Molecular Identification and Prevalence of the Mite Carpoglyphus lactis (Acarina: Carpoglyphidae) in Apis mellifera in the Republic of Korea.

Apis mellifera, especially weak ones, are highly vulnerable to Carpoglyphus lactis mites, which can rapidly infest and consume stored pollen, leading to weakened colonies and potential colony collapse. This study aimed to ascertain and investigate the prevalence of this mite in honeybee colonies across nine provinces in the Republic of Korea (ROK). A total of 615 honeybee colony samples were collected from 66 apiaries during the spring and 58 apiaries during the summer of 2023. A 1242 bp segment of the Cytochrome c oxidase subunit 1 (COI) gene was amplified using the polymerase chain reaction method. The detection levels of C. lactis in the honeybees were compared between winter and summer. Based on the COI sequence analysis, the nucleotide sequence similarity of C. lactis mites isolated in the ROK with those from China (NC048990.1) was found to be 99.5%, and with those from the United Kingdom (KY922482.1) was 99.3%. This study is the first report of C. lactis in Korean apiaries. The findings of this study demonstrate a significantly higher detection rate in winter, which is 4.1 times greater than that in summer (p < 0.001). Furthermore, the results underscore the usefulness of molecular diagnostic techniques for detecting C. lactis mites.

Large-Scale Application of Double-Stranded RNA Shows Potential for Reduction of Sacbrood Virus Disease in Apis cerana Apiaries.

Sacbrood virus (SBV) infection has emerged as a remarkable threat to Apis cerana colonies in South Korea, necessitating prompt control measures. In this study, RNA interference (RNAi) targeting the VP3 gene was developed to assess its safety and efficacy in protecting and treating SBV in vitro and in infected colonies in South Korean apiaries. The efficacy of VP3 double-stranded RNA (dsRNA) was demonstrated in laboratory-based experiments, wherein infected larvae treated with VP3 dsRNA exhibited a 32.7% increase in survival rate compared to untreated larvae. Data from a large-scale field trial indicate the efficacy of dsRNA treatment since none of the treated colonies had symptomatic SBV infections, whereas disease was observed in 43% (3/7) of the control colonies. In the 102 colonies exhibiting symptoms of SBV disease, RNAi treatment provided partial protection with weekly treatment, prolonging the survival period of colonies to 8 months compared to 2 months in colonies treated at 2- and 4-week intervals. Therefore, this study demonstrated that RNAi is a valuable tool for preventing SBV disease outbreaks in healthy and low-level SBV-infected colonies.

Thymosin Beta 4 Inhibits LPS and ATP-Induced Hepatic Stellate Cells via the Regulation of Multiple Signaling Pathways.

Risk signals are characteristic of many common inflammatory diseases and can function to activate nucleotide-binding oligomerization (NLR) family pyrin domain-containing 3 (NLRP3), the innate immune signal receptor in cytoplasm. The NLRP3 inflammasome plays an important role in the development of liver fibrosis. Activated NLRP3 nucleates the assembly of inflammasomes, leading to the secretion of interleukin (IL)-1ß and IL-18, the activation of caspase-1, and the initiation of the inflammatory process. Therefore, it is essential to inhibit the activation of the NLRP3 inflammasome, which plays a vital role in the immune response and in initiating inflammation. RAW 264.7 and LX-2 cells were primed with lipopolysaccharide (LPS) for 4 h and subsequently stimulated for 30 min with 5 mM of adenosine 5'-triphosphate (ATP) to activate the NLRP3 inflammasome. Thymosin beta 4 (Tß4) was supplemented to RAW264.7 and LX-2 cells 30 min before ATP was added. As a result, we investigated the effects of Tß4 on the NLRP3 inflammasome. Tß4 prevented LPS-induced NLRP3 priming by inhibiting NF-kB and JNK/p38 MAPK expression and the LPS and ATP-induced production of reactive oxygen species. Moreover, Tß4 induced autophagy by controlling autophagy markers (LC3A/B and p62) through the inhibition of the PI3K/AKT/mTOR pathway. LPS combined with ATP significantly increased thee protein expression of inflammatory mediators and NLRP3 inflammasome markers. These events were remarkably suppressed by Tß4. In conclusion, Tß4 attenuated NLRP3 inflammasomes by inhibiting NLRP3 inflammasome-related proteins (NLRP3, ASC, IL-1ß, and caspase-1). Our results indicate that Tß4 attenuated the NLRP3 inflammasome through multiple signaling pathway regulations in macrophage and hepatic stellate cells. Therefore, based on the above findings, it is hypothesized that Tß4 could be a potential inflammatory therapeutic agent targeting the NLRP3 inflammasome in hepatic fibrosis regulation.

Enhanced alcohol degradation and hepatic protective effects of an Acetobacter Pasteurianus-derived product, CureZyme-ACE, in an acute intoxication rat model.

