Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology


Weeks in Review


Weeks to Publication
Indexed in KCI, KoreaMed, Synapse, DOAJ
Open Access, Peer Reviewed
pISSN 2288-0585 eISSN 2288-6850

September, 2001. Vol. 4 No. 2.

Review article

Antimicrobial Resistance of Helicobacter pylori

Mi Ae Lee, M.D.

Ann Clin Microbiol 2001 September, 4(2): 73-77. Published on 20 September 2001.

H. pylori가 1983년 발견된 이래 만성위염 및 소화성궤양의 중요한 원인균이며 위선암 및 위림프종 발생의 중요한 위험인자로 인식되고 있다. H. pylori의 치료는단일 약제로는 불가능하고 현재여러가지병용요법들이 시도되고 있으나 만족할 만한치료성적을얻을수없는데, 이러한 치료 실패요인으로 가장 큰 원인은 항균제 내성균주의증가와환자의non-compliance를들고있다.

또한 H. pylori는 매우 까다로운 균이고 항균제 감수성 검사방법에 따라 결과가 달라질 수 있는데 이에 대한 기준이 아직 정립되어 있지 않다. National Committee for Clinical Laboratory Standards (NCCLS)에서1999년 처음으로 H. pylori의 항균제 감수성 검사법으로 한천희석법(agar dilution)을 추천하였으나, 내성의breakpoint는 정해져 있지 않았다. 2000년 들어 NCCLS [1]에서 clarithromycin의 breakpoint 기준만을 제시하고있어 검사실간의 차이가 크고 검사법간의 차이가 크므로, 저자는 H. pylori의 항균제 내성현황, 감수성 검사의 필요성, 방법 및 내성기전을 중심으로 저자의 경험과 문헌을바탕으로 기술하고자 한다.

[in Korean]

Review article

Chlamydia pneumoniae and Atherosclerosis

Won-Kil Lee, M.D.

Ann Clin Microbiol 2001 September, 4(2): 78-81. Published on 20 September 2001.

Chlamydia pneumoniae는 숙주세포가 산생한 에너지에 의존하며, 세포 내에서만 생존이 가능한 기생체로서 잠복성 감염이나 만성 감염을 주로 일으키는 세계적으로 널리 퍼져있는가장흔한감염원인중하나라고 한다. 이 균에 의한 급성 감염은 호흡기를 주로 침범하지만 증상이 경하거나 없다고 하며, 또한 이 균은 지역사회 폐렴의 흔한 원인균[1]이기도 하다. 특히 이균은 죽상(粥狀; 혹은 동맥)경화증을 비롯한 몇 개의 염증성 질환의 병리기전에 원인으로서 관여[2]하기 때문에 많은 연구자들의 관심의 대상이기도 하다고 한다.

죽상경화증은 대(大) 혹은 중(中) 동맥의 내피(endothelium) 내에 생긴 죽상경화 플라크(plaques)에 의해 부분적인 폐쇄를 일으키는 일련의변화를특징으로하고있으며, 만일 침범된 동맥의 내경이 70%이상 감소될 만큼 플라크가 커지게 되면 혈류의 흐름이 심각하게 나빠져서 협심증과 간헐성 파행(intermittent claudication)과 같은 죽상경화증의 임상증상을 나타낸다[3]고한다.

[in Korean]

Review article

Microarray Gene Expression Analysis

Sunjoo Kim, M.D.

Ann Clin Microbiol 2001 September, 4(2): 82-86. Published on 20 September 2001.

Arrays are used for many purposes, most prominently to measure level of gene expression for tens of thousands of genes simultaneously. Microarrays consist of probe DNA attached to the solid surface (chips), which is hybridized with fluorescent labeled cDNA samples. Microarrays can be classified into two categories. Oligonucleotide array uses 25 bp oligonucleotide probe DNA that is synthesized in situ on the solid surface photolithographically. Avidin-phycoerythrin is used to develop fluorescence. Compared to oligonucleotide array, cDNA microarray is more flexible to customize. The size of cDNA produced by RT-PCR, ranges from 250 to 750 bp. Spotter and twocolor scanner are needed for cDNA microarray. The ratio of Cy5/Cy3 is plotted and clustered for each gene to see the expression pattern. With the fast growing computer technologies and improved understanding for the genes, microarray is a promising tool to enhance our knowledge about genetically complicated diseases. We can choose the most effective drug to the specific pathogen for each person according to the expression pattern. Gene therapy would be applied prophylactically for the patients who have disease marker genes in the future. In spite of high price and technical subtleness of microarray, we had better to be accustomed to this system because we are living in the post-genomic era.

