• Journal of Environmental Health Sciences
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• v.19 no.1
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• pp.71-76
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• 1993

Nasal carrige of Staphylococcus was studied in relation to its significance as a source of the Staphylococci that caused hospital-acquired infection. Due to the trend of the increasing r esistance of S. aureus to many antimicrobial agents, it is necessary to study the sensitivity to antibiotics of this infectious microorganisms. 50 persons from general hospital and 50 college students were the object of this study. The following results were obtained 3 0 Strains of S. aureus were isolated. The rate of S. aureus nasal carrying were 26% in college students and 34% in hospital personnel. S. aureus which showed resistance to penicillin were 90%, tetracyclin 43%, erythromycin 37% and oxacillin 17%. The number of penicillin resistance of S. aureus were 11 (84%) in college students and 16 (94%) in hospital personnel. The number of strains of penicillin resistant S. aureus which produced 13-1actamase were 9 (82%) in college student and 14 (88%) in hospital personnel. Methicillin-resistant S. aureus (MRSA) which showed resistance to erythromycin and penicillin G were 100%, tetracyline, cephalothin and clindamycin were over 40% respectively, gentamicin 20%, SAM 20% and chloramphenicol 0%.

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.300-316
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• 1998

The various oriental herbal medicines, which have usually been used for treatment of reducing fever, purging intense heat and detoxication, were screened to determine the antibacterial activity and the minimal inhibitory concentration against antibiotics-resistant Staphylococcus aureus. The results obtained were as follows: 1. Among the 23 oriental medicines tested, the water-soluble extract of Coptis japonica showed very excellent antibacterial activity against antibiotics-sensitive and -resistant S. aureus. A little activity was found in the extracts of Scutellaria baicalensis, Eriobotrya japonica and Prunus mume against antibiotics-sensitive S. aureus and in that extracts of P. mume, Schizandra chinensis and S. baicalensis against antibiotics-resistant S. aureus. When C japonica was used, the high antibacterial activity was shown against Bacillus subtilis and other extracts showed a little or no antibacterial activity against B. subtilis and E. coli as a control. 2. The highest antibacterial activities against antibiotics-resistant S. aureus were found in the ethanol-soluble extract of C japonica. Other ethanol-soluble extracts of S, baicalensis, S. chinensis and P. mume showed a little activity against both antibiotics-sensitive and antibiotics-resistant S. aureus. 3. Among the medicinal herbs tested, the water- and ethanol extracts of C. japonica showed very excellent antibacterial activity against the pathogenic S. aureus and both Escherichia coli and Bacillus subtilis used as a control. 4. When the water-soluble extracts of C. japonica and S. baicalensis, minimal inhibitory concentrations (MICs) against antibiotics-sensitive S. aureus were $20mg/m{\ell}\;and\;30mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of C. japonica and P. scabriosaefolia were $7.5mg/m{\ell}\;and\;12mg/m{\ell}$, respectively. 5. For the MICs against antibiotics-resistant S. aureus, the water-soluble extracts of C. japonica and P. mume showed $15mg/m{\ell}\;and\;10mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of C. japonica and P. mume were $13mg/m{\ell}\;and\;20mg/m{\ell}$, respectively. As a result, the highest antibacterial activity was found in both water- and ethanol-soluble extracts of C. japonica against antibiotics-resistant S. aureus. And the water- and ethanol-soluble extracts of S. baicalensis, S. chinensis and P. mume showed comparatively high antibacterial activities against both antibiotics-sensitive and -resistant S. aureus.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.146-150
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• 2017

Staphylococcus aureus is a pathogenic bacterium that causes food poisoning, exhibits a strong capacity to form biofilm, and is highly resistant to antimicrobial agents. The purpose of this study was to investigate the antimicrobial characteristics of corosolic acid against S. aureus. S. aureus showed high susceptibility to corosolic acid in a concentration-dependent manner. The minimum inhibitory concentration and colony-forming ability determined by the broth microdilution method showed that corosolic acid had strong antimicrobial activity against the bacteria. The diameters of the inhibition zone and numbers of colony forming units at each concentration of corosolic acid were also measured. In addition, corosolic acid displayed potent biofilm inhibition activity against S. aureus at concentrations below its minimum inhibitory concentration. These results suggest that corosolic acid can be used to effectively prevent biofilm formation by S. aureus, thereby making S. aureus more susceptible to the action of antimicrobials.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.788-797
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• 2001

