• Korean Journal of Veterinary Research
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• v.10 no.1
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• pp.39-45
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• 1970

A total of 835 quarter milk samples of 212 dairy cows from 14 herds were examined for mastitis and the results obtained were as follows; 1. Three hundred and fifty-eight quarters(42.9%) from 149 cows(70.3%) were found to be infected with mastitis. It was found that 11(1.3%) of the infected quarters were clinical mastitis and all of the rest were subclinical mastitis. 2. Streptococcus agalactiae(62 quarters) and Staphylococcus aureus(42 quarters) were the main two causative organisms of the mastitis. Streptococcus dysgalactiae, Streptococcus uberis, other streptococci, Corynebacteria, and Yeast were also found to cause the infection. 3. The majority of Staphylococcus aureus strains were sensitive to penicillin, orbenin, terramycin, and leucomycin, however, the most of Streptococcus strains were sensitive to penicillin and orbenin only. 4. Penicillin and orbenin were highly effective in the treatment of mastitis, especially orbenin for Staph ylococcus aureus infection and penicillin for Streptococcal infection. 5. A mastitis control program for dairy farms in Korea was discussed and recommended.

• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.43-54
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• 2012

Group B streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in developed countries. This article reviews the neonatal invasive GBS disease, maternal GBS colonization, and prevention strategies in the context of recent epidemiological changes in Korea. Although Korean neonates had been supposed to have low incidence of invasive GBS disease, GBS has been recently reported to be the most common cause of invasive neonatal infection after 1990s. Among Korean pregnant women, GBS carriage rate in the vagina and rectum has been reported to be much lower than that in Western countries. However, it has increased in recent studies. For decision making about preventive strategy for neonatal GBS disease in Korea, further studies are required in terms of the incidence of neonatal GBS infection and serotype distribution. In addition, studies about maternal carriage rate and serotype distribution have to be continued.

• Korean Journal of Veterinary Research
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• v.16 no.2
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• pp.191-195
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• 1976

On the basis of pigment production on brain heart infusion agar medium containing crocin, differentiation of mastitic streptococcus was investigated. Intensive crocin reaction was showed in braille heart infusion agar when maximum volume of gardenia powder was 5.0 mg/ml and dark-violet pigmentation of Str. uberis and Group D (Str. facalis) Streptococcus were differentiated from negative strains of Str. dysgalactiae. Also, although most of Str. agalactiae was producted pigment, a few was not affected with the crocin reaction.

• Food Science of Animal Resources
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• v.31 no.4
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• pp.609-616
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• 2011

In this study, a LCH1227 bacterial strain that possesses anti-listerial activity was isolated from fermented food and identified as Lactobacillus salivarius LCH1227 based on its morphological and biochemical properties, as well as its 16S rRNA gene sequences. Anti-listerial substance also inhibited the growth of various Gram-positive bacteria, such as vancomycinresistant Enterococcus faecalis, Streptococcus agalactiae, Bacillus cereus, Lactobacillus fermentum. The highest level of production of antimicrobial substances from L. salivarius LCH1227 occurred during the early stationary phase. The antilisterial activity was found to be stable over a broad range of pH values (2.0-12.0) and after heat treatment. However, it was inactivated by proteolytic enzymes, indicating its proteinaceous nature. The apparent molecular mass of the partially purified anti-listerial substance, as measured by Tricine-SDS-PAGE, was approximately 5 kDa.

• Journal of Veterinary Clinics
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• v.25 no.5
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• pp.346-354
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• 2008

The combined effects of EDTA-Tris and eighteen antimicrobial agents have been evaluated in eight clinically isolated methicillin-resistant bacteria (Staphylococcus aureus, Escherichia coli, Streptococcus uberis and Streptococcus agalactiae) from bovine mastitis. The antimicrobial activity was evaluated by measuring the minimal bactericidal concentration (MBC) for the antibiotics alone or in combination with EDTA-Tris in Mueller-Hilton broth and milk. Combined use of EDTA-Tris and antibiotics potentiated or antagonized activity of antibiotics against mastitic pathogens. Milk increased the antibiotic potency of erythromycin and spiramycin on S. aureus. Culture in milk changed patterns of EDTA-Tris combinational effects compared with that in standard Mueller-Hilton broth. Combined with EDTA-Tris in milk, synergic effects were observed in colistin, dihydrostreptomycin, kanamycin, erythromycin, gentamycin, oxytetracycline, streptomycin to E. coli, Str. uberis, and Str. agalactiae. However, significant antagonistic effects of milk on antibiotic susceptibility in combination with EDTA-Tris were noted in neomycin, streptomycin, penicillin, roxithromycin, and amoxicillin. This study indicates that combination therapy of EDTA-Tris with antibiotics in bovine mastitis should be used with caution because of the possible antagonistic effects of antibiotic combination with EDTA-Tris on mastitic pathogens. In addition, antibiotic susceptibility test in combination with EDTA-Tris in milk culture condition can be benefit in search of effective treatment regimen for some antibiotic-resistant bacteria of mastitis.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.511-521
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• 2001

