• Pediatric Infection and Vaccine
• /
• v.15 no.1
• /
• pp.45-51
• /
• 2008

Purpose : Better understanding of the epidemiology of Streptococcus pneumoniae affects preventive and therapeutic strategies for children with otitis media. This study was undertaken to examine the prevalence of pneumococcal serotypes causing otitis media in children. Methods : Pneumococcal isolates obtained from the ear discharge of children with otitis media between January 2001 and December 2006 were characterized by serotyping and antibiotic susceptibility testing. Results : There were 54 pneumococcal isolates from 54 children with otitis media. The median age of patients was 13 months, and the proportion of children <5 years old was 81%. The predominant serotypes, in order of decreasing frequency, were 19A (44%), 19F(28%), 6B (7%), 6A (4%), 9V (4%), and 1 (4%); 23 isolates (43%) belonged to types included in the heptavalent pneumococcal conjugate vaccine (PCV7). The proportion of serotype 19A and 19F accounted for 72% of overall pneumococcal isolates, which accounted for 84% of pneumococcal isolates from otorrhea of children <5 years old (vs 20% in children ${\geq}5$ years old, P<0.001). All serotypes isolated from 3 vaccinees of PCV7 were 19A. There was no significant diminution in otitis media caused by pneumococcal vaccine serotypes after the introduction of PCV7. The frequency of nonsusceptibility to penicillin, erythromycin, and trimethoprim-sulfamethoxazole was higher in serotype 19A than in other non-vaccine serotypes, respectively. The frequency of multiple drug resistance was 96% in serotype 19A, compared with 29% in other non-vaccine serotypes (P=0.001). Conclusion : 19A was the most common pneumococcal serotype causing otitis media and represented a large proportion of strains with multiple drug resistance in children younger than 5 years of age.

• Korean Journal of Veterinary Research
• /
• v.44 no.2
• /
• pp.217-224
• /
• 2004

This study was carried out to investigate the antibiotic resistance pattern of Listeria spp. and Staphylococcus aureus. A total of 17 (14.8%) L. monocytogenes, 13 (11.3%) L. innocua, 7 (7%) L. welshimeri, and 83 (72.2%) S. aureus were isolated from commercial poultry carcasses in Seoul and Kyonggi province during the period between 2001 and 2003. Antibiotic susceptibility test of all Listeria strains isolated was performed by the disk agar diffusion method. Antibiotics used in the study were as follows; Amikacin (An), Ampicillin (Am), Cephalothin (Cf), Chloramphenicol (C), Ciprofloxacin (Cip), Erythromycin (E), Gentamicin (Gm), Imipenem (Ipm), Kanamycin (K), Minocycline (Mi), Neomycin (N), Norfloxacin (Nor), Ofloxacin (Ofx), Penicillin (P), Streptomycin (S), Tetracycline (Te), Tobramycin (Nn), Trimethoprim (Tmp), Trimethoprim/Sulfamethoxazloe (Sxt), and Vancomycin (Va). The antibiotic resistance pattern of S. aureus isolates was performed by the disk agar diffusion method. For the latter program, antibiotics used to the study were as follows; Cf, C, Cip, Clindamycin (Cc), E, Gm, Ipm, Nafcillin (Nf), Oxacillin (Ox), P, Te, Sxt, and Va. Of the 17 L. monocytogenes isolates, 94.1% were resistant to Te, 88.2% to Mi, 11.8% to Nor, 11.8% to S, 5.9% to Cip, and 5.9% to C. Of 13 L. innocua, 53.8% were resistant to Te, 23.1% to Mi, 23.1% to S, 7.7% to Cip, and 7.7% to Nor. Of 7 L. welshimeri, 57.1% were resistant to Te, and 14.3% to Am. Of 83 S. aureus, 100% were resistant to Te, 86.7% to Gm, 34.9% to P, 15.7% to Cip, 12% to Cc, 9.6% to E. The multiple antibiotic resistance patterns of L. monocytogenes isolates were observed in Te Mi Cip (5.9%), Te Mi Nor (5.9%), Te Mi (76.5%), and Te Nor (5.9%). Multiple antibiotic resistance was also found in L. innocua isolates. Resistant to Te Mi S Cip Nor was 7.7%, Te Mi S (7.7%), Te Mi (7.7%), and was 7.7% to Te S. Antibiotic resistance patterns for S. aureus isolats were demonstrated to Te Gm P Cip Cc E (6.0%), Te Gm Cip Cc E (3.6%), Te Gm P Cc (1.2%), Te Gm P (15.6%), Te Gm Cip (2.4%), Te P Cip (2.4%), Te Gm Cc (1.2%), Te Gm (56.6%), Te P (9.6%), and to Te Cip (1.2%). The results of this study suggest a high incidence of Lsteria spp. and S. aureus on poultry carcasses. The contaminated poultry carcasses may be a potential vehicle for foodborne infections due to multiple antimicrobial resistant organisms.

