Mediastinal Tuberculous Lymphadenitis with Periodic Fever / 감염과화학요법

A 60-year-old man undergoing maintenance hemodialysis presented with periodic fever, which resembled Pel-Ebstein fever of Hodgkin's lymphoma. Despite scores of diagnostic evaluations, origin of the fever remained obscure. On positron emission tomography/computed tomography scan, focal hot uptakes were seen in the mediastinum and mediastinoscopic biopsy showed many acid-fast bacilli with chronic granulomatous inflammation and necrosis. After a week of anti-tuberculosis medication, the patient remained afebrile without recourse to antipyretics.

A Case of Aortic Aneurysm Rupture Infected by Clostridium septicum in a Patient with Colon Cancer / 감염과화학요법

Infected aortic aneurysm a life-threatening disease entity. Clostridium septicum is a very rare pathogen of infected aneurysms that carries a high mortality rate and demonstrates a strong association with an derlying colonic or hematologic neoplasm. Herein, we report a case of ruptured aortic aneurysm infected by C. septicum in a patient with colon cancer. This is the first reported case of infected aneurysm caused by C. septicum in Korea. Early diagnosis, appropriate antibiotic therapy, and prompt surgical interventions are required considering the rapid downhill progression of C. septicum-induced infected aneurysm.

Mediastinal Tuberculous Lymphadenitis with Periodic Fever / 감염과화학요법

A 60-year-old man undergoing maintenance hemodialysis presented with periodic fever, which resembled Pel-Ebstein fever of Hodgkin's lymphoma. Despite scores of diagnostic evaluations, origin of the fever remained obscure. On positron emission tomography/computed tomography scan, focal hot uptakes were seen in the mediastinum and mediastinoscopic biopsy showed many acid-fast bacilli with chronic granulomatous inflammation and necrosis. After a week of anti-tuberculosis medication, the patient remained afebrile without recourse to antipyretics.

A Case of Aortic Aneurysm Rupture Infected by Clostridium septicum in a Patient with Colon Cancer / 감염과화학요법

Infected aortic aneurysm a life-threatening disease entity. Clostridium septicum is a very rare pathogen of infected aneurysms that carries a high mortality rate and demonstrates a strong association with an derlying colonic or hematologic neoplasm. Herein, we report a case of ruptured aortic aneurysm infected by C. septicum in a patient with colon cancer. This is the first reported case of infected aneurysm caused by C. septicum in Korea. Early diagnosis, appropriate antibiotic therapy, and prompt surgical interventions are required considering the rapid downhill progression of C. septicum-induced infected aneurysm.

Prognostic Significance of Infection Acquisition Sites in Spontaneous Bacterial Peritonitis: Nosocomial versus Community Acquired

Spontaneous bacterial peritonitis (SBP) is an ascitic fluid infection as a complication of end stage liver disease. The outcome is related to the severity of hepatorenal function, gastrointestinal bleeding, and many others; however it is not well known whether the infection acquisition sites have an effect on the prognosis of SBP. In order to identify the prognostic significance of the acquisition sites, we studied 106 patients who were diagnosed as culture positive SBP between October 1998 and August 2003. Thirty-two episodes were nosocomial and 74 were community acquired. Gramnegative bacilli such as Escherichia coli were dominant in both of the nosocomial and community-acquired SBPs. Despite significantly higher resistance to cefotaxime in nosocomial isolates compared to community-acquired isolates (77.8% vs. 13.6%, p=0.001), no difference was found regarding short or long term prognosis. Infection acquisition sites were not related to short or long term prognosis either. Shock, gastrointestinal bleeding and renal dysfunction were related to short term prognosis. Only Child-Pugh class C was identified as an independent prognostic factor of long-term survival.

