• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.169-176
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• 1992

In order to compare the intraspecific variation in host-parasite relationship of Clonorchis sinensis, six strains of inbred mice, ICR, DDY, GPC, BALB/c, nude and DS, were infected orally with 20 metacercariae of C. sinensis. The biologic incubation period of C. sinensis was the shortest in DDY mice, 21.2 days in average, followed by GPC 21.4, BALB/c and DS 23.2, ICR and nude 23.4 days, respectively. The fertile period of the cuke was also the longest in the DDY strain, 164 days on average, followed by GPC 132, BALB/c 97, nude 37, DS 32 and ICR 28 days. The egg-laying capacity of the cuke in DDY and GPC was relatively high and stable compared with the other four strains of mice. It was found that there are intraspecific variations in biologic incubation period, fertile period, and fecundity of C. sinensis. The DDY mouse is likely to be the most suitable experimental animal among the six strains of the mice tested. Key words: Mouse strain, Clonorchis sinensis, egg-laying capacity.

• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.127-133
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• 2020

Parvimonas micra is a non-spore-forming anaerobic gram-positive coccus and a known commensal of the skin, gums, vagina, and gastrointestinal tract. It is rarely associated with severe infections, which typically follow invasive procedures such as dental treatment. We describe a case of a brain abscess caused by P. micra in an immunocompetent 11-year-old boy without periodontal disease. He presented with a 7-day history of headaches and vomiting, and complained of diplopia that began on the day of presentation. He did not have any recent dental treatment or specific past medical history. A brain abscess in the left frontoparietal lobe was noted on brain magnetic resonance imaging. P. micra was cultured from brain abscess aspirate. He was successfully treated with surgical drainage and combined antibiotic therapy with ceftriaxone and metronidazole for 6 weeks.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.335-335
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• 2011

곰팡이에 의한 감염과 바이오 필름 형성이 우리 인간에게 매우 유해하다는 것은 익히 알려진 바이다. 일례로, 이는 우리가 먹는 음식을 오염시키고 치아를 상하게 하며 수도관을 부식시키고 또 우리 몸속에 집어넣는 의료기기에서 자라 심각한 질병을 유발시키는 등 여러가지 문제를 일으킨다. 곰팡이 감염과 바이오 필름 형성을 막기 위해 항생제 및 화학물질 등을 이용하는 방법들이 있으나 저항성이 증가된 균주의 출현, 환경오염 등의 문제점을 유발시키고 있다. 따라서 좀더 지속적이고 환경친화적인 기술개발이 요구되어지고 있다. 강한 살균력이 있다고 알려져 있는 대기압 플라즈마는 이러한 기술개발에 적용해볼 필요가 있다. 본 연구에서는 상온 대기압 플라즈마를 만들어 내는 여러 타입의 장치를 이용하여 곰팡이 살균과 이스트 바이오필름 형성 저해에 대한 조사를 하였고 플라즈마 처리에 따른 곰팡이 세포들의 세포학적 분자생물학적 영향에 대해 조사해 보았다. 대기압 상온 플라즈마 제트는 대기중에서 방안의 온도로 플라즈마가 생성되며 이를 페트리디쉬위에 접종된 이스트(Saccharomyces cerevisiae) 위 10 mm에서 조사한 결과 2분 이상의 처리를 했을 때 바이오 필름형성을 하지 못함을 보였고 곰팡이(Neurospora crassa)포자에 처리했을 때는 처리시간에 비례하여 발아하는 포자수가 감소하고 포자의 모양도 수축되는 것으로 관찰되었다. 대기압 플라즈마 제트는 대면적이 아닌 국부적 살균으로 살균력은 보이나 그 효율성이 낮아 이를 보완하기위해 DBD 형식의 플라즈마 장치를 만들었으며 이는 페트리디쉬의 모든 면을 동시에 조사할 수 있는 장점이 있다. 다만 제트와는 달리 플라즈마의 생성구간이 넓고 얇아 시료와 2~3 mm 간격을 띄우고 조사하였다. 제트와 마찬가지로 살균의 효과를 보였으며 기존의 단점을 극복하여 동시에 더 많은 면적을 조사 할 수 있게 되었다. 이를 통해 플라즈마의 살균능력을 직접 확인하였고 앞으로 더 많은 실험과 연구를 통해 일련의 과정들에 대한 원인을 규명하고자 한다.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.184-189
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• 2020

Lyme disease is a common vector-borne disease caused by Borrelia burgdorferi. Erythema migrans represents the most common manifestation during the early phase of this disease; however, systemic manifestations involving the nervous system, joints, or heart are known to occur. We report a case of Lyme disease accompanied by cardiac complications in a 13-year-old Korean male adolescent. The patient developed annular erythematous lesions on his lower extremities after a field trip during his visit to Connecticut, USA, for a boarding school camp, and his skin lesions were consistent with erythema migrans. Indirect immunofluorescence assay and Western blot analysis for Lyme immunoglobulin M showed positive results. Electrocardiography revealed a first-degree atrioventricular block, and he was diagnosed with Lyme carditis and received a 4-week course of oral doxycycline. Follow-up electrocardiography performed a week later revealed normal findings, and the patient showed an uneventful recovery. Lyme carditis often presents as an asymptomatic heart block that can progress to an advanced heart block; however, this condition is reversible with appropriate antibiotic treatment.

