• Urogenital Tract Infection
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• v.13 no.3
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• pp.66-71
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• 2018

Purpose: To determine the appropriate regimen of antibiotic prophylaxis for the prevention of bacterial infections in patients receiving percutaneous nephrolithotomy (PCNL). Materials and Methods: Forty patients, who planned to undergo PCNL from October 2015 to August 2017, were assigned randomly into two groups. Patients in the single-dose group (n=20) were administered an intravenous single dose of 2 g ceftriaxone 30 minutes before PCNL, whereas those in the three-days regimen group (n=20) were administered a preoperative intravenous single dose of 2 g ceftriaxone and an additional postoperative oral cefpodoxime proxetil (100 mg twice a day) for three days. The incidences of infectious complications in the two groups, such as pyrexia, systemic inflammatory response syndrome (SIRS), and sepsis, were compared. Results: Fever (axillary temperature >$38.0^{\circ}C$) did not develop in any of the patients in the single-dose group but developed in one patient (5.0%) in the three-day regimen group due to pneumonia (p=0.3). SIRS developed in a total of eight patients (20.0%), four patients from each group. None of the patients in either group developed sepsis after PCNL. Conclusions: The three-day prophylactic antibiotic regimen did not demonstrate better efficacy for the prevention of bacterial infections in patients with PCNL compared to the single-dose prophylactic antibiotic regimen.

• IMMUNE NETWORK
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• v.22 no.6
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• pp.48.1-48.13
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• 2022

With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, which are randomly mutated, the dominant strains in regions are changing globally. The development of preclinical animal models is imperative to validate vaccines and therapeutics against SARS-CoV-2 variants. The objective of this study was to develop a non-human primate (NHP) model for SARS-CoV-2 Delta variant infection. Cynomolgus macaques infected with Delta variants showed infectious viruses and viral RNA in the upper (nasal and throat) and lower respiratory (lung) tracts during the acute phase of infection. After 3 days of infection, lesions consistent with diffuse alveolar damage were observed in the lungs. For cellular immune responses, all macaques displayed transient lymphopenia and neutrophilia in the early stages of infection. SARS-CoV-2 Delta variant spike protein-specific IgM, IgG, and IgA levels were significantly increased in the plasma of these animals 14 days after infection. This new NHP Delta variant infection model can be used for comparative analysis of the difference in severity between SARS-CoV-2 variants of concern and may be useful in the efficacy evaluation of vaccines and universal therapeutic drugs for mutations.

• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.31-39
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• 2016

Purpose: The aim of this study was to investigate the prognostic factors for Pneumocystis jirovecii pneumonia (PCP) and to evaluate the influence of PCP prophylaxis in pediatric patients. Methods: From January 2002 to April 2015, patients aged <18 years with a diagnosis of confirmed PCP at our institute were reviewed retrospectively. Clinical characteristics and outcomes were compared according to the groups with or without PCP prophylaxis. Risk factors associated with PCP-related death were analyzed by logistic regression analysis. Results: During study period, a total of 24 patients were diagnosed with PCP by immunofluorescence assay and/or PCR. The median age of the patients was 5 years (range, 3 months-18 years) and 23 (96%) had immunocompromised conditions including hematologic disorders with or without hematopoietic stem cell transplantation (n=15), solid organ transplantation (n=4), and primary immune deficiency (n=4). Most common presenting symptoms were tachypnea and cough (92%, each). At the time of diagnosis, 79% (19/24) and 25% (6/24) suffered from respiratory failure and multi-organ dysfunction syndrome (MODS), respectively. Mechanical ventilation was required in 8 (33%) patients and 5 (21%) patients died of PCP. Multivariate analysis showed that MODS at initial presentation was an indicator of poor prognosis (OR, 17.1 [95% CI 1.13-257.67]; P=0.04). Compared to the patients without PCP prophylaxis, the frequency of MODS at diagnosis, need for mechanical ventilation and length of hospital days were significantly less common in the children who received PCP prophylaxis. Conclusions: MODS at presentation was a significant predictor for poor outcome and PCP prophylaxis could alleviate the clinical courses of pediatric PCP. Prospective study will be mandatory to determine the risk factors for development and deterioration of PCP in children.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.75-80
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• 2015

