Farms In Korea Research Articles

Genetic characteristics and antimicrobial resistance of Staphylococcus aureus isolates from pig farms in Korea: emergence of cfr-positive CC398 lineage

BackgroundLivestock-associated Staphylococcus aureus (LA-SA) has gained global attention because of its ability to colonize farm animals and transmit to the environment and humans, leading to symptomatic infections and the spread of antimicrobial resistance (AMR). In the last decade, numerous studies have reported a high prevalence of S. aureus clonal complex (CC) 398 in pig farms.ResultsIn this study, 163 S. aureus isolates were collected from healthy pigs (n = 110), farm environments (n = 42), and farm workers (n = 11), and their AMR profiles and epidemiological characteristics were analyzed. We identified 51 (31.3%) methicillin-resistant S. aureus (MRSA) and 112 (68.7%) methicillin-susceptible S. aureus (MSSA), with 161 (98.8%) isolates belonging to the CC398 lineage. The highest prevalence of spa type t571 was observed among the CC398 isolates. All 47 sequence type (ST) 398 MRSA isolates carried staphylococcal cassette chromosome mec (SCCmec) V, while four ST541 isolates carried SCCmec IV. High levels of resistance to commonly used antibiotics, including phenicols, quinolones, lincosamides, macrolides, aminoglycosides, and tetracyclines, have been observed on Korean pig farms. Notably, 21 cfr-positive CC398 isolates (four ST541-SCCmec IV MRSA and 17 ST398 MSSA) displaying increased resistance to linezolid were identified in healthy pigs.ConclusionsIn summary, these findings suggest that the multidrug-resistant CC398 S. aureus lineage predominantly colonizes healthy pigs and farm environments in Korea. The emergence of cfr-positive S. aureus at human-animal interfaces presents a significant threat to food safety and public health.

Rapid and portable microfluidic chip-based qPCR for quality assurance of commercial seaweeds (lavers) in the supply chain

Lavers, an important type of seaweed rich in health-promoting substances, have seen a surge in global demand. However, their similar morphological characteristics among different species make them vulnerable to food fraud. To address this issue and ensure quality assurance, we developed a portable microfluidic quantitative polymerase chain reaction (qPCR) method to monitor six laver species, comparing its effectiveness with conventional qPCR. Our portable microfluidic qPCR system used a plate-shaped heat block for rapid heat transfer, combined with a microfluidic-based biochip for quick detection. The primers were specifically designed to target the chloroplast genes rbcL and rbcS. Specificity using 17 seaweed species showed no cross-reactivity, and the sensitivity of the assay was 1 × 10−4 ng. Furthermore, we enhanced the portable microfluidic qPCR for field applications by integrating it with a simple DNA extraction method. To validate the on-site rapid identification of laver species, we evaluated 79 laver samples collected from fish farms in Korea and commercially available laver products. We discovered instances where products were adulterated with cheaper species or replaced with others that resemble them. This method proves to be rapid, sensitive, reliable, and applicable for effectively managing and monitoring lavers in the supply chain.

Fast and stable pedicel detection for robust visual servoing to harvest shaking fruits

This study introduces a fast and stable pedicel detection method for robust visual servoing (RVS), supplemented with video stabilization (ViS) and fast pedicel detection, to realize automated harvesting of shaking fruits. By incorporating ViS, the system effectively mitigates the effects of motion blur, thereby ensuring consistent and precise object detection. In addition, the Fourier spectrum-based band-stop filter (FSBF) is used to improve clarity. The proposed approach also leverages the fast point feature histogram (FPFH) for fast pedicel detection, achieving real-time detection rates of 15–37 fps. Furthermore, it incorporates 6D pose estimation, culminating in the implementation of a 6D pose-based robust visual servoing (6DRVS) system. The performance of this system is evaluated using standard metrics such as perception accuracy, approach accuracy, precision, recall, accuracy, and F1-score in both preliminary tests and on-site experiments at two cucumber farms in Korea. The 6DRVS, supplemented with fast pedicel detection and ViS, exhibited improvements across all evaluation metrics. It recorded 90.00% perception accuracy, 82.22% approach accuracy, 0.957 precision, 0.938 recall, 0.900 accuracy, and 0.947 F1-score, highlighting its essential role in ensuring precise and efficient harvesting.

