• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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• pp.155-155
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• 2001

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.280-285
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• 2004

Pathological and bacteriological studies were made of a total of 111 udders from slaughtered Korean native cows originating from various locations in Chonnam province. Incidence of supernumerary teats was 8.1%. Gross lesions were found in 21.4% of mucous membranes of total teat cisterns; these lesions comprised epithelial hyperplasia (12.6%), congestion (4.1%), slight fibrosis (3.8%) and severe fibrosis with congestion (0.9%). Gross lesions in the glandular tissues were found in 35.1% of cows; these lesions comprised slight fibrosis (27.9%), moderate fibrosis (6.3%) and severe fibrosis with pus (0.9%). Mastitis was found only in one cow. One hundred and twenty-five strains of microorganisms were isolated from mammary gland fragments of the cows. Pathogens most commonly isolated were Staphylococcus spp.; most of them were minor mammary pathogens. Major mammary pathogens were Streptococcus spp. (9.6%) and E. coli (2.4%). Most of the isolates were susceptible to many of 13 antimicrobial agents used, but Streptococcus spp. and Gram-negative rods showed resistance to 7 and 8 agents, respectively. 97.5% of the isolates showed susceptibility to amoxicillin, but only 55.8% to erythromycin.

• Korean Journal of Agricultural Science
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• v.26 no.1
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• pp.71-76
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• 1999

The methanolic extracts from the elm (Ulmus davidiana var japonica) root barks which have been known as an oriental medicine Eubackpie for the treatment of edema, ulcer and inflammation were examined for their bacteriocidal effects on mastitis pathogens of milk cows. The growth of the pathogenic bacteria such as Staphylococcus aureus and Streptococcus sp. No. 12 was markedly inhibited by the chloroform fraction among the extracts, and these antibacterial activities were also supported by MIC test. Water-soluble mucilage was obtained from the root barks with a yield of 36.8~40.2% by dry weight basis. This substance appeared to be a kind of polysaccharide with $61.0{\pm}1.0%$ carbohydrate content, and to have hygroscopic and astringent properties due to its high viscosity and water absorption.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.295-305
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• 2012

The aim of this study was to isolate microorganisms from half milk samples of dairy goats by California mastitis test (CMT) during the lactation period and to further investigate the susceptibility of isolated organisms to antimicrobial drugs. From a total of 235 half milk samples with CMT scores of 2 or above from 366 dairy goats distributed throughout Jeonnam province, microorganisms were isolated from 198 (83.5%) samples either singly (99.0%) or in combination (1.0%). The most prevalent microorganism was the coagulase-negative Staphylococcus spp., (44.4%, n=88) followed by Staphylococcus aureus (24.2%, n=48), Escherichia coli (11.1%, n=22) and Streptococcus spp. (7.6%, n=15). Isolated bacteria also included Bacillus spp. (2.5%, n=5), Pseudomonas spp. (2.5%, n=5), Micrococcus spp. (1.5%, n=3), Corynebacterium spp. (1.5%, n=3), Enterococcus facium (1.0%, n=2), Morganella morganii (0.5%, n=1) and Streptococcus agalactiae (0.5%, n=1). During the summer season, a high prevalence of all microorganisms were observed in which Staphylococcus spp. (30.8%), Escherichia coli (8.6%), and Streptococcus spp. (5.6%) were among the most prevalent bacteria isolated. Staphylococcus spp. was also shown to be high in the winter (21.7%). In most samples, the presence of bacterial pathogens in goat milk led to the increase in the total somatic cell count (SCC). Most of the half milk samples of dairy goats with bacterial contamination showed SCC of ${\geq}1{\times}10^6cells/ml$ (90.4%). Minor pathogens (11.4%) were more detected from milk samples with SCC of < $1{\times}10^6cells/ml$ than major pathogens (4.1%), while the major pathogens tended to be higher from samples with SCC of ${\geq}3{\times}10^6cells/ml$. Susceptibility of these bacteria to 12 antimicrobial agents was tested by the Kirby-Bauer disc diffusion method. Results indicated that more than 90% of bacteria isolated from CMT 2+ dairy goat half milk samples were susceptible to trimethoprim/sulfamethoxazole, amoxicillin/clavulanic, enrofloxacin and cephalothin while they were resistant to tetracycline (44.7%).