Excessive alcohol consumption induces acute intoxication and various hepatic diseases. In this study, we investigated the effect of the CureZyme-ACE (CA), Acetobacter Pasteurianus (AP)-derived product, in acute intoxication rats. The ethanol and acetaldehyde levels of serum were lower in rats treated with CA than those who only treated ethanol. The activities of alcohol dehydrogenase and acetaldehyde dehydrogenase also recovered faster in the CA group than only-ethanol group. The transaminase levels (AST, ALT) in the CA group were significantly lower than only-ethanol group. In addition, Hepatic histological analyses and stomach wall were demonstrated that the CA-treated group recovered faster than only-ethanol group. With regard to most characteristics, we found that CA had dose-dependent effects. At high concentrations of CA, there were no differences in the tested parameters compared to those of normal rats. These findings indicate that CA reduces the serum alcohol concentration and some of the hepatic damage caused by alcohol intoxication.

Combined Effects of Wheat Sprout and Isolated Soy Protein on Quality Properties of Breakfast Sausage.

The objective of this study was to investigate the effects of different concentrations of WSP (wheat sprout powder) and ISP (isolated soy protein) on the quality of breakfast sausage. Treatments were formulated as follows: Control, T1 (2.0% ISP), T2 (1.5% ISP + 0.5% WSP), T3 (1.0% ISP + 1.0% WSP), T4 (0.5% ISP + 1.5% WSP) and T5 (2.0% WSP). The treatments were analyzed for color, pH, cooking loss, emulsion stability, protein solubility, viscosity, texture properties and sensory evaluation. Lightness and redness were reduced and yellowness was increased as increased level of WSP, due to the dark green color of WSP (p<0.05). The pH values of all samples were affected by WSP which has lower pH (p<0.05). The emulsion stability and cooking loss of treatments were improved with increasing level of WSP (p<0.05). The protein solubility, viscosity and overall texture properties of the sausage indicated significant differences in relation to the level of WSP and ISP (p<0.05). The sensory evaluation indicated that the greatest flavor and overall acceptability in sausage was achieved at WSP 1% combination with ISP 1% (T3) (p<0.05). Therefore, these results indicate that breakfast sausage containing 1% WSP and 1% ISP is the optimal formulation, taking into consideration the overall physico-chemical properties and sensory evaluation.

Surveillance of Rift Valley Fever Virus in Mosquito Vectors of the Republic of Korea.

Rift Valley fever (RVF) is an acute mosquito-borne viral zoonotic disease that affects mainly domestic ruminants and humans. RVF virus (RVFV) was first identified in Kenya in 1931 and was reported to be endemic in Africa but has recently spread to the Arabian Peninsula. With increasing climate change and globalization of trade in animals and animal products, there is great concern that the disease will spread worldwide to regions such as Europe, Asia, and the Americas. Although RVFV has not been reported in the Republic of Korea (ROK), the possibility of RVFV introduction is increasing because transmissible mosquito vectors are present and direct flights to Africa were added in 2012. For these reasons, we conducted a surveillance study to detect RVFV in mosquito vectors collected around the airport and harbor from 2012 to 2013. A total of 36,734 mosquitoes were collected and tested by real-time RT-PCR. A total of 1837 mosquito pools were used, and all were confirmed to be negative. This is the first report in the ROK concerning RVFV surveillance in mosquito vectors, and continuous surveillance will be conducted for the early warning of RVFV introduction.

Characterization of Salmonella enterica serovar Typhimurium and Salmonella enterica serovar 4,[5],12:i:- isolates from pigs presenting with diarrhea in Korea.

Between 2011 and 2012, a total of 896 pig fecal samples were collected from nine provinces in Korea, and 50 salmonella enterica susp. enterica serovar Typhimurium (S. Typhimurium) was isolated. The characteristics of the 50 strains were analyzed, and 4 strains were identified as Salmonella enterica subsp. enterica serovar 4,[5],12:i:-. Salmonella 4,[5],12:i:- could not be distinguished from S. Typhimurium through phage typing, antimicrobial resistance testing or multiple-locus variable-number tandem repeat analysis (MLVA). However, among the four Salmonella 4,[5],12:i:- strains, one (KVCC-BA1400078) was identified as a Salmonella 4,[5],12:i:- clone isolated from humans in the United States, and another (KVCC-BA1400080) was identified as DT193, which has been primarily isolated from humans and animals in European countries. The presence of Salmonella 4,[5],12:i:- in Korea poses a significant threat of horizontal transfer between pigs and humans.

Serological surveillance studies confirm the Rift Valley fever virus free status in South Korea.

Rift Valley fever is a mosquito-borne zoonotic disease of domestic ruminants. This disease causes abortions in pregnant animals, and it has a high mortality rate in newborn animals. Recently, a Rift Valley fever virus (RVFV) outbreak in the Arabian Peninsula increased its potential spread to new regions worldwide. In non-endemic or disease-free countries, early detection and surveillance are important for preventing the introduction of RVFV. In this study, a serological surveillance was conducted to detect antibodies against RVFV. A total of 2382 serum samples from goats and cattle were randomly collected from nine areas in South Korea from 2011 to 2013. These samples were tested for antibodies against RVFV, using commercial ELISA kits. None of the goats and cattle were positive for antibodies against RVFV. This finding suggests that this disease is not present in South Korea, and furthermore presents the evidence of the RVFV-free status of this country.