Emergence of Salmonella Infantis carrying the pESI megaplasmid in commercial farms of five major integrated broiler operations in Korea

Considering Salmonella transmission occurs through several routes in integrated broiler operations, control of nontyphoidal Salmonella in commercial farms is essential. This study aimed to compare the distribution of persistent Salmonella serovars in environments and dead chickens between 5 major integrated broiler operations in Korea. The prevalence of Salmonella-positive farms in dust prior to placement by operations was 0 to 25%, but the prevalence in dust and feces at the time of depletion was increased to 16.7 to 41.7% and 16.7 to 66.7%, respectively. Moreover, the prevalence of farms with Salmonella in chickens that died within 1 week old and at 4 to 5 weeks old ranged from 8.3 to 58.3% and 16.7 to 41.7%, respectively. The prevalence of Salmonella enterica serovar Infantis-positive farms in dust prior to placement and in chickens that died within 1 week old was 5.2 and 3.4%, respectively, but the prevalence in dust and feces at the time of depletion and in chickens that died at 4 to 5 weeks old was significantly increased to 27.6, 41.4, and 20.7%, respectively (P < 0.05). Interestingly, the plasmid of emerging S. Infantis (pESI) was only identified in S. Infantis, and the prevalence of multidrug-resistance was significantly higher in pESI-positive S. Infantis (99.2%) than in pESI-negative S. Infantis (6.7%) (P < 0.05). The distribution of pulsotypes between pESI-positive and pESI-negative S. Infantis were varied, but a majority of S. Infantis were clustered only 2 pulsotypes. Moreover, pESI-positive S. Infantis harbored more virulence factors than pESI-negative S. Infantis. This study is the first report on characteristics of S. Infantis carrying the pESI plasmid in commercial broiler farms in Korea.

Diagnosis of Subclinical Mastitis-Causing Pathogens Using MALDI-TOF Mass Spectrometry in a Certified Organic Dairy Farm in Korea

Diagnosis of Subclinical Mastitis-Causing Pathogens Using MALDI-TOF Mass Spectrometry in a Certified Organic Dairy Farm in Korea

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

First Detection and Genetic Characterization of Swine Orthopneumovirus from Domestic Pig Farms in the Republic of Korea.

Novel swine orthopneumovirus (SOV) infections have been identified in pigs in the USA and some European countries but not in Asian countries, including South Korea, to date. The current study reports the first SOV infections in four domestic pig farms located in four provinces across South Korea. The detection rate of SOV in oral fluid samples using qRT-PCR was 4.4% (14/389), indicating the presence of the virus in pigs at commercial farms in Korea. Two complete genome sequences and one glycoprotein (G) gene sequence were obtained from SOV-positive samples. The complete genome analysis of KSOV-2201 and KSOV-2202 strains showed 98.2 and 95.4% homologies with a previously reported SOV, and the phylogenetic tree exhibited a high correlation with a previously reported SOV strain from the US and a canine pneumovirus (CPnV) strain from China. Based on the genetic analysis of the viral G gene, the murine pneumonia virus (MPV)-like orthopneumoviruses (MLOVs) were divided into two genogroups (G1 and G2). Seventeen CPnVs and two feline pneumoviruses were grouped into G1, while the Korean SOV strains identified in this study were grouped into G2 along with one SOV and two CPnVs. These results will contribute to expanding our understanding of the geographical distribution and genetic characteristics of the novel SOV in the global pig population.

Estimating the time of infection for African swine fever in pig farms in Korea

African swine fever (ASF) is a highly contagious and lethal disease with characteristics of hemorrhagic fever. ASF outbreaks in pig farms significantly damage the entire pork industry. Understanding the transmission dynamics of ASF is crucial to effectively respond. Notably, it is important to know when the infection started on the outbreak farm. This study aimed at establishing a procedure for estimating the time of infection on pig farms affected by the ASF outbreak in Korea. The protocol for sampling to detect ASF virus infection, the estimation of the time interval between infection and detection, and the estimation of the infection stage parameters for the simulation model were described. After infection, fattening sheds (9.8 days in median) had the longest detection time compared with pregnant (8.6 days) or farrowing sheds (8.0 days). The intervals were 8.8 days for farrow-to-finisher farms, 7.0 days for farrow-to-weaning farms, and 9.5 days for fattening farms. The findings of this study provide valuable insights into ASF outbreaks in pig farms thus, improving the disease control ability.

Ammonia and Particulate Matter Emissions at a Korean Commercial Pig Farm and Influencing Factors.