• Pediatric Infection and Vaccine
• /
• v.13 no.2
• /
• pp.130-136
• /
• 2006

Purpose : The purpose of this study is to confirm the epidemiologic change of the causative organisms of neonatal and pediatric bacterial meningitis in Korea. And we tried to evaluate the risk factors correlated with prognosis which was available on the day of admission. Methods : Retrospectively, we reviewed the medical records of 57 patients admitted for bacterial meningitis at six hospitals affiliated with Catholic Medical Center for 6 years(Jan. 2000~Dec. 2005). Results : 22 cases(38.6%) of them were neonates under 28 days and 35 cases were infants and children ; 16 cases(28.1%), under 1 year ; 6 cases(10.5%), under 5 years ; 13 cases (22.8%), under 15 years. In neonates, 16 cases(72.7%) were caused by group B streptococcus (GBS). In infants and children, S. pneumoniae(25.7%), H. influenzae type b(Hib)(22.8%) and N. meningitidis(22.8%) were common cause of bacterial meningitis in order. In the informations available on the day of admission, weight deficit for age under 3 percentile, increased CRP level and decreased glucose level of CSF were related to poor prognosis(P<0.05). Conclusion : GBS became a leading cause of neonatal bacterial meningitis. Though, pneumoccocal, Hib and meningococcal meningitis were confirmed as major causes of bacterial meningitis. The routine immunization of pneumococcal and Hib vaccines will be considered, and it is necessary to introduce meningococcal vaccines to our country in the future.

• Pediatric Infection and Vaccine
• /
• v.13 no.2
• /
• pp.115-123
• /
• 2006

Purpose : We investigated whether there had been any change in the epidemiology of Streptococcus pneumoniae in Korea before and after introduction of heptavalent pneumococcal conjugate vaccine(PCV7). Methods : Between September 2001 and August 2006, clinical isolates were collected from patients with pneumococcal infection in Severance Hospital, Seoul, Korea. We analyzed trends in serotype distribution and antibiotic resistance before and after the introduction of PCV7. Results : There were 363 strains of Streptococcus pneumoniae isolated from clinical specimens; 143 before and 220 after PCV7 introduction. The predominant serotypes, in order of decreasing frequency, were 19F, 19A, 23F, 6B, 6A, 3, 9V, 14, 11A, 4, 29, and 18C; 152 isolates(41.9%) belonged to types included in PCV7. The proportion of clinical isolates that were nonsusceptible to penicillin increased from 58.8% in 2001 to 83.6% in 2006(P=0.046). There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7. In children younger than age 2 years, the proportion of clinical isolates that were vaccine serotypes was higher than in persons older than age 15 years (59.3% vs 37.8%, P=0.004). Conclusions : There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7, therefore more universal pneumococcal immunization program is recommended especially for children younger than age 2 years.

