• Pediatric Infection and Vaccine
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• v.26 no.1
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• pp.1-10
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• 2019

Purpose: We investigated the distribution and antimicrobial resistance of pneumococcal isolates from hospitalized children at Asan Medical Center for recent 4 years, and aimed to recommend proper choice of empirical antibiotics for pneumococcal infection. Methods: From March 2014 to May 2018, children admitted to Asan Medical Center Childrens' Hospital with pneumococcal infection were subjected for evaluation of minimal inhibitory concentration (MIC) for ${\beta}-lactams$ and macrolide antibiotics. Patient's age, underlying disease, gender were retrospectively collected. Using Monte Carlo simulation model and MIC from our study, we predicted the rate of treatment success with amoxicillin treatment. Results: Sixty-three isolates were analyzed including 20.6% (n=13) of invasive isolates, and 79.4% (n=50) of non-invasive isolates; median age were 3.3 years old, and 87.3% of the pneumococcal infections occurred to children with underlying disease. Overall susceptibility rate was 49.2%, 68.2%, and 74.6% for amoxicillin, parenteral penicillin, and cefotaxime respectively. 23.8% and 9.5% of the isolates showed high resistance for amoxicillin, and cefotaxime. Only 4.8% (n=3) were susceptible to erythromycin. Monte Carlo simulation model revealed the likelihood of treatment success was 46.0% at the dosage of 90 mg/kg/day of amoxicillin. Conclusions: Recent pneumococcal isolates from pediatric patients with underlying disease revealed high resistance for amoxicillin and cefotaxime, and high resistance for erythromycin. Prudent choice of antibiotics based on the local data of resistance cannot be emphasized enough, especially in high risk patients with underlying disease, and timely vaccination should be implemented for prevention of the spread of resistant strains.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.114-118
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• 2014

A total of 122 ESBL-producing intestinal bacteria were collected from regional hospitals in the Chungcheong area. Combination disk test (CDT) was performed for antimaicrobial susceptability using cefotaxime and cefotaxime/clavulanate according to Clinical Laboratory Standard Institute (CLSI). Mutiplex PCR using specific primers was performed for a detection of ESBL-genotypes and enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out for the tracking of molecular epidemiology. In the confirmation test using CDT, 73 out of 76 (96.1%) ESBL-producing Escherichia coli and 43 out of 46 (93.4%) ESBL-producing Klebsiella pnemoniae were positive. In the multiplex PCR, 60.5% of E. coil were positive for CTX-M-2 type gene and 56.5% of K. pneumoniae were positive for VEB -1 type gene. In the ERIC-PCR, E. coil isolates formed 5 clusters and K. pneumoniae isolates were grouped into 4 clusters depending on region. Genotypes of clinical isolates are useful for detection and differentiation of ESBL producing intestinal bacteria. The ERIC-PCR method is thought to be helpful for establishing a regional surveillance system for infection due to its formation of different clusters depending on region.

• Pediatric Infection and Vaccine
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• v.26 no.2
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• pp.112-117
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• 2019

Eikenella corrodens rarely causes invasive head and neck infections in immunocompetent children. We report a case of epidural abscess caused by E. corrodens in a previously healthy 13-year-old boy who presented with fever, headache, and vomiting. On physical examination upon admission, there was no neck stiffness, but discharge from the right ear was observed. Brain magnetic resonance imaging (MRI) revealed approximately 4.5-cm-sized epidural empyema on the right temporal lobe as well as bilateral ethmoid and sphenoid sinusitis, right mastoiditis, and right otitis media. During treatment with vancomycin and cefotaxime, purulent ear discharge aggravated, and on follow-up brain MRI, the empyema size increased to $5.6{\times}3.4cm$ with interval development of an abscess at the right sphenoid sinus. Burr hole trephination was performed, and foul-smelling pus was aspirated from the epidural abscess near the right temporal lobe. Pus culture yielded E. corrodens. Endoscopic sphenoidotomy was also performed with massive pus drainage, and the same organism was grown. The patient was treated with intravenous cefotaxime for 3 weeks and recovered well with no other complications. Therefore, E. corrodens can cause serious complications in children with untreated sinusitis.