In Vitro Activity of Cefditoren against Respiratory Pathogens / 감염과화학요법

BACKGROUND: Cefditoren is a third generation orally administered cephalosporin with excellent activity against respiratory pathogens. This study was performed to determine the comparative antibacterial activity of cefditoren against clinical isolates of respiratory tract infection. MATERIALS AND METHODS: According to the NCCLS guideline, in vitro activities of cefditoren and other antibiotics were tested against respiratory pathogens including 117 isolates of Streptococcus pneumoniae, 60 isolates of Haemophilus influenzae, and 31 isolates of Moraxella catarrhalis. RESULTS: The level of cefditoren activity against S. pneumoniae (MIC50/90, 0.5/1 microgram/mL) was superior to amoxicillin+/-clavulanate (MIC50/90, 4/16 microgram/mL), clarithromycin (MIC50/90, >32/>32 microgram/mL), and most of the marketed cephalosporins (MIC50/90, 8-64/16-128 microgram/mL). Although the MIC of cefditoren was relatively higher than those of new fluoroquinolone agents (MIC50/90, 0.03-1/0.06-1 microgram/mL), it was comparable to ceftriaxone (MIC50/90, 0.5/1 microgram/mL). In addition, cefditoren was active against two quinolone resistant pneumococci strains with MIC of 0.5 microgram/mL. In detail, cefditoren was active against pneumococci strains with MIC50 and MIC90 values of 0.015/0.12, 0.12/0.5, and 0.5/1 microgram/mL for penicillin-susceptible, -intermediate, and -resistant pneumococci, respectively. Cefditoren was also active against all respiratory isolates of H. influenzae (MIC50/90, 0.03/0.06 microgram/mL) and M. catarrhalis (MIC50/90, 0.03/0.05 microgram/mL) irrespective of beta-lactamase production or ampicillin resistance. CONCLUSION: Cefditoren is considered to be a good option for outpatient treatment of respiratory infections, particulary if there is concern about S. pneumoniae infection with decreased susceptibility to penicillin or beta-lactamase producing organisms.

The Relation between the High-level Resistance to Fluoroquinolones and the Over-expression of the acrA among Quinolone-Resistant Escherichia coli-Quantification of acrA by Using Real time PCR and Northern hybridization / 감염과화학요법

BACKGROUND: Target point mutation of DNA topoisomerase, which is the typical mode of quinolone resistance, cannot explain high level resistance to quinolones. Therefore, many authors looked into over expression of efflux pump as the possibility. After quantificating the arcA mRNA, which controls AcrAB- TolC, the authors tried to find out the difference in the expression of arcA mRNA according to MIC of ciprofloxacin. The authors also tried to determine the usefulness of real time PCR, which is more reproducible and takes less time than preexisting immunoblot assay, through quantification of acrA. MATERIAL AND METHODS: Mutations in topoisomerase (GyrA, ParC) of 20 quinolone resistant E. coli isolates were identified by PCR and direct DNA sequencing. AcrA level was measured by real time PCR. GAPDH of E.coli was used as endogenous control. The expression of acrA was confirmed through northern hybridization method, the results obtained by real time PCR were compared. RESULTS: 1) Topoisomerase mutations were found in all quinolone resistant E. coli strains. 2) AcrA expression in fluoroquinolone-resistant E. coli was quantified by using real time PCR. There was no relationship between the ratio of acrA expression to GAPDH and MIC of ciprofloxacin. 3) With Northern hybridization, we compared the band of acrA to that of GAPDH in compactness and area. No difference in the expression according to MIC could be found. 4) The results of AcrA/GAPDH were significantly correlated between the real-time PCR and northern blot (P<0.05, correlation coefficiency 0.98). CONCLUSION: In this study, no relationship between overexpression of AcrA gene and high level fluoroquinolone resistance. Therefore, we assume that mechanism other than AcrAB efflux pump is involved in and contribute to high-level fluoroquinolone resistance. However, the degree of efflux pump expression could be confirmed with real time PCR using acrA mRNA. Therefore, real time PCR could be used in the molecular biologic study on the mechanism of resistance to antibiotics.

In Vitro Activity of Cefditoren against Respiratory Pathogens / 감염과화학요법

BACKGROUND: Cefditoren is a third generation orally administered cephalosporin with excellent activity against respiratory pathogens. This study was performed to determine the comparative antibacterial activity of cefditoren against clinical isolates of respiratory tract infection. MATERIALS AND METHODS: According to the NCCLS guideline, in vitro activities of cefditoren and other antibiotics were tested against respiratory pathogens including 117 isolates of Streptococcus pneumoniae, 60 isolates of Haemophilus influenzae, and 31 isolates of Moraxella catarrhalis. RESULTS: The level of cefditoren activity against S. pneumoniae (MIC50/90, 0.5/1 microgram/mL) was superior to amoxicillin+/-clavulanate (MIC50/90, 4/16 microgram/mL), clarithromycin (MIC50/90, >32/>32 microgram/mL), and most of the marketed cephalosporins (MIC50/90, 8-64/16-128 microgram/mL). Although the MIC of cefditoren was relatively higher than those of new fluoroquinolone agents (MIC50/90, 0.03-1/0.06-1 microgram/mL), it was comparable to ceftriaxone (MIC50/90, 0.5/1 microgram/mL). In addition, cefditoren was active against two quinolone resistant pneumococci strains with MIC of 0.5 microgram/mL. In detail, cefditoren was active against pneumococci strains with MIC50 and MIC90 values of 0.015/0.12, 0.12/0.5, and 0.5/1 microgram/mL for penicillin-susceptible, -intermediate, and -resistant pneumococci, respectively. Cefditoren was also active against all respiratory isolates of H. influenzae (MIC50/90, 0.03/0.06 microgram/mL) and M. catarrhalis (MIC50/90, 0.03/0.05 microgram/mL) irrespective of beta-lactamase production or ampicillin resistance. CONCLUSION: Cefditoren is considered to be a good option for outpatient treatment of respiratory infections, particulary if there is concern about S. pneumoniae infection with decreased susceptibility to penicillin or beta-lactamase producing organisms.

