CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein) is widely used in the field of livestock breeding. However, its low efficiency, untargeted cutting and low safety have greatly hampered its use for introducing single base mutations in livestock breeding. Single base editing, as a new gene editing tool, can directly replace bases without introducing double strand breaks. Single base editing shows high efficiency and strong specificity, and provides a simpler and more effective method for precise gene modification in livestock breeding. This paper introduces the principle and development of single base editing technology and its application in livestock breeding.
Animals ; Gene Editing ; CRISPR-Cas Systems/genetics* ; Livestock/genetics* ; Mutation ; Technology

livestock-associated (LA)-methicillin-resistant Staphylococcus aureus (MRSA) in livestock animal has become a significant zoonotic concern. In the present study, we investigated nationwide prevalence of LA-MRSA across pork production chain including pig farms, slaughterhouses, and retail markets. A total of 40 MRSA strains were isolated during the investigation and the overall prevalence of MRSA was 3.4% (n = 37), 0.6% (n = 2), and 0.4% (n = 1) in pig farms, slaughterhouses, and retail markets, respectively. Multilocus sequence typing analyses revealed that the 2 most significant clonal lineages in pork production chain in Korea were ST398 (n = 25) and ST541 (n = 6). All of the 40 MRSA isolates were further characterized to investigate key genotypic and phenotypic correlates associated with the emergence and spread of clonal complex 398 (CC398; ST398, and ST541) LA-MRSA. Although the prevalence of swine-associated MRSA was still relatively low and mostly restricted to pig farms, multidrug-resistant CC398 LA-MRSA isolates with new spa types (t18102 and t18103) were identified as a major clonal lineage. The CC398 LA-MRSA strains tended to exhibit increased levels of multiple drug resistance (MDR) phenotype compared with non-CC398 MRSA strains. Of note, in comparison with non-CC398 MRSA isolates, CC398 LA-MRSA isolates exhibited significantly enhanced tetracycline (TET) and zinc resistance. These findings suggested that co-selection pressure associated with MDR phenotype, especially TET resistance, and zinc resistance may have played a significant role in the emergence and persistence of CC398 LA-MRSA in pig farms in Korea.]]>
Abattoirs ; Agriculture ; Animals ; Drug Resistance, Multiple ; Farmers ; Korea ; Livestock ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Multilocus Sequence Typing ; Phenotype ; Prevalence ; Red Meat ; Staphylococcus aureus ; Swine ; Tetracycline ; Zinc

A total of 123 Coxiella burnetii strains detected in cattle from a nationwide survey in Korea were classified into five genomic groups: I (0.8%), II (14.6%), III (12.2%), IV (66.7%), and V (5.7%). Acute Q-fever strains (Groups I, II, and III) comprised 27.6% and chronic strains (Groups IV and V) comprised 72.4%. At a dairy farm where both types were present, the detection rate was 6.7-times higher than that of another farm where only chronic strains were detected. Both acute and chronic Q-fever strains are widespread in Korea, and their presence could represent an active transmission to livestock and humans.
Agriculture ; Animals ; Cattle ; Coxiella burnetii ; Coxiella ; Humans ; Korea ; Livestock

Foot-and-mouth disease (FMD) is one of the most important livestock diseases in East Africa with outbreaks reported annually that cause severe economic losses. It is possible to control disease using vaccination, but antigenic matching of the vaccine to circulating strains is critical. To determine the relationship between foot-and-mouth disease viruses circulating in districts along the Uganda and Tanzanian border between 2016 and 2017 and currently used vaccines, phylogenetic analysis of the full VP1 virus sequences was carried out on samples collected from both sides of the border. A total of 43 clinical samples were collected from animals exhibiting signs of FMD and VP1 sequences generated from 11 of them. Eight out of the 11 sequences obtained belonged to serotype O and three belonged to serotype A. The serotype O sequences obtained showed limited nucleotide divergence (average of 4.9%) and belonged to topotype East Africa-2, whereas the most common O-type vaccine strain used in the region (O/KEN/77/78) belonged to East Africa-1. The serotype A viruses belonged to topotype Africa-G1 (average nucleotide divergence 7.4%), as did vaccine strain K5/1980. However, vaccine strain K35/1980 belonged to Africa G VII with an average sequence divergence of 20.5% from the study sequences. The genetic distances between current vaccine strains and circulating field strains underscores the crucial need for regular vaccine matching and the importance of collaborative efforts for better control of FMD along this border area.
Africa ; Africa, Eastern ; Animals ; Disease Outbreaks ; Foot-and-Mouth Disease Virus ; Foot-and-Mouth Disease ; Livestock ; Serogroup ; Tanzania ; Uganda ; Vaccination ; Vaccines

