Avermectin produced by Streptomyces avermitilis is an anti-nematodal agent against the pine wood nematode Bursaphelenchus xylophilus. However, its potential usage is limited by its poor water solubility. For this reason, continuous efforts are underway to produce new derivatives that are more water soluble. Glycosylation is generally used to enhance the aqueous solubility and biological activity of natural compounds. Uridine diphosphate (UDP)-glycosyltransferase (BLC) from Bacillus licheniformis is involved in the biosynthesis of the bioactive compound by transferring UDP-activated sugar moieties to acceptor molecules. Here, the enzymatic glycosylation of avermectin was catalyzed by uridine diphosphate (UDP) glycosyltransferase from Bacillus licheniformis with various UDP-sugars. As a result, the following four avermectin B1a glycosides were produced: avermectin B1a 4’’-β-D-glucoside, avermectin B1a 4’’-β-D-galactoside, avermectin B1a 4’’-β-L-fucoside and avermectin B1a 4’’-β-2-deoxy-D-glucoside. The avermectin B1a glycosides were structurally analyzed based on HR-ESIMS, 1D and 2D nuclear magnetic resonance (NMR) spectra. The solubility of avermectin B1a4’’-β-D-glucoside and avermectin B1a4’’-β-D-galactoside in water are 49 and 21 times higher than that of avermectin B1a. Consistent with the improved water solubility of avermectin glycosides, the anti-nematodal effect of avermectin B1a4’’-β-D-glucoside was found to exhibit the highest activity,which was approximately 32 times greater than that of avermectin B1a, followed by avermectin B1a 4’’-β-2-deoxy-D-glucoside, avermectin B1a 4’’-β-L-fucoside, and avermectin B1a 4’’-β-D-galactoside. These results show that glycosylation of avermectinB1a effectively enhances itsin vitro anti-nematodal activity and that avermectin glycosides can be further applied for treating infestations of the pine wood nematode B. xylophilus.

It has been known that the ability of Shiga toxinproducing Escherichia coli (STEC) to produce Stx2e in culture media plays a role in the diagnosis of edema disease and determination of subunit vaccine candidates in STEC isolates. To examine the efficiency of Stx2e production in several commercial media, a Stx2e-producing strain (KEFS1302) was grown in four different media: ISO-Sensitest broth (ISB), E. coli broth (ECB), trypticase soy broth (TSB), and Mueller Hinton broth (MHB), with or without mitomycin C at 37°C (250 rpm) for 6 h. Toxin production was measured by enzyme-linked immunosorbent assay. In the presence of mitomycin C, ECB was found to be the most suitable medium, reaching a production peak (OD600 = 1.2) at 1 h; Stx2e was mostly produced during the logarithmic phase (within 3 h). On the other hand, toxin production in ISB reached a peak at 3 h after incubation in the absence of mitomycin C. Stx2e was purified by fast protein liquid chromatography (FPLC) using anion-exchange chromatography. The 43 kDa band of Stx2e was confirmed by western blot using the ECB supernatant. Our results showed that ECB and ISB media would be a suitable medium for mass production of Stx2e even if the toxin production is dependent on time.

The seroprevalence of major infectious abortion agents was investigated in native Korean goats from Jeonnam province using ELISA. A total of 98 blood samples were collected from goats. Overall, 48 (49.0%), 11 (11.2%), and 1 (1.0%) serum samples tested positive for C. burnetii, T. gondii, and C. abortus, respectively, while none of the samples were positive for B. abortus or N. caninum. Moreover, a PCR assay conducted to detect C. burnetii antigens in goats with a history of abortion revealed 18 (38.3%) of 47 goats were C. burnetii positive by both the ELISA and PCR assay.

A female wild raccoon dog was referred with a history of generalized seizure. Mild leukocytosis was noted on laboratory tests. Gross lesions included nasal hemorrhage, hemothorax, and hemorrhage in the urinary bladder with hematuria. Microscopically, interstitial and purulent bacterial pneumonia was observed in the lungs. In the cerebellum, characteristic eosinophilic intracytoplasmic and intranuclear inclusion bodies were found in Purkinje cells, and severe demyelination was observed in the cerebellar white matter. Canine distemper virus (CDV) infection was suspected and confirmed after detection of CDV nucleoprotein RNA in the cerebrum and the lungs by nested reverse transcription polymerase chain reaction (RT-PCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP). Based on the histopathological and molecular diagnostic findings, it was concluded that the raccoon dog was infected with CDV.

