To date, most serodiagnostic methods for brucellosis screening are based on antibodies against lipopolysaccharides of Brucella spp. However, this approach has the drawback of yielding false-positive results due to cross-reactivity with lipopolysaccharides of other related pathogens, especially Yersinia enterocolitica O:9. In this study, Brucella abortus AspC was cloned and expressed by PCR amplification into a pCold TF expression system to obtain recombinant AspC (rAspC). The immunogenicity of rAspC was confirmed by western blotting of Brucella-positive bovine serum. rAspC-based ELISA was performed to determine whether rAspC could be used in the serodiagnosis of bovine brucellosis. rAspC reacted strongly with anti-Brucella antibodies in positive sera in the tube agglutination test (TAT), but did not show strong reaction with most negative samples. In particular, the average OD492 value at the highest TAT titer showed a 1.4-fold increase with respect to the cutoff value. The accuracy, specificity, and sensitivity of rAspC were 71.88%, 78.33%, and 68%, respectively. These findings suggest that rAspC might be valuable for the serological diagnosis of bovine brucellosis.
Porcine epidemic diarrhea virus (PEDV) causes porcine epidemic diarrhea (PED) and a considerable economic loss in the swine industry. In this study, the virucidal efficacy of a disinfectant composed of citric acid, benzalkonium chloride and phosphoric acid against PEDV was investigated. Virucidal efficacy was assessed as the infectivity of PEDV toward Vero cells after exposure of the virus to the disinfectant. PEDV was exposed to the disinfectant in the presence of either hard water (HW) or an organic matter suspension (OM). In HW condition, PEDV was inactivated by 600-fold dilutions of the disinfectant. In the presence of OM, the disinfectant showed virucidal activity after a 200-fold dilution. As the disinfectant possesses virucidal activity against PEDV, it should be an effective reagent to use to limit the spread of animal viral diseases.
The efficacy of chemical disinfectants is reduced owing to the inactivation of active ingredients after dilution. This study investigated the effect of time on the efficacy of six different disinfectants, after dilution, against avian influenza virus. When used at the recommended concentration, most disinfectants showed efficacy at a high concentrations in the presence of organic materials immediately after dilution, while sodium dichloroisocyanurate-based products, after dilution, showed reduced efficacy over time at low concentrations in the absence of organic materials. Most disinfectants were neutralized by organic materials; however, this could be compensated for by increasing the product dosage. For successful decontamination in farms, disinfectants should be used at high concentrations in accordance with the manufacturers’ recommendations. Furthermore, the presence of organic materials must be taken into consideration, and diluted disinfectant solution should be prepared no more than a day before use.
The ultimate goal of this study is to assess the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To understand the movement of degradable nanoparticle HGC in the body, we intravenously injected a dose of 20 mg/kg of Cy5.5-labeled HGC with size ranging from 320 to 400 nm into ICR mice, and measured the amount of fluorescence remaining in blood and several organs at various time intervals. In blood, the level of Cy5.5-labeled HGC was the highest at 15 min, then after 30 min it decreased rapidly and reached a plateau form 30 min to 28 days. In the tissue we confirmed the presence of nanoparticles at high levels in the order of kidney>liver>submandibular gland until 28 days after injection. However, we did not find the presence of the particles in the brain or testes. These results will provide basic information on HGC as a drug delivery agent.
This study was conducted to evaluate the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To determine the movement of degradable HGC nanoparticles in the body, 20 mg/kg of lutetium177-labeled HGC (Lu177-HGC) with the size ranging from 320 to 400 nm was injected intravenously into ICR mice, and the amount of radioactivity remaining in blood and several organs was measured at various time points during the period of 5 days. In the pharmacokinetics analysis using the Lu177 radioisotope, the free Lu177 was mainly distributed and accumulated in the order of kidney>liver>lung at 1 day after the injection of the radioisotope. However, the Lu177-HGC showed a high distribution of nanoparticles in the order of liver>spleen>kidney during the experimental period of 5 days. These results would provide a basic pharmacokinetics for the use of HGC as a drug carrier in drug delivery system.
Several national control plans have been formulated and carried out to prevent domestic animals from various infectious diseases in Korea. Typical plans include the prevention of diseases by vaccination and the quarantine activities to reduce or cut off the occurrence and transmission. Although such great efforts to prevent diseases every year, difficulties have been experienced in controling transmittable diseases like foot-and-mouth disease and bird influenza. The present study was conducted to investigate the awareness, knowledge, difficulties and routine activities in controling infectious diseases on persons-in-charge of preventive measures in national live stock breeding facilities. A questionnaire survey composed of 81 questions in three categories was carried out on 30 subjects (12 veterinarians and 18 ordinary workers) serving in nine national breeding stock farms. According to the results of the survey analysis, the difficulties and concerns in carrying out preventive measures experienced by the veterinarians and the ordinary workers were similar. Shortage of budgets and manpower was the top ranked concern in performing preventive measures for both the veterinarians and the ordinary workers. Manual or guideline on controling infectious diseases for routine or emergency case were established in all of the facilities, however those were not executed practically in most cases. Instructional training on those manual and controling wild animal to prevent contacting breeding stock were not performed in most facilities surveyed.
Tabinidae(horseflies), which are known worldwide as important mechanical vectors of virus, bacteria, protozoans, and helminths, cause disease in humans and animals. To the best of our knowledge, reports of horseflies associated with horse farms in Korea are rare, and knowledge of the horsefly fauna in Jeju is poor. The objective of this study was to evaluate the incidence of horseflies at a horse farm. Flies were collected using traps baited with natural attractants at a large horse farm during summer (Aug.-Sep. 2011). A total of 28,339 flies from 21 traps were collected on the large horse farm in Jeju. The most abundant were non-sucking flies (25,524; 90.07%) followed by sucking flies (2,226; 7.86%) and Tabanidae (589; 2.07%). Result of species analysis of 4 Tabanidae, ranked in descending order, are as follows: T. grisenus (45.2%), T. rufidens (25.3%), T. takasagoensis (21.6%), and Hybomitra bimaculata (7.9%). Although studies on vector ecology are essential to understanding, predicting, and controlling insect-borne diseases, relatively few studies on tabanids in Jeju have been reported. This paper presents the first comprehensive collection of data on the horse fly fauna of this part of the horse concentrated region. Further research is needed to investigate pathogens on the horse of horseflies.
Edible meat co-products (ECoPs) have recently received significant attention, particularly those for human consumption, because of the nutritional advantages of by-products and the worldwide emphasis on reducing economical loss by wasting. According to the regulations of the Animal and Plant Quarantine Agency in Korea, Korean edible by-products include more diverse internal organs than other nations, such as liver, lung, heart, stomach, pancreas, spleen, kidney, small intestine and colon, but there are no specific regulations for processing these by-products in Korea. Food borne pathogens such as salmonella, campylobacter and E.coli commonly reside in the gut flora of animals, including those that are clinically healthy. It is therefore very important that hygiene requirements are followed when stomachs and intestines are treated for human consumption, in order to prevent these pathogens passing into the human food chain. The requirements for these products have not always been well understood, and the guide attempts to explain these in a way that is helpful for operators.