Purpose: Ventilator-associated pneumonia (VAP) is a serious threat in critically ill pediatric patients. Data regarding Stenotrophomonas maltophilia VAP in pediatric population is limited. We evaluated the clinical data of S. maltophilia associated VAP in critically ill pediatric patients. Methods: A retrospective chart review was performed in pediatric patients 18 years old or younger who developed S. maltophilia associated VAP at Samsung Medical Center, Seoul Korea from January 2008 to December 2012. Results: A total of 31 patients were identified S. maltophilia associated VAP. Median age was 8 months (range, 0.5 month to 16.6 years) and 13 patients were male (40.6%). Underlying illnesses were cardiologic diseases (n=11, 34.4%), hematologic oncologic malignancies (n=7, 25%), neurologic diseases (n=4, 12.5%), pulmonary diseases (n=3, 9.4%), and others (n=4, 12.5%). The median duration of ventilator use before S. maltophilia VAP diagnosis was 14 days (range, 4-256 days). Overall mortality at 30 days was 12.5% (4/32). Conclusions: S. maltophilia should be also considered as a possible pathogen for VAP in critically ill pediatric patients. Empiric antibiotic choice should include agents that are active against S. maltophilia in patients who are deteriorating on broad spectrum beta-lactam antimicrobial agents.

• Pediatric Infection and Vaccine
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• v.6 no.1
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• pp.93-100
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• 1999

Purpose : For evaluation of acute Mycoplasma pneumoniae(M. pneumoniae) pneumonia in children, we have studied the Mycoplasma indirect particle agglutination test, cold hemagglutinin test, ESR, CRP, and total white blood cell counts and it's differential count retrospectively. Methods : The total numbers of patients whom compatible with diagnostic criteria of acute M. pneumoniae peumonia were 56 cases from Jan. to Dec. 1997. The diagnostic criteria were 1) onset of fever(${\geq}38.0^{\circ}C$) and coughing were within 7 days, 2) rhonchi and/or role was audible on chest, 3) pneumonic infiltration on chest X-ray, and 4) M. pneumoniae indirect particle agglutination test titer was higher than 1:640, or initial titer was less than 1:640 but increased more than 4 folds after week. We classified the enrolled patients according to initial antibody titer, such as soup A(${\leq}1:640$) and group B(${\geq}1:320$). We compared group A and B by demographic findings, clinical symptoms and signs, and laboratory findings. Results : 1) The male and female sex ratio was 1:1.4, and average onset age was $5.8{\pm}2.96$ years. 2) The average body temperature on admission was $38.5{\pm}0.1^{\circ}C$ and productive coughing was noticed in 52 cases(93%). 3) The average total white cell counts were $10,470{\pm}877.0/mm^3$ in group B patients, which was significantly higher compared to $7,761{\pm}508.5/mm^3$ in group A(p<0.014). 4) The average value of ESR and CRP were within normal range in both group. 5) The most common site of pneumonic infiltration was right lower lobe of lung in both groups. 6) There were no correlation between antibody titer and cold hemagglutinine titer in patients and cold hemagglutination titer were less than 1:64 in 25 cases(45%). Conclusion : The clinical manifestations of pneumonia, findings of chest x-ray, and indirect particle agglutination test were useful on diagnosis of M. pneumoniae pnumonia onset within 7 days, but cold hemagglutinin test was a little diagnostic meaning.

• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.156-164
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• 2018

Purpose: We aimed to identify the epidemiology and the clinical characteristics of human parainfluenza virus type 4 (HPIV-4) infection compared to HPIVs 1-3 infections in Korean children. Methods: We reviewed medical records of children with HPIV infection who visited Seoul National University Children's Hospital from 2015 to 2017. Detection of respiratory viruses was performed using real time-polymerase chain reaction (rt-PCR), which could differentiate HPIVs 1-4. Diagnosis was classified as a febrile illness, upper respiratory tract infection (URI), croup, bronchiolitis, or pneumonia. The epidemiology, demographic features, and clinical characteristics among HPIV types were compared. The clinical data were analyzed only for the previously healthy children. Results: Of the 472 children diagnosed with HPIV infection, 108 (22.9%) were previously healthy: 24 (22.2%), 19 (17.6%), 39 (36.1%), and 26 (24.1%) in HPIV types 1, 2, 3, and 4, respectively. The median age of children with HPIV-4 infection was 11 (0-195) months: the proportion of children aged < 2 years and 2 to < 5 years were 65.4% and 19.2%, respectively. Clinical diagnoses of HPIV-4 infection were bronchiolitis (38.5%), pneumonia (30.8%), and URI (30.8%). Croup was the most prevalent in HPIV-2 (21.1%) and none in HPIV-4 infection (P=0.026). Hospital admission rates among HPIV types were not significantly different (P>0.05). Conclusions: We observed seasonal peak of HPIV-4 infection in 2015 and 2017. HPIV-4 was a common respiratory pathogen causing lower respiratory tract infection in hospitalized children.

• Korean Journal of Clinical Pharmacy
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• v.22 no.1
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• pp.55-64
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• 2012

The quinolones are broad-spectrum antibiotics and enhanced antimicrobial activity has extended the use of the quinolones beyond the traditional indications for quinolone antibiotics in the treatment of urinary tract infections. The quinolones are effective in a wider variety of infectious diseases, including skin and respiratory infections. Because of their excellent safety and tolerability, they have become popular alternatives to penicillin and cephalosporin derivatives in the treatment of various infections. A retrospective study was performed to evaluate efficacy and safety of IV quinolones for inpatient use. Total 117 patients who administerd quinolones for longer than 3 continuous days at community hospital from October 1st, 2008 to December 31st, 2008 were reviewed. The criterias for drug evaluation were included the validation of indication, outcome, dosage and side effects. In the results, ciprofloxacin 13 (total 93), levofloxacin 3 (total 59) and moxifloxacin 2 (total 19) cases were not met the criterias based on the culture results. Major indications were pneumonia (ciprofloxacin 16.3%, levofloxacin 67.8%, moxifloxacin 84.2%), urinary tract infection (ciprofloxacin 44.1%), skin infection (ciprofloxacin 7.5%, levofloxacin 20.3%, moxifloxacin 10.5%), intra-abdominal infection (ciprofloxacin 10.8%, moxifloxacin 5.3%), etc.. In the results of quinolone monotherapy, the frequencies were each ciprofloxacin 74.2%, levofloxacin 50.8% and moxifloxacin 47.4%. In the results of dosage validation, the validities were each ciprofloxacin 54.8%, levofloxacin 94.9% and moxifloxacin 100.0%. In the results of duration validation, the validities were each ciprofloxacin 59.1%, levofloxacin 78.0% and moxifloxacin 89.5%. Adverse drug reactions were reported for total 49 cases and those were gastrointestinal tract effects including nausea, vomiting, diarrhea and central nervous system effects including headache, dizziness. In summary, the quinolones appropriately used for hospitalized patients based on this study. A focused approach emphasizing "correct use of quinolones" may reduce development of antimicrobial resistance and maximize class efficacy. Consequently, correct use of antibiotics will contribute to decrease medical expenses for person and community.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.61-67
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• 2011

