Enrofloxacin (EFX) is one of the 2nd generation quinolone antibiotics and is now widely used as a broad-spectrum antibiotic for industrial animals. Previous study showed that EFX reduces the cellular metabolic activity of spleen cells and modulates the inflammatory responses. However, little is known about its toxicity on bone marrow (BM) cells. In this study, BM cells were treated with EFX and cellular metabolic activity, cell death, the change of neutrophil (CD11b+Gr1+ cells) proportion, and antigen uptake ability of granulocytes were measured. Compared to the control, EFX-treated cells showed the decrease of cellular metabolic activity, the increase of cell death, and the decreased proportion of neutrophils. In contrast, the antigen uptake ability of granulocytes in BM cells was increased by EFX. These data suggest that EFX has only limited toxicity on BM cells. And also, EFX is safe on BM cells in a range of concentration, 6.25 – 25 μg/mL. This study can provide available data for the safety or toxicity of EFX.
To attenuate and control the spread of infectious disease, a body of research has been conducted to generate safe vaccines and to continue national-level surveillance. However, understanding on viability and persistence of avian influenza virus (AIV) in infected carcasses, and effective disposal approaches are still limited up to date. Here, using HA test and RT-PCR, we assessed active status of AIV and degradation of viral RNA in collected specimens at different sites and time points. First, AIV infectivity was recovered until day 2, and viral nucleic acids persisted to day 14 and 21 in inorganic and organic samples, respectively, in sealed vials incubated at room temperature. Second, AIV was totally inactivated in all examined specimens, and viral RNA was not detectable at all time points tested at least one month post-infection in AIV-inoculated carcasses buried directly in soil or fiber reinforced plastic (FRP) bin. Lastly, among different burial sites in South Korea, 6 out of 17 sampling sites in Jeonbuk province showed the presence of viral genetic materials, while the rest of the field samples displayed neither the presence of infective AIV nor detectable viral RNA. This study showed a linear relation between time and degradation degree of viral RNA in buried samples suggesting that burial disposal method is effective for the control or at least attenuation of spread of AI infection in infected animals although consistent monitoring is required to verify safety of disposal.
A liver mass was incidentally revealed in a 10-year-old male neutered Himalayan cat on radiographic examination conducted in a local animal hospital. The abdominal distention had worsened over the past five months, along with intermittent vomiting and nausea for two weeks. Serum chemistry was unremarkable, except for elevated alkaline phosphatase and gamma-glutamyl transferase levels. Radiography revealed a round-shaped soft mass in the cranial abdomen. Abdominal ultrasonography showed a well defined, massive, fluid-filled cyst with multiple lobes, and heterogeneous echogenicity in the pancreas. Computed tomography examination revealed hypoplasia of the left lobes of the liver, but the vascular changes and enhancement of the mass were not observed on contrast computed tomography images. The herniation of the abdominal fat through the diaphragm was incidentally observed on sonography and computed tomography scan. The patient was tentatively diagnosed with pancreatic cyst. The laparotomy revealed that the origin was not related to the pancreas, but was suspended from the liver. The mass was multilobular and filled with approximately 120 ml of fluid containing a few white blood cells. The patient recovered from anesthesia, but showed postoperative respiratory depression and died of cardiac arrest 15 hours later. Histopathologically, the mass was definitively diagnosed to be hepatic cellular carcinoma.
Canine parvovirus type-2 (CPV-2) has been reported worldwide as the main agent associated with acute hemorrhagic enteritis, resulting in high morbidity, especially in young dogs. CPV-2 has three genetic variants, 2a, 2b, and 2c. Here, we report three cases of canine parvovirus enteritis associated with CPV-2a (2 samples) and -2c (1 sample) infections that occurred in three young dogs suffering from enteritis. Isolates from dog diarrheic fecal samples were sequenced by polymerase chain reaction (PCR) and identified as two types of CPV-2a and one type of CPV-2c. This work constitutes the first isolation and genetic characterization of CPV-2c in the Republic of Korea.