[in Korean]

Original article

Isolation Trend of Enteropathogenic Bacteria in 1969-1998

Hee Bong Shin, Seok Hoon Jeong, Myeungsuk Kim, Won Ho Kim, Kyungwon Lee, and Yunsop Chong

Ann Clin Microbiol 2001 September, 4(2): 87-95. Published on 20 September 2001.

Background: Diarrheal disease has been one of the most common health problem in Korea with Salmonella and Shigella being the major bacterial pathogens. Prevalence of enteric bacterial pathogens may differ significantly depending on the socioeconomic status of a country. Therefore, rapid improvement of living conditions in Korea should have profound effect on the incidence of enteric infection. In some Salmonella infections, proper antimicrobial treatment is important to reduce morbidity and mortality, but rapid change of the susceptibility makes the susceptibility unpredictable. So, there is a need to describe the change of antimicrobial susceptibility of Salmonella.

Methods: In this study, stool culture results at Severance Hospital during the years 1969-1998 were analyzed to determine the trends of enteric bacterial isolation and the susceptibility of the isolates.

Results: The proportion of S. typhi was reduced to 1.4% in 1994-1998. The proportion of Shigella was over 50% of all enteric pathogens until 1983, while only 14 strains were isolated during the last 5 years. Campylobacter spp. became the second most prevalent organism with the decrease of Shigella isolation. Ampicillin- and cotrimoxazole-susceptible nontyphoidal Salmonella gradually decreased to 76% and 90%, respectively in 1994-1998 and even several extended-spectrum β-lactamase-producing strains were detected. Strains of ampicillin-resistant S. typhi were first detected in 1995.

Conclusions : Typhoid fever and shigellosis are rare disease now in urban clinical setting while nontyphoidal Salmonella infection is a prevalent one. Campylobacter is the second most common enteric bacterial pathogen. With the increase of antimicrobial resistance of nontyphoidal Salmonella and appearance of resistant S. typhi, difficulties in the treatment of these infections may be expected in the future. 

[in Korean]

Original article

Comparison of EASY 24 Plus, API 20E, and VITEK GNI+ for Identification of Enterobacteriaceae

Mi Ae Lee, M.D., Hyang Sook Park, M.T., Sunjoo Kim, M.D., and Eui Chong Kim, M.D.

Ann Clin Microbiol 2001 September, 4(2): 96-101. Published on 20 September 2001.

Background:Several automated and nonautomated systems have been developed and are commercially available for the identification of gram-negative bacilli. EASY 24E+ kit was recently developed as Korean kit for identification of gram-negative bacilli. So we evaluated the accuracy and clinical utility of EASY 24E+ compared with API 20E and VITEK GNI+.

Methods:The 221 clinical isolates of Enterobacteriaceae, including 17 C. freundii, 20 E. cloacae, 31 E. coli, 6 E. aerogenes, 29 K. pneumoniae, 3 K. oxytoca, 11 M. morganii, 13 P. mirabilis, 16 Salmonella  spp., 20 S. marcescens, 9 Shigella spp.,22 S. sonnei, 16 S. typhi, 8 Y.  pseudotuberculosis and 10 control strains were identified by API 20E, EASY 24E+, and VITEK GNI+. Discrepant strains were performed repeat identifications and we evaluated overall accuracy.

Results:All of control strains were correctly identified by three systems. The overall correct results at species level and at the genus level for 221 clinical isolates, were 96.8% and 99.1% by the VITEK GNI+, 97.7% and 97.7% by the EASY 24+ and 99.1% and 100% by the API 20E. All of Salmonella spp., S. typhi and Shigella spp. were correctly identified by all three systems and the discrepant identifications of species were 2 Y. pseudotuberculosis, 3  K. pneumoniaeand 2 K. oxytoca by VITEK GNI+, 4 C. freundii and 1 P. mirabilis by EASY 24+, and 2 S. marcescens by API 20E.

Conclusions:All three identification systems are accurate methods for the identification of Enterobacteriaceae, and EASY 24+ is comparable with API 20E and VITEK GNI+.

[in Korean]

Original article

Nested Polymerase Chain Reaction Assay of Helicobacter pylori in Saliva

Tae Hee Han, M.D., and In Ki Paik, M.D.

Ann Clin Microbiol 2001 September, 4(2): 102-107. Published on 20 September 2001.

Background : The aim of this study was to investigate the prevalence of Helicobacter pylori in the saliva of infected patients and the relation between H. pylori in the saliva and the severity of gastric infection.

