In this study, occurrence of canine brucellosis was surveyed in kennels, indoor dogs and stray dogs in Korea, and infrequent restriction site-polymerase chain reaction (IRS-PCR) was applied to analyze DNA polymorphism of Brucella canis (B. canis) isolates. Among a total of 501 dogs tested, B. canis antibodies by both rapid screening agglutination with 2-mercaptoethanol (2-ME RSAT) and immunochromatographic assay were detected in only 14.1% of kennel dogs. There were no seropositive cases in indoor dogs and stray dogs. DNA polymorphism was observed in 16 B. canis isolates by the IRS-PCR. Sixteen isolates were tested with primers, PsalA, PsalC, PsalG and PsalT, and different primers produced different DNA patterns. In regard to the IRS-PCR pattern of 16 isolates, 9 (56.3%) belonged to the IRS-PCR type I. The remaining 7 were differentiated as type Ⅱ, Ⅲ and Ⅳ. An application of the primer PsalC provided discrimination between B. canis isolated in 2005 and others.

Streptomyces (S.) fradiae is a microbe with broad-spectrum antimicrobial activity, isolated from soil. In the present study, antibacterial effects of S. fradiaea against Salmonella (S.) gallinarum was determined. S. fradiae inhibited growing of S. gallinarum in Luria-Bertani media agar. Moreover, ingestion of S. fradiae markedly inhibited mortality of chickens experimentally infected with S. gallinarum. There is no side effect by S. fradiaeon, in safety of chickens and antibiotic material residues in chicken meat. Taken together, S. fradiae have the antibacterial effects against S. gallinarum. Therefore, we concluded that S. fradiae might be a good microbial candidate for treatment or control of fowl typhoid in chickens.

In korea, burial is the most common method of disposing animal carcasses culled due to brucellosis infection. However, burial has many disadvantages such as shortage of appropriate burial sites, possibile pollution of ground water supply, and negative view of the public. In this study, we have reviewed 3 legal methods for disposing bovine carcasses, which are burial, incineration, and rendering. We also described the overall process, advantages and disadvantages, and required costs for each method. About 75% of bovine brucellosis outbreak farms had less than 3 reactors, and in our study, rendering required the least amount of cost for farms with a small number of reactors (1-3 heads). Our findings suggest that the use of rendering should be encouraged for farms with bovine brucellosis and other methods considered only if rendering is inappropriate.

In this study, we evaluated the stability and potency of live attenuated rinderpest vaccines of lapinized-avianized tissue culture strain origin, which had been produced annually from 2005 to 2008. When immune responses to the vaccines were evaluated using two Holstein calves weighing 100~150 kg, neutralizinng antibody titer of 1 : 16 was induced at 21 days post vaccination. When calves were also inoculated with vaccines lots that had been stored for 39 months at 4℃, same level of antibody titer was observed. Using the virus titer test, we found that all batches of the vaccine that had been kept for 3, 10, 15, 22, 27, 34, 39, and 45 months showed no significant loss of titers, and fulfilled the requirement necessary (greater-than or equal to 3 logTCID∧50) to be used as the national rinderpest vaccine reserve in Korea. In this study, we demonstrated that stability and potency of the rinderpest vaccines were maintained over three years when kept at 4℃ storage. This indicates that it maybe feasible to extend the expiration period of this vaccine from one year to three years.

Rabbit hemorrhagic disease (RHD) is caused by RHD virus (RHDV) and is one of the most fatal diseases of rabbits. Acute death of rabbits occurred in a farm located in the Gyeonggi province of South Korea. The virus was isolated and confirmed as RHDV based on reverse transcription polymerase chain reaction and hemagglutination assay (HA), and the isolate was designated as KV0801. The nucleotide sequence was deduced. Molecular analysis showed that the KV0801 isolate can be classified as a pandemic antigenic variant strain, RHDVa. The VP60 nucleotide sequence and deduced amino acid homology between KV0801 and other Korean isolate, RHF89, which was isolated in 1988, were 92.1 and 94.3%, respectively. The pathogenicity of the KV0801 isolate at an HA titer ranging from 16,384 to 0.16 HA units was evaluated in five-month-old SFP rabbits. The rabbits inoculated with KV0801 isolate containing more than 1.63 HA units died within six days of inoculation. These results suggest that a highly pathogenic RHDVa is circulating in the rabbit populations of Korea.