• Journal of Yeungnam Medical Science
• /
• v.16 no.1
• /
• pp.60-68
• /
• 1999

A nationwide survey was conducted to investigate the annual occurrence rate of neonatal sepsis, maternal risk factors in neonatal sepsis, localized infection in neonates, causative organisms in nosocomial infection and the most common causative organism for neonatal sepsis in Korea. Clinical and bacteriological data wele collected from 37 neonatal units to perform retrospective review of the medical records of the newborn infants who were confirmed as having neonatal sepsis and whose blood culture was collected to isolate organisms for one year study period from January to December in 1997. 78,463 neonates were born at 37 hospital in 1997, and 20,869 neonates were admitted to the neonatal units, During this period, 772 episodes of neonatal sepsis were recorded in 517 neonates. The occurrence rate of neonatal sepsis was 0.73%(0~2.95%). Male to female ratio was 1.15:1, and 303 cases(42.1%) were born prematurely. The main pathogens of early onset of sepsis were S. aureus(20%), S. epidermidis(14.4%) and coagulase negative staphylococcus(14. 4%). Gram negative bacilli including Enterobacter spp (7.2%), E. coli(5.1%), Klepstella(4.5%), Pseudomonas(3.7%) and Enterobacter faectum(3.6%) accounted for 24.1% of sepsis. Group B beta-hemolytic streptococcus were isolated only in two cases. Common obstetric factors were PROM(21.1%), difficulty delivery(18.7%), fetal tachycardia(5.3%), chorioamnionitis(4.9%), and maternal fever(4.7%). The main pathogens of late-onset sepsis were S. aureus(22.3%), S. epidermidis(20.4%) and CONS(9.9%). There were 6 cases(1.0%) of Candida sepsis, Frequent focal infections accompanying sepsis were pneumonia(26.1%), urinary tract infection(10.5%), meningitis(8.2%), and arthritis(3.6%), S. epidermidis(22.0%) and s. aureus(21.7%) were also the most common pathogens in 373 nosocomial infection.

• Microbiology and Biotechnology Letters
• /
• v.35 no.2
• /
• pp.158-162
• /
• 2007

Methicillin-resistant Staphylococcus aureus (MRSA) is one of a major nosocomial pathogen worldwide and the emergence of this strain has become a major clinical problem. This study was performed for 13 hospitals with more than 400 beds in the country by collecting samples including hands and nasal cavities of doctors, nurses, guardians and patients. Also, additional 320 samples of hands and nasal cavities of 160 community resident in different locations and regions were collected. In all of medical environments and community resident, 625 strains of S. aureus were detected. Among 625 strains of S. aureus, 585 strains(93.6%) showed the resistance to at least one kind of antimicrobial and 112 strains (17.9%) showed multi-drug resistance with the resistance to 4 different types of antimicrobial. Total 152 MRSA strains (24.3%) were isolated from medical environment and community resident. In nasal cavity and hand, 49 MRSA (19.4%) and 103 (27.6%) MRSA were isolated, respectively Minimum inhibitory concentration(MIC) test is used to measure for susceptibility of MRSA isolated to oxacillin. At a concentration $16{\mu}g/ml$ of oxacillin, 11 strains were inhibited. 32 strains at $32{\mu}g/ml$, 41 strains at $64{\mu}g/ml$, 3 strains at $128{\mu}g/ml$, 25 stains at $256{\mu}g/ml$ and 40 strains at over $256{\mu}g/ml$ were inhibited. It was considered that medical environment showed higher than livestock and marine environments in MRSA detection rate.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.5
• /
• pp.619-624
• /
• 2011

Tea extract (TE) has been shown to have anti-tumor properties in a wide variety of experimental systems. We evaluated green tea extract (GTE) as a biochemical modulator for the antitumor activity of cisplatin and doxorubicin in the treatment of human lung cancer A549 cells. Cells were grown in RPMI-1640 medium supplemented with 10% (v/v) heat-inactivated fetal bovine serum and two antibiotics (100 units/mL penicillin and $100\;{\mu}g$/mL streptomycin). Two types of TE, epigallocatechin galate (EGCG) and GTE, were used in this experiment. The cells were seeded at $1{\times}10^4$ cells/well in the RPMI-1640 media with or without TE ($100\;{\mu}g$/mL) and then treated with different concentrations of doxorubicin ($0{\sim}14\;{\mu}g$/mL) or cisplatin ($0{\sim}35\;{\mu}g$/mL). After incubation in 5% $CO_2$ at $37^{\circ}C$ for 24 hr, cell viability was determined with a MTT assay. We used a Western blot to detect the influence of EGCG and GTE on the expression of p53 and caspase-3 genes in the A549 cells. A549 cell viability decreased to 15% with a $10\;{\mu}g$/mL concentration of cisplatin, and to 21% with a $8\;{\mu}g$/mL concentration of doxorubicin, as measured with the MTT assay. However, pre-treatment of the cells with EGCG ($100\;{\mu}g$/mL) or GTE ($100\;{\mu}g$/mL) resulted in decreased cell viability with $6\;{\mu}g$/mL of cisplatin and $4\;{\mu}g$/mL of doxorubicin. There was no apparent change in cell viability between EGCG or GTE administration in cisplatin- or doxorubicin-induced cytotoxicity in A549 cells. The levels of p53 and caspase-3 in the A549 cells increased with both EGCG and GTE treatment. We found that GTE could potentially affect cisplatin- or doxorubicin-induced cytotoxicity of A549 cells, which may be useful in the chemotreatment of cancer.