Osteoarthritis occurs when the cartilage that gradually deteriorates as common aging-associated disease in humans and animals. There is no cure, but the treatments are available to manage to relieve pain through medication such as steroids. Growing interest has been focused on the role of cell-based therapies using mesenchymal stem cells (MSCs). In addition, mesenchymal stem cells can be isolated from almost adult tissues and known for their potential of becoming cartilage. Clinical and experimental studies indicate that the development of treatment using stem cells is double-edged sword involving a possibility such as tumorigenesis. This study focused on the electrical features during articular cartilage development and hypothesized that external electric fields promote pre-chondrogenic condensation without concern relating to genetic modification or exogenous factors. Here, it has been reported that exogenous direct electric fields drive pre-chondrogenic condensation which is the stage where cartilage formation begins by condensation of stem cells and cartilage cells in the microenvironment of the joint. Time-dependent observations also support the contribution of electrical stimulation (ES) to induce gradual aggregation of MSCs into highly compact structures within 3 days. Collectively, our findings provide the potential of electrical stimulation-driven chondrogenesis of mesenchymal stem cells in the absence of exogenous factors for repair of cartilage defects.
Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. Use of low-frequency ES for therapeutic purposes has been increasing during the last decades. Mesenchymal stem cells (MSCs) represent an appealing alternative cell source for cartilage repair. There are studies that induce differentiation into cartilage cells by treating the growth factors in stem cells or altering the properties of stem cells by genetic modification. In this study, we exposed equine adipose tissue-derived MSCs (eAD-MSCs) to ES and assessed changes in the chondrogenic differentiation potential. The cells obtained from equine adipose tissue attached to culture plates and expanded in vitro. Flow cytometric analysis at third passage indicated that the cells were strongly positive for CD44, CD90, and CD105, but negative for CD13, CD34, and CD45. Next, ES was applied to eAD-MSCs cultured under condition of high-density micromass under ES of 10 V/cm, with duration of 10 ms and a frequency of 2.0 Hz for three days. Gene expression of chondrogenic markers such as collagen type II, Aggrecan, and Sox9 was analyzed at three days of ES. As a result, we observed the differentiation potential of eAD-MSCs into chondrocytes by specific ES in absence of exogenous growth factors. We also found that ES upregulated the expression of heat shock protein 70, which affects cartilage formation. This study may contribute to the differentiation of MSCs into chondrogenic lineage under specific ES condition.
Growth factors and cytokines play an important role in delaying skin aging. However, there has been no animal stability test reported for them yet. In the present study, we examined the plausibility of Growth factor and Cytokine Mixtures (GCM) as a cosmetic ingredient by assessing skin irritation and ocular irritation for hypersensitivity using New Zealand white rabbits. Skin safety study was performed to evaluate the potential toxicity of GCM based on the irritation test. For the irritation test, GCM was applied to the rabbit skin, and no adverse reaction, such as erythema and edema, had been observed from the exposed skin sites. In the ocular irritation test, the treatment of GCM did not cause any adverse reaction on rabbit eyes, including cornea, iris, and conjunctiva tissues. From the results, both tests proved that GCM makes no irritable reaction on skin and eye mucous membrane of rabbit. Hence, it may be suggested that GCM can be safely applied as a cosmeceutical ingredient without causing any significant hypersensitivity reaction.
The goal of the current study was to explore the relationship between vehicle movement frequency and a disease outbreak by using the example of the highly pathogenic avian influenza (HPAI) outbreak in 2014 in the Republic of Korea. To explore the relationship between the HPAI outbreak status of Korean provinces and vehicle movements, both an ordinary least square model (OLS) and a maximum entropy model (MaxEnt) were built. The HPAI outbreak status of each province was used as a dependent variable. The number of poultry farm vehicle movements within the province (within variable), the number of poultry farm vehicle movements from one province to another province (outbound variable), the number of poultry farm vehicle movements from other provinces to one province (inbound variable), and the number of poultry farms in each province were included in the models as independent variables. Results of the OLS model were as follows: the estimated coefficient of the log-transformed within variable was -0.30, that of the log-transformed outbound variable was 0.71, that of the log-transformed inbound variable was -0.30, and that of the number of poultry farms was 0.07; however, only the number of poultry farms per province was statistically significant. Results of the MaxEnt model were as follows: the median relative contribution of the log-transformed outbound variable was 52.0 (range: 12.2–83.9), that of the log-transformed inbound variable was 34.4 (range: 8.8–83.4), that of the log-transformed within variable was 3.7 (range: 1.8–7.3), and that of the number of poultry farms per province was 0.7 (range: 0.0–11.7). The area under the receiver operating characteristics curve was 0.683. The results of current study should be helpful for planning a national HPAI surveillance program to locate surveillance resources with the consideration of risk level of provinces.