• Korean Journal of Veterinary Service
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• v.20 no.3
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• pp.261-279
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• 1997

The study for a effect of monitoring on bovine mastitis was conduced for improvement of raw milk from Jan. to Dec. in 1996. Sampling the milk of 367 cows(1, 406 quarters) from 5 herds in Inchon and were carried out California mastitis test(CMT), somatic cell count(SCC), isolation of pathogens and antibiotic sensitivity tests. The results were summarized as follows, 1. The number of bovine mastitis was 177 cows(48.2%) and 371 quarters(26.4%) : clinical mastitis : 25 cows(6.8%), 32 quarters(2.3%) and subclinicsl mastitis : 152 cows(41.4% ), 339 quarters(24.1%). Incidence rate of mastitis by season were Summer 52.0%, Fall and Winter 48% and Spring 41%. Incidence rate of mastitis by quarters were Summer 30%, Fall 28%, Winter 25% and Spring 21%, respectively. 2. In the distribution of CMT degree by quarter, CMT positive(CMT$\pm$) of 1, 406 quarters milk were 50.1% (704 quarters). The ratio of CMT positivity by quarter were left front quarter 55.8%, right front quarter 48.9%, right hind quarter 48.6% and left hind quarter 47% The ratio of CMT positivity by season were Summer 54.1%, Fall 49.7%, Spring 48.5% and Winter 48% 3. The highest mean SCC by season among 5 herds was "A" herd. Mean SCC (cell/ml) of A herd were Summer 2, 032, 000cells/ml, Fall 1, 109, 000cells/ml, Winter 782, 000cells/ml and Spring 577, 000cells/ml. The lowest mean SCC by season among 5 herds was "E" herds. Mean SCC of E herd were Summer 1, 064, 000cells/ml, Spring 795, 000cells/m1, Fall 429, 000cells/ml and Winter 400, 000cells/ml. Mean SCC of the other herds by season were little difference. 4. The milk samples of "A" herd were collected from 10 cows. In 3 seasons, mean SCC of No. 2 and 3 cows were than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 6, 7 and 8 cows were than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Summer 4 cows, Winter 3 cows, Spring and Fall 1 cow respectively. The milk samples of "B" herd were collected from 14 cows. In 3 seasons, mean SCC of No. 1 cow was more than 1, 000, 000cells/ml. In 2 seasons, mean SCC of No. 5, 9 and 14 cows were more than 1, 000, 000cells/ml. In 1 season, No. 3, 6 and 7 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Fall and Winter 4 cows respectively, Summer 3 cows and Spring 1 cow. The milk samples of "C" herd were collected from 18 cows. In 2 seasons, mean SCC of No. 16 cow was more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 1, 2, 6, 7, 13, 15 and 18 cows were more than 1, 000, 000cells/ml respectively. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Summer 5 cows, Fall 3 cows, Spring 2 cows and Winter 1 COW. The milk sampes of "D" herd were collected 24 cows. In 3 season, mean SCC of No. 14 cow was more than 1, 000, 000cells/ml. In 2 seasons, mean SCC of No. 14 and 18 cows were more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 1, 2, 3, 8, 12, 17, 19, 20 and 21 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows were distributed Fall 15 cows, Spring and Winter 4 cows respectively and Summer 3 cows. The milk samples of "E" herd were collected from 27 cows. In 2 seasons, mean SCC of No. 6, 7 and 21 cows were more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 2, 4, 7, 11, 14, 16 and 23 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows were distributed Spring and Fall 5 cows respectively, Summer and Winter 2 cows, respectively. 5. The rate of isolated pathogenic microorganisms from bovine mastitis were summarized as follows : Staphylococcus sp 168 strains(45.8%), Streptococcus sp 82 strains(22.3%), Gram(-) sp 45 strains(12.3%), Gram(＋) sp 51 strains and the other sp 21 strains(5.7%). 6. The highest of antibiotic sensitivity test of each microorganism was summarized as follows : Staphyolcoccus sp - cephalosporin 76%, gentamicin 55%, Streptococcus sp - ampicillin 61%, cephalosporin 63%, Gram(-) sp - gentamicin 58%, Gram(＋) sp - cephalosporin 63%, The other sp - cephalosporin 90%. Microorganisms showed the highest sensitivity(68%) to cephalospsorin. Microorganisms showed the highest sensitivity(68%) to cephalospsorin.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.3
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• pp.169-175
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• 2022

Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.66-72
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• 2010

Pediococcus pentosaceus SA131 was isolated from jeotgal, is the bacteriocin producer against bovine mastitis pathogens, Streptococcus uberis E290, Enterococcus gallinarum E362, and Staphylococcus epidermidis ATCC 12228. The medium composition for pediocin SA131 production by P. pentosaceus SA131 was optimized using response surface methodology. Component of medium was studied as carbon source (glucose, fructose, lactose, glycerol, sucrose, maltose, and mannitol), nitrogen source (beef extract, yeast extract, peptone, malt extract, and tryptone), mineral and surfactant ($MgSO_4$, $KH_2PO_4$, $(NH_4)_2SO_4$, $MnSO_4$, NaCl, sodium acetate, and Tween 80). Through one factor-at-a-time experiment, glucose, fructose, yeast extract, malt extract, NaCl, $MgSO_4$, and Tween 80 were determined as the good ingredient. The effects of major factors for pediocin SA131 production were investigated by two-level fractional factorial designs (FFD). By a $2^4$ FFD, fructose, yeast extract, and $MnSO_4$ were found to be the important factors for the bacteriocin production. Subsequently, a $2^3$ central composite design (CCD) was adopted to derive a statistical model for optimizing the composition of the fermentation medium. The estimated optimum composition for the production of pediocin SA131 by P. pentosaceus SA131 was as follows; 0.13% fructose, 1% glucose, 1.8% yeast extract, 2.58% $MnSO_4$, 0.2% NaCl, and 0.2% Tween 80. The pediocin production under optimized medium was increased to 1,000 AU/mL, compared to the 400 AU/mL in MRS medium.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.457-462
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• 2008

