• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.295-303
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• 2006

To provide microbial information for the safety of agricultural production, the presence of enterotoxin genes and antibiotic susceptibility of 14 isolated Staphylococcus aureus (11.7%) strains were investigated using PCR-based methods and disk diffusion method, respectively. Among enterotoxin-encoding genes, sea was detected from two isolates (14.3%), sea and sed genes were co-detected from three isolates (21.4%), and sea, sed, and see genes in seven isolates (50.0%), whereas seb, sec, and tsst were not detected in any isolate. Nine (64.3%), eight (57.1%), six (42.9%), two (14.3%), and one (7.2%) isolates were resistant to penicillin, novobiocin, amphicillin, erythromycin and oxacillin, and doxycycline and kanamycin, respectively. Methicilline-resistant S. aureus was found in roller of B farm and in hydroponic solution of D farm.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.12-19
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• 2009

The aim of this study is to assess the antibiotic activity of Actinomyces in plaque from black stained primary teeth to Streptococcus mutans. Samples were obtained from four children, 2-6 years of age, who had black stains on all erupted primary teeth. 16 different Actinomyces spp. were isolated, and antibiotic activity test with paper disc method was done. The results were as follows, 1. No.1 and No.5 Actinomyces spp. showed the antibiotic activity to Streptococcus mutans and the activity of No.5 Actinomyces spp. could compete with that of Oxacillin. 2. No.1 and No.5 Actinomyces spp. also exhibited the antibiotic activity to Bacillus cereus, Bacillus subtilis commonly used as experimental bacteria for testing antibiotic activity. 3. For identification of No.1 and No.5 spp., PCR analysis was done. No.5 spp. matched Actinomyces viscosus at 97% level but No.1 spp. didn't match.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.447-455
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• 2013

Objectives: This study aims to understand the concentration, diversity, and antibiotic characteristics of staphylococci present in the indoor air of child-care facilities. Methods: Air sampling was performed from October 2012 to January 2013 in 120 child-care facilities in Seoul, Korea. Methicillin-resistant bacteria were selected from the total obtained airborne bacteria and subjected to 16S rRNA analysis for methicillin-resistant staphylococcal species determination. Identified staphylococcal strains were tested for resistance to a range of antibiotics. Results: Average total airborne bacterial concentration was $508.9{\pm}246.3CFU/m^3$. Indoor concentration of total airborne bacteria had a significant positive correlation with the $CO_2$ concentration in the child-care facilities. Methicillin-resistant staphylococci were present in 13.3% of the child-care facilities studied. A total of four species (S. epidermidis, S. cohnii, S. saprophyticus, S. sp.) and 55 strains were identified from the indoor air of the child-care facilities. Staphylococcus cohnii was the most common species (54.5%), followed by S. epidermidis (38.2%). All of the isolated staphylococcal strains exhibited high resistance to oxacillin, erythromycin, mupirocin, and ceftizoxime. Especially, S. saprophyticus strains showed more multidrug resistance to oxacillin, vancomycin, clindamycin, erythromycin, lincomycin, ceftizoxime, mupirocin, and tetracycline than did other species. Conclusion: The results of this study showed that a monitoring system for multidrug-resistant bacteria is needed in facilities for children, as the community-associated infections of these bacteria are increasing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.220-226
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• 2014

Sixty-seven Vibrio parahaemolyticus isolates from surface seawater from the Wando area, on the southern coast of Korea, were analyzed for their susceptibility to 15 different antimicrobials and the presence of virulence genes. According to the disk diffusion susceptibility test, all of the strains studied were resistant to ampicillin and oxacillin, while decreasing percentages were resistant to vancomycin (64.2%), streptomycin (56.7%), amikacin (31.3%), kanamycin (22.3%), cephalothin (20.9%), erythromycin (10.4%), ciprofloxacin (4.5%), and tetracycline (3.0%). All of the strains were susceptible to five antimicrobials: chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. Fifty-nine isolates (88.1%) were resistant to three or more classes of antimicrobial and defined as multidrug resistant, and two strains were resistant to seven antimicrobial agents. The minimum inhibitory concentration (MIC) of the 67 V. parahaemolyticus isolates to ampicillin and oxacillin ranged from 512-2,048 and $64-512{\mu}g/mL$, respectively. All 67 isolates were also examined for the presence of the tdh and trh virulence genes using the polymerase chain reaction (PCR). However, no isolates possessed either tdh or trh. The VPA0477 (${\beta}$-lactamase) gene, present in all of the tested strains, was validated as a new specific marker gene in PCR assays for the accurate detection and identification of V. parahaemolyticus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.587-595
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• 2019