Quantifying emission factors of ammonia and particulate matter (PM) in livestock production systems is crucial for assessing and mitigating the environmental impact of animal production and for ensuring industry sustainability. This study aimed to determine emission factors of ammonia, total suspended particles (TSPs), PM10, and PM2.5 for piglets and growing-finishing pigs at a commercial pig farm in Korea. It also sought to identify factors influencing these emission factors. The research found that the emission factors measured were generally lower than those currently used in Korea, but were consistent with findings from individual research studies in the literature. Seasonal variations were observed, with ammonia emissions peaking in spring and autumn, and PM emissions rising in summer. Correlation analyses indicated that the number of animals and their average age correlated positively with both ammonia and PM emission factors. Ventilation rate was also positively correlated with PM emissions. Future extended field measurements across diverse pig farms will offer deeper insights into the emission factors of pig farms in Korea, guiding the development of sustainable livestock management practices.

Comparative genetic characterisation of third-generation cephalosporin-resistant Escherichia coli isolated from integrated and conventional pig farm in Korea

Pig-farming systems consist of integrated or conventional farms, and many antimicrobials are used to treat bacterial infections. The objective of this study was to compare characteristics of third-generation cephalosporin resistance and extended-spectrum β-lactamase (ESBL)/pAmpC β-lactamase-producing Escherichia coli between integrated and conventional farms. Third-generation cephalosporin-resistant E. coli was collected from integrated and conventional pig farms from 2021 to 2022. Polymerase chain reaction and DNA sequencing were performed for the detection of β-lactamase-encoding genes, molecular analysis, and identification of genetic relationships. To determine the transferability of β-lactamase genes, conjugation assays were conducted. Antimicrobial resistance rates were higher in conventional farms than in integrated farms; ESBL- and pAmpC-lactamase-producing E. coli rates were higher in conventional farms (9.8%) than in integrated farms (3.4%). Fifty-two (6.5%) isolates produced ESBL/pAmpC β-lactamase genes. Isolates from integrated farms harboured CTX-15 (3 isolates), CTX-55 (9 isolates), CTX-229 (1 isolate), or CMY-2 (1 isolate) genes; isolates from conventional farms harboured CTX-1 (1 isolate), CTX-14 (6 isolates), CTX-15 (2 isolates), CTX-27 (3 isolates), CTX-55 (14 isolates), CTX-229 (1 isolate), and CMY-2 (11 isolates) genes. Of the 52 ESBL/pAmpC β-lactamase-producing E. coli isolates, class 1 integrons with 11 different gene cassette arrangements were detected in 39 (75.0%) isolates, and class 2 integrons were detected in 3 isolates. The most common sequence type in both integrated and conventional farms was ST5229, followed by ST101, and then ST10. Third-generation cephalosporin-resistant patterns and molecular characteristics differed between integrated and conventional farms. Our findings suggest that continuous monitoring of third-generation cephalosporin resistance on pig farms is necessary to prevent the dissemination of resistant isolates.

Comparison of LCOE of the Southwest Offshore Wind Farm According to Types and Construction Methods of Supporting Structures

In order to understand the economic feasibility of an offshore wind farm, this paper analyzed the differences in LCOE (levelized cost of energy) according to the support type and construction method of the substructure in terms of LCOE and sensitivity analysis was conducted according to the main components of LCOE. As for the site to be studied, the Southwest Offshore Wind Farm was selected, and the capital expenditures were calculated according to the size of the offshore wind farm and the installation unit. As a result of the sensitivity analysis, major components showed high sensitivity to availability, turbine related cost, weighted average cost of capital and balance of system related cost. Moreover, the post-piling jacket method, which was representatively applied to the substructure of the offshore wind farm in Korea, was selected as a basic plan to calculate the capital expenditures, and then the capital expenditures of the pre-piling jacket method and the tripod method were calculated and compared. As a result of analyzing the LCOE, it was confirmed that the pre-piling jacket method of the supporting structure lowers the LCOE and improves economic feasibility as the installation number of turbines increases.

Coastal warming heightens direct impacts of seawater temperature on nutrients near aquaculture farms in Korea

The potential roles of temperature and phytoplankton in nutrient cycling throughout the water column were investigated nearby aquaculture farms. Using the convergent cross mapping (CCM), we examined the relative strength of phytoplankton and temperature effects on nutrients. High δ15N values of particulate organic matter in the inner bay were detected compared to those in the outer bay. δ15N values >5 ‰ throughout the bay indicate that nitrogen influxes from the aquaculture farms are the critical nitrogen source in the study region. Our CCM models revealed that temperature positively and strongly affected the potential regeneration of nutrients, associated with PO43− while phytoplankton utilized nutrients as soon as available. The temperature–driven nutrient regeneration was higher in the bottom layer than that in the surface layer, indicating that temperature was a more important controlling factor in nutrient fluxes from the surface sediments.

Complete genome sequence of Lactococcus taiwanensis strain K_LL004, encoding hydrolytic enzymes of plant polysaccharides isolated from grasshopper (Oxya chinensis sinuosa).

