• 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.

• YAKHAK HOEJI
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• v.30 no.1
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• pp.8-13
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• 1986

It has been assumed that nitrite, one of the precursor of N-nitrosamine, in human saliva must have been formed from salivary nitrate through the action of microorganism in the oral cavity. In this paper, we have tested the concentration of nitrite and nitrate in human saliva and the degrees of nitrate reduction by oral microflora and identified some bacteria which were able to reduce nitrate. The concentration of nitrite and nitrate was 1.7~9.5ppm and 9.0~28.5ppm respectively. The numbers of total bacteria and nitrate reducing bacteria in four korean human saliva sample were 15~63${\times}10^8$ CFU and 1.0~6.0${\times}10^8$ CFU and the main nitrate reducing bacteria were Streptococcus uberis which was presented in large quantities and showed remarkable reductive activity. Lastly, we knowed that N-dimethylnitrosamine was formed by the reaction between dimethylamine and nitrite in the presence of St. uberis in vitro.

• 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 Veterinary Clinics
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• v.24 no.3
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• pp.305-307
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• 2007

Lactoferrin-binding proteins (LBP) has not been well characterized in Streptococcus uberis isolated from milk of bovine mastitis and to date this protein is considered to be an important virulence factor in Streptococcal mastitis. To determine the more efficient extraction method of LBP from four S. uberis strains, we used two different extraction methods (mutanolysin and sodium dodecyl sulfate) in this study. Bacterial proteins extracted were electrophoresed by 10% polyacrylamide gels in the presence of sodium deodecyl sulfate and gels were transferred onto nitrocellulose membrane. Rabbit anti-bovine lactoferrin antibody and HRP-conjugated donkey anti-rabbit IgG antibody were used to detect LBP. This Western blotting analysis demonstrates that extraction method with SDS extracted 110 kDa and 112 kDa LBPs more efficiently compared to the mutanolysin extraction method.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.334-340
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• 2010

It is well known that smoking as well as drinking is a factor of stomatopathy, however there are few investigations about comparison of oral flora between smokers and non-smokers. In this study, we isolated the oral flora of 30 smokers and 30 non-smokers and cultured them on blood agar plates. The isolated pathogenic microorganisms were tested for antibiotic susceptibility and resistance using the Kirby-Bauer antibiotic testing method. Each colony was stained using the Gram staining method and was identified by an automatic identifier, known as the VITEK system. We isolated 41 colonies from smokers' oral cavity, and they were sorted as 63% of Gram-positive cocci, 29% of Gram-negative cocci, 3% of Gram-positive bacilli, and 5% of Gram-negative bacilli by gram staining, whereas 38 colonies were isolated from non-smoters' oral cavity, and their proportions were 55% of Gram-positive cocci, 26% of Gram-negative cocci, 3% of Gram-positive bacilli, and 16% of Gram-negative bacilli. The VITEK system revealed specific distribution of bacteria species that Streptococcus mutans (6/41), Gemella morillorum (6/41), Streptococcus oralis (2/41), Streptococcus pneumoniae (1/41), Staphylococcus aureus (3/41), Streptococcus anginosus (1/41), Streptococcus intermedius (1/41), Streptococcus uberis (1/41), and Streptococcus sanguinis (1/41) in smokers oral cavity whereas Streptococcus sanguinis (8/38), Staphylococcus aureus (1/38), Staphylococcus auricularis (1/38), Streptococcus uberis (1/38), Streptococcus intermedius (1/38), Streptococcus mutans (1/38), and Streptococcus oralis (1/38) in those of non-smokers'. Three cases of Staphylococcus aureus from smokers produced Beta-lactamase and were identified methicillin-resistance Staphylococcus aureus (MRSA). However one case of Staphylococcus aureus from non-smoker did not produce Beta-lactamase and was sensitive to methicillin. In conclusion, the distribution of oral flora was different between smokers' and non-smokers' oral cavity, especially Gemella morillorum and MRSA were predominantly found in smoker's oral cavity. These results are useful in the treatment and prevention of patients with stomatopathy caused by smoking.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.71-95
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• 1995