Methods : Active gastric infection was determined by the 13C-urea breath test. Bacteria in saliva were detected by the nested polymerase chain reaction, using primer sets EHC-U/EHC-L and ET5U/ET-5L.

Results : The PCR assay was able to detect as few as 5 H. pylori /mL. A total of 82 (71.9%) out of 114 patients with gastroduodenal diseases were positive by 13C-urea breath tests. Among these 82 patients, 21 (25.6%) were PCR positive in their saliva. H. pylori was present in the saliva of patients with highly active gastric infections (〉50 δ‰). No H. pylori was detected in saliva of patients with no active gastric infections.

Conclusions : In patients with highly active gastric infections, H. pylori may be transmitted via saliva. The PCR assay of H. pylori in saliva is not useful for detecting gastric infection but may be a useful tool for the screening of highly infectious patients.

[in Korean]

Original article

Survey on Changes in Mycobacterial Testing Practicies in Korean Laboratories

Chulhun L. Chang, M.D., Tae Sung Park, M.D., Mi-Na Kim, M.D., Nam Yong Lee, M.D., Hee-Joo Lee, M.D., and Jin-Tae Suh, M.D.

Ann Clin Microbiol 2001 September, 4(2): 108-114. Published on 20 September 2001.

Background:Since 1997 in which first survey for mycobacterial practices of hospitals in Korea were carried on, changes of practice and concept in mycobacterial testing have been expected because advanced testing methods have been surged for last five-year-period. We purposed to follow-up survey to monitor practices changes, and in addition, situation of quality control.

Methods:Questionnaires was composed of items including mycobacterial test methods, test volume, turnaround time (TAT), and quality control measure. It was sent to 90 laboratories of general hospitals, tuberculosis specialty hospitals and commercial laboratories in April 2001.

Results:Sixty-seven (74%) of 90 laboratories replied to this survey. Five of 67 laboratories (7%) were using fluorochrome method for AFB stains. In five among 58 laboratories that performed AFB cultures (8%), liquid media have been used. Mycobacterial species was identified by molecular biologic methods or high-performance liquid chromatography in 18 laboratories (34%). Average TAT of culture and identification for Mycobacterium tuberculosis was 11 days at the laboratory using Mycobacteria Growth Indicator Tube (MGIT) 9600 system and PCR method, while that at the laboratory using Ogawa media and biochemical method was 35.8 days. TATs of susceptibility tests undertaken at three laboratories were 28-60 days. Only six laboratories were joining external quality control program, even though most laboratories wanted to participate in.

Conclusions:TATs for mycobacterial culture and susceptibility tests were too long to have the laboratories take a pivotal role to control tuberculosis. To improve Korean mycobacterial laboratories, it is necessary that the national health insurance system supports the newer rapid methods for mycobacterial tests and nationwide external quality control program is introduced.

[in Korean]

Original article

Evaluation of a Polymerase Chain Reaction Assay and BACTEC Culture for the Detection of Mycobacterium tuberculosis in Clinical Specimens

Chang Jae Lee, M.D., Seung Jung Kee, M.D., Jong Hee Shin, M.D., Soon Pal Suh, M.D., and Dong Wook Ryang, M.D.

Ann Clin Microbiol 2001 September, 4(2): 115-121. Published on 20 September 2001.

Background: The PCR assay for the detection of M. tuberculosis has been used for 5 years in Chonnam National University Hospital. To evaluate the reliability of the PCR assay, the PCR results were compared with those of culture and clinical diagnosis.

Methods : This study analyzed the results of BACTEC culture and PCR for detection of M. tuberculosis between Jan. 1996 and Dec. 1998. A total of 7,430 specimens for the PCR, 16,163 specimens for the TB BACTEC culture and 4,810 specimens (3,167 patients) submitted for both PCR and BACTEC culture were analyzed for the clinical evaluation of PCR.

Results: When compared with BACTEC culture results, PCR had a sensitivity of 66.1% (127/192) and a specificity of 97.0% (3,631/3,740) for the detection of M. tuberculosis in respiratory specimens. The sensitivity, specificity, positive and negative predictive values for the PCR assay for the diagnosis of tuberculosis patients were 64.7%, 98.5%, 84.8%, and 95.6%, respectively; the values for BACTEC culture were 86.7%, 100%, 100%, and 98.3%, respectively. In addition, 39 out of 71 PCR positive cases which were BACTEC culture-negative had clinical data supporting the diagnosis of tuberculosis. The average detection times were 5 hours in PCR but 15.8 days in BACTEC culture.