The emergence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) in livestock animals have become a worldwide public health concern. While the prevalence and genetic profiles of MRSA strains in pigs and pork meat have been actively studied, livestock-associated MSSA strains have only been characterized in a few small-scale studies. In this investigation, we assessed the nationwide prevalence of MSSA in the Korean pig production chain, including pig farms, slaughterhouses, and retail markets. Among the 41 MSSA strains, the predominant clonal lineages were sequence type (ST) 398 (n = 15, 37%) and ST5 (n = 13, 32%). Although the overall prevalence of MSSA (2.58%) was low and mostly restricted to pig farms, ST398 MSSA strains showed higher level of multidrug resistance phenotype versus non-ST398 MSSA strains. In addition to the MDR phenotype, all of the ST398 MSSA strains exhibited resistance to tetracycline as they harbored the tet(K), tet(L), and/or tet(M) genes. However, ST398 MSSA strains did not exhibit increased resistance to zinc compared with the non-ST398 strains. This study is the first to provide evidence of ST398 MSSA emergence in livestock animals in Korea. Further studies are necessary to elucidate the potential of ST398 MSSA strains for human transmission. Our findings suggest that the MDR phenotype and high levels of tetracycline resistance may have played an important role in the emergence and prevalence of ST398 MSSA in pig farms in Korea.
Abattoirs ; Agriculture ; Animals ; Drug Resistance, Multiple ; Humans ; Korea ; Livestock ; Meat ; Methicillin-Resistant Staphylococcus aureus ; Phenotype ; Prevalence ; Public Health ; Red Meat ; Staphylococcus aureus ; Staphylococcus ; Swine ; Tetracycline ; Tetracycline Resistance ; Zinc

OBJECTIVES: The emergence of resistant bacteria is being increasingly reported around the world, potentially threatening millions of lives. Amongst resistant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) is the most challenging to treat. This is due to emergent MRSA strains and less effective traditional antibiotic therapies to Staphylococcal infections. The use of bacteriophages (phages) against MRSA is a new, potential alternate therapy. In this study, morphology, genetic and protein structure of lytic phages against MRSA have been analysed. METHODS: Isolation of livestock and sewage bacteriophages were performed using 0.4 μm membrane filters. Plaque assays were used to determine phage quantification by double layer agar method. Pure plaques were then amplified for further characterization. Sulfate-polyacrylamide gel electrophoresis and random amplification of polymorphic DNA were run for protein evaluation, and genotyping respectively. Transmission electron microscope was also used to detect the structure and taxonomic classification of phage visually. RESULTS: Head and tail morphology of bacteriophages against MRSA were identified by transmission electron microscopy and assigned to the Siphoviridae family and the Caudovirales order. CONCLUSION: Bacteriophages are the most abundant microorganism on Earth and coexist with the bacterial population. They can destroy bacterial cells successfully and effectively. They cannot enter mammalian cells which saves the eukaryotic cells from lytic phage activity. In conclusion, phage therapy may have many potential applications in microbiology and human medicine with no side effect on eukaryotic cells.
Agar ; Bacteria ; Bacteriophages ; Caudovirales ; Classification ; DNA ; Electrophoresis ; Eukaryotic Cells ; Head ; Humans ; Livestock ; Membranes ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Methods ; Microscopy, Electron, Scanning Transmission ; Microscopy, Electron, Transmission ; Sewage ; Siphoviridae ; Staphylococcal Infections ; Tail

