• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.508-513
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• 2010

Ninety three strains (4.2%) of Vibrio parahaemolyticus were isolated from 2,239 samples of commercial marine products during 2006-2008 in Seoul, Korea. We examined 16 antimicrobial susceptibilities of 93 V. parahaemolyticus isolates. Antibiotic resistance of V. parahaemolyticus was most frequently observed to ampicillin (93.5%), followed by cephalothin (90.3%), streptomycin (87.1%), ticarcillin (55.9%), and amikacin (40.9%). Antibiotic susceptibility was most frequently observed to nalidixic acid, chloramphenicol and ampicillin/sulbactam (100%), followed by trimethoprim/sulfamethoxazole (98.9%), gentamicin and tetracycline (82.8%), and ceftriaxone (63.4%). In addition, the isolates also displayed intermediate resistance to kanamycin (79.6%), ciprofloxacin (64.5%), amikacin (47.3%) and cefoxitin (43.0%). All isolates were resistant to more than two drugs. The most prominent multiple drug resistance was 3 drug resistance (37.6%), followed by 4 drug (24.7%), 5 drug (17.2%), and 6 drug resistance (11.8%). The most prominent multiple drug resistance pattern was the cephalothin-streptomycin-ampicillin resistance pattern (22.6%), followed by cephalothinticarcillin-streptomycin-ampicillin (18.3%) and cephalothin-ticarcillin-streptomycin-ampicillin-amikacin (9.7%). Multiple drug resistance patterns of V. parahaemolyticus from marine products require continuous monitoring.

• Research in Plant Disease
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• v.29 no.2
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• pp.168-173
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• 2023

Agricultural antibiotics are widely used to inhibit the growth of phytopathogenic bacteria involved in plant diseases. However, continuous antibiotic overuse in crop production may lead to the development of antibiotic resistance in phytopathogenic bacteria. This study was conducted to evaluate the resistance to three different agricultural antibiotics (oxytetracycline+streptomycin, streptomycin, and validamycin A) in 91 strains of phytopathogenic bacteria including Pectobacterium carotovorum, Pseudomonas syringae pv. actinidiae, Clavibacter michiganensis subsp. michiganensis, C. michiganensis subsp. capsici, and Xanthomonas arboricola pv. pruni. Bacterial growth in the presence of various concentrations of validamycin A was also assessed spectrophotometrically by analyzing the optical density. All strains did not grow when the cells were exposed to oxytetracycline+streptomycin or 100× of streptomycin. However, among the 91 strains, 4% and 2% strains showed bacterial growth at the concentrations of 1× and 10× of streptomycin, respectively. Furthermore, 97%, 93%, and 73% strains were resistant to the 1×, 10×, and 100× of validamycin A, respectively, and especially, P. carotovorum contained the highest resistance to the validamycin A. Minimum bactericidal concentration values of validamycin A did not correlate with the patterns of agricultural antibiotic resistance. Further studies are needed to understand the incidence and development of antibiotic resistance in phytopathogenic bacteria.

• Journal of Life Science
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• v.10 no.3
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• pp.262-272
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• 2000

As a part of investigation for basic epidemiology of diarrheogenic disease, we attempted isolation of Escherichia coli from patients with diarrhea. Seven hundred and twenty-one strains of E. coli were isolated from 1,239 patients with diarrhea. Seasonal distribution of patient with diarrhea was shown the most high at August (18.2%). Age group distribution of patient was shown the most high at children (54.6%, 2 to 10 years old). The serotypes of 721 E. coli isolates were in order of serotype O44 (16.8%), O153 (8.6%), O1 (7.5%), O166(5.7%), O8 and O86a (4.7%), and O125 (4.6%). The supernates cultured 36 strains among 721 E. coli isolates were indicated cytotoxicity against monolayered Vero cells. All of the isolates were susceptible to amikacin. The isolates were resistant in order of novobiocin (99.0%), moxalactam (97.1%), carbenicillin (96.1%), tetracycline (90.4%), ampicillin (85.9%), gentamicin (84.0%), streptomycin (78.4%), cephalothin (46.6%) and polymyxin B (4.2%). In the antibiotic resistant patterns, 125 kinds of multiple resistance patterns of E. coli isolates were detected. The highest resistant pattern was ampicillin-carbenicillin-chloramphenicol-cephalothin-erythro-mycin- gentamicin-moxalactam-novobiocin-penicillin G-streptomycin-tobramycin-tetracycline-tri methoprim type (24.3%).

