• 대한수의학회지
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• 제39권4호
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• pp.765-771
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• 1999

Unlike most Escherichia coli strains, E coli O157 : H7 didn't ferment sorbitol within 24h of incubation and showed a negative reaction for $\beta$-glucuronidase. We developed a new medium for the rapid isolation of E coli O157 : H7 using sorbitol MacConkey agar with cefixime, potassium tellurite and 4-methylumbelliferyl-${\beta}$-D-glucuronide (MUG) as a primary plating medium. The addition of $20{\mu}g/ml$ of vancomycin in enrichment broth for E coli O157 : H7 inhibited lots of Gram positive bacteria. Three strains (10.3%) of 29 non-O157 E coli strains and 3 strains (8.3%) of 36 Salmonella spp were inhibited at the $0.05{\mu}g/ml$ of cefixime and 23 strains (79.3%) of 29 non-O157 E coli strains and 12 strains (33.3%) of 36 Salmonella spp were inhibited at the $2.0{\mu}g/ml$ of potassium tellurite. But none of the E coli O157 : H7 was affected at these concentration. The addition of MUG at $100{\mu}g/ml$ level to sorbitol MacConkey agar with cefixime and potassium tellurite (CTM-SMAC) aided in the rapid isolation of E coli O157 : H7 from samples by checking sorbitol-negative and $\beta$-glucuronidase negative phenotypes simultaneously. In conclusion, inoculation of a positive in the O157 screening test from enrichment broth on CTM-SMAC appeared to be a rapid, cost-effective and sensitive method for the isolation of E coli O157 : H7.

• 대한수의학회지
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• 제47권2호
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• pp.139-145
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• 2007

Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.

• 대한수의학회지
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• 제62권3호
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• pp.24.1-24.7
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• 2022

Incidences of major feline viral diseases provide basic information for preventing viral disease in cats. Despite the growing interest in feline viral diseases, sero-surveillances have been lacking. In this study, we analyzed the diagnoses of feline viral diseases and conducted a sero surveillance of feline panleukopenia virus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), and feline infectious peritonitis virus (FIPV) in Korean cats. Of the 204 confirmed cases since 2015, the numbers of diagnoses for FPV, FIPV, FCV, feline influenza virus, and FHV-1 were 156, 32, 12, 3, and 1 case, respectively. In total, 200 sera, collected between 2019 and 2021, were screened for the presence of antibodies against FPV, 2 FCVs, FHV-1, and FIPV using a hemagglutination inhibition test and a virus-neutralizing assay (VNA). The overall seropositive rates in cats tested for FPV, the 2 FCVs, FHV-1, and FIPV were 92.5%. 42.0%, 37.0%, 52.0%, and 14.0%, respectively. A low correlation (r = 0.466) was detected between the VNA titers of 2 FCV strains. The highest incidence and seropositive rate of FPV reveal that FPV is circulating in Korean cats. The low r-value between 2 FCVs suggests that a new feline vaccine containing the 2 kinds of FCVs is required.

• 대한수의학회지
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• 제38권4호
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• pp.843-852
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• 1998

From Jan. 1996 to Oct. 1997, 29 pigs with 40-70 days old showing dyspnea inappetite and polyserositis were collected and carried out necropsy, bacterial culture, histopathology, avidin biotin complex(ABC) stain, fluorescent antibody(FA) test, and electron microscopy. In the study, 4 strains from 3 pigs were isolated from meninges, pleura and synovial fluid and also were identified as Haemophilus parasuis serovar 5. Main histopathological lesions of 29 pigs with polyserositis were frequently composed of fibrinous peritonitis(27), pleurisy(22), interstitial pneumonia(21), fibrinous epicarditis(20), fibrinopurulent meningitis(8) and synovitis(4). By ABC stain, 11/29(37.9%) pigs with polyserositis were confirmed to have H parasuis serovar 5 in the cytoplasm of macrophages and neutrophils in cerebral meninges, epicardium, pleura surface of lung or serosa of spleen. ABC stain(20.8~40.0%) to detect H parasuis serovar 5 in tissues was more sensitive than bacterial culture(10.3%), but less sensitive than FA test(62.5%) using frozen tissues even though the result of 8 cases. By electron microscopy, a bacterium was also detected in the cytoplasm of macrophages in purulent exudate of cerebral meninges. Consequently, we confirmed that H parasuis serovar 5 has been involving to cause pigs with polyserositis and can be detected by FA and ABC stain as reliable diagnostic tools.

• 한국동물위생학회지
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• 제43권3호
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• pp.147-154
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• 2020

Standard samples were prepared for this study, and applied for BactoScan^TM and BactoCount^TM in order for quality control evaluation for total bacterial count in raw milk. Accordingly, the preparation of two lots of standard samples for quality control were lyophilized, which contain Lactobacillus lactis. The standard samples were prepared into three different levels of bacterial counts, those were Low 30,000~40,000, Medium 70,000~90,000, High 150,000~220,000 CFU/mL, respectively. Then, the proficiency tests were performed in total 19 laboratories for measuring total bacterial counts. The total bacterial counts in the standard samples showed 37~42, 82~105, 214~240 CFU/mL in the first lot, and it showed 30~36, 67~75, 131~163 CFU/mL in the second lot in low, medium and high levels, respectively. Based on these results, the absolute values of z-scores of six standard samples in 18 laboratories were ≤2, which means the samples are satisfactory. However, z-score in one laboratory was ≤3, which means the sample is questionable. Using two standard samples, the correlation between BactoScan^TM and BactoCount^TM was 0.9982, which means the results of total bacterial count measurement of both equipment were equivalent. Therefore, the standard samples manufactured in this study for quality control of total bacterial count using BactoScan^TM and BactoCount^TM in the raw milk could be applied to proficiency tests.

