• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.69-73
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• 1975

A Total of 173 streptococci isolated from 536 dairy cattle in Gyeonggi Province identified by Lancefield serological reaction and other biological properties. Antibiotics sensitivity test was also examined and the results obtained were as follows: 1. A total of 173 isolates of 167 strains (96.5%) were reacted with group A,B,C,D,E and G antisera. 2. Of the 167 positive strains, 75 strains were identified to Streptooccus uberis, 56 to Streptococcus agalactiage and 26 to Streptococcus dysgactiae, respectively. Also, Sreptococcus pyogenes, group D and group G streptococci were rarely isolated. 3. In results of antibiotic sensitivity tests, the most isolates were sensitive to leucomycin and erythromycin but less sensitive to streptomycin. and kanamycin.

• 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.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.275-288
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• 1995

The inhibitory effect of cell wall extracts of streptococci, have been investigated to know host-parasite relationship or pathogenesis of abscess formation. Streptococci isolated from the infected root canals were sonicated to get cell wall extracts which have been known as one of the factors of pyogenesis. Lymphocytes separated by density gradient were stimulated with phytohemagglutinin and exposed to cell wall extracts of Streptococcus sanguis, S. mitis, S. uberis, S. mutans (ATCC 10449), and S. faecalis (ATCC 19433). [$^3H$]-thymidine uptake of lymphocytes was analyzed with scintillation counter and lactate dehyrogenase (LD) activity was measured with autochemistry analyzer. S. faeealis had the strongest inhibitory effect. beginning at $100\;{\mu}g/ml$ concentration of sonic extracts. S. sanguis and S. mitis had inhibitory effect at $300\;{\mu}g/ml$, while S. uberis and S. mutans showed no inhibitory, effect on DNA syntheis even at $300\;{\mu}g/ml$. Each streptococci showed different inhibitory effect on the DNA synthesis of lymphocytes, which finding indicated wide spectrum of susceptibility of lymphocytes according to streptococcus spp. There were no significant difference of LD activities between control and each streptococcal extracts. Streptococcal sonic extracts did not affect the morphological findings or number of colonies activated lymphocytes. These finding suggested the inhibitory effect of sonic extract of streptococci to lymphocytes could be detected by DNA synthesis inhibition, not by cellular membrane damage.

• 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.

• 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.

• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.99-105
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• 1974

A total of 2,053 quarter milk samples of 518 dairy cows from 46 herds were examined for mastitis and results obtained were as follows: 1. A total of 428 quarters(20.8%) of 271 dairy cows(52.3%) from 41 herds(89%) were found to be infected with mastitis. 2. It was found that 71 quarters(3.5%) of 41 cows(7.9%) from 21 herds(45.6%) were clinical mastitis and 357 quarters(17.3%) of 230 cows(44.4%) from 20 herds (43.4%) were subclinical mastitis. 3. The main causative organisms of the mastitis were Staphylococcus aureus(26%), Streptococcus uberis(16%), and Streptococcus agalactiae(10%). 4. The majority of causative organisms were very resistant to colistin(85.9%), penicillin(67%), and streptomycin(39%). Most of the other drugs were highly effective as inhibitor for the most causative organisms in vitro. However sulfisoxazole was moderatively effective against them.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.315-320
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• 1975

A total of 364 quarter milk samples of 91 dairy cattle from 4 area around Jeonju in Jeonbug area were examined for infection rate and causative abets of mastitis by the Laboratory Procedures used in the Connecticut Mastitis-Control Program. The results obtained were as follows: 1. One hundred and thirty quarters (35.7%) from 67 cows (73.6%) were found to be infected with mastitis. It was found that 5 (1.37%) of the infected quarters were clinical mastitis and all of the rest were subclinical mastitis (125 quarters). 2. The main causative agents were found to be Staphylococcus aureus (46 quarters), Streptococcus agalactiae (49 quarters), streptococcus disgalactiae (18 quarters), Steptococcus uberis (13 quarters). Corynebacteria, Coliform organisms, Pseudomonas were also occasionally found to be causative organisms. 3. Having examined the number of infection Quarter per head of mastitis dairy cattle samplings, major findings were that the average number of infection quarter to total dairy cattle examined was 1.4 quarters, and that average number of infection quarter to the infected cattle was 1.9 quarters.

• Korean Journal of Veterinary Research
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• v.54 no.1
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• pp.49-52
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• 2014

This study was conducted to compare the patterns of mastitic pathogens and the antimicrobial susceptibility of Staphylococcus (S.) aureus from conventional milking (CM) and robotic milking (RM) dairy herds. To accomplish this, the minimum inhibitory concentrations of 14 antimicrobial agents were tested against S. aureus by the microdilution method. Regardless of the milking system, S. aureus, coagulase negative staphylococcus, and Streptococcus uberis were isolated. Additionally, significant differences in the antimicrobial susceptibility of S. aureus isolates between RM and CM farms were only observed in response to tetracycline.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.531-537
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• 1993

A study was carried out to define the relationship between the N-acetyl-$\beta$-D-glucosaminidase(NAGase) levels and isolated pathogenic bacteria in 379 quarter fore milk of mastitis suspected samples collected in this clinics. All samples were tested the NAGase, California mastitis test(CMT), Somatic cell count(SCC) and bacterial culture. Except 111 from 379 samples, 268 bacteria-positive quarter fore milk samples were classified into the latent and mastitis infection group by SCC($500,000cells\;per\;m{\ell}$), and the mean NAGase levels($nmol/min/m{\ell}$) of each isolated pathogen in mastitis infection group were Staphylococcus aureus 3.067, Coagulase-negative staphylococci 4.083, Staphylococcus aureus 3.594, Str. uberis 3.513, Str. dysgalactiae 1.640, E coli 4.441 and gram negative rods 4.560, respectively. Most of the relationship between mean SCC and NAGase in each pathogen group were highly significant using a student t test(p<0.05). When the mastitis pathogens were classified into minor(Coagulase-negative staphylococci, Corynebacterium sp.) and major pathogen group(Staphylococcus aureus, Streptococcus agalactiae, Str. uberis, Str. dysgalactiae, gram negative rods), the NAGase levels were higher at major than minor pathogen group. On the other hand, when the mastitis milk samples were classified by SCC($500,000cells\;per\;m{\ell}$) and by the presence of pathogen(IDF scheme), the NAGase levels were also higher at the mastitis than latent infection. The possibility of combining SCC and NAGase data in order to give the more difinitive diagnosis is discussed.