Veterinary drugs can remain as residues in animal-derived food products, and therefore, many countries conduct residue monitoring programs for imported livestock products. However, because the types and authorizations of veterinary drugs vary among countries, it is necessary for importing nations to establish residue monitoring systems tailored to their specific circumstances. This study aimed to develop an algorithm to quantitatively evaluate and score the risk of veterinary drug residues that may be present in imported livestock products, thereby enabling risk-based prioritization. The overall risk score was calculated as the product of exposure and toxicity factors. To minimize uncertainty, the algorithm utilized objective and accessible data obtained from both domestic and international sources. The exposure factor was determined using the number of residue violations and the estimated exposure value, which was calculated based on withdrawal periods and maximum residue limits (MRLs). The toxicity factor was evaluated using the acceptable daily intake (ADI) and the regulatory importance of the substances. The regulatory importance was classified according to the antimicrobial resistance (AMR) ranking criteria of the World Health Organization (WHO) and the World Organisation for Animal Health (WOAH), while substances not covered by these classifications were ranked based on their impact on the human intestinal microbiota. According to the results of residue violation grading by country and substance, when focusing on meat (excluding dairy products), the United States had the highest number of Grade 5 substances (seven), followed by Canada, Brazil, Mexico, Spain, Uruguay, and Chile, which each contained Grade 5 substances. In domestic livestock products, 14 substances—including cefazolin and amoxicillin—were classified as Grade 5 in beef, eight substances—including amoxicillin and cefquinome—as Grade 5 in pork, and bifenthrin as a Grade 5 substance in poultry. Based on MRL grading, phenylbutazone, norgestomet, and flumethasone were classified as Grade 5 in beef; phenylbutazone, altrenogest, and flumethasone in pork; and phenylbutazone and dexamethasone in poultry. For ADI-based grading, oleandomycin, cefadroxil, avilamycin, norgestomet, and dexamethasone were identified as Grade 5 substances. Withdrawal period grading indicated that gentamicin was categorized as Grade 5 across all livestock types, including cattle, swine, poultry, and milk. In terms of regulatory importance, danofloxacin, ceftiofur, spiramycin, erythromycin, and enrofloxacin were classified as Grade 5 substances. The risk-prioritization algorithm developed in this study identified five substances—ampicillin, closantel, phenylbutazone, ractopamine, and zeranol—as having the highest possible risk score (25 points) in imported beef. This algorithm enables risk-based prioritization using the results of national residue monitoring programs conducted by exporting countries, thereby allowing importers to establish inspection priorities tailored to their own contexts. Consequently, the developed algorithm can be effectively utilized to identify high-risk veterinary drugs by exporting country and livestock type, supporting the establishment of more efficient monitoring plans for imported livestock products.
복어는 동아시아 요리의 고급 원료로 상업적 가치가 높 은 수산자원이나, 야생 복어의 테트로도톡신은 치명적인 식중독 사건을 꾸준히 유발하고 있다. 자주복은 한국, 일 본, 중국에서 인기 있는 복어 종으로, 테트로도톡신이 없 는 복어 생산을 위해 양식되는 주된 어종이다. 따라서 양 식 자주복과 자연산 자주복의 구별은 식품 안전과 규제측면에서 매우 중요하다. 본 연구에서는 국내 온라인 및 오프라인 시장에서 판매되는 100개의 자주복 제품을 대상 으로 ‘양식 및 자연산’ 여부를 PCR 기반 방법을 이용하 여 확인하였으며, PCR 결과를 제품의 표시사항 정보와 비 교하였다. PCR 분석에는 자연산 자주복과 양식 자주복의 유전적 다양성 차이를 보이는 6개의 마커를 이용하였다. PCR 분석 결과 모든 양식 자주복 제품에서는 6개 마커에 서 모두 완전한 증폭 패턴을 보였으나, 자연산 자주복 제 품에서는 0 - 5개 마커에서 만 무작위 증폭 패턴을 나타냈 다. 따라서 6개 유전 마커의 증폭 패턴을 이용한 분석법 은 향후 자주복 제품의 허위표시 모니터링 및 테트로도톡 신 유무의 신속 검사에 널리 활용될 수 있을 것이다. 또 한 본 연구 결과는 현행 복어 종 판별을 보완할 수 있는 기초자료를 제공해 줄 수 있다.