• Journal of Plant Biotechnology
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• v.2 no.1
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• pp.35-41
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• 2000

Transgenic cabbage (Brassica oleracea ssp. capitata) plants resistant to the commercial herbicide Bast $a^{R}$ were obtained by Agrobacterium tumefaciens - mediated transformation. Hypocotyl segments of in vitro grown plants were infected with Agrobacterium tumefaciens LBA 4404 harboring plasmid pMOG6-Bar which contains hpt and bar genes. Explants were cultured on callus induction medium (MS basal medium + 1 mg/L NAA + 2 mg/L BA + 2 mg/L AgN $O_3$+ 100 mg/L carbenicillin + 250 mg/L cefotaxime) supplemented with 15 mg/L hygromycin. Hygromycin resistant calluses were transferred to shoot regeneration medium (MS basal medium + 0.1 mg/L NAA + 2 mg/L BA + 3% sucrose + 2 mg/L AgN $O_3$+ 15 mg/L hygromycin + 250 mg/L cefotaxime + 100 mg/L carbenicillin). In order to induce roots, elongated shoots were placed on the MS medium without plant growth regulators and hygromycin. Southern blot analysis of several putative transgenic plants indicated that one to five intact copies of Apt and bar genes were incorporated into the genome. Expression of bar gene was confirmed by Northern blot analysis and by herbicide resistant phenotype. Seed progeny from self-pollinated transformants expressed the herbicide resistance and showed Mendelian segregation of the introduced gene.e.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.568-584
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• 1994

Bacteria have been regarded as major etiolgic factors in root canal infections. Infected root canal flora from thirteen patients who had visited to conservative department of Wonkwang dental hospital were cultured on blood agar plates. Cultued microorganisms were isolated and identified with Gram stain and biochemical tests using Vitek Systems(BioMeriux, MO, USA); Antibiotic susceptibillity was performed with disk diffusion and broth microdilution using Vitek Systems. Gram positive cocci(65 %) were predominant, which were composed of 6 Streptococcus viridans group, 5 Staph. spp., and 4 Enterococcus faecium, in the isolatd 23 strains. Gram negative rods (26 %) were the next common bacteria, which were composed of 5 non - fermentative Gram negative rods, and 1 Enterobacter cloacae. Most strains of S. viridans group and E. faecium were susceptible to antibiotics including penicillin. But strains of Staphylococcus spp. and non - fermentative Gram negative rods showed marked resistance to antibiotics except tetrancyclin and cefotaxime. Most results between disk diffusion and microdilution were all agreed, but the results of non - fermentative Gram negative rods were susceptible to cefotaxime in disk diffusion method but resistant in microdilution.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.366-372
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• 2009

This study was conducted to develop new lines expressing the characteristic of early flowering by introducing MdMADS2 gene in chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) ‘Zinba'. Transformation of chrysanthemum was conducted by Agrobacterium tumefaciens LBA4404 harboring the binary vector containing MdMADS2 controlled by double CaMV 35S promoters. Ninety three shoots were regenerated from 1,463 leaf segment explants cultured on the first selection medium (MS basal salts + 1.0 mg/L BA + 0.5 mg/L IAA + 10 mg/L kanamycin + 400 mg/L cefotaxime, pH 5.8) after co-cultivation, and 20 out of the 93 shoots rooted on the second selection medium containing 20 mg/L kanamycin and 400 mg/L cefotaxime. Many escapes (98.6%) were removed on the selection stage for rooting. Nineteen lines were confirmed as transgenic plant with transgene by PCR analysis. Six transgenic plants flowered 2-11 days earlier than non-transgenic plant without big change of phenotype, and especially, 3 (Mo-7, Mo-11, Mo-17) out of 6 transgenic lines showed a significant reduction in days to flowering compared to non-transgenic plant. Introduction and expression of MdMADS2 gene in them were confirmed by Southern and real-time PCR analyses, respectively.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.1
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• pp.6-17
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• 2008

From the total 116,429 clinical specimens submitted to "C" hospital from January 2005 to December 2006, 2,195 strains of streptococci were isolated. Twenty four species of Streptococcus were identified with 0.1~19.8% isolation frequencies, of which S. pneumoniae was 19.8%, S. agalactiae 16.2%, S. anginosus 9.8%, S. constellatus 5.0%, S. oralis 3.9%, S. mitis 3.3%, S. pyogenes 2.7%, S. salivarius subsp. salivarius 2.2%, S. sanguinis 1.9%. For S. pneumoniae, clinical specimens showing over 9.0% isolation rate were 82.8% in sputum, 9.2% in blood, and for Streptococcus species other than S. pneumoniae, 18.0% in sputum, 16.0% in urine and 9.7% in blood. The antimicrobial agents that showed over 90.0% susceptibility were cefotaxime, gatilfloxacin, imipenem, levofloxacin, linezolid, moxifloxacin, rifampin and sporfloxacin in S. pneumoniae, ampicillin, cefotaxime, cetriaxone, levofloxacin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin in S. agalactiae, chloramphenicol, clindamycin, levofloxacin and vancomycin in S. anginosus, levofloxacin, vancomycin in S. constellatus subsp. constellatus, vancomycin in S. oralis, vancomycin in S. mitis, chloramphenicol, clindamycin, levofloxacin, quinupristin/dalfopristin and vancomycin in S. pyogenes, chloramphenicol, levofloxacin and vancomycin in S. salivarius subsp. salivarius, chloramphenicol, levofloxacin and vancomycin in S. bovis II, chloramphenicol, levofloxacin, quinupristin/dalfopristin and vancomycin in S. dysgalactiae subsp. dysgalactiae, levofloxacin, chloramphenicol and vancomycin in the whole group of 10 Streptococcus spp. other than Streptococcus pneumoniae.