The Relation between the High-level Resistance to Fluoroquinolones and the Over-expression of the acrA among Quinolone-Resistant Escherichia coli-Quantification of acrA by Using Real time PCR and Northern hybridization / 감염과화학요법

BACKGROUND: Target point mutation of DNA topoisomerase, which is the typical mode of quinolone resistance, cannot explain high level resistance to quinolones. Therefore, many authors looked into over expression of efflux pump as the possibility. After quantificating the arcA mRNA, which controls AcrAB- TolC, the authors tried to find out the difference in the expression of arcA mRNA according to MIC of ciprofloxacin. The authors also tried to determine the usefulness of real time PCR, which is more reproducible and takes less time than preexisting immunoblot assay, through quantification of acrA. MATERIAL AND METHODS: Mutations in topoisomerase (GyrA, ParC) of 20 quinolone resistant E. coli isolates were identified by PCR and direct DNA sequencing. AcrA level was measured by real time PCR. GAPDH of E.coli was used as endogenous control. The expression of acrA was confirmed through northern hybridization method, the results obtained by real time PCR were compared. RESULTS: 1) Topoisomerase mutations were found in all quinolone resistant E. coli strains. 2) AcrA expression in fluoroquinolone-resistant E. coli was quantified by using real time PCR. There was no relationship between the ratio of acrA expression to GAPDH and MIC of ciprofloxacin. 3) With Northern hybridization, we compared the band of acrA to that of GAPDH in compactness and area. No difference in the expression according to MIC could be found. 4) The results of AcrA/GAPDH were significantly correlated between the real-time PCR and northern blot (P<0.05, correlation coefficiency 0.98). CONCLUSION: In this study, no relationship between overexpression of AcrA gene and high level fluoroquinolone resistance. Therefore, we assume that mechanism other than AcrAB efflux pump is involved in and contribute to high-level fluoroquinolone resistance. However, the degree of efflux pump expression could be confirmed with real time PCR using acrA mRNA. Therefore, real time PCR could be used in the molecular biologic study on the mechanism of resistance to antibiotics.

Pre-travel medical consultation for international travelers / 대한내과학회지

No abstract available.

Clinical Features of VRE Infection, Microbiologic Characteristics and Genetic Relatedness of VRE Isolates from Six University Hospitals / 감염

BACKGROUND: In recent years, vancomycin-resistant enterococci (VRE) have become one of major nosocomial pathogens in Korea. VRE infection presents as an increasingly difficult clinical problem in the treatment and management. The purpose of this study was to determine the clinical features, microbiologic characteristics, and genetic relatedenss of clinical VRE isolates which were collected from six university hospitals, distributed nationwide in Korea. In addition, we aimed to elucidate the possibility of VRE dissemination between hospitals. METHODS: During one year (January, 1999 to January, 2000), 107 clinically suspected VRE isolates were collected from six university hospitals and were subjected to vancomycin resistance genotyping by vanA, vanB, vanC1 and vanC2 PCR. Those 70 isolates with vanA genotype were examined antimicrobial susceptibility by agar dilution method. Pulsed-field gel electrophoreis (PFGE) were used for discriminating the genetic relatedness of VRE isolates. Clinical characteristics of the 61 patients with vanA VRE infection were analyzed for the identification of risk factors for VRE infection. RESULTS: Out of 107 clinical VRE isolates from six hospitals, 70 isolates (65.4%) were vanA genotype VRE (67 E. faecium, 3 E. faecalis). Their MIC90 of vancomycin, teicoplanin and ampicillin were >512 microgram mL, 512 microgrammL and >512 microgrammL respectively. The prevalance of high-level resistance to gentamicin and streptomycin were 96.9% and 78.1%, respectively. Prolonged hospital stay, cerebro-vascular disease, use of third generation cephalosporins, use of Foley catheter and levin tube were associated with VRE infection. 64 vanA VRE (61 E. faecium, 3 E. faecalis) had unique PFGE pattern within each hospital and showed no evidence of VRE transmission between hospitals. CONCLUSION: This study demonstrated the most common vancomycin resistance genotype among clini-cal VRE isolates in Korea were vanA type VRE. vanA genotype VRE had unique PFGE pattern within each hospital and showed no evidence of inter-hospital transmission. This study suggested that maintaining HICPAC guidelines, restricted vancomycin usage and periodic surveillance in patients with high risk factors are important in preventing the emergence and spread of VRE infection within hospitals.