Foot-and-mouth disease (FMD) is the most contagious disease of mammals. The use of inactivated vaccine can be chosen to prevent or control FMD. However, vaccination against one serotype of FMDV doses not cross-protect against other serotypes and may not protect fully against some strains of the same serotype. Appropriate selection of vaccine strain is an important element in the control of FMD. The immunity of vaccine antigens should be matched against newly circulating viruses. The phylogenetic analysis of serotype Asia1 reported from China, Mongolia, North Korea and Russia since 2005 shows that they are all classified into genetic group V, but the strain, Asia1/Shamir (ISR/89) which have been used as a vaccine strain in Korea, is clustered into different genetic group. So, in this study the serological relationship between the isolate (Asia1/MOG/05; MOG) and the Shamir stain was determined by ELISA and virus neutralization test. Even though the matching value of the virus (MOG) against the vaccinated sera in target animals was not so high, the vaccinated animals elicited antibodies enough for protection after vaccinated once or twice. Conclusively, we suggest that the vaccine containing Asia1/Shamir antigen could protect the genetic group V strains circulating in East Asia currently if vaccinated twice or the more.

Biofilm has been described as a barrier, which produced by microorganisms to survive and protect themselves against various environments, like antibiotic agents. Staphylococcus spp. is a common cause of nosocomial and environmental infection. Thirty-six and thirty-five Staphylococci were isolated from animals and air, respectively. Based on the biofilm forming ability of the bacterium reported in our previous report, relationship between biofilm formation and antibiotic-resistance was investigated in this study. Regarding antibiotics susceptibility, cefazolin was the most effective agent to the bacteria. Strong biofilm-forming Staphylococcus spp. isolates might have a higher antibiotic resistance than weak biofilm isolates regardless of the presence of antibiotic resistance genes (p less than 0.05). This result suggested that the chemical complexity of the biofilm might increase the antibiotic resistance due to the decrease of antibiotic diffusion into cells through the extensive matrix.

Bovine enteroviruses (BEVs) were separated into two groups, BEV-1 and BEV-2. BEVs, found in cattle worldwide, usually cause asymptomatic infections and are excreted in the feces of infected animals. Antibodies against BEV have been found in different species including human, cattle, sheep, goats, dogs, horses and monkeys in the world. This study aimed to investigate prevalence of the neutralizing antibodies for BEVs in human and animals in Korea. Antibodies against BEV-1 in humans, cattle, pigs, goats, horses and dogs were shown to be 46.8%, 48.3%, 70.6%, 11.5% and 6.3% respectively. Also, antibodies against BEV-2 were shown to be 98.7%, 68.1%, 89.2%, 59.4%, 9.4% and 96.9% respectively. We found that the neutralizing antibodies against these viruses are common in Korea. The prevalences of antibodies against BEV-1 were lower than those against BEV-2 in humans and in all animals except horses. These results showed that the BEV is considered endemic in cattle in many regions in Korea.

The aim of the present study was to determine the acute and subacute potential of trichlorfon in guppies (Poecilia reticulata). We first defined the 24h median tolerance limit (TLm∧24h) of the fish to trichlorfon. Guppies were then treated with TLm∧24h and 1/10 TLm∧24h trichlorfon concentrations to evaluate of any histological alterations occurred. The TLm∧24h value of trichlorfon was 11 ppm. This concentration resulted in acute toxicity to the gills and kidneys with edema, hyperplasia of the gill lamellae, and vacuolated degeneration and necrosis of renal tubular cells. In the case of subacute toxicity using a 10-fold dilution of the TLm∧24h value (1.1 ppm), no behavioral changes, external lesions or histopathological changes were observed. Therefore, safe concentration of trichlorfon might be 1.1 ppm in guppy for controlling parasitic infections.

Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. Escherichia coli and Staphylococcus aureus are the major causative agents of bovine mastitis. These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Bovine mastitis causative micro-organisms can survive in 1-2 weeks in feces and bed complexes. Low level of percentage of water content (PWC) of feces and bed complexes can reduce the spreading of bovine mastitis incidence from environmental contamination. In this study, we developed the fecal dehydrating system and determined the elimination rates of bovine mastitis causative agent from feces and bed complexes. To develop the fecal dehydrating system, the screw pressurized dehydrating system was used and the maximum rate of dehydrating was reached to 52% PWC using 90% PWC (wet base) of fecal and bed complexes. The elimination rates of the dehydrating system for E. coli and S. aureus were reached at 41.19±7.84% to 62.55±8.71% in various percentages of PWC of feces and bed complexes (80, 85 and 90%). These results suggested that the application of fecal dehydrating system would reduce can exposure of dairy cattle to bovine mastitis causing agents contaminated feces and bed complexes, and can be used for environmental bovine mastitis control avoiding misuse or abuse of chemical disinfectants and antibiotics in dairy farm.