Eighty-three Vibrio parahaemolyticus isolates from surface seawater in Gomso Bay on the west coast of Korea, and commercial fisheries from Gunsan fisheries center were analyzed for the presence of virulence genes and susceptibility to 30 different antimicrobials. All 83 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction; however, neither gene was found in any of the isolates. A disk diffusion susceptibility test, showed that all of the strains studied were resistant to clindamycin, oxacillin, ticarcillin, and vancomycin, and also revealed varying levels of resistance to ampicillin (98.8%), penicillin G (95.2%), streptomycin (20.5%), cefoxitin (14.5%), amikacin (6.0%), cephalothin (4.8%), and erythromycin (3.6%). However, all of the strains were susceptible to 19 other antimicrobial agents, including cefepime, cefotaxime, chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. All 83 isolates (100%) were resistant to five or more classes of antimicrobials, and two strains exhibited resistance to ten antimicrobial agents. The average minimum inhibitory concentrations against V. parahaemolyticus of clindamycin, oxacillin, ticarcillin, and vancomycin were 55.9, 98.3, 499.3, and 44.3 ㎍/mL, respectively. These results provide new insight into the necessity for seawater sanitation in Gomso Bay and commercial fisheries, and provide evidence to help reduce the risk of contamination by antimicrobial-resistant bacteria.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.47-52
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• 2005

This study was carried out to identify bacterial strains adhered to human scalp hair and to investigate the antibiotic susceptibility of them. A total of 39 isolates were obtained from patients in intensive care units and healthy persons. The most common species isolated was Staphylococcus epidermidis (19 isolates), followed by S. aureus (14 isolates), S. waneri (5 isolates), and S. pasteuri (1 isolate). The susceptibility of isolates to amikacin, ampicillin, bacitracin, carbenicillin, cefazolin, cefoperazone, chloramphenicol, erythromycin, gentamicin, methicillin, nalidixic acid, neomycin, oxacillin, penicillin, streptomycin, tetracycline and vancomycin was determined by the disk diffusion method. All of the antibiotic resistant isolates were obtained from patient scalp hair. To examine the effect of conventional shampoo and detergent SDS on removing of bacteria from hair, we treated hair with culture solution of S. aureus. The bacteria attached to hair were not removed even by repeated washing with detergents. These results suggested that hair could be a source of bacterial contamination in hospital.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.194-200
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• 2009

Community-acquired antimicrobial resistant bacteria are an emerging problem whole world-wide. Generally, Hands are main mediator of pathogen transmission as compared with other body parts. So, the purpose of this research was to investigate the microbiological quality and antimicrobial susceptibilities of samples which were collected from the door knob and surface in public- and home-facilities, and also hand. Of total 191 samples, 71 samples (37%) were shown to be of high-level total bacterial count (>$10^8\;CFU/cm^2$). And presence of Staphylococcus and Enteric bacilli was observed in 61 samples (32%) and 76 samples (40%), respectively. Antimicrobial susceptibilities of staphylococcal isolates from the samples were tested for six different antimicrobial agents, which are in wide spread clinical use in Korea, as well as four new antimicrobials, daptomycin, linezolid, quinupristin/dalfopristin and tigecycline. Among staphylococcal isolates, antimicrobial resistance were observed in oxacillin (n=6), mupirocin (n=7), vancomycin (n=1), quinupristin/dalfopristin (n=2) and gentamicin (n=5). Fortunately, all the isolates were susceptible to new antimicrobial such as daptomycin, linezolid and tigecycline. Furthermore 4 Enterococcus faecalis were isolated from four hand samples, and all these isolates exhibited multidrug resistance to four different antimicrobial (oxacillin, quinupristin/dalfopristin, mupirocin, gentamicin). Also, 5 Escherichia coli were isolated from surface in home (n=3), door knob in public facilities (n=1) and hand (n=1). Escherichia coli isolated from hand was high-level resistant to tigecycline ($128{\mu}g$/ml) and gentamicin ($64{\mu}g$/ml).