• Journal of Life Science
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• v.11 no.3
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• pp.266-272
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• 2001

A total of 79 Salmonella spp. were isolated from Pusan area in 2000. The serotypes of 79 Salmonella isolates were classified as 42 strains of S. typhi(53.1%), 24 strains of S. enteritidis(30.4%), 9 strains of S. montevideo(11.4%), 2 strains of S. typhimurium(2.5%), 1 strain of S. infantis(1.3%) and 1 strain of S. indiana(1.3%) strains(16.5%) of Salmonella sp. were isolated at May July, respectively. The isolates of S. typhi were sensitive to most sntibiotics except streptomycin. All isolates of S. typhi were especially sensitive to tobramycin, gentamicin, colistin, kanamycin, samikacin, sulfamethozazole/ trimethoprim, cefriaxone, ceftazdime, cifrofloxacin, cefoxitin and cefotaxime. Isolates of S. enteritidis wer presented higher resistance than isolates of S. typhi. Twenty-four strains of S. enteritidis were sensitive to kanamycin, amikacin cifrofloxacin, cefoxitin and cefotaxime, however 13 strains(54.2%) of S. enteritidis were resistant to carbenicillin, ampicillin and ticarcillin. Nine strains of S. montevideo were sensitive to most antibiotics except carbenicillin and streptomycin. Each 1 stain of S. indiana and S. infantis was sensitive to most antibiotics used in this study except streptomycin. Three kinds of resistant pattern (CB, SM, TE, AM, TC). In the case of S. enteritidis isolates, 9 kinds resistant pattern were detected. Most frequent resistant pattern of S. enteritidis isolates was CB, AM, TC type(16.7%)

• Plant Resources
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• v.6 no.2
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• pp.108-113
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• 2003

This study was carried out to obtain basic information for possibility of oral vaccine in carrot using Agrobacteruim -mediated transformation system. The epitope region of porcine epidemic diarrhea virus (PEDV) spike gene which is classified as a member of the Coronaviridae and causes an acute enteritis in pigs was successfully expressed in carrot (Daucus carota) using the Agrobacterium-mediated transformation system. Hypocotyl segments of in vitro germinated plantlets were infected with Agrobacteriun tumefaciens LBA 4404 harboring PEDV spike gene. Embryogenic callus (EC) was induced on MS selection medium with 1 mg/L 2,4-D, 50 mg/L kanamycin and 300 mg/L cefotaxime after 45 days of culture. Subcultured ECs on MS selection medium without 2,4-D were converted to somatic embryos (SE) of various stage; globular, heart and torpedo stage. Putative transgenic embryos were selected on MS medium with 50 mg/L kanamycin and 300 mg/L cefotaxime. Regenerated plantlets from transformed SE were induced on MS medium containing 50 mg/L kanamycin after 30 days of culture. Genomic PCR confirmed the integration of PEDV spike gene into nuclear genome of carrot and northern blot analysis demonstrated the expression of PEDV spike gene in transgenic carrot.

• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.269-272
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• 1997

Cotyledonary petioles of Brassica napus cocultivated with Agrobacterium vectors for 72 h were transferred to MS medium with 0.5 mg/L NAA, 2.0 mg/L BA, 30 mg/L kanamycin, 100 mg/L cefotaxime, 30 g/L sucrose, 3 mg/L $\textrm{AgNO}_{3}$ and 2 g/L Gelrite. The cotyledonary petioles with green shoots were selected at a frequency of 17.5% in a selection medium and then rooted. Southern blot analysis confirmed the rolC and NPT IIgenes were incorporated into the regenerated plants. The stable inheritance of rolC gene was confirmed in progeny test of transgenic plants.