• Pediatric Infection and Vaccine
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• v.29 no.3
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• pp.173-178
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• 2022

Streptococcus intermedius is a small, non-motile, Gram-positive, non-sporeforming, and aerotolerant anaerobic coccus. It is a part of the normal microflora in the oral cavity and upper respiratory, gastrointestinal and female urogenital tracts. It is an opportunistic pathogen that causes serious infections in patients with immunocompromised states or cardiac diseases as a result of trauma or invasive procedures. We describe a case of septic arthritis of the hip caused by S. intermedius in an immunocompetent healthy 7-year-old boy without a history of periodontal disease or invasive procedures. He had hip joint pain three weeks ago, and the fever began on the day of the visit. He had been healthy and had not undergone any invasive procedures recently. Septic arthritis of the hip was indicated in the magnetic resonance imaging of the hip. S. intermedius was identified in the hip joint fluid aspiration and blood culture. He was successfully treated with surgical intervention and antibiotic therapy with ceftriaxone followed by amoxicillin for five weeks.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.83-89
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• 2001

Newcastle disease virus, CBP-1 strain isolated from Korean pheasants was passaged for 173 times by 9-day-old specific pathogenic free (SPF) embryonated eggs at $37^{\circ}C$ (parent strain) and subsequently passaged for 15 (cold attenuation (CA) -15) and 30(cold attenuation (CA) -30) times by 10-day-old of commercial broiler chicks embryonated eggs at $29^{\circ}C$, respectively, The Physical and chemical properties (sensitivity to lipid solvents, low pH and thermostability), pathogenicity (mean death time, intracerebral pathogenic index and intravenous patho-genic index), safety, booster or protective effect and characterization of temperature sensitivity were measured in cold attenuated CA-15 or 30 strain and compared to those of parent CBP-1 strain. NDV, CBP-1 CA-30 strain acquired cold attenuation and decreased infectivity at $41^{\circ}C$ compared to those of parent strain grown at $37^{\circ}C$. It lost hemagglutination activity (HA) and cell infectivity at $56^{\circ}C$ for 30, 60, and 120 Min. CA-30 strain treated with ethyl ether also lost its HA and cell infectivity. Both CA-30 and parent strains exhibited a little resistant to HA at pH 3.0 glycine HCI buffer. Intracerebral pathogenic index (ICPI) and intravenous pathogenic index (IVPI) of parent strain were 1.12 and 1.45, but decreased to 0.75 and 0.00 in CA-30 strain, respectively. The safety was evaluated by mortality in chicks inoculated with 10$^{4.0}$ EID$_{50}$ /0.1 ml. The mortalities of parent, CA-30 and commercial Bl strains were 17.5, 12.0 and 0.0%, respectively. The safety of CA-30 strain was higher than that of parent strain. The booster effects of CA-30 strain and parent strain performed in 4-week-old chicks after being vaccinated with primary commercial Bl strain.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.214-222
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• 2004

Purpose: Appropriate antibiotic therapy is important in childhood urinary tract infection and the selection of anibiotics is based on antimicrobial sensitivity of Escherichia coli. Extended-Spectrum ${\beta}-Lactamase(ESBL)$ is an enzyme produced by gram-negative bacilli that has the ability to hydrolyse penicillins, broad-spectrum cephalosporin and monobactam. There have been many reports of outbreaks of hospital infection by ESBL-producing organism. However, community-acquired infection with ESBL-producing organism are rare. This study was performed to retrospectively identify the incidence, characteristics and risk factors of ESBL (+) E. coli in community-acquired childhood UTI. Methods: In 288 children admitted in Ewha Womans University Hospital with E. coli UTI from Mar 2001 to February 2003, ESBL was isolated. ESBL was confirmed by the utilization of an automatized machine(Vitek GNS 433 card) using liquid medium dilution method according to National Committee for Clinical Laboratory Standard. The clinical characteristics, risk factors, antimicrobial resistance and treatment effectiveness were compared with ESBL(-) E. coli UTI. Results: Of 288 E. coli isolates, 31(10.8%) produced ESBL and 93.5%(29/31) occurred in infants younger than 6 month of age(P<0.01). No significant differences were noted in prior antibiotic use, prior admission history and underlying urogenital anomaly. Antimicrobial resistance was significantly higher in ESBL(+) E. coli compared with control patients (P<0.05). Although ceftriaxone showed 100% resistance in ESBL(+) E. coli, bacteriologic sterilization rate after ceftriaxone therapy was higher(96.8%). However, the recurrence rate of febrile UTI within 6 months was higher(25.8%) than control patients(6.6%). Conclusion: Epidemiologic study is required to find out any new risk factors of community-acquired ESBL(+) E. coli UTI and changes in selection of empirical antibiotics should be considered.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.15-20
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• 2010