Brucellosis is the most common zoonosis worldwide, which is caused by Brucella spp. In humans, it can be mainly occurred by direct contact with infected animals or consumption of contaminated dairy products. This study focused on human brucellosis caused by B. melitensis discovered from Chinese worker in Korea in 2015. We investigated molecular epidemiological evidence to find the infection source. We first performed several PCR methods including 16S rRNA PCR, multiplex PCR and real-time PCR to identify Brucella species. We also conducted MLVA typing for epidemiological trace-back analysis. The isolate from the patient was confirmed to B. melitensis through Brucella-specific PCR. In clustering analysis with B. melitensis from foreign countries, this human isolate was correlated with B. melitensis isolates from humans and sheep in China by 99.9% similarity. Thus, we assumed the brucellosis patient has been already infected in China followed by migration to Korea according to molecular epidemiological analysis with history evidence. Moreover, we suggest it needs to take measures to reduce the risk for intercountry transmission of brucellosis due to the influx of infected people from abroad.
This study was conducted to investigate the mechanism of the oxidation process of meat. In the instrumental color, redness, yellowness, and chroma showed significant differences during storage period (P<0.05), whereas hue angle increased (P<0.05), but no significant difference in lightness(P>0.05). The results of TBARS increased significantly during storage period (P<0.05). The thiol and carbonyl contents increased significantly during storage period(P<0.05). Metabolites analysis showed that lactic acid, proline, phenylalanine, mannose, talose, lysine, and tyrosine were significantly different with the storage periods (P<0.05). All the samples used in the experiment were able to confirm that sample went through normal oxidation process with indicators and components were increased or decreased. Further research is needed to study the correlation between metabolite materials.
This study was investigated the synergistic antibacterial effects from the combination of sulfamethazine (SMZ) and tiamulin (SMT) against Salmonella Typhimurium (S. Typhimurium) and Actinobacillus pleuropneumoniae (A. pleuropneumoniae) isolated from pigs. Minimum inhibitory concentrations (MICs) and fractional inhibitory concentration (FIC) index were determined for 10 bacteria from 13 swine farms in Gyeongsangnam province by the National Committee for Clinical Laboratory Standards broth microdilution procedure. Antimicrobial agents tested included SMZ, tiamulin and SMT. Against S. Typhimurium and A. pleuropneumoniae, the MIC ranges of SMZ, tiamulin and SMT were 125-500, 15.625-62.5 and 15.625-62.5 μg/mL, respectively. In addition, the FIC index ranges of SMT against S. Typhimurium and A. pleuropneumoniae were 0.19-0.38 and 0.19-0.62, respectively. In conclusion, SMT has a high antibacterial activity against S. Typhimurium and A. pleuropneumoniae, then the combination may be applied for the treatment of swine diseases caused by S. Typhimurium and A. pleuropneumoniae.
The present study evaluated the repellent activity and the improvements in egg production and mortality rate on laying hens infested with poultry red mites (PRM) administered with a mixture of Korean traditional herbal methanolic extracts (CHE, Foeniculum vulgare : Sophora flavescens : Cinnamomum cassia : Glycyrrhiza glabra = 1:1:1:1, w/w/w/w). PRM numbers per laying hens in CHE-0.5 administered with CHE 0.5 kg/ton feed were significantly decreased compared to those in Non-CHE (control) during overall experimental periods (1st week post-treatment, p<0.05; 2nd week post-treatment, p<0.01; 3rd-4th week post-treatment, p<0.001). In CHE-1.0 administered with CHE 1.0 kg/ton feed, PRM numbers were significantly decreased compared to those in Non-CHE during the whole experimental periods (1st week post-treatment, p<0.01; 2nd-4th week post-treatment, p<0.001). After administration of CHE for 4 weeks, egg production and mortality rate in CHE-0.5 and CHE-1.0 were significantly improved compared to those in Non-CHE (p<0.05). In addition, hematological and blood biochemical parameters in all CHE-treated groups were insignificantly different compared to those in Non-CHE. This study showed that CHE (0.5 and 1.0 kg/ton feed) had a repellent activity on PRM in laying hens and effects on the improvement in egg production and mortality rate of laying hen. CHE could be an effective and safe candidate for the control of PRM and the improvement in egg production and mortality rate of laying hens.