Bovine brucellosis causes abortion and infertility. The authors conducted this study in order to determine pathological lesions of Korean native cows and fetuses who received experimental vaccination with Brucella abortus RB51 and were challenged with Brucella abortus 2308. Gross and histopathological lesions in endometrium and placenta were observed in cows of the vaccinated group. Twenty-five percent of pregnant cattle in the vaccinated group showed endometritis and placentitis, which was three times lower, compared with the non-vaccinated group. The pathological lesions in the uterus and placenta in both groups were consistent with previous reports. Therefore, vaccination in heifers using Brucella abortus RB51 may not provide adequate protection against infection with Brucella abortus virulent strain.

The present study was conducted to investigate serotype distribution and biofilm formation of Actinobacillus (A.) pleuropneumoniae isolated from pneumonic lungs of pigs. A total of 37 A. pleuropneumoniae were isolated between January 2009 and June 2010. Serotypes of A. pleuropneumoniae isolates were determined using two different PCRs. The majority of isolates belonged to serotype 5 (n=31, 83.8%), and the others belonged to serotype 1 (n=4, 10.8%), and 2 (n=2, 5.4%), respectively. The ability of biofilm formation of the isolates was also determined by quantitative microtiter plate assay. Biofilm formation was observed in both 23 (62.2%) of the 37 field isolates and seven (43.8%) of the 16 reference strains. On the other hand, biofilm formation was various according to the serotypes: 20 (64.5%) of serotype 5, and three (75.0%) of serotype 1. However, two isolates of serotype 2 did not produce the biofilm in this study. Consequently, A. pleuropneumoniae serotype 5 was the most frequently detected (83.8% of the isolates), and 23 (62.2%) of 37 isolates exhibited biofilm positive phenotype in this study.

Grossly, a lot of soft white nodules, 0.5～1.5 cm in diameter, were randomly scattered in liver of a slaughtered Korean Native Cattle. The surface of liver was roughened by those nodules. Histopathologically the nodules were consisted of numerous mature blood vessels, which had variable size and wall thickness, and which were encircled by much connective tissue. Masson's trichrome stain clearly revealed the proliferated blood vessels and perivascular stroma and, immunohistochemical staining revealed that endothelial cells of proliferated blood vessels were positive for Von Willebrand Factor. Based on gross and histopathological lesions, and immunohistochemical staining, the case was confirmed as hepatic vascular hamartoma and it is the first case report in Korea, as far as we know.

Climate data were obtained over an eight-year period (July 2013 to June 2021) using an automatic weather observation system (AWS) installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using climate data, the statistical and meteorological characteristics of the local circulation between the Nakdong River and Mt. Geumo were analyzed. This study is based on automatic weather observation system data for Dongyeong, along with comparative climate data from the Korea Meteorological Administration (Chilgok) and the Gumi meteorological observatory. Over the eight- years, mountain and valley winds have occurred 48 times a year on average, with the highest occurring in May and the weakest winds in June and December. When mountain winds occurred, the temperature in the nearby lowland region more strongly decreased than when valley winds blew. However, the potential to use mountain winds to improve urban thermal environments is limited because mountain winds occur infrequently in summer when a drop in nighttime temperature is required.

Eight years (2014–2021) of climate data were collected from an automatic weather observation system installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using these data, we investigated local bio-climatological indices (warmth index, WI; coldness index, CI; and effective accumulated temperature, EAT) of the mountain region adjacent to the Keimyung Dongyeong forest. The study area’s WI and CI were 109.3℃ and –11.3℃ per month, respectively, averaged across 8 years. These values are indicative of an evergreen broad-leaved forest in the warm temperate climate zone, suitable for cultivating sweet persimmons and figs. Additionally, EAT in Dongyeong was 2,113.7℃, averaged across 8 years, suitable for growing crops such as corn, soybean, and potato.

The relationship between night cooling rate and meteorological elements was investigated over the past five years (2016-2020), using weather data from the new (Daegu(143)) and old (Shinam(860)) Daegu Regional Meteorological Agency located in the suburban and urban regions, respectively. There was a correlation between the total daily amount of solar radiation (Stot) and the night cooling rate in the both regions. However, a higher correlation was observed at the new Daegu Regional Meteorological Agency station (Daegu(143)). In particular, data from the new Daegu Regional Meteorological Administration's observatory, which experiences a low thermal storage effect caused by artificial structures, showed a higher correlation between nighttime cooling and weather factors. The reason for this is that the lesser the heat storage effect caused by the artificial structures, the better the effect of surface radiation cooling on temperature reduction. These findings confirm that the correlation between night cooling and weather factors can be used to assess the impact of artificial structures in cities.