This study was conducted to investigate the residue pattern in milk of tetrachlorvinphos oral product used in dairy cows and to suggest an appropriate withdrawal period for the tetrachlorvinphos oral product in milk. The oral product containing tetrachlorvinphos was administered per oral to Holstein dairy cows at a dose of 3.4 g of the active ingredient per 100 kg body weight (maximum dose). Milk was collected at 12-hour intervals during administration and up to 120 hours after termination of administration to determinate tetrachlorvinphos residue in milk by LC-MS/MS. Tetrachlorvinphos residues at each time point and the maximum residue level for tetrachlorvinphos in milk (0.01 mg/kg) were applied to a non-statistical model to establish the withdrawal period of the test product. The recovery, precision, coefficient of determination(R2), limit of detection (LOD) and limit of quantitation (LOQ) of the analytical methods used to quantify tetrachlorvinphos were 98%~104%, 5%~11%, 0.9981~ 0.9991 and 2 μg/kg, 7 μg/kg, respectively. These parameters met all the method validation criteria suggested by the Ministry of Food and Drug Safety and were used as an analytical method for tetrachlorvinphos in milk. When this product was administered to dairy cows at 1x dose by feeding, the tetrachlorvinphos was undetectable in milk (below the limit of detection) in all cows during the dosing period and up to 120 hours after termination of administration. Therefore, we suggest the withdrawal period of this product in milk as 0 days.
Gentamicin is an aminoglycoside antibiotic effective against aerobic gram-negative bacteria and is also used in veterinary medicine, particularly in the swine and bovine industries. However, no gentamicin product is currently approved for treating equine diseases in Korea. The present study aims to examine the time-dependent residue of gentamicin in horses after intravenous injection (IV) via jugular vein. The test product was injected at 6.6 mg/kg BW via jugular vein in nine horses. Blood was collected from the horse's jugular vein at 15 minutes, 30 minutes, 1, 4, 8, 12, 24 and 48 hours after injection. To purify the gentamicin in serum, 100μL of 20 mM HFBA in DW, 100 μL of 30% trichloroacetic acid and 300 μL of 20 mM heptafluorobutyric acid (HFBA) in acetonitrile (ACN) were added to 500 μL of serum and supernatant was applied to LC-MS/MS after centrifugation. LC-MS/MS-8050 analyzed the level of gentamicin in serum with Electrospray ionization (ESI) and multiple reaction monitoring (MRM) positive mode. Gentamicin C1 was 478 m/z and product ions were 322, 157 m/z. Precursor ion of Gentamicin C1a was 450 m/z and product ions were 322, 160 m/z. Precursor ion of Gentamicin C2 and C2a was 464 m/z and product ions were 322, 160 m/z. The LC column was a C18 and mobile phase composed of 20 mM HFBA in 5% ACN and 20 mM HFBA in 50% ACN. The amount of gentamicin was calculated by adding four components of gentamicin (C1, C1a, C2 and C2a). The pharmacokinetic parameters of gentamicin were calculated by the WinNonlin program. The Cmax of gentamicin in horse serum was 93 ± 17 μg/kg and the Tmax was 0.25 ± 0 hours. The T1/2 was 6.41 ± 2.32 hours and the CLt was 0.05 ± 0.01L/hr/kg. The Vd was shown as 0.44 ± 0.13 L/kg and the MRT was 1.98 ± 0.55 hours. In conclusion, our data provides useful pharmacokinetic parameters for gentamicin in horses following IV injection.
In this study, an simultaneous LC-MS/MS multi-residue analytical method was developed and validated for the residues of six neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) in honey. Sample preparation included a combination of QuEChERS extraction kit and liquid-liquid extraction method to effectively extract pesticide components from the honey matrix and optimized analytical conditions to achieve high sensitivity and selectivity. The limits of detection (LOD) and the limits of quantitation (LOQ) were set in the range of 6-15 ng/mL and 19-44 ng/mL, respectively and the correlation coefficient (R²) was greater than 0.99, confirming good linearity. In addition, the intra-day recoveries for each pesticide were 75-104%, and the coefficient of variation (CV) was less than 20%, which met the guideline recommended by the Ministry of Food and Drug Safety. The LC-MS/MS method developed in this study is expected to be used as a multi-residue analysis method for 6 neonicotinoid pesticides in honey.
이상의 결과를 종합하면, 혼합유산균 2종(Bifidobacterium animalis ssp. Lactis Bf141와 Lactobacillus rhamnosus Lb102)의 섭취는 고지방식이 유도 비만 마우스에서 체중, 체지방, 제지방, 골밀도 등 주요 체성분에 영향을 주지 않았다. 혼합유산균은 식욕 조절 효과를 위해 측정한 사료 섭취량에도 영향을 주지 않았으며, 간 조직 무게에도 영향을 미치지 않았다. 인슐린저항성과 포도당신생합성의 주요 지표인 공복혈당량 또한 혼합유산균 급여에 의해 변화 하지 않았다. 또한 혼합유산균은 심혈관질환의 지표로 사용되는 혈중 중성지방 및 총 콜레스테롤에 영향을 주지 않았으며, 체내 지방의 소화 및 흡수율에서도 영향을 미치지 않았다. 결론적으로, 고지방식이유도 비만 마우스를 이용하여 혼합유산균(Bf141 + Lb102)의 항비만 생리활성 을 검증한 결과, 유의미한 물리적, 대사적 표현형 개선은 검증되지 않았다. 따라서, 추후 개별 보다 다양한 혼합 조건 및 농도로 연구를 설계하여 혼합유산균의 항비만 효과를 검증할 필요성이 있다.