Conclusions : This study shows that PCR itself is not satisfactory enough to detect M. tuberculosis in clinical specimens. However, when it combines with BACTEC culture, they can be a powerful and rapid diagnostic tool to detect M. tuberculosis in clinical specimens.

[in Korean]

Original article

Clinical Characteristics of Pediatric Patients with Candidemia

Kung Ok Yoo, M.D., Sang Khoo Lee, M.D., Chang Jae Lee, M.D., Jong Hee Shin, M.D., Soon Pal Suh, M.D., and Dong Wook Ryang, M.D.

Ann Clin Microbiol 2001 September, 4(2): 122-128. Published on 20 September 2001.

Background:The incidence of candidemia in paediatric patients has increased over the last decade. We analysed the clinical characteristics of pediatric patients with candidemia over a 3-year period in Chonnam National University Hospital.

Methods:The medical records of 28 patients with candidemia diagnosed between 1996 and 1998 were retrospectively reviewed. Clinical characteristics including underlying illness, risk factors, therapy and outcome were assessed in relation to causing Candida species.

Results:The causing agents were mainly non-C. albicans species (24/28 cases, 81.5%). Underlying illnesses of patients were malignancy (n=12), surgical diseases (n=4), prematurity (n=2), and other medical illnesses of (n=10). Studies on clinical status at positive culture revealed antibiotic exposure (28/28, 100%), placement of central venous catheter (CVC, 16/28, 57.1%), use of total parenteral nutrition (15/28, 53.6%), and chemotherapy (14/28, 50%). Twenty patients were treated with amphotericin B and/or fluconazole and 15 patients’CVCs were removed. Overall mortality due to candidemia was 25%(7/28).

Conclusions:These data show that most of pediatric candidemia cases are caused by non-C. albicans species and associated with a relatively lower mortality rate.

[in Korean]

Original article

Utility of 293 Cells in Culture of Enteroviruses

Han-Sung Kim, Wonkeun Song, and Kyu-Man Lee

Ann Clin Microbiol 2001 September, 4(2): 129-133. Published on 20 September 2001.

Background:Viral isolation in cell culture remains as a reference method for diagnosis of enteroviral infection. Enteric adenoviruses are cultivated in 293 cells. Enteroviral and enteroadenovrial tropisms for the gastrointestinal tract lead to the assumption that 293 cells would be useful in enteroviral isolation. We evaluated usefulness of 293 cells in the diagnosis of enteroviral infection.

Methods:Human embryonic lung fibroblasts (HEL), HeLa, RD and 293 cells were used to evaluate viral isolation from clinical specimens, susceptibilities of the cell lines to reference enteroviral strains and influence to stool extracts on the viral isolation. Forty-four stool specimens collected from patients during the epidemic period of type 9 echoviral aseptic meningitis and type 30 echoviral culture-positive 33 stool and 58 cerebrospinal fluid (CSF) specimens were inoculated onto cell lines.

Results:Echovirus type 9 was isolated from 31 of 44 stool specimens. Of 31 echovirus 9 isolates, 22 (71.0%), 21 (67.7%), 6 (19.4%) and 3 (9.7%) were detected in HEL, 293, RD and HeLa, respectively. Of 33 echovirus 30 isolates from stool specimens, 32 (97.0%) were detected in 293; 17 (51.5%) were detected in RD. Of 58 echovirus 30 isolates from CSF specimens, 39 (67.2%) were detected in 293; 30 (51.7%) were detected in RD. 293 cells were sensitive for coxsackievirus A9 reference strain and echovirus 7 reference strain. Stool extracts induced enhanced cytopathic effect by echovirus 9 infection in 293 and HEL.

Conclusions:293 cells are useful in the diagnosis of echoviral and some enteroviral infection.

[in Korean]

Original article

Analysis of Enterovirus Genotypes Using Single-Strand Conformational Polymorphism

Jung-Hyun Kim, Jung-Hee Lee, Je-Kue Lee, Won-Ki Bang, Jung-Yon Hong, and Eui-Chong Kim

Ann Clin Microbiol 2001 September, 4(2): 134-138. Published on 20 September 2001.

Background: Epidemics of aseptic meningitis due to enteroviruses has occurred annually in the late spring and early summer season. The early detection of such epidemics is important for the prevention of further infection. Enteroviruses consist of 67 serotypes but one or two serotypes may be the causative agents of epidemics in the year and several different serotypes involve sporadic cases. In order to discriminate epidemics from sporadic infection, the serotype should be determined. We evaluated the significance of the single-strand conformational polymorphism (SSCP) of reverse transcription-polymerase chain reaction (RT-PCR) products of 5’-untranslated region (UTR) for the determination of serotypes.