Purpose : This study was performed to investigate the epidemiologic characteristics of human bocavirus (HBoV)-associated lower respiratory tract infections (LRTIs) in children. Methods : Nasopharyngeal aspirate samples were obtained from 658 children who had been hospitalized for LRTIs in Seoul National University (SNU) Children's Hospital and SNU Bundang Hospital from March 2000 to September 2005. Multiplex RT-PCR was performed to detect 11 respiratory viruses including respiratory syncytial virus, adenovirus, rhinovirus, parainfluenza viruses 1 and 3, influenza viruses A and B, human metapneumovirus, HBoV, human coronavirus (HCoV) OC43/ 229E, and HCoV-NL63. Clinical data were reviewed retrospectively. Results : Overall, respiratory viruses were detected in 325 (49.4%) among 658 patients. HBoV was detected in 62 cases (9.4%) and was responsible for 19.1% of virus-positive cases. HBoV was prevalent among infants and young children aged from 3 months to 5 years with the mean age of 25.3 months. Co-detection of HBoV and other respiratory viruses was observed in 37.1% which is significantly higher than average co-detection rate (12.3%) among overall virus-positive cases (P=0.000). HBoV was identified mainly in late spring and early summer from May to July. Conclusion : This study describes epidemiologic features of HBoV in Korean children compared with those associated with other respiratory viruses. HBoV was prevalent among LRTIs in childhood, especially in late spring and early summer season in Korea.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.1-8
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• 2014

Purpose: The aim for this study was to investigate clinical manifestation of seasonal influenza A and B during the 2012 winter season in Wonju, South Korea. Their clinical and laboratorial characteristics and effect of oseltamivir were compared and analyzed. Methods: Children under the age of 18 years who visited the Wonju Severance Christian Hospital with fever or acute respiratory symptoms and who were diagnosed with influenza A or B by rapid antigen test from nasopharyngeal swab were selected for the study. The medical records of patients were retrospectively reviewed. Results: Influenza A was detected in 374 patients (83.7%), and influenza B in 72 (16.6%). The incidence of influenza A was highest in February (n=186), while that of influenza B was highest in March (n=36). The most common symptoms were fever (n=434, 97.1%) and cough (n=362, 81.0%). No significant differences were observed between influenza A and B in symptoms and laboratory data. Patients who had used oseltamivir within 2 days showed statistically lower admission rate, shorter admission duration, and lower incidence of pneumonia. Conclusion: This study found no statistical difference between influenza A and B, in symptoms, progression, and laboratory test, but those who were treated with oseltamivir given within 2 days of the onset of fever experienced more positive outcomes.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1529-1538
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• 2017

Klebsiella pneumoniae is an opportunistic and clinically significant emerging pathogen. We investigated the relative roles of Toll-like receptor (TLR) 2 and TLR4 in initiating host defenses against K. pneumoniae. TLR2 knockout (KO), TLR4 KO, TLR2/4 double KO (DKO), and wild-type (WT) mice were inoculated with K. pneumoniae. Mice in each group were sacrificed after either 12 or 24h, and the lungs, liver, and blood were harvested to enumerate bacterial colony-forming units (CFU). Cytokine and chemokine levels were analyzed using enzyme-linked immunosorbent assay and real-time PCR, and pneumonia severity was determined by histopathological analysis. Survival was significantly shortened in TLR4 KO and TLR2/4 DKO mice compared with that of WT mice after infection with $5{\times}10^3CFU$. TLR2 KO mice were more susceptible to infection than WT mice after exposure to a higher infectious dose. Bacterial burdens in the lungs and liver were significantly higher in TLR2/4 DKO mice than in WT mice. Serum $TNF-{\alpha}$, MCP-1, MIP-2, and nitric oxide levels were significantly decreased in TLR2/4 DKO mice relative to those in WT mice, and TLR2/4 DKO mice showed significantly decreased levels of $TNF-{\alpha}$, IL-6, MCP-1, and inducible nitric oxide synthase mRNA in the lung compared with those in WT mice. Collectively, these data indicate that TLR2/4 DKO mice were more susceptible to K. pneumoniae infection than single TLR2 KO and TLR4 KO mice. These results suggest that TLR2 and TLR4 play cooperative roles in lung innate immune responses and bacterial dissemination, resulting in systemic inflammation during K. pneumoniae infection.