• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.219-225
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• 2017

This study was investigated the synergistic effects from the combination of cefalexin and gentamicin (CCG) against Staphylococcus spp. isolated from bovine milk. Minimum inhibitory concentrations (MICs) and fractional inhibitory concentration (FIC) index were determined for 16 bacteria from 13 bovine farms in Gyeongsangnam province by the National Committee for Clinical Laboratory Standards broth microdilution procedure. Antimicrobial agents tested included cefalexin, gentamicin and CCG. Against Staphylococcus spp. tested, the MIC ranges of cefalexin, gentamicin and CCG were 0.25~1.0, 0.5~0.125 and $0.06{\sim}0.125{\mu}g/mL$, respectively. In addition, the FIC index ranges of CCG against most of the isolates was 0.28~0.43 and the FIC index of CCG against 2 strains of Staphylococcus haemolyticus (S. haemolyticus) was 0.59. In conclusion, CCG has a high antibacterial activity against Staphylococcus isolates, then the combination may be applied for the treatment of bovine mastitis caused by Staphylococcus spp.

• Journal of Veterinary Clinics
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• v.10 no.1
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• pp.141-145
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• 1993

The present study was performed in order to clarify the significance of serum amyloid A(SAA) estimation for the diagnosis of bovine amyloidosis and SAA as a useful parameter for the health status in herds. Twelve dutch dairy cows with final diagnosis(2 with amyloidosis, 3 with acute inflammatory disease and 7 with chronic inflammatory disease) were used to charify the significance of SAA determination for the diagnosis of bovine amyloidosis. The SAA concentration in the group of inflammatory disease was higher than that of amyloldotic group. Further the SAA value in the group of acute inflammatory disease was higher than that of chronic ones. To clarify the significance of SAA estimation as a useful parameter for the health status in herds, two Korean dairy farms(A and B) were selected and the SAA concentration was determined in total 76 cows(49 from A farm and 27 from B farm). The SAA concentration in cows from A farm was ranged with 0～169%. The cows with high level of SAA(31～169%) had the disease histories(1 with retained placenta, 3 with chronic mastitis, 2 with acute mastitis, 1 with abortion and acute mastitis, 1 with ovarian dysfunction, 1 with downer cow syndrome and 1 with laceration of the teat). The SAA value in the cows from B farm was ranged with 0～29% and disease history was not detected. In conclusion the SAA determination only is thought to be difficult for the diagnosis of bovine amyloidosis. Furthermore SAA estimation is thought to be a useful parameter for the health status in herds.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.314-317
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• 2005

The potential therapeutic effect of ozone gas on bovine mastitis was investigated. Eighteen quarters from 18 lactating cows with chronic mastitis were included. The 18 quarters were assigned to the control group (treatment with antibiotics for 3 days), experimental group I (0.1 ppm ozone treatment, for 7 days) and experimental group II (1ppm ozone treatment, for 3days). In experimental group I, milk somatic cell counts were lower on day 7 after ozone treatment, compared to the pretreated counts, but were higher than the control counts. In experimental group II, somatic cell counts were significantly decreased (p<0.05) on day 7 compared to the pretreatment counts, and they were lower than the control counts. There were no changes in leukocyte, neutrophil, or lymphocyte numbers, N/L ratios, N/L ratios, or serum total protein in the control and experimental groups. We concluded that ozone gas treatment(1ppm for 3days) might be effective for treatment of bovine mastitis.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.33-41
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• 2007

Streptococcus spp. comprising Streptococcus (S.) uberis S. dysgalactiae strains is major causeof bovine mastitis from particularly well-managed or low somatic cell count herds that have successfullycontrolled contagious pathogens. In this study, antimicrobial susceptibility and genetic characteristics of S.uberis isolated from clinical or subclinical mastitis milk at 2003 were investigated. Eighty seven isolatesof Streptococus spp. were identified by the conventional biochemical methods. The antimicrobialsusceptibility by disk diffusion method was determined for 46 S. uberis, 11 S. bovis, 10 S. oralis, 6 S.uberis and 14 other Streptococcus spp.. Overall, the tested strains were susceptible to tetracycline (11.5%),amikacin (14.9%), streptomycin (16.1%), neomycin (26.4%), kanamycin (35.6%), gentamicin (65.2%),oxacillin (70.1%), ampicillin (75.9%), chloramphenicol (78.2%), and cephalothin (97.7%). Additionally, S.uberis strains were susceptible to pencillin G (97.8%), but resistant to erythromycin (76.0%) by minimalinhibitory concentration test. The multiple-drug resistance rate of isolated bacteria to 4 more thanamplification fingerprinting patterns amplifed with primer 8.6d showed that 3 to 8 number of distinguishableDNA fragments ranged from 180 bp to 1,20 bp. Thirty seven isolates of S. uberis strains were subtypedinto 8 distinct patterns. Each subtype revealed a typical pattern of antimicrobial susceptibilities. Thesefindings demonstrate that S. uberis isolates were mastitis pathogens of diverse serotypes, and oftenencountered the diverse resistant patterns.