The usefulness of three PCR methods were evaluated for the epidemiological typing of Staphylococcus aureus: an enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), repetitive extragenic palindromic element PCR (REP-PCR), and 16S-23S intergenic spacer PCR (ITS-PCR). The analysis was performed using a collection of S. aureus strains comprised of 6 reference and 79 isolates from patients with various diseases. Among the 85 S. aureus strains tested, 6 references and 6 isolates were found to be susceptible to methicillin, whereas the remaining 73 isolates were resistant to it. PCR methods are of special concern, as conventional phenotypic methods are unable to clearly distinguish among methicillin-resistant S. aureus (MRSA) strains. The ability of the techniques to detect different unrelated types was found to be as follows: ERIC-PCR, 19 types; REP-PCR, 36 types; and ITS-PCR, 14 types. On the basis of combining the ERIC, REP, and ITS fingerprints, the 85 S. aureus strains were grouped into 56 genetic types (designated G1 to G56). The diversities for the 85 S. aureus strains, calculated according to Simpson\`s index, were 0.88 for an ERIC-PCR, 0.93 for a REP-PCR, and 0.48 for an ITS-PCR, and the diversity increased up to 0.97 when an ERIC-PCR and REP-PCR were combined. The above discrimination indices imply that the genetic heterogeneity of S. aureus strains is high. Accordingly, this study demonstrates that DNA sequences from highly conserved repeats of a genome, particularly a combination of ERIC sequences and REP elements, are a convenient and accurate tool for the subspecies-specific discrimination and epidemiologic tracking of S. aureus.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.19-25
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• 1999

A total of 137 strains of Staphylococcus aureus were isolated from dairy cow's milk with subclinical mastitis from 33 herds in 5 provinces and 36 strains of S aureus from clinical mastitis from 4 herds where the mastitis were severe problem. Arbitrary primed polymerase chain reactions with 10 bp oligonucleotide primer were performed and the PCR products were analysed with image analyzer, The S aureus strains were genotyped into 20 distinct DNA fingerprinting profiles. The size of PCR products ranged from 163 to 2,479 bp and PCR products of 506, 770, 784 and 2,479 bp were the most prevailing bands. Genotype 3 was founded in all 5 provinces. The various genotypes were identified in newly founded dairy herds, however, only one or two genotypes were identified in the closed herds. In clinical mastitis, only a limited number of different S aureus genotype was founded in each of the herds in comparision with subclinical mastitis. The results demonstrated that PCR-based DNA fingerprinting analysis of S aureus strain can be used to study epidemiology of mastitis, in addition, common genotype in geographic region can be useful for the development of an effective S aureus bacterin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1163-1166
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• 2002

Antimicrobial activity of silver ion was tested against 3 kinds of food-borne microorganisms-Salmonella typhimurium, Staphylococcus aureus and Vibrio parahaemolyticus-using paper disk and broth medium methods. In paper disk method, silver ion showed antimicrobial activity against S. typhimurium and V. parahaemolyticus at the concentration above 2 ppm and 10 ppm, respectively, where as it was not detected in S. aureus with 20 ppm of silver ion concentration. In broth medium, the growth of S. typhimurium and V. Porahaemolyticus could be retarded at 0.3 ppm and 0.5 ppm of silver ion concentration respectively. In the presence of 1.0 ppm of silver ion, the growth of S. typhimurium was inhibited completely. In S. aureus, the growth was retarded at 5 ppm and was inhibited at l5 ppm completely.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.195-200
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• 2007