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.393-405
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• 1989

This study was carried out to treatment test for bovine mastitis by the determination of adenosine triphosphate (ATP) based on firefly bioluminescence. The results obtained are followed; 1. In the susceptibility test, cephalothin which looks the most effective were sensitive to Staphylococcus sp. (72.3%), Micrococcus sp. (84.2%), Streptococcus sp. (72.7%) and Gram positive bacilli (72.7%), Gram negative bacilli were sensitive to gentamicin (92.3%) and Yeast-like-fungi was the most sensitive to clotrimazole, and nystatin in order. 2. When the number of bacteria, such as Staphylococcus aureus, Candida tropicalis isolated from the mastitis milk were counted by conventional agar plating technique, and compared with the concentration of bacterial ATP, it gave a good linear relationship. The content of ATP per Staphylococcus aureus, cell was 3.1fM and Candida tropicalis showed the high level of A TP (90fM). 3. The ATP assay was applied to the determination of minimal inhibitory concentration (MIC) of various antibiotics. When Staphylococcus aureus was incubated in the presence of different concentration of tetracycline, erythromycin, kanamycin and streptomycin sulfate and the growth was monitored by the conventional agar plating technique and ATP assay, both methods shown the same results that they were 1mcg/ml, 2mcg/ml, 6.25mcg/ml and 8mcg/ml, respectively. 4. For the determination of susceptibility of sensitive and resistant Staphylococcus au reus isolated for the milk with mastitis to tetracycline, erythromycin kanamycin and streptomycin sulfate, the minimum time required for the test was determined by the assay of ATP every 30 minutes during incubation of 3 hours at $37^{\circ}C$. ATP concentration time curve calculated on both resistant and sensitive strains incubated 3 hours as the optimum time for the determination of susceptibilities of various antibiotics exemed. The ATP concentration of each test broth (antibiotic containing), expressed as a percentage of its own control brith (antibioticfree) indicated values of 30% to be indicative of each antibiotic sensitivity. Single time point ATP assay carried out on the various sensitive and resistant of Staphylococcus aureus to antibiotics examined after 3 hours at $37^{\circ}C$ correlated exactly with disc diffusion and MIC. 5. In the cure of intramammary treatment of bovine mastitis in lactating quarters, the cure rate of Staphylococcal mastitis showed to cephalexin (80%), cloxacillin and gentamicin (70%), ampicillin and oxytetracycline (60%), and Streptococcal mastitis showed to cephalexin (85%), penicillin (80%), cloxacillin and oxytetracycline (75%), and ampicillin (70%), but intramammary antimycotic drug (clotrimazol) were only a little effect about fungal mastitis.

• Korean Journal of Veterinary Service
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• v.23 no.1
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• pp.45-59
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• 2000