Bacteria have been regarded as a one of major etiologic factors in root canal infections. In endodontic treatment the effective removal of pathogenic microorganisms in the root canal is the key to successful outcome. Bacterial cell wall components may play an important role in the development of pulpal and periapical disease. The purpose of this study was to evaluate the effect of sonic extracts of Streptococcus spp. on cultured L929 cells and to characterize cell wall protein profiles of Streptococcus spp. Streptococcus spp. were isolated from infected root canals and identified with Vitek Systems(Biomeriux, USA). Five streptococci, namely S. sanguis, S. mitis, S uberis, S. mutans (ATCC 10449) and S. faecalis (ATCC 19433) weere enriched in brain heart infusion broth. Cell pellets were sonicated and cell wall extracts were dialyzed and membrane filtered. Prepared cell wall proteins were applied to cultured L929 cell. The cell reaction were evaluated by monitoring DNA synthesis, cell numbers and the change of cell morphology. The total cell wall protein profiles of microorganisms were characterized by sodium dodecyl sulfate polyacrylamide-gel eledruphoresis(SDS-PAGE). DNA synthesis of L929 cells were reduced by the increasing concentration of sonic extracts. DNA synthesis was significantly suppressed in more than $50{\mu}g$/ml of sonic extract conentration in five streptococci. S. nutans (ATCC 10449) showed stronger suppression on DNA synthesis than remaining four streptococci, which had the similar effect on DNA synthesis. Analysis of DNA synthesis measured by [$^3H$]-thymidine uptake was more sensitvie method than cell counting. Sonic extracts affected the microscopic findings of L929 cells. The protein profiles indicated that all five strains shared two major proteins with molecular masses of 70.8 and 57.5 kD respectively. S. uberis and S. mutans shared common minor proteins of which molecular weights were 147.9 and 112.2 kD respectively. However some minor proteins were unique for S. mitis, S. uberis and S. faecalis.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.137-142
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• 2007

The antibacterial activity of Korean honey bee venom (KBV) was examined against seven major bacterial mastitis pathogens, Enterococcus faecium, Escherichia coli, Methicillin resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus intermedius, Streptococcus oralis and Streptococcus uberis isolated from infected mammary quarters of cows. Seven bacterial mastitis pathogens were studied for antibacterial activity of the KBV by disc diffusion assay, minimal inhibitory concentrations (MIC) and bacterial count in milk samples. The KBV showed activity against Ent. faecium, E. coli, MRSA, Staph. aureus, Strep. intermedius. The order of susceptibility of the bacteria against the KBV was Staph. aureus>MRSA>E. coli>Strep. intermedius>Ent. faecium>Strep. oralis>Strep. uberis. The MIC against Staph. aureus, MRSA and E. coli were stronger effect as compared with standard drug. The effect of the KBV ($100{\mu}g\;ml^{-1}$) on the viability of Ent. faecium, E. coli, MRSA, Staph. aureus, Strep. intermedius, Strep. oralis and Strep. uberis in milk differed significantly with each other within 12 h incubation period. The results indicate that KBV has significant antibacterial effects against major bacterial mastitis bacteria, Ent. faecium, E.coli, MRSA, Staph. aureus, Strep. intermedius. Results of the study indicate the potential use of KBV as alternative to antibiotic therapy. Further investigations are needed though to confirm its efficacy and its effects on the animals.

• Journal of fish pathology
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• v.20 no.2
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• pp.109-117
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• 2007

This study was performed to identity non hemolytic streptococcus from cultured flounder (Paralichthys olivaceus) with Streptococcosis in the Jeju island. The result of BIOLOGTM test was Streptococcus uberis that simility of 0.5 and 98% identified in MicroLogTM system (Release 4.05). Carbohydrate utility pattern was dextrin, N-acetyl-D-glucosamine, arbutin, maltose, maltotriose, D-cellobiose, D-fructose, D-mannose, α-D-glucose, D-mannitol, β-methyl D-glucoside, salicin, sucrose, D-trehalose, pruvatic acid methyl ester, mono-methyl succinate, glycerol. In addition hemolysis test for S. parauberis and were S. iniae hemolysis in BAP (Blood agar plate). Antibiotic test for S. parauberis were Ampicillin, Amoxicillin and Fluoroquinolone sensitivity. Mutiplex PCR assay were detected S. pauberis (718 bp), S. iniae (870 bp) L. garviae (1,100 bp). Dectected S. parauberis (718 bp) were result of 16S rRNA sequence identified with S. parauberis (Gene bank accession number X89967). All isolated S. parauberis that with bouned by one group. The result were S. pauberis that γ-hemolytic chain form cocci and negative reaction of catalase, Multiplex PCR assay were 718 bp amplicon size.

• 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.

• Journal of fish pathology
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• v.20 no.1
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• pp.49-60
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• 2007

Non-hemolytic Streptococcus parauberis isolated from diseased olive flounder, Paralichthys olivaceus in the South coast of Korea were identified by physiological, biochemical and genetic analysis in order to define the different characteristics geographically. First, twelve strains of S. parauberis were isolated from catalase-negative gram-positive cocci by multiplex PCR assay. Phenotypic identifications were performed with commercially available kit (API 20 Strep and API ZYM system). Analysis of API profiles of the isolates showed that strains were identified as either of Lactococcus lactis, S. constellatus or S. uberis. Moreover, S. parauberis isolated from olive flounder differed from that of turbot (X89967) to the test of not Voges-Proskauer, arginine, hippurate, alkiline phosphatase and pyrroidonyl arylamidase but β-glucuronidase. All S. parauberis isolates were sensitive to florfenicol, ampicillin, ofloxacin and vancomycin but were resistant to oxolinic acid, flumequine, nalidixic acid and sulfisoxazol. However, the 16S rDNA sequences of the isolates showed 99% similarity to S. parauberis KCTC 3651 (AY584477) and a great homogenecity among the flounder isolates.