• 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.57 no.2
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• pp.117-126
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• 2017

Bovine mastitis is an important microbial disease in the dairy industry. We investigated the frequencies of bacterial pathogens in 62 farms and pathogen antibiotic resistance from mastitis samples (n = 748). We tested the antimicrobial activity of chicken and duck egg white and lysozyme purified from chicken egg white. Moreover, we compared the microbiomes of normal and mastitic raw milk obtained by 16S rRNA gene pyrosequencing and culture methods. The results showed that the frequencies of Gram-positive pathogens (Enterococcus faecalis 37% and Staphylococcus aureus 36%) were higher than that of a Gram-negative pathogen (Escherichia coli 15%). Resistance frequencies to ampicillin and norfloxacin were lowest in Staphylococcus aureus (21%), Enterococcus faecalis (23%), and Escherichia coli (33%), and the antimicrobial activity of chicken egg white was higher than those of lysozyme and duck egg white. Pyrosequencing results revealed clear differences between the microbiomes of mastitic and normal raw milk samples and revealed a slightly similar, but clearly different, composition of pathogens compared to that from the culture method. Thus, pyrosequencing may be useful for elucidating changes in microbiomes during mastitis progression and treatment. A chicken egg white and antibiotic combination may help with mastitis treatment; however, further studies are needed.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.524-527
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• 2009

Spontaneously infected and non-infected dairy cows were assessed in a cross-sectional study aimed at determining whether bovine leukocyte markers may diagnose intra-mammary infections (bovine mastitis). Animals located in herds where bovine mastitis was highly prevalent were investigated (n = 31 animals). The expression of three cell-surface markers (CD11b, CD4 and CD8) was assessed, and the somatic cell count (SCC) and bacteriological analyses (both cultures and PCR tests) were also conducted. Cows identified as infected revealed statistically significant higher milk leukocyte CD11b, CD4 percentage and milk CD4/CD8 ratios than non-infected cows. Immunological markers may diagnose spontaneous bovine mastitis.

• 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.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.61-67
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• 1985

One hundred and twenty seven strains of Gram-negative rods (72 E. coli, 45 Klebsieila pneumoniae, 8 Enterobacter spp. and 2 Pseudomonas aeruginosa) isolated from bovine mastitis were examined for resistance to ampicilin, carbenicillin and cefazolin, ${\beta}$-lactamase activity and transferable ${\beta}$-lactamase plasmids. Stains resistant to ampicillin were 13.9% in E. coli, 93.3% in Klebsiella pneumoniae, 87.5% in Enterobacter. spp. and all in Pseudomonas aeruginosa, Resistance of E. coli, Klebsiella pneumoniae and Enterobacter spp. to ampicillin was due to the ${\beta}$-lactamases, but all Pseudomonas aeruginosa exhibited a high level of the non-enzymic resistance. Transferable plasmid-mediated ${\beta}$-lactamase synthesis was demonstrated in 61.9% of Klebsiella pneumoniae, 50% of E. coli and 42.9% of Enterobacter spp. The same ${\beta}$-lactamase plasmids specified different resistance levels to various ${\beta}$-lactam antibiotics in different recipients.

• Journal of the korean veterinary medical association
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• v.23 no.10
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• pp.663-670
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• 1987

In order to investigate the rate of clinical mastitis and the average number of somatic cell in a milk, the number of somatic cell in the milk counted from 82 normal Holstein cows in the area of Kyungi-Do. And the chemical values of blood were examined fr