Objective : This experimental study was performed to investigate the effect of Jinpi-san on Staphylococcus aureus(S. aureus) and Staphylococcus epidermidis(S. epidermidis) that induce keratitis. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$ according to density Jinpi-san(100%, 10%, 1%, 0.1 %). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on S. aureus in Jinpi-san was $40{\mu}l$ undiluted solution. 2. MIC on S. epidermidis in Jinpi-san was $20{\mu}l$ undiluted solution. Conclusions : These results indicate that Jinpi-san can be used to cure S. aureus, S. epidermidis that induce eye disease(keratitis). If further study is performed, the use of eye drops will be valuable and beneficial in the clinical medicines.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.263-269
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• 2016

Temperate phages have been suggested to carry virulence factors and other lysogenic conversion genes that play important roles in pathogenicity. In this study, phage TEM123 in wild-type Staphylococcus aureus from food sources was analyzed with respect to its morphology, genome sequence, and antibiotic resistance conversion ability. Phage TEM123 from a mitomycin C-induced lysate of S. aureus was isolated from foods. Morphological analysis under a transmission electron microscope revealed that it belonged to the family Siphoviridae. The genome of phage TEM123 consisted of a double-stranded DNA of 43,786 bp with a G+C content of 34.06%. A bioinformatics analysis of the phage genome identified 43 putative open reading frames (ORFs). ORF1 encoded a protein that was nearly identical to the metallo-β-lactamase enzymes that degrade β-lactam antibiotics. After transduction to S. aureus with phage TEM123, the metallo-β-lactamase gene was confirmed in the transductant by PCR and sequencing analyses. In a β-lactam antibiotic susceptibility test, the transductant was more highly resistant to β-lactam antibiotics than S. aureus S133. Phage TEM123 might play a role in the transfer of β-lactam antibiotic resistance determinants in S. aureus. Therefore, we suggest that the prophage of S. aureus with its exotoxin is a risk factor for food safety in the food chain through lateral gene transfer.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1284-1291
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• 2022

The rise of methicillin-resistant Staphylococcus aureus (MRSA) has resulted in significant morbidity and mortality, and clinical treatment of MRSA infections has become extremely difficult. Sortase A (SrtA), a virulence determinant that anchors numerous virulence-related proteins to the cell wall, is a prime druggable target against S. aureus infection due to its crucial role in the pathogenicity of S. aureus. Here, we demonstrate that isovitexin, an active ingredient derived from a variety of traditional Chinese medicines, can reversibly inhibit SrtA activity in vitrowith a low dose (IC₅₀=24.72 ㎍/ml). Fluorescence quenching and molecular simulations proved the interaction between isovitexin and SrtA. Subsequent point mutation experiments further confirmed that the critical amino acid positions for SrtA binding to isovitexin were Ala-92, Ile-182, and Trp-197. In addition, isovitexin treatment dramatically reduced S. aureus invasion of A549 cells. This study shows that treatment with isovitexin could alleviate pathological injury and prolong the life span of mice in an S. aureus pneumonia model. According to our research, isovitexin represents a promising lead molecule for the creation of anti-S. aureus medicines or adjuncts.

• Biomedical Science Letters
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• v.11 no.3
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• pp.295-299
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• 2005

Staphylococcus aureus is an important animal and human pathogen implicated in a variety of disease including food-poisoning caused by staphyloccal enterotoxins (SEs). In order to investigate the difference in genomic types and to monitor the transmission of S. aureus isolates, a total of 25 S. aureus isolates from different sources were determined for their genotypic characteristics by pulsed-field gel electrophoresis (PFGE) in addition to their ability to enterotoxin production and antibiotic resistance patterns in this study. All the isolates were susceptible to amikacin, and the resistance pattern to ampicillin and penicillin were most common among 14 different patterns. Eleven of 24 isolates produced one of three SEs, SEA, SEC or SED. Sixteen representative PFGE patterns were obtained by Smal restriction fragments of S. aureus isolates. Analysis of dendrogram based on PFGE band patterns suggested that food-poisoning outbreaks be caused by the diverse sources of food, of which their raw materials were infected with S. aureus. Also, it could be concluded that PFGE was a powerful tool for epidemiological tracing of infection source for food-initiated outbreaks.