Xenotransplantation of pig organs is complicated by the existence of polytropic replication-competent porcine endogenous retroviruses (PERV) capable of infecting human cells. Two classes of infectious human-tropic replication-competent PERVs (PERV-A and PERV-B) and one class of ecotropic PERV-C are known. The potential for recombination between ecotropic PERV-C and human-tropic PERVs adds another level of infectious risk. A recombinant PERV-A/C (PERV-A14/220) virus is 500-fold more infectious than PERV-A. Two determinants of this high infectivity was identified; one was isoleucine-to-valine substitution at position 140 in RBD (receptor binding domain), and the other lies within the PRR (proline rich region) of the envelope protein. To examine whether the effects of the cytoplasmic tail of the PERV-C Env on fusogenesity also influences infectivity, we constructed a pseudotype retroviral vectors containing MoMLV core protein and PERV envelopes. Pseudotyping experiments with the PERV envelope glycoproteins indicated that recombinant PERV-A/C virus is 10-fold more infectious than PERV-A by lacZ staining. This result supports the suggestion that viral transduction of PERV-A/C is enhanced by a membrane-proximal cytoplasmic amphiphilic ${\alpha}$-helix in PERV-C Env tail.

• Journal of Gastric Cancer
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• v.8 no.4
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• pp.237-243
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• 2008

Purpose: Postoperative Infectious complications are recognized as major complications that are associated with surgery. Although many studies have focused on the risk factors of postoperative complications, little is known about the risk factors of infectious complications after gastric cancer surgery, and especially after elective gastrectomy. There is now more and more interest in the risk factors of infectious complications in relation to controlling infection and as indicators of qualitatively assessing infectious complications. The aim of this study was to evaluate the risk factors related with infectious complications after performing elective gastrectomy for treating gastric cancer. Materials and Methods: We retrospectively reviewed a total of 788 patients who had undergone elective gastrectomy for gastric cancer between Jan. 2000 and Dec. 2007. The characteristics of the patients were divided according to the patients' factors and the operations' factors. Results: The patients' mean age was 58.9 (range: 24~91) years; 545 were male and 243 were female. The mean duration of the hospital stay was 20.3 days (range: 5~135 days), the mean operation time was 181.3 minutes (range: 65~440 minutes). The total complication rate was 17.1% (n=135) and the complication rate was 38.5% (n=52) among the 135 patients with infectious complications. The infectious complications were surgical site infection (59.7%), Pneumonia (19.3%), intra-abdominal abscess (11.5%), pseudomembranous colitis (5.7%), bacteremia (1.9%) and hepatic abscess (1.9%). On the univariate analysis, the significant risk factors were male gender, blood transfusion, smoking at the time of diagnosis, alcohol drinking, diabetes mellitus and previous cardiovascular disease (P<0.05 for all). On multivariate analysis that used a logistic regression model, the significant independent risk factors were smoking at the time of diagnosis (OR: 2.877. 95% CI: 1.449~5.713), blood transfusion (OR: 3.440, 95% CI: 1.241~9.534), diabetes mellitus (OR: 3.150, 95% CI: 1.518~6.538), and previous cardiovascular disease (OR: 2.784, 95% CI: 1.4731~5.2539). Conclusion: Pre- or post-operative blood transfusion and the patient's medical history such as previous cardiovascular disease, diabetes mellitus, smoking etc. are the risk factors for infectious complications after undergoing elective gastrectomy for gastric cancer. The patients that have these risk factors need to be treated with great care to prevent infectious disease after elective gastrectomy.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.182-192
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• 2011

Purpose : Atopic findings may be associated with severity of pneumonia in 2009 pandemic influenza A (H1N1) infection, which could suggest a possible association between atopic findings and the severity of viral infections. Thus, we studied association between atopic findings and severity of disease in children with H1N1 influenza infection. Methods : A retrospective study was performed in 74 children admitted in a single tertiary institute and confirmed as H1N1 patients by reverse transcriptase (RT) - polymerase chain reaction (PCR). They were divided into 2 groups according to the severity of pneumonia. We evaluated whether the atopic finding is risk factor between the two groups. Results : Children with severe pneumonia had higher percentages of serum eosinophilia (88% vs 40%, P <0.001), asthma (65% vs 35%, P =0.011), allergic rhinitis (71% vs 40%, P =0.009), and IgE level (P =0.007). We found positive correlations between aeroallergen sensitizations and severity of pneumonia (82% vs 53%, P =0.007). Conclusion : Among patients with H1N1 pneumonia, asthma and atopic findings are risk factors for severity of pneumonia.