The present study was conducted to investigate the epidemiological properties of salmonellosis of poultry farms in Kyongbuk province during the relied from November 1998 to November 1999 And antibiotic susceptibility and biochemical characteristics of 120 Salmonella cultures isolated from chicken samples were also investigated. The results obtained through this study were summarized as follows, 1. Among 667,200 chickens of 31 flocks in 17 layer farms and 9 broiler farms, 61,350 chickens of 31 flocks were died with salmonellosis. The death rate of 25 farms varied from 0.1% to 75.0%, and the average death rate was 9.2%. 2. According to etiological agents, fowl typhoid was shown the most predominant outbreak among the salmonellosis during a year, which accounted for 8R.0%(22/25) of the total case 3. The serotypes of 120 Salmonella isolates were identified as 7 strains(5.8%) of S pullorum, 10 strains(8.4%) of S typhimurium and 103 strains(85.8%) of S gallinarum. 4. Most outbreak of fowl typhoid were prevalent on the layer chicken farms(77.1%), and the summer season(45.5%) also appeared the most hazardous season during the year. 5. It seemed that the Hyline breed(70.6%) was the most susceptible among the layer chicken breeds, and followed by Isabrown(23.5%), Tetra(5.9%) in order. 6. In layers, 76.4% of fowl typhoid occurred commonly from 14 to 40 weeks including the early laying peroid, but in broiler farms, all cases was outbreak within first second weeks. 7 All the strains of S pullorum were resistant to lincomycin(Lm), penicillin(Pm), and steptomycin(Sm), but sensitive to amikacin(Ak), ampicillin(Am), cephalothin(Ce), ciprofloxacin (CiP), chloramphenicol(Cm), colistin(Co), enrofloxacin(Enr), furazolidone(Fu), gentamicin(Gm), kanamycin(Km), neomycin(Nm), polymyxin(Po), and teracycline(Tc). All the strains of S typhimurium were resistant to Lm(100%), Pm(100%), Po(90%), and Sm(90%), but were sensitive to Ak, Am, Ce, CiP, Cm, Co, Enr, Fu, Gm, Km, Nm, and Tc. 8. Minimum inhibitory concentration(MIC) of 103 strains of S gallinarum were also evaluated and their patterns were much more variable than others. All the strains of S gallinarum were sensitive to Ak, Am, Ce, Cip, Cm, Enr, Fu, Km, and Nm, but resistant to Lm(100%), and Sm(100%), 99(96.1%) to Co, 83(80.6%) to Pm, and 83(80.6%) to Po, 55(53.4%) to Gm, and 33(32.0%) to Tc. 9. The multiple drug resistance patterns of 120 Salmonella strains were CoLmPmPo Sm pattern(34.2%), CoGmLmPmPoSmTc(20.8%), CoGmLmPmPoSm(13.3%), CoGmLmSm(7.5%), LmPmSm(7.5%), LmPm(6.7%), CoLmSmTc(3.3%),, CoGmLmSmTc(1.7%), GmLmSmTc(1.7%), CoGmLmPoSm(0.1%), LmPmPo(0.1%), CoLm Sm(0.1%), and LmSm(0.1%), in order.

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.48-55
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• 2010

Purpose : Staphylococcal scalded skin syndrome (SSSS) is a relatively uncommon superficial blistering skin disease that is due to Staphylococcus aureus. We had experienced a regional outbreak of SSSS over 3 years in healthy children. Methods : We retrospectively reviewed the medical records of those patients diagnosed as SSSS. Most of neonatal cases were nosocomial infections and excluded from the analysis. The clinical features, laboratory findings, the isolation and antibiotic resistance of S. aureus, the antibiotic management and other supportive treatments were analyzed. Results : Fifty-five patients with SSSS were admitted to our hospital from October 2001 to September 2004. The median age of patients was 3.0 years. Of the 55 patients, 9 were the generalized type, 13 were the intermediate type and 33 were the scarletiniform rash. All the patients were living in neighborhood of the Jinju area. S. aureus were isolated from 9 of the patients and all of the isolated S. aureus were methicillin resistant. All the patients except two were treated with intravenous flocloxacillin or nafcillin and/or cefotaxime. All the patients recovered during the follow-up period of 2 to 3 weeks. Conclusion : We experienced a regional outbreak of SSSS in previous healthy children. Further study for finding the carriers of S. aureus caused SSSS and preventing the spread of this disease is needed. Additionally, guidelines for treating SSSS due to methicillin resistant S. aureus should be established.

• Journal of Life Science
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• v.8 no.1
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• pp.40-50
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• 1998