Megabenthos samples were collected using 10-min trawls towed at 17 stations from 2015 to 2016. The dominant species (>1% of the total density) were Stegophiura sterea (10.4%) and two subtropical species, Mactrinula dolabrata (9.0%) and Acila divaricate (8.3%), respectively. The community structure of the megabenthos fell into four groups: the southeast, the southernmost region off Jeju Island, the frontal zone of the South Sea with C3, and a diagonal area from the south coast to the western side of Jeju Island. The total numbers of species, diversity, density and biomass were higher in the C3 region of the South Sea. Environmental factor analysis showed that differences in the megabenthos community were related to depth, gravel contents, and sorting value (σ). These results indicate that changes in the marine environmental conditions in the South Sea of Korea affect the megabenthos species’ composition and diversity.
방울토마토의 수경재배 중 붕소+칼슘+규소 및 칼슘+규소의 복합 엽면시비가 수확 후 품질과 MAP 저장 중 저장성에 미치는 영향을 알아보고자 본 연구를 실시하였다. 엽면시비한 방울 토마토(‘Unicorn’)는 반숙 과상태에서 수확하여 산소투과성 필름으로 포장한 5oC, 11oC, 그리고 24oC에서 25일, 15일, 10일간 저장하였다. 붕소+칼슘+규소 복합처리한 방울토마토가 3가지 저장온도 모두에서 호흡과 에틸렌 발생이 억제되어 MAP 저장중 가장 낮은 생체중 감소와 가장 높은 외관상 품질을 보였다. 수확 후 조사한 방울토마토의 경도, 산도, 비타민 C 함량은 붕소+칼슘+규소 복합처리에서 가장 높았으며, 3가지 온도 모두에서 MAP 저장 후에도 모두 높게 유지되었다. 그러나 과피색, 라이코펜 함량과 당도는 수확 후에는 엽면시비 처리로 차이가 없었으나, 3가지 온도 모두 붕소+칼슘+규소 복합처리에서 가장 낮은 수치를 보였다. 이상의 결과로 볼 때 붕소+칼슘+규소 복합처리는 방울토마토의 수확후 생리 작용을 억제하고 경도, 산도, 비타민 C 함량을 높여 저장성을 향상시키는 것으로 판단되었다
Medical mushroom, Phellinus linteus and Phellinus baumii called as “Sanghwang” have cultivated in Korea. PL has been studied extensively for its extraordinary capacity of suppressing cancer or enhancing body immunity. The mycelial materials of PL have mainly been used as research samples worldwide because fruiting bodies was difficult to be artificially cultivated. Alternatively, P. baumii (variety, ‘Jangsu’) have been cultivated in Korea. However, fruiting body morphology of P. baumii is clearly different to that of PL. Generally, Phellinus spp. including P. linteus slowly grow on artificial medium such as Potato Dextrose Agar (PDA). In contrast, P. baumii strains were rapidly grown on the artificial media when compared to other Phellinus spp. and thus it was considerable that its mycelial growing ability can be acted as a factor for producing fruiting bodies. This study aimed to find Phellinus isolates having high mycelial growth rate. Five Phellinus isolates that show rapid growth rate on YGM medium were selected from 36 Phellinus isolates collected in Korea. They were identified on nucleotide sequences of rDNA-ITS region. Phellinus linteus strain and Phellinus spp. showing mycelial growth rate comparing to P. baumii were characterized on cultural and bioactive characteristics (antioxidant activity and immune activation).
UDP-glucose 4-epimerase (UGE; EC 5.1.3.2) is an enzyme that plays an essential role in the interconverts UDP-D-glucose (UDP-Glc) and UDP-Dgalactose (UDP-Gal). Five members of the Chinese cabbage (Brassica rapa) UDP-glucose 4-epimerase gene family, designated BrUGE1 to BrUGE5, have been cloned and characterized. Quantitative PCR shows that the BrUGE1and BrUGE4 mRNA are most abundant among other BrUGE genes, accounting for more than 55% of total BrUGE transcripts in most of the tissues examined. All genes showed organ specific expression pattern, two of which (BrUGE1 and 4) actively responded after Pectobacterium carotovorum subsp. carotovorum infection, while four genes (BrUGE-1, -3, -4 and -5)were shown to respond considerably against salt, drought and abscisic acid (ABA) treatments. To better understand the function of the UGE gene, we constructed a recombinant pART vector carrying the BrUGE1 gene under the control of the CaMV 35S promoter and nos terminator and transformed using Agrobacterium tumefaciens. We then investigated BrUGE1 overexpressing rice lines at the physiological and molecular levels under biotic and abiotic stress conditions. Bioassay of T3 progeny lines of the transgenic plants in Yoshida solution containing 120 mM Nacl for 2 weeks, confirmed that the BrUGE1 enhances salt tolerance to transgenic rice plants. Also T3 progeny lines of the transgenic plants, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed tolerance to bacterial blight. These results showed that BrUGE1 can be used as potential genetic resource for engineering Brassica with multiple stress resistance.