii DNA sequences exhibited 97.1–100% homology with those obtained from various hosts in other countries. To the best of our knowledge, this is the first study to report T. gondii infection using the blood samples of domestic ruminants in the ROK. The results revealed that the prevalence of T. gondii infection is higher in goats than in cattle as determined by molecular detection. Thus, these findings suggest that T. gondii can be transmitted from ruminants to humans via meat consumption. [ABSTRACT FROM AUTHOR]

Background: Bovine viral diarrhoea virus (BVDV) is an important viral pathogen that has an economic impact on the livestock industry worldwide. Autophagy is one of the earliest cell‐autonomous defence mechanisms against microbial invasion, and many types of viruses can induce autophagy by infecting host cells. Objectives: The aim of this study was to identify the role of autophagy in the pathogenesis of non‐cytopathic (ncp) BVDV2 infection. Methods: Madin–Darby bovine kidney (MDBK) cells were treated with ncp BVDV2, rapamycin, or 3‐methyladenine (MA) and ncp BVDV2 and then incubated at 37°C for 24 h. Cells were harvested, and the effects of autophagy were determined by transmission electron microscopy (TEM), confocal laser microscopy, western blotting and qRT‐PCR. Apoptotic analysis was also performed using western blotting and flow cytometry. Results: In ncp BVDV2‐infected MDBK cells, more autophagosomes were observed by TEM, and the number of microtubule‐associated protein 1 light chain 3B (LC3B) with green fluorescent protein puncta was also increased. The ncp BVDV2‐infected cells showed significantly enhanced conversion of LC3‐I to LC3‐II, as well as upregulation of autophagy‐related proteins, including ATG5 and Beclin 1, and substantial degradation of p62/SQSTM1. These results are similar to those induced by rapamycin, an autophagy inducer. E2 protein expression, which is associated with viral replication, increased over time in ncp BVDV2‐infected cells. Inhibition of autophagy by 3‐MA in ncp BVDV2‐infected MDBK cells downregulated the expressions of LC3‐II, ATG5 and Beclin 1 and prevented the degradation of p62/SQSTM1. Moreover, the expressions of phosphorylated Akt and procaspase‐3 were significantly increased in ncp BVDV2‐infected cells. In addition, the mRNA level of protein kinase R (PKR) was significantly reduced in ncp BVDV2‐infected cells. Conclusions: Our results demonstrate that ncp BVDV2 infection induced autophagy in MDBK cells via anti‐apoptosis and PKR suppression. Therefore, autophagy may play a role in establishing persistent infection caused by ncp BVDV. [ABSTRACT FROM AUTHOR]

Calf diarrhea leads to substantial economic losses in the livestock industry worldwide due to medical treatment costs, retarded growth performance, and even death. The objective of this study was to investigate changes in serum protein profiles and acute phase proteins in calves with diarrhea and identify the association between these changes and diarrhea. A total of 185 Korean beef calves were used and divided into 3 groups by age: 1 to 10 days ( n = 46), 11 to 20 days ( n = 65), and 21 to 30 days ( n = 74). Blood and fecal samples were collected from each calf. Serum concentrations of total protein, protein fractions (albumin, α1-globulin, α2-globulin, β-globulin, and γ-globulin), haptoglobin (Hp), and serum amyloid A (SAA) were analyzed. Compared to calves without diarrhea, calves with diarrhea had significantly lower albumin concentrations at 11 to 20 days and 21 to 30 days of age ( P = 0.017 and P = 0.000, respectively) and significantly higher α1-globulin fractions at 21 to 30 days of age ( P = 0.01). Interestingly, α2-globulin fractions were significantly higher in diarrheic calves in all age groups, whereas γ-globulin fractions were significantly lower in calves with diarrhea aged 1 to 10 days, compared with normal animals. In calves with diarrhea, the concentration of Hp was significantly higher, whereas SAA levels were not different between normal and diarrheic calves. In addition, a positive correlation was found between α2-globulin and Hp ( P = 0.0004). Taken together, these results provide useful information about the use of serum protein profiles and Hp as prognostic and diagnostic markers for animal health status., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)