Methods: The specimens of patients were cultured with RD cell and the RT-PCR was performed in case of the positive cytopathic effect. For the amplification of 153-bp of 5’-UTR, primers (EN1: 5’-CTC CGG CCC CTG AAT GCG GCT AAT-3’; EN2: 5’-ATT GTC ACC ATA AGC AGC CA-3’) were used. The RT-PCR products were denatured with 95% formamide at 95℃for 5 min and SSCP was performed. 12.5% polyacrylamide gel (49/1 acrylamide/bis) was made by using Mighty SmallTM SE245 Dual Gel Caster (Hoefer Scientific Instruments Inc., USA). Electrophoresis was done at 10 mA for 1.5 h, and silver nitrate stain was performed. The SSCP patterns were compared with serotypes determined by sequence analysis of VP1 region.

Results : Coxsackievirus A9 (two strains), coxsackievirus A16 (10), coxsackievirus B2 (two), coxsackievirus B3 (two), echovirus 3 (two), echovirus 11 (two), echovirus 16 (seven), echovirus 19 (two), echovirus 30 (three), and enterovirus 71 (six) showed the different SSCP patterns according to their serotypes. The same pattern was observed in the same serotype, except echovirus 30 showing two different patterns.

Conclusions : The SSCP of RT-PCR products of 5’-UTR may be helpful to determine the serotype and discriminate epidemics from sporadic cases. This has the advantage to be able to test the specimens directly without the viral culture. But the serotype should be determined by other method such as neutralization or sequence analysis in case of the first isolate in the epidemic season and the stains showing the new SSCP patterns.

[in Korean]

Case report

A Case of Hafnia alvei Peritonitis with Septicemia

Wonkeun Song, M.D., Taek-Kyung Kim, M.T., Min-Jeong Park, M.D., and Kyu Man Lee, M.D.

Ann Clin Microbiol 2001 September, 4(2): 139-141. Published on 20 September 2001.

Hafnia alvei is gram-negative bacilli that is rarely isolated from human specimens and is rarely considered to be pathogenic. It has been associated with gastroenteritis, pneumonia, meningitis, bacteremia, and nosocomial wound infections. But, no case of extraintestinal H. alvei infection was documented in Korea to our knowledge. A 50-year-old man with hepatocellular carcinoma was admitted to our hospital via emergecy department because of abdominal pain. The peritoneal fluid and 3 consecutive blood cutures yielded H. alvei. The organism was susceptible to all antimicrobial agents tested, except cefazolin. Despite treatment with intravenous cefotaxime, the patient was expired after 4 days due to septicemia.

[in Korean]

Case report

A Case of Septicemia by Plesiomonas shigelloides

Hyun Mi Cho, Young Uh, Kap Jun Yoon, Won Yeon Lee, and Hyo Youl Kim

Ann Clin Microbiol 2001 September, 4(2): 142-145. Published on 20 September 2001.

Plesiomonas shigelloides is an oxidase-positive, fermentative, gram-negative rod currently classified as a member of the family Vibrionaceae. P. shigelloides has been implicated as the causative agents of gastroenteritis as well as extraintestinal infections such as septicemia, neonatal meningitis, cellulitis, and cholecystitis. Septicemia due to P. shigelloides is very rare but is severe and has been associated with a high mortality rate. We report a case of septicemia caused by P. shigelloides in a 66-year-old male with diabetes mellitus who had diagnosed as liver cirrhosis 7 years before.

[in Korean]

Case report

A Case of Enterococcus casseliflavus Bacteremia

Young Uh, Hyeun Gyeo Lee, Gyu Yel Hwang, Kap Jun Yoon, and Hyo Youl Kim

Ann Clin Microbiol 2001 September, 4(2): 146-149. Published on 20 September 2001.

Although Enterococcus casseliflavus with intrinsic low-level vancomycin resistance has rarely been isolated from clinical specimens, this organism may cause serious invasive infections such as endocarditis and bacteremia. This low prevalence may be due, in part, to the inability of automated systems to recognize this organism. Vancomycin may not be effective against E. casseliflavus, despite in vitro results that indicate vancomycin susceptibility. It is important that all E. casseliflavus isolates obtained from clinical specimens that are related to serious infections should be identified to species level for appropriate antibiotic therapy. We report a case of bacteremia caused by E. casseliflavus in a 44-year-old female patient with liver disease.

[in Korean]