Epidemiologic and Clinical Features of Adult Patients with Measles During 2000 Epidemic / 감염

BACKGROUND: Measles is an acute highly contagious infection caused by measles virus. Since the introduction of measles vaccines in 1963, measles has been dramatically decreased in Korea. However, measles outbreaks have occurred periodically every 4 to 6 years during the 1990s. During 2000, measles outbreak of large scale occurred throughout the country and the total of 32,088 cases were reported. The majority of affected population was infants and school-aged children, but measles was reported also among adolescent and adult population. There was no report about the epidemiology of adult measles cases during the last decade. In this study, we retrospectively analyzed the epidemiologic and clinical features of adult measles patients in Korea. METHODS: From July of 2000 to January of 2001, 50 adult cases of measles had been admitted to Korea University Hospital. Medical records of these 50 patients, who were clinically diagnosed as measles, were reviewed. Demographic data, clinical features, history of measles vaccination and laboratory findings were evaluated. RESULTS: The median age of patients was 23 years : 28 (56%) were male. Most cases (49/50, 98%) occurred between November of 2000 to January of 2001 and 8 (16%) patients were associated with outbreaks. The occupation of patients was diverse but, students (28%) and office workers (20%) were the most common. 44 (88%) of 50 patients had no underlying diseases. Adult measles patients demonstrated similar clinical symptoms, which were shown in children with measles. In laboratory findings, mean WBC count was 4,933/micro L and 18 (36%) patients had thrombocytopenia. 21 (42 %) patients had complication of measles, and hepatitis was the most common episodes among them. Measles vaccination history revealed that 5 (10%) had two-dose and 7 (14%) had one-dose measled vaccine. In 35 patients, measles IgM antibody test was done. It appears that IgM positive rate among one-dose measle vaccination group, two-dose measle vaccination group, and group with unknown vaccination history were 86% (6/ 7), 40% (2/5), and 78% (18/23), respectively. Most (94%) of patients were hospitalized and more than two-third of patients were isolated. All the patients were recovered without sequelae. CONCLUSION: In 2000 measles outbreak, adult measles had the typical clinical features similar to those in the children and the severe complication was rare. Adult measles patients demonstrated low measles vaccination rate and occurred mainly among the students and office workers.

Clinical and Genetic Characteristics of Infection by Penicillin-resistant Streptococcus pneumoniae from Community and Hospital / 감염

BACKGROUND: During the last three decades, the resistance of S. pneumoniae to penicillin has been rapidly increasing in many parts of the world, especially in Korea. To characterize the clinical features and epidemiology of penicillin-resistant S. pneumoniae (PRSP) infections in the community and hospital, as well as to investigate the possible spread of resistant clone, we performed the antimicrobial susceptibility tests, pulsed filed gel electrophoresis (PFGE) and penicillin-binding protein (PBP) profile analysis of PRSP isolates. METHODS: A total 48 PRSP isolates from patients who visited or were admitted to Korea University Guro hospital during the period form July 1998 to June 1999 were studied. Anitimicrobial susceptibility tests for 48 isolates were performed with microbroth dilution method to determine the minimal inhibitory concentration of 11 antibiotics. 39 isolates and 35 isolates were subjected to PFGE and PBP profile analysis, respectively to investigate the genetic relatedness between PRSP isolates. RESULTS: Pneumonia was most common site of infection in the community and the hospital as 50%. There were no significant differences of clinical features and prognosis between community and hospital isolates. But, patients with serious underlying diseases had poor prognosis despite of acquisition site. High level penicillin resistance were observed in 69%, multi-drug resistance were 64.6% of isolates. PFGE showed that 13 of 29 community acquired infection were identical PFGE pattern but not that of 23F Spanish clone. There were various PFGE patterns were observed from community and hospital acquired infection isolates. Some of them were existed in both. PBP profiles showed more diverse, even if in isoaltes of the same PFGE pattern. CONCLUSOIN: In our study, high level penicillin resistance and multi-drug resistance were observed in PRSP clinical isolates. No clinical and prognostic differeces were observed between community and hospital acquired infections. Molecular epidemiology study were suggest the there were various genotypes of PRSP within our society. Some of them were observed in the hospital and community. Therefore, there was an evidence of communication of PRSP clones between the community and hospital.