Microorganisms were isolated and identified from bovine 296 quarters which showed positive reaction by California Mastitis Test (CMT) in 40 farms of Jeju from September 1999 to June 2000. The organisms associated with the mastitis of bovine were 11 different bacterial species in this study. Which of them, Staphylococcus aureus was the most predominant species as 152 (51.4%) isolates. Other identified species included 49 (16.5%) coliform, 47 (15.8%) Streptococcus dysgalactiae, 15 (5.1%) Bacillus spp., 8 (2.7%) Staphylococcus epidermidis, 6 (2.1%) Streptococcus agalactiae, 5 (1.7%) Enterococcus faecalis, 5 (1.7%) Corynebacterium spp., 3 (1.0%) Streptococcus uberis, 1 (0.3%) Pseudomonas aeruginosa and 1 (0.3%) Pasteurella haemolytica. Almost of all the islolated beacterial species showed high sensitivity against kanamycin (98.6%), cephalothin (98.0%), streptomycin (94.9%), gentamicin (94.6%), ampicillin (92.2%) and polymyxin B (90.2%). On the contrary, they showed resistance against penicillin (47.0%), tetracycline (37.2%), cefazolin (26.0%), bacitracin (22.6%) and erythromycin (19.9%). Eighty-one isolates were not resistant to any antibiotics and 215 drug resistant isolates showed 89 different drug resistance patterns from single to nine multiple antibiotics resistance patterns.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.181-189
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• 2022

Streptococcus is one of the major pathogen groups inducing bovine mastitis. The aim of this study was to investigate the antimicrobial resistance patterns of Streptococcus species isolated from bovine mastitis milk samples in Korea from 2016 to 2021. In total, 181 (10.3%) Streptococcal isolates were collected from 1,761 quarter milk samples at 122 farms; S. uberis 39.2% (n=71), S. dysgalactiae 29.3% (n=53), S. equinus 9.9% (n=18), S. suis 6.1% (n=11), S. parauberis 4.4% (n=8), S. lutetiensis 3.9% (n=7), others 7.2% (n=13). However, S. agalactiae was not isolated. The isolates showed the highest resistance rate to tetracycline (55.2%) followed by erythromycin (45.3%) and pirlimycin (36.5%). In contrast, all isolates were susceptible to ceftiofur, cephalothin, penicillin/novobiocin, and only single S. equinus isolate was resistant to both ampicillin and penicillin. Of 181 isolates, 64 (35.4%) were multidrug resistance (MDR). The resistance to pirlimycin of S. uberis (73.2%) was much higher than that of other species (0~36.4%). All S. suis isolates were resistance to tetracycline. S. dysgalactiae showed lower resistance to erythromycin, pirlimycin and tetracycline than S. uberis and S. suis. The rate of MDR was relatively higher among S. uberis (73.2%) than among S. suis (36.4%), S. dysgalactiae (15.1%), others (0%). In conclusion, antimicrobial resistance in Streptococcus spp. should be regularly examined for appropriate therapies because the resistance patterns were various among the individual species.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.503-508
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• 2004

The antimicrobial substance produced by Lactobacillus bulgaricus was inactivated by protease. It showed inhibitory activity against Staphylococcus aureus ATCC6538, Streptococcus agalactiae ATCC14364, some Gram-positive and Gram-negative bacteria, and characteristics of a bacteriocin. The optimal temperature and culture time for the production of bacteriocin were $30^{\circ}C$ and 10 h, respectively, in the culture of L. bulgaricus. The bacteriocin production started in the exponential phase and reached a maximum at the early stationary phase. Using Staph. aureus ATCC6538 and Strep. agalactiae ATCC14364, known as common bovine mastitis pathogens, as indicator strains for determination of the bacteriocin activity, the antimicrobial activity of the bacteriocin was found to be stable in acidic and neutral pH's (2- 7) even at lOOT, whereas it was lost at high pH (10- 11) and $100^{\circ}C$. The mode of action for the antimicrobial activity was bacteriocidal, and the molecular weight determined by SDS-PAGE and overlay method was 14 kDa.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.679-682
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• 2008

A lactic acid bacterium producing an antimicrobial substance against Escherichia coli O157:H7 was isolated from raw milk and identified as Lactobacillus amylovorus ME-1. In addition to E. coli O157 :H7, the antimicrobial substance also inhibited the growth of Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyrogenes, and Yersinia enterocolitica. The antimicrobial substance was stable at pH 2-12 and $121^{\circ}C$ for 15 min and insensitive to proteinase K, protease, amylase, and catalase. Purification of the antimicrobial substance was conducted through methanol and acetonitrile/ethylacetate extraction, ultrafiltration with a 500 Da cutoff, thin layer chromatography (TLC) with silicagel 60, and high performance liquid chromatography (HPLC) with a $C_{18}$ reverse phase column. The ${\lambda}_{max}$ of the purified antimicrobial substance was determined as 192 nm by ultra violet (UV) scanning, while the molecular weight was estimated as 453 Da based on the mass spectrum. Accordingly, the current results suggest that the antimicrobial substance from the L. amylovorus ME-1 was not a bacteriocin, but rather a new non-proteinaceous substance distinct from acidophilin, acidolin, diacetyl, and reuterin.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.11
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• pp.1699-1713
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• 2020

Bovine mastitis, an inflammation of the mammary gland, is the most common disease of dairy cattle causing economic losses due to reduced yield and poor quality of milk. The etiological agents include a variety of gram-positive and gram-negative bacteria, and can be either contagious (e.g., Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma spp.) or environmental (e.g., Escherichia coli, Enterococcus spp., coagulase-negative Staphylococcus, Streptococcus uberis). Improving sanitation such as enhanced milking hygiene, implementation of post-milking teat disinfection, maintenance of milking machines are general measures to prevent new cases of mastitis, but treatment of active mastitis infection is dependant mainly on antibiotics. However, the extensive use of antibiotics increased concerns about emergence of antibiotic-resistant pathogens and that led the dairy industries to reduce the use of antibiotics. Therefore, alternative therapies for prevention and treatment of bovine mastitis, particularly natural products from plants and animals, have been sought. This review provides an overview of bovine mastitis in the aspects of risk factors, control and treatments, and emerging therapeutic alternatives in the control of bovine mastitis.