Staphylococuus aureus and Escherichia coli is increasingly responsible for outbreaks of nosocomial infection around the world. Because serious infections due to these organisms currently necessiate use of non-$\beta$-lactam antimicrobial therapy and because strains is ofen resistant to many antimicrobial agents, infections with this organism are difficult to treat. Isolated strains from post operaton wounds of PNU hospital patient were tested for the antimicrobial susceptibility, resistant pattern and combined action to the 6 antibiotics. The minimal inhibitory concentraction of each antibiotic anc antibiotics combining in various ratios were measured by checkerboard dilution method. the synergism was determined through calculating the fractional inhibitory concentraction index (FICI). In case of S. aureus, 15 strains was shown to be highly sensitive to streptomycin and 13 strains to cephalothin. In case of E. coli, it is excellent senstitive 16 strains, sensitive 4 strains on cefoperazone, as like S. aureus, and thus the sensitive is most to be 66%. As the result of gaining MIC from S. aureus upon agar dilution method, MIC$_{50}$ was 8$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml and thus the streptomycine is shown to be lowest. In case of E, coli, S. MIC$_{50}$ was 4$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml, in streptomycin and thus is shown to be lower than S. aureus. As the result of comparing the resistance aspect of combining the antibiotics on S. aureus and E. coli, the resistant strain can be known to be reduced to the large range more than each 40% than combining with only aminoglycoside-series or cephalosporine-series. As the result of combining aminoglycoside-series, streptomycin and cephalothin or cefuroxime sensitive to S. aureus and E. coli in the above mentioned results, the increase or imporovement of effect is over 73% and 80%, respectively, thus the case od combining 2 antibiotics is shown to be better in the effect. Isolated strains from operating wounds were for the antimicrobial susceptibility. In case of S. aureus 15 strains was shown to be sensitive very much on streptomycin. In case of E. coli it is excellent sensitive 16 strains. As the results of combining aminoglycosides-series, streptomycin and cephalosporine series, cephalothin and cefuroxime, the increase or improvement of effect is over 73%, thus case of combining 2 antibiotics is shown to be better in the effect.

• Journal of Life Science
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• v.21 no.4
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• pp.589-595
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• 2011

This work focused on screening and characterizing antibiotic-producing actinomycetes to develop new antibiotics that can overcome the growing resistance of disease-causing microbes. One-hundred actinomycetes strains were isolated from soil samples from Chungcheongbuk-do, Korea using various kinds of actinomycetes isolation media, including a starch casein agar medium and potato dextrose agar (PDA). Among them, strain BCNU 1030 was determined to show strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Biochemical, physiological, and 16S rRNA sequence analyses indicated that strain BCNU 1030 belonged to the genus Streptomyces. Strain BCNU 1030 exhibited antibiotic activity against a wide range of bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentration (MIC) of BCNU 1030 dichloromethane extract was determined to be $0.78\;{\mu}g/ml$ for MRSA CCARM 3090. Therefore, Streptomyces sp. BCNU 1030 has potential for anti-MRSA drug development.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.927-932
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• 1994

A total of 34 Salmonella sp. an d25 Shigella sp. were isolated from 311 patients with diarrhea. The isolation rates of Salmonella sp. ad Shigella sp. were 10.9% and 8%, respectively. The serogroups of 34 Salmonella sp. were in order of group D(50%), group B(38.25), group E(8.8%) and group C 92, 9%0. the serogroups of 25 Shigella sp. were group D(96%) and group B(4%). Seasonal distribution of isolated Salmonella sp. and Shigella sp. were shown the most high at July, 17.65% and 64%, respectively. Age group distribution of isolated Salmonella sp. and Shigella sp. were shown the most high at twenties and thirties (23.5%), and teens(76%), respectively. The Salmonella isolates were resistant in order of prevalence use of streptomycin(SM) (100%), erythromycin (EM) and movobiocin (NB)(90.6%), penicillin G(PG) (65.6%) and cephalexin (CPX)(46.9%). the isolates of Shigella sp. were resistant in order of prevalence use of EM (95.8%), NB(91.7%), SM(87.5%). Eighteen kinds of resistant patterns of Salmonella ioslates were detected. The multiple resistance patterns of Shigella isolates were mostly SM, EM, NB type (79.2%). The minimum inhibitory concentration of Salmonella sp. and Shigella sp. and Shigella sp. isolated from patients with diarrhea were tabulated.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.396-400
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• 2015

Enterobacteriaceae is one of the major families responsible for public health threats. Due to the emergence of pathogens with antibiotic resistance, great concern has been raised regarding the prevalence of antibiotic resistant bacteria in natural environments. Therefore, the diversity of Gram negative Enterobacteriaceae was investigated in water samples collected from five streams in Korea using the cultivation method. Profiling of multi-drug resistance was conducted with isolates via disk diffusion assay. The results indicated that the Gram negative Enterobacteriaceae consisted of the following genus; Citrobacter, Enterobacter, Escherichia, Klebsiella, Kluyvera, Pantoea, Plesiomonas, Raoultella, Shigella and Enterobacter. These latter strains represented 49% of identified isolates. In addition, 78.3% of the identified genus exhibited resistance against more than seven out of thirteen tested antibiotics, suggesting a high prevalence of multi-drug resistant bacteria in natural environments.