• Journal of Periodontal and Implant Science
• /
• v.26 no.2
• /
• pp.469-490
• /
• 1996

The initial events required for periodontal regeneration is the attachment, spreading, and proliferation of appropriated cells at the healing sites. These have been reported that minocycline stimulates the attachment of periodontal ligament cells, and also $TGF-{\beta}1$ enhances the proliferation of periodontal ligament cells. The purpose of the present study was to evaluate the effects of $TGF-{\beta}1$ on the cellular activity of minocycline treated human periodontal ligament cells. Periodontal ligament cells were obtained from the explants of healthy periodontal ligaments of extracted 3rd molars or premolar teeth extracted from the patients for orthodontic treatment. The cells were cultured in minimal essential medium(${\alpha}-MEM$) supplemented with 10.000units/ml penicillin, $10,000{\mu}g/ml$ streptomycin and 10% FBS(fetal bovine serum) at $37^{\circ}C$ in a humidified atmosphere of 5% carbon dioxide and the 5th to the 8th passages of the cells were used. To evaluate the effect of minocycline on cell attachment, the cells were seeded at a cell density of $1.5{\times}10^4$ cells/well in 24-well culture plates and treated with $20{\mu}g/ml$ and $100{\mu}g/ml$ of minocycline for 1.5 h. After trypsinization, the cells were counted with hemocytometer and were taken photographs for observation of cellular morphology. To evaluate the effect of $TGF-{\beta}1$ on minocycline-pretreated periodontal ligament cells, the cells were seeded at a cell density of $1{\times}10^4$ cells/ well in 24-well culture plates and treated with $20{\mu}g/ml$ and $100{\mu}g/ml$ of minocycline for 1.5 h. After incubation, 1 and 10ng/ml of $rh-TGF-{\beta}1$ were also added to the each well and incubated for 1 and 2 days, respectively. Then, MTT assay, DNA synthesis($^3H-thymidine\;assay$), and protein and collagen assay(3H-proline assay) were carried out. In the MIT assay, after 200ul MTT solutionlconeentration of 5mg/ml) were added to the each well of the 24-well plates and incubated for 3 hours, and 200 ul DMSO were added so as to dissolve insoluble blue formazan crystals which was formed in incubated period. Then it read plates on a ELISA reader. For mitogenic assay, 1 uCi/ml $^3H-thymidine$ was added to each well for the final 2 hours of the incubation periods. After labeling, the wells were washed 3 times with ice cold PBS and 4 times with 5% TCA to remove unincorporated label and precipitate the cellular DNA. DNA, with the incorporated $^3H-thymidine$, was solubilized with 500 ul of 0.1% NaOH/0.1% SDS. A 250 ul aliquot was removed from each well and placed in a scintillation vial with 4ml of scintillation cocktail. Using an liguid scintillation counter, counts per minute(CPM) were determined for each samples. 3 uCi/ml $^3H-proline$ was added to each well for the final 4 hours of the incubation periods and total protein and percent collagen synthesis were carried out. The results indicate that minocycline treated group with $100{\mu}g/ml$ concentration for 1.5 hours significantly increased than that of control in cell attachment, and cell process is also evident compared with that of control in cell morphology, and the cellular activity and DNA synthesis rate of cells treated minocycline and $TGF-{\beta}1$ significantly increased than that of control values, but were below to values of the $TGF-{\beta}1$ only treated group in MIT assay and $^3H-thymidine\;assay$, and the total protein synthesis of minocycline and $TGF-{\beta}1$ treated group also significantly increased than that of control values, but the percent collagen synthesis of tested group significantly decreased to compared with control. On the above the findings, the tested group of minocycline and $TGF-{\beta}1$ did not increase the effect on the cell activity than $TGF-{\beta}1$ only tested group and the tested group of minocycline inhibited cell activity. This results indicate that minocycline was effective on cell attachment in early stage, but it is harmful to cell activity, that inhibitory effect of minocycline was compensated with stimulatory effect of $TGF-{\beta}1$.