The Lactococcus taiwanensis strain K_LL004 was isolated from the gut of a grasshopper (Oxya chinensis sinuosa) collected from local farm in Korea. L. taiwanensis strain K_LL004 is the functional probiotic candidate with an ability to hydrolyse plant polysaccharides. The complete genome of the L. taiwanensis strain K_LL004 contains one circular chromosome (1,995,099 bp) with a guanine + cytosine (GC) content of 38.8%. Moreover, 1,929 Protein-coding sequence, 19 rRNA genes, and 62 tRNA genes were identified based on results of annotation. L. taiwanensis strain K_LL004 has a gene, which encodes hydrolytic enzymes such as beta-glucosidase and beta-xylosidase, that hydrolyzes plant polysaccharides.

Situational analysis on fluoroquinolones use and characterization of high-level ciprofloxacin-resistant Enterococcus faecalis by integrated broiler operations in South Korea.

Fluoroquinolones are classified as "critically important antimicrobials for human medicine"; however, their extensive use in livestock poses a significant health risk to humans as it leads to the rapid spread of antimicrobial resistance. This study confirmed that 40.0%-71.4% of the farms in three of the five integrated broiler operations were administered ciprofloxacin (CIP). Moreover, preventive purposes (60.9%), veterinarian prescriptions (82.6%), drinking water route (100%), and 1 to 3 days (82.6%) of age were significantly highest (P < 0.05). 194 high-level ciprofloxacin-resistant (HLCR) Enterococcus faecalis (E. faecalis) were found in 65 of 74 farms, and of which, the prevalence of qnrA (63.9%), tetM (60.3%), ermB (64.9%), blaz (38.7%), and catA (34.0%) was significantly highest (P < 0.05). 154 (79.4%) isolates showed MDR, and the distribution of MDR was significantly differences among the operations (P < 0.05). All HLCR E. faecalis possessed double mutations in gyrA and parC, and S83I/S80I (90.7%) mutations were most commonly identified. Interestingly, the distribution of isolates with MICs ≥ 512 for both CIP and moxifloxacin was significantly higher in CIP-administered farms (56.5%) than in non-CIP-administered farms (41.4%) (P < 0.05). Also, the prevalence of strong or moderate biofilm formers in HLCR E. faecalis was significantly higher than that of weak and no biofilm formers (P < 0.05). HLCR E. faecalis were heavily distributed in the broiler farms in Korea; therefore, it is necessary to minimize the prevalence of resistant bacteria via structural management regulations such as cleaning and disinfection of farm environments.

Control of oomycete pathogens during Pyropia farming and processing using calcium propionate

The oomycete pathogens Pythium porphyrae, causing red rot disease, and Olpidiopsis spp. causing Olpidiopsis-blight, cause serious economic losses to Pyropia sea farms in Korea. During the washing step for Pyropia processing, these pathogens proliferate rapidly, significantly reducing the quality of the final product. To develop non-acidic treatments for these pathogens, various calcium salts were tested against the infectivity of P. porphyrae and Olpidiopsis pyropiae on Pyropia gametophytes, and calcium propionate was the most effective. When Pyropia blades were immersed in 10 mM calcium propionate for 1 h after inoculation with the oomycete pathogen, infection rate of both oomycete pathogens on day 2 was significantly lower (7.1%) than control (&gt;95%). Brief incubation of Pyropia blades in calcium propionate also reduced the spread of infection. The infected area of Pyropia thallus was reduced to 14.3% of the control in 2 days after treatment with 100 mM calcium propionate for 30 s. In field experiments conducted in actual aquaculture farms, it has been shown that a brief 30 s wash every two weeks with 100 mM calcium propionate can effectively reduce the spread of oomycetes throughout the entire culture period. The above results suggest that calcium propionate can be a useful means for controlling the spread of oomycetes not only during laver processing but also during aquaculture.

2020년 국내 양식 흰다리새우(Litopenaeus vannamei)의 TS, IMN, NHP 및 DIV1 모니터링

Disease monitoring in aquatic animals is important to minimize disease transmission and provide important information for effective quarantine measures. In this study, Taura syndrome (TS), infectious myonecrosis (IMN), necrotizing hepatopancreatitis (NHP), and decapod iridescent virus 1 (DIV1) were monitored in 2,592 whiteleg shrimp (Litopenaeus vannamei) collected from 108 shrimp farms in Korea from September to October 2020. A disease detection and monitoring experiment was conducted according to the WOAH

Role of Smart Farm as a Tool for Sustainable Economic Growth of Korean Agriculture: Using Input–Output Analysis