Although canine brucellosis has been known to be an important re-emerging zoonosis, the pathophysiological mechanisms of Brucella canis infection remains clues to be solved. Different culture models, single and co-culture models, were constructed with canine epithelial cells, D17 and macrophage, DH82 to investigate the induction of immune responses in in vivo B. canis infection. Expression of genes related with induction of immune responses, Th1, Th2 and Th17, was compared in the two different models after the bacterial infection. In this study, expression of cytokine genes, IL-1β, IL-5, IL-6, IL-10, IL-23, and TNF-α was quantified in the DH82 at different time points using RT-qPCR in the two different culture systems after the infection. Cytokine genes related with Th1, IL-1β and TNF-α and Th17, IL-6 and IL-23 were expressed with time-dependent manners in the both systems (p<0.05). However, increase of Th2-related cytokine genes expression was not detectable in the both systems by comparison with control. The expression of Th1 and Th17 related cytokine genes was earlier in single cell culture than those in co-culture model (p<0.05). In general, amounts of the expressed genes were shown higher in single cell model than those in co-culture models. This study indicate that Th1 and Th17-associated immune responses are central to B. canis infection in dogs. In addition, it suggests a specific role of epithelial cells in the B. canis infection in vivo, which should resolved in the further study.
The goal of the current study was to estimate the contribution of poultry farm vehicle movement frequency to the 2014 highly pathogenic avian influenza (HPAI) epidemic using both global and local regression models. On one hand, the global model did not consider the hypothesis that a relationship between predictors and the outcome variable might vary across the country (spatially homogeneous), while on the other hand, the local model considered that there was spatial heterogeneity within the country. The HPAI outbreak status in each province was used as a dependent variable and the number of poultry farm vehicle movements within each province (within variable), the number of poultry farm vehicle movement from one province to another province (outbound variable), the number of poultry farm vehicle movements from other provinces to one province (inbound variable), and the number of poultry farms in each province were included in the model as independent variables. The results of a global model were as follows: estimated coefficient of the log-transformed within variable was 0.73, that of the log-transformed outbound variable was 2.04, that of the log-transformed inbound variable was 0.74, and that of the number of poultry farms was 1.08. Only the number of poultry farms was a statistically significant variable (p-value < 0.001). The AIC score of the global model was 1397.5. The results of the local model were as follows: estimated median coefficient of the log-transformed within variable was 0.75, that of the log-transformed outbound variable was 2.54, that of the log-transformed inbound variable was 0.60, and that of the number of poultry farms was 0.07. The local model’s AIC score was 1382.2. The results of our study indicate that a local model would provide a better understanding of the relationship between HPAI outbreak status and poultry farm vehicle movements than that provided by a global model.
The poultry red mite (PRM), Dermanyssus gallinae, is one of the most important external parasites in the poultry industry. PRM adheres to birds’ bodies, and its hematophagy causes anemia and itching, and reducing egg production (~20%). Fipronil is a toxic pesticide used to control PRM. Thus, an environmentally friendly alternative control agent is needed. In this study, the effectiveness of various environmentally friendly PRM control measures including an acaricide consisting of synthetic silica, clove extracts, garlic extracts, and a probiotic solution were evaluated, comparing them to a combined treatment using the chemical acaricides. Each agent was tested in vitro using two approaches, in which PRMs were either added to environments containing acaricide, or sprayed in situ. Within 10 hours of inoculation, all the environmentally friendly acaricides except for the probiotic solution killed or rendered immotile significantly more mites than the control, normal saline (p < 0.05). The performance of the environmentally friendly acaricides, except for synthetic silica, was significantly weaker than that of commercial chemical acaricides. (p < 0.05). Further tests to determine the optimal concentration of amorphous synthetic silica agent for complete PRM control found this to be 400 g/L. PRM motility following treatment showed the same pattern: the synthetic silica agent and chemical acaricide killed mites, while application of other environmentally friendly agents resulted in living, but immotile, insects, or those with reduced motility. As a result, these environmentally friendly acaricides, especially the synthetic silica agent, could be used as alternatives to chemical acaricides for PRM control.
Porcine epidemic diarrhea virus (PEDV) infects all-age pigs and causes enteric diseases. Genetic diversities in isolates been reported from each country, and those diversities highlighted in pathogenicity and vaccine. In this manuscript, we are reporting of new PEDV isolation in Korea, and with genetic characteristics. Our new isolate belongs to G2b and put the name as CNUP6-2018.
Viral protein 2 (VP2) of porcine parvovirus (PPV) is responsible for inducing neutralizing antibodies in immunized animals. It is the major viral structural protein. In this study, novel subunit vaccines against PPV based on virus-like particles (VLPs) formed from VP2 proteins (PPV 13-7 Korean strain) were expressed in an insect baculovirus cell system and purified using Ni-NTA affinity column chromatography. These VP2 proteins assembled into virus-like particles (VLPs). They showed antigenic properties similar to those of natural PPV. In addition, they showed high hemagglutination (HA) titers (211 for PPV 13-7 Korean strain). This study provides a foundation for the application of the difference immunization of recombinant protein in the diversity of PPV VP2 genes and in vaccination against PPV in the future.