Quinolone-resistant E. coli Bacteremia: Clinical & Microbiologic Characteristics / 감염

From the prudent use of quinolone in clinical practice, quinolone-resistant E. coli strains are being isolated with increasing frequency in the community as well as in the hospital. To analyze the risk factors, clinical features and prognosis of QREC, we reviewed the microbiologic records of E. coli bacteremia patients, estimated the quinolone consumption and performed the PFGE to compare genetic diversity. From 1994 to 1998, 40 episodes of QREC bacteremia were observed, 15 cases (37.5%) were hospital acquired. Overall, there is significant correlation between the increased incidence of QREC bacteremia and the upward trend in quinolone use in the hospital as out-and in-patients medication (P=0.003, r=0.98). When we compare the 40 case patients with 80 simultaneous control patients who had quinolone-susceptible E. coli bacteremia, the case patients more frequently had chronic underlying illness, prior use of quinolones and other antibiotics. Quinolone resistance was not significantly associated with higher mortality. A logistic regression analysis identified prior quinolone (P=0.001) use and prior use of other antibiotics (P=0.04) as the only independent risk factors for QREC bacteremia. 10-or 8-different PFGE patterns were observed in QREC isolates from community and hospital. They revealed little evidence of clonal spread, and may have emerged in direct response to the selective pressure exerted by antibiotic use.

A Case of Clostridium Septicum Sepsis Associated with Malignancy / 감염

Clostridium septicum is a toxin producing anaerobic, motile, spore-forming, spindle shaped Gram positive rod that may cause devastating systemic illness in patients with neutropenia and underlying hematologic or gastrointestinal malignancy. Clostridium septicum sepsis usually have fulminating clinical courses, and unless the appropriate antibiotics are administered soon after admission, the outcome is fatal. We experienced a case of sepsis due to Clostridium septicum, in a 65-year-old woman with peripheral T-cell lymphoma and diabetes mellitus. She was admitted due to abdominal pain, fever, chilling, nausea, vomiting and watery diarrhea, followed by rapidly progressive course. This patient was not improved by intensive care and continuous antibiotic therapy, expired at the 4th hospital day. Clostridium septicum grew from premortem blood cultures.

Clinical Features and Prognosisof Community-acquired Pneumonia in the Elderly Patients / 감염

BACKGROUND: Community-acquired pneumonia (CAP) is more frequent in the elderly and results in higher morbidity and mortality. Korea is undergoing extraordinary demographic change. Elderly patients constitute an even-increasing proportion of the population but there have been few studies on the epidemiological investigation of the CAP in the elderly. The purpose of this study was to characterize the background, etiology, clinical course and outcome of CAP in elderly compared with younger patients. METHODS: During the study period (from 1st January to 31th December 1997), 214 patients with CAP were reviewed with regard to epidemiological, clinical, laboratory and microbiological data. 119 elderly patients (> or =65 years-old of age) were compared with 95 younger patients (<65 years-old of age). The both groups were compared with each others in terms of variables related to CAP. RESULTS: Comparison of epidemiological data between older and younger patients revealed a high prevalence of alcoholics (40% vs 56%), current smoker (33% vs 56%), malignancy (8% vs 24%) in the elderly. In terms of complication and clinical manifestation, shock (1% vs 6%), intubation (6% vs 20%), mechanical ventilation apply (5% vs 18%), respiratory failure (2% vs 12%), dyspnea (26% vs 56%), altered consciousness (0% vs 13%), extrapulmonary symptom (11% vs 18%) and bilateral infiltration (8% vs 20%) showed higher incidence in the elderly than in the younger patients. Causative organisms are identified in 47% (56/119) of elderly patients: those identified most frequently were S. pneumoniae (25%), K. pneumoniae (20%), S. aureus (16%), other Gram-negative bacilli (13%) and H. influenzae (11%). The overall mortality were significantly higher in the elderly patients (24%) than younger patients (5%). Two independent risk factors, those were related to the mortality of the elderly:higher APACHE II score (RR:3.43, 95% CI=1.43~7.21) and requirement of endotracheal tube (RR:4.73; 95% CI=1.72~16.5). CONCLUSION: CAP in the elderly shows more serious clinical and abnormal laboratory features than younger patients. In elderly, S. pneumoniae was the most common causative organism for CAP but other agents, particularly K. pneumoniae was isolated frequently. The severity of illness at initial presentation such as high APACHE II score and requirement of endotracheal tube were the major variables affecting the outcome.