• 대한수의학회지
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• 제46권4호
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• pp.347-353
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• 2006

Serum samples of 30 chickens per flock from 6 grand parent stock (GPS) farms and 70 parent stock (PS) farms were collected for seroprevalent study of pullorum disease-fowl typhoid (PD-FT) infection by serum plate agglutination test (SPA). The incidence of PD-FT infection in GPS flocks and PS flocks were 0% and 15.7%, respectively. Especially PS flocks infected with PD-FT showed age dependent patterns that 22.2% of flocks between 20 to 30 weeks of age and 38.9% of flocks between 30 to 40 weeks of age were positive. The incidence of GPS flocks and PS flocks using Salmonella (S.) gallinarum 9R (SG9R) live vaccine were 33.3% and 58.6%, respectively. The sero-positive rate of 11 flocks were 6.7-83.3% by SPA and 2.9-55.6% by enzyme linked immunosorbent assay (ELISA), and ELISA showed more lower antibody levels than SPA. Furthermore, specific antibodies produced by SG9R vaccination were detectable by SPA using SG9R antigen without cross-reaction with the PD-FT infection.

• 대한수의학회지
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• 제49권3호
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• pp.221-229
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• 2009

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 strain 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.

• 대한수의학회지
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• 제41권1호
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• pp.43-49
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• 2001

As compared with reaction of antibody for sonicated antigen of Brucella abortus strain RB51 and 1119-3 by Western blot analysis, Brucella field positive sera was detected strong reaction at 40~80 kDa LPS of strain 1119-3, but detected very weak reaction at strain RB51 partly. Otherwise, as we analyzed major immunogen of RB51 by antisera bled periodically during 6 months after RB51 vaccination. we detected strong immunological reaction at 17, 18 and 8 kDa antigen of RB51. Especially, reaction of 8 kDa antigen by Western blot coincided with reaction of dot-blot assay in RB51-antibody detection method. We also compared with reaction of field sera by STAT(standard tube agglutination test), dot-blot assay and Western blot (reaction of 8 kDa antigen of strain RB51). 16 sera of 4~5 months after RB51 vaccination are all negative by STAT, and 12 field brucellosis positive serum are all positive, and also 12 of 16 sera vaccinated RB51 are positive by dot-blot assay and reaction of 8kDa antigen by Western blot. but 1 of 15 Brucellosis negative sera reacted nonspecifically dot-blot assay.

• 생명과학회지
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• 제20권6호
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• pp.964-967
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• 2010

본 연구는 동물유래 E. coli에서 plasmid-mediated quinolone resistance (PMQR) 유전자의 분포도를 조사하였다. 55주의 E. coli를 대상으로 PCR을 수행한 결과, PMQR 양성균은 11주이었으며 그 중 2주는 두 개의 PMQR 유전자를 동시에 가지고 있었다. PMQR 유전자의 염기서열 분석 결과, qnrS, aac(6')-Ib-cr, qepA로 확인되었고 qnrS (1.8%)와 aac(6')-Ib-cr (7.3%) 보다는 qepA (14.5%)가 높은 분포도를 나타내었으며, qnrA와 qnrB는 검출되지 않았다. 11주의 PMQR 양성균의 MIC를 측정한 결과, 대부분의 PMQR 양성균이 검사한 항생제에 내성을 보였지만 일부에서 감수성 균주도 확인되었다. 또한, aac(6')-Ib-cr 유전자는 단독으로 존재할 때 보다 qnrS 또는 qepA와 함께 존재할 때 내성이 더욱 증가함을 알 수 있었다. 내성유전자 전달능 실험에서 11주 모두 PMQR 유전자를 전달하였으며, PMQR 유전자를 전달받은 수용체에서 공여체와 동일한 내성 phenotype 및 PMQR 유전자를 확인 할 수 있었다.

• 대한수의학회지
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• 제57권1호
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• pp.31-36
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• 2017

Japanese encephalitis (JE) is an important zoonosis caused by the mosquito-transmitted JE virus (JEV), which is a causative agent of reproductive failure in pregnant sows. Detection of JEV antibodies in swine is performed by hemagglutination inhibition (HI), virus neutralization (VN), and the plaque reduction neutralization test (PRNT). The most stringent PRNT is the 90% endpoint PRNT ($PRNT_{90}$). These conventional assays are difficult to carry out in diagnostic laboratories with insufficient instruments or cell culture systems. An alternative assay that is easily conducted and time efficient is required. In this study, we improved the indirect enzyme-linked immunosorbent assay (I-ELISA) with clarified antigen for the detection of JEV antibodies. The I-ELISA results obtained from 175 swine serum samples were compared with HI, VN, and $PRNT_{90}$ results. The sensitivity of I-ELISA was 91.8%, 95.0%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. The specificity of I-ELISA was 92.2%, 94.7%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. Moreover, the I-ELISA results were significantly correlated with the HI (r = 0.93), VN (r = 0.95), and $PRNT_{90}$ (r = 0.92) results. These results suggest that the improved I-ELISA is useful for serosurveillance of JEV in swine.