This study focused on smart farms in Korea to confirm that the fourth industrial revolution technology is a tool that can be used for sustainable economic development in agriculture. This study used the input–output table, which included the production-inducing effects of the demand inducement model, value-added inducing effects, supply shortage effects of the supply inducement model, and the interlinkage effect. These methods were used to compare the impact of smart farm machinery on agriculture and the impact of smart farms on the Korean economy compared to conventional agriculture, thereby confirming the extent of the effect of fourth industrial revolution technology on agriculture. This study was conducted to determine whether this agricultural sector could lead to sustainable economic development. The analysis revealed that the production-inducing effects of smart farms showed a greater ripple effect than those of the agricultural sector. However, both value-added inducing effects and supply shortage effects showed a larger ripple effect in the agricultural sector. Considering only the indirect effect, the smart farms were found to evenly affect secondary and tertiary industries. In the case of value-added inducing and supply shortage effects, agriculture was found to have a greater impact on the secondary industry, whereas smart agri-machines and farms had a greater impact on the tertiary industry. Moreover, according to the interlinkage effect, agriculture was classified as a raw industry with final demand, and smart farms as a manufacturing industry with intermediate demand. These results have several implications. For the fourth industrial revolution technology to lead sustainable economic growth in agriculture, continuous creation of new value by developing various types of business models linked to other industries in consideration of the industrial characteristics of smart farms and agri-machines is necessary. In addition, to fully demonstrate the economic effects of smart farms, continuous management and support are required so that smart technologies can be strategically utilized in the agricultural sector.

Occurrence of cfr-Positive Linezolid-Susceptible Staphylococcus aureus and Non-aureus Staphylococcal Isolates from Pig Farms.

The emergence and spread of cfr-mediated resistance to linezolid in staphylococci have become a serious global concern. The acquisition of cfr confers multidrug resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A (PhLOPSA phenotype). However, occurrence of cfr-positive and linezolid-susceptible staphylococci has been identified. To investigate the mechanism underlying linezolid susceptibility in cfr-positive Staphylococcus aureus and non-aureus staphylococci (NAS) isolates from pig farms in Korea. Eleven cfr-positive and linezolid-susceptible staphylococci were analyzed for mutations in domain V of 23S rRNA, ribosomal proteins (L3, L4, and L22), cfr open reading frames (ORFs), and cfr promoter regions. The effect of the cfr mutation (Q148K) on the PhLOPSA phenotype was determined using plasmid constructs expressing either the mutated (cfrQ148K) or nonmutated cfr genes. All 11 (six S. aureus and five NAS) cfr-positive and linezolid-susceptible isolates had a point mutation at position 442 in cfr ORFs (C to A) that resulted in the Q148K mutation. No mutations were detected in 23S rRNA, L3, L4, or L22. The Q148K mutation in Cfr is responsible for phenotypes susceptible to PhLOPSA antimicrobial agents. To our knowledge, this is the first study to report the causal role of a single nucleotide mutation (Q148K) in cfr of S. aureus and NAS isolates in PhLOPSA resistance. Continued nationwide surveillance is necessary to monitor the occurrence and dissemination of mutations in cfr that affect resistance phenotypes in staphylococci of human and animal origin.

Review of Semi-closed Greenhouse Previous Studies and Required Technology Analysis for Improving Energy Efficiency

Purpose: With the spread of smart farms in Korea, there is a clear tendency to consume electricity and heat energy in the agricultural sector. In line with the carbon-neutrality policy, measures to reduce energy in the greenhouse industry should be developed. Although Korea is currently focusing on expanding the number of smart farms, developed countries such as the Netherlands have been researching and developing semi-closed greenhouses, which increase crop productivity and improve energy efficiency, since the early 2000s. In this study, the necessity of a semi-closed greenhouse, which is being introduced as an alternative to the existing greenhouse technology, was considered, and the applied technology elements were examined and directions for future research were suggested. Method: From 2005 to 2020, we analyzed 26 foreign papers and articles on semi-closed greenhouses. Semi-closed greenhouse research was conducted from the viewpoints of energy efficiency and crop productivity improvement. Result: A semi-closed greenhouse starts by closing the windows on the roof, to use the surplus heat produced during summer or during daytime in winter. The technological elements used in the efficient environmental control of semi-closed greenhouses are 1) heat storage, 2) air treatment system, 3) air conditioning system, 4) heating system, and 5) dehumidifier system. Semi-closed greenhouse systems have been introduced and proven in Europe. It is necessary to verify the system suitability for the hot and humid Korean climate in summer and study the energy efficiency performance of each element.