In a population-based study with 4 years of follow up, we evaluated the prevalence of Coxiella burnetii in cattle on Ulleung Island, Korea. In this study, the rates of C. burnetii infection in cattle on Ulleung Island were determined by PCR and were found to be 0.3–1.0% in the period 2011–2014. All 17 C. burnetii partial 16S rRNA gene sequences from PCR-positive cattle were identical and 2 geographic representatives were included in our analysis. The nucleotide sequences of the 2 samples showed high (98.4–100%) identity with C. burnetii sequences obtained from the GenBank. In this long-term tracking study, the number of cattle positive for C. burnetii on Ulleung Island was low. To prevent the transmission of C. burnetii on Ulleung Island, control strategy should include biosecurity improvement in surveillance, livestock management, administering suitable tests before purchasing animals to detect C. burnetii shedders, and restricting movements between herds.
Animals ; Base Sequence ; Cattle ; Coxiella burnetii ; Coxiella ; Databases, Nucleic Acid ; Follow-Up Studies ; Genes, rRNA ; Korea ; Livestock ; Phylogeny ; Polymerase Chain Reaction ; Prevalence

Echinococcus granulosus is an important zoonotic parasite globally causing cystic echinococcosis (CE) in humans and animals. In this study, prevalence of CE and variation of cox1 gene sequence were analyzed with isolates E. granulosus collected from different areas in northern Xinjiang, China. The survey showed that 3.5% of sheep and 4.1% of cattle were infected with CE. Fragment of cox1 was amplified from all the positive sheep and cattle samples by PCR. In addition, 26 positive samples across the 4 areas were included. The isolates were all E. granulosus sensu stricto (s.s.) containing 15 haplotypes (Hap1-15), and clustered into 2 genotypes, G1 (90.1%, 91/101) and G3 (9.9%, 10/101). Hap1 was the most common haplotype (48.5%, 49/101). Hap9 were found in humans samples, indicating that sheep and cattle reservoir human CE. It is indicate that E. granulosus may impact on control of CE in livestock and humans in the region.
Animals ; Cattle ; China ; Cross-Sectional Studies ; Echinococcosis ; Echinococcus granulosus ; Echinococcus ; Genotype ; Haplotypes ; Humans ; Livestock ; Parasites ; Polymerase Chain Reaction ; Prevalence ; Sheep

From October 2015 to August 2018, tapeworm proglottids were obtained from 10 patients who were residents of Daegu and Gyeongbuk provinces and had a history of raw beef consumption. Most of them had no overseas travel experience. The gravid proglottids obtained from the 10 cases had 15–20 lateral uterine branches. A part of internal transcribed spacer 1 (ITS1) DNA of the 10 cases, amplified by polymerase chain reaction (PCR) and digested with AleI restriction enzyme, produced the same band pattern of Taenia saginata, which differentiated from T. asiatica and T. solium. Sequences of ITS1 and cytochrome c oxidase subunit 1 (cox1) showed higher homology to T. saginata than to T. asiatica and T. solium. Collectively, these 10 cases were identified as T. saginata human infections. As taeniasis is one of the important parasitic diseases in humans, it is necessary to maintain hygienic conditions during livestock farming to avoid public health concerns.
Agriculture ; Cestoda ; Daegu ; DNA ; DNA, Ribosomal ; Electron Transport Complex IV ; Gyeongsangbuk-do ; Humans ; Livestock ; Parasitic Diseases ; Polymerase Chain Reaction ; Public Health ; Red Meat ; Republic of Korea ; Taenia saginata ; Taenia ; Taeniasis

Zoonoses are the diseases that are transmitted to human being from vertebrate animals either from livestock animals or from wildlife. Recently, zoonoses are increasingly common as a result of incremental human-animal contact. Propagative infections in wild animals and livestock are transmitted to human beings who are encountered with them. In general, wild animals can transmit infectious agents to livestock, and then livestock further transmit them to human being is a simple model of on how zoonotic diseases get transmitted to human being. This model emphasizes the importance of early detection of zoonoses by surveillance at its incipient stage. Cooperation between the respective ministries plays an important role in the identification of zoonoses and planning for the formulation of better preventive and control policy and strategy. We will be able to predict the occurrence of zoonotic diseases in human on the basis of disease trends in wildlife and livestock once when we obtain the surveillance data and data generated by respective ministries through sound cooperation and collaboration.
Animals ; Animals, Wild ; Cooperative Behavior ; Humans ; Livestock ; Vertebrates ; Zoonoses