Lactococcus lactis NK34, isolated from jeotgal (Korean traditional fermented fish), produces bacteriocin against bovine mastitis pathogens such as Staphylococcus aureus 7, S. aureus 8, Staphylococcus chromogenes 10, S. chromogenes 19, Staphylococcus hominis 9, Streptococcus uberis E290, Enterococcus faecium E372, Streptococcus agalactiae ATCC 13813, Pseudonocardia autotrophia KCTC 9455, and Staphylococcus simulans 78. Lacticin NK34 was inactivated by protease XIV but not by protease IX, protease XIII, proteinase K, $\acute{a}$-chymotrypsin, trypsin, and pepsin. Also, lacticin NK34 was stable over a pH range of 2 to 9 for 4 hr and withstood exposure to temperatures of 30-$100^{\circ}C$ for 30 min. Lacticin NK34 showed bactericidal effects against S. simulans 78. This bacteriocin was purified using ammonium sulfate precipitation, ion exchange chromatography, ultrafiltration, and hydrophobic chromatography. Tricin-SDS-PAGE of purified bacteriocin gave the same molecular weight (3.5 kDa) as nisin. The gene encoding this bacteriocin was amplified by PCR using nisin gene-specific primers. It showed similar sequences to this nisin Z gene. These results indicate that lacticin NK34 is a nisin-like bacteriocin, and could be used as an antimicrobial alternative for livestock.

• Animal Bioscience
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• v.37 no.4
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• pp.709-717
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• 2024

Objective: Abnormally increased somatic cell counts (SCCs) in milk is usually a sign of bovine subclinical mastitis. Mutual interaction between the host and its associated microbiota plays an important role in developing such diseases. The main objective of this study was to explore the difference between cows with elevated SCCs and healthy cattle from the perspective of host-microbe interplay. Methods: A total of 31 milk samples and 23 bovine peripheral blood samples were collected from Holstein dairy cattle to conduct an integrated analysis of transcriptomic and metagenomics. Results: The results showed that Ralstonia and Sphingomonas were enriched in cows with subclinical mastitis. The relative abundance of the two bacteria was positively correlated with the expression level of bovine transcobalamin 1 and uridine phosphorylase 1 encoding gene. Moreover, functional analysis revealed a distinct alternation in some important microbial biological processes. Conclusion: These results reveal the relative abundance of Ralstonia and Sphingomonas other than common mastitis-causing pathogens varied from healthy cows to those with subclinical mastitis and might be associated with elevated SCCs. Potential association was observed between bovine milk microbiota composition and the transcriptional pattern of some genes, thus providing new insights to understand homeostasis of bovine udder.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.177-184
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• 2003

The present study was conducted to investigate isolation and antimicrobial drug susceptibility of clinical mastitic milking total 610 (897 quaters) dairy cattles from 36 dairy farms in Gyeongnam south area (Cosung, Masan) during the period from March 1999 to August 2002. The results obtained were summerized as follows . 1. Incidence of bacterial infection in four quaters was showed that right anterior quarter was 178(19.8%), right posterior quarter was 292(32.6%), left anterior quarter was 148 (16.2%), and left posterior quarter was 279 (31.1%), respectively. Isolation rate of posterior two quarters was higher 2 times than anterior two quarters. 2. Incidence of double infections of 897 clinical mastitic milk were showed that single infection was 549 (61.2%), double infection was 167(18.6%), triple infection was 9(1%) and no isolation was 172(19.2%). 3. Isolation of infected etiologic bacteria was showed that Streptococci spp., was 267(31%), Staphylococci spp., was 267(41%), S aureus, was 48(5.6%), G(-) bacillus was 126(5.6%), and Corynebactrium spy. was 52(6%), respectively, from total 861 samples. 4. The results of antimicrobial drug susceptibility of all isolates were showed that Streptococci spp., Staphylococci spp., S aureus, (G)(-) bacillus, and Corynebactrium spp. were susceptible to cefuroxime, cefoperazone, amoxicillin, cefazolin, ampicilin, penicillin, gentamicin, erythromycin, cloxacilin, ciprofloxacin, sulfamethoxasole/trimetoprim, teteracyclin, and norfloxacin (> 70%), but some of them were resistant to neomycin, streptomycin colistin, and cephalothin(> 60). 5. The results of drug susceptibility obtained from each farms had different susceptibility, even though, etiological microorganisms were same in each farms.