In vitro activities of antimicrobials against Brucella abortus isolates from cattle in Korea during 1998-2006.

In vitro activities of 13 antibiotics were assessed against 85 Brucella abortus isolates from naturally infected cattle in the Republic of Korea during 1998-2006, using broth microdilution test. Tetracyclines showed the most excellent activity against B. abortus, displaying MIC values of 0.5 µg/ml or below. In particular, minocycline showed the lowest MIC50/90 values (0.125/0.125 µg/ml) in this study. Among four fluoroquinolones tested, ciprofloxacin (MIC50/90, 0.5/1 µg/ml) and norfloxacin (MIC50/90, 8/8 µg/ml) had the most and the least activities, respectively. Gentamicin (MIC50/90, 1/1 µg/ml) was more effective than streptomycin, erythromycin, rifampin, and chloramphenicol (MIC50/90, 2/2 µg/ml).

The development of a selective medium for the Brucella abortus strains and its comparison with the currently recommended and used medium.

The Brucella spp. are fastidious and relatively slow-growing organisms. The isolation of such strains in a variety of specimens often requires the use of a selective medium to reduce or eliminate the growth of unexpected microorganisms. The modified Brucella selective (MBS) medium, which contains improved antibiotic mixtures, erythritol as the only carbon source, and neutral red as a pH indicator, showed good selectivity for the Brucella abortus strains, including the RB51 vaccine strain. Erythritol in the MBS medium was able to promote and/or recover the delayed growth of the B. abortus strains through the antibiotic mixtures. The Brucella colonies, which assumed a pinkish color at their central part, were easily differentiated from other organisms. The MBS medium also allows the isolation of the Brucella strains even in contaminated specimens and/or in specimens containing small numbers of viable organisms. Moreover, this medium can be applied to environmental samples for the isolation of the Brucella strains, and it can thus offer epidemiologic traceback sources for the dissemination or transfer of diseases. Therefore, the MBS medium can be applied as a useful tool of important control measures in the eradication programs.

Quantitative Rose Bengal Test for diagnosis of bovine brucellosis.

The Rose Bengal Test (RBT) is the most widely used screening test for brucellosis in both humans and animals. Owing to its apparent simplicity of reading, however, interpretations of the RBT results can be affected by personal experience. This study describes a simple way to improve the accuracy and uniformity of reading the RBT reaction by counting the number of agglutinated particles using transparent OHP film with Quantity One, which was originally designed to count the bacterial colony numbers on agar plates. Using this system, the reactivities of three Rose Bengal antigens from different sources against international standard serum (1,000 units, VLA, UK) could be numerically measured: the intensity scale ranged from zero to around 1,600. This system enabled us to compare the antigenicity of Rose Bengal antigens from three different sources by using statistical analyses such as regression and mean intensity. Collectively, mathematical measuring of the reaction intensity used in this study may help interpret subtle test results by providing more reliable data and additional statistical information on the herd. In addition, the method would also be applicable to other agglutination test for other diseases.

Application and evaluation of the MLVA typing assay for the Brucella abortus strains isolated in Korea.

BACKGROUND: A Brucella eradication program has been executed in Korea. To effectively prevent and control brucellosis, a molecular method for genetic identification and epidemiological trace-back must be established. As part of that, the MLVA typing assay was evaluated and applied to B. abortus isolates for analyzing the characteristics of the regional distribution and relationships of foreign isolates. RESULTS: A total of 177 isolates originating from 105 cattle farms for the period 1996 to 2008 were selected as representatives for the nine provinces of South Korea. A dendrogram of strain relatedness was constructed in accordance with the number of tandem repeat units for 17 loci so that it was possible to trace back in the restricted areas. Even in a farm contaminated by one source, however, the Brucella isolates showed an increase or decrease in one TRs copy number at some loci with high DI values. Moreover, those 17 loci was confirmed in stability via in-vitro and in-vivo passage, and found to be sufficiently stable markers that can readily identify the inoculated strain even if minor changes were detected. In the parsimony analysis with foreign Brucella isolates, domestic isolates were clustered distinctively, and located near the Central and Southern American isolates. CONCLUSION: The MLVA assay has enough discrimination power in the Brucella species level and can be utilized as a tool for the epidemiological trace-back of the B. abortus isolates. But it is important to consider that Brucella isolates may be capable of undergoing minor changes at some loci in the course of infection or in accordance with the changes of the host.

Antimicrobial resistance observed in Escherichia coli strains isolated from fecal samples of cattle and pigs in Korea during 2003-2004.

A total of 744 Escherichia coli strains isolated from 830 fecal samples of healthy cattle and pigs in all provinces of Korea were examined for resistance to 16 antimicrobials. The most frequently observed resistance in cattle isolates was to tetracycline (30.5%), followed by resistance to streptomycin (20.4%), ampicillin (12.0%) and chlorampenicol (6.9%). Prevalences of resistance to the same four antimicrobials in swine isolates were 96.3%, 66.8%, 66.1%, and 47.6%, respectively. The prevalence of resistance in pigs was much higher than that in cattle, with 98.3% of pig isolates and 37.1% of cattle isolates showing resistance to one or more of the antimicrobial agents tested.