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.21-35
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• 2018

Objectives The objective of this study is to determine the antimicrobial effect of Daehwanggyeonu-san(Dahwangqianniu-san,DGE) and synergistic effects with antibiotics oxacillin, ampicillin, and gentamicin against Methicillin-Resistant Staphylococcus aureus(MRSA). Methods The antibacterial activity of DGE extract was evaluated againest MRSA strains by using the Disc diffusion method, broth microdilution method(minimal inhibitory concentration; MIC), checkerboard dilution test. The checkerboard dilution test was used to examined synergetic effect of oxacillin, ampicillin, gentamicin, ciprofloxacin with DGE extract. Results DGE showed antimicrobial activity against MRSA with an MIC value of $125{\sim}250{\mu}g/mL$. In the checkerboard test, the interation of DGE with all tested antibiotics produced almost synergy or partial synergy against MRSA. Conclusions This study shows that DGE reduced the MICs of several antibiotics tested, and a remarkable antibacterial effect of DGE, with membrane permeability enhancers and ATP synthase inhibitors. This study can be a valuable source for the development of a new drug with low MRSA resistance.

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.81-85
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• 2011

Recently, antimicrobial resistance of microorganisms has been a major concern of its relation to food safety and national health, therefore, customer's needs to organic animal food is still increasing. In this study, we reviewed the usage of antimicrobials in animal farms and antimicrobial resistance of microorganisms isolated from organic dairy farm environments. The isolates from dairy farms were Acinetobacter sp., A. lwoffi, A. johnsonii, A. towneri, Aerococcus viridans, Aeromonas media, A. veronii, Bacillus pseudofirmus, B. pumilus, B. licheniformis, Corynebacterium glutamicum, Escherichia coli, Enterococcus faecium, Lysinibacillus fusiformis, Paenibacillus illinoisensis, Staphylococcus epidermidis, S. hominis, Streptococcus equinus, S. lutetiensis, and Saccharomyces cerevisiae. Indicator microorganisms isolated from organic dairy farms were tested for susceptibility to 20 types of antimicrobials. E. coli (ATCC 25922) isolated from dairy farm fence showed resistance to 8 types of antimicrobials, such as oxacillin, penicillin, vancomycin, etc., and E. faecium isolated from feces showed resistance to 9 types of antimicrobials, such as cephalothin, oxacillin, streptomycin, etc., respectively. However, these results showed less antimicrobial resistance compare with customary dairy farm.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.381-385
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• 2011

Methicillin-resistant Staphylococcus aureus (MRSA) is one of major pathogen causing hospital infection and several diseases such as purulent infection, bacteremia. The isolation ratio of MRSA is gradually increased up to 80% in the hospital, which makes a limitation for treatment of antibiotics because the isolated MRSA show resistance to methicillin as well as other antibiotics. This study proposes that mecA detecting methods which are not commonly used because of cost in the hospital is a more accurate method than Susceptibility Testing to detect a MRSA. We compared Staphylococcus aureus ATCC 29213 as a negative control and 20 MRSA strains isolated from patients by these two methods. We amplified mecA gene by polymerase chain reaction (PCR) and confirmed the PCR products by sequencing. All of the MRSA showed oxacillin and cefoxitin resistance whereas 85% (16/19) of the strains had mecA wildtype. These results suggest that some of the MRSA are mecA mutants therefore mecA genotyping reinforces the MRSA detection by antibiotic susceptibility test.