• Korean Journal of Microbiology
• /
• v.42 no.3
• /
• pp.185-194
• /
• 2006

The aim of this study was to identify the bacteria isolated from endodontic lesions by cell culture and to determine the antimicrobial susceptibility of them against 8 antibiotics. The necrotic pulpal tissues were collected from 27 infected root canals, which were diagnosed as endodontic infection. Samples were collected aseptically from the infected pulpal tissue of the infected root canals using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing $500{\mu}l\;of\;1{\times}PBS$. The sample solution was briefly mixed and plated onto a BHI-agar plate containing 5% sheep blood. The agar plates were incubated in a $37^{\circ}C$ anaerobic chamber for 2 to 5 days. The bacteria grown on the agar plates were identified by comparison of 16S rRNA gene (rDNA) sequencing method at the species level. To test the sensitivity of the bacteria isolated from the infected root canals against 8 antibiotics, minimum inhibitory concentrations (MIC) were determined using broth dilution assay. The data showed that 101 bacterial strains were isolated and were identified. Streptococcus spp. (29.7%) and Actinomyces spp. (21.8%) were predominantly isolated. The 9 strains were excluded in antimicrobial susceptibility test because they were lost during the experiment or were not grown in broth culture. The percentage of bacteria susceptible for each antibiotic in this study was clindamycin, 87.0% (80 of 92); tetracycline, 75.0% (69 of 92); cefuroxime axetil, 75.0% (69 of 92); amoxicillin + clavulanic acid (5:1), 71.7% (66 of 92); penicillin G, 66.3% (61 of 92); erythromycin, 66.3% (61 of 92); amoxicillin, 44.6% (41 of 92); and ciprofloxacin, 31.5% (29 of 92). The susceptibility pattern of 8 antibiotics was dependent on the host of the bacteria strains rather than the kinds of bacterial species. These results indicate that antibiotic susceptibility test should be performed when antibiotics are needed for the treatment of infected root canals.

• Journal of Sericultural and Entomological Science
• /
• v.24 no.2
• /
• pp.55-72
• /
• 1983

These studies were done to find out any difference, ultrastructural, physical or chemical, between the shells of diapausing and non-diapausing eggs of the silkworm, Bombyx mori L. 1. From the electron-microscopic observation, the egg shells have four distinctive layers. In addition to the four layers, the shells in the diapausing eggs has another layer with low electron density on its surface. 2. The permeability of the egg shell to hydrochloride was much lower in diapausing egg than in non-diapausing egg. Also the permeability changed in the opposite directions with the egg age: the diapausing eggs decreased while non-diapausing ones increased. 3. The permeability increased when the diapausing egg shell was treated with HCl. When they were treated with ether, however, the increase in permeability was much smaller. It seems there was an ether soluble material involved in the content of the egg shell. 4. The diapausing eggs were also much more resistant to desiccation than the non-diapausing ones. The former, when treated with HCl or chilling, became less resistant to desiccation. 5. The positive histochemical response of the egg shell to PAS-Alcian blue and protein stainings suggests presence of abundant proteins and carbohydrates in the egg shell. On the other hand, the staining response to lipid was more positive in the inner layers than in the outer layer of the shell. 6. The egg shell adhesives seems to be mucopolysaccharides produced by colleterial glands, since the oviposited eggs showed a positive responses to carbohydrate and negative to lipid-staining chemicals, but not the mature oocytes in the ovarioles. 7. There were two bands on the electrophoretic pattern of the SH proteins extracted from the egg shells both in the diapausing egg and non-diapausing one: a slow moving major component and a fast moving minor one. However, the electrophoretic mobility showed a difference in the minor components between them. It is evident that the fast moving minor one of non-diapausing egg ran a little further than that of diapausing egg. 8. In amino acids analysis, no significant differences were found in their composition between diapausing and non-diapausing egg and SH proteins contain relatively more glycine and less cystine.