Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology
Jung Oak Kang
Ann Clin Microbiol 1998 September, 1(1): 1-3. Published on 20 September 1998.
Hoan Jong Lee
Ann Clin Microbiol 1998 September, 1(1): 4-10. Published on 20 September 1998.
Joon Haeng Rhee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 11-13. Published on 20 September 1998.
Eui-Chong Kim, M.D.
Ann Clin Microbiol 1998 September, 1(1): 14-14. Published on 20 September 1998.
Sook Jin Jang, M.D.
Ann Clin Microbiol 1998 September, 1(1): 15-21. Published on 20 September 1998.
Recently, two groups reported independently on the isolation of new positive-trand RNA viruses, designated hepatitis G virus (HGV) & GB virus C (GBV-C). Sequence analysis revealed that both genomes are different isolates of the same virus & represent a new genus of Flaviviridae.
The prevalence of HGV ranges from 0.9 to 10% among blood donors throughout the world. A high prevalence of HGV RNA has been found in subjects with frequent parenteral exposure, including intravenous drug users, patients on hemodialysis, patients with hemophilia and patients with anemia.
HGV is a blood borne virus that is parenterally transmitted. Vertical transmission has also been reported. HGV commonly occurs as a coinfection with another hepatitis virus such as HCV or HBV. However, HGV coinfection usually does not alter the clinical course or level of biochemical marker and the response to antiviral therapy of chronic hepatitis B or C in these patients. Acute HGV infection rarely causes acute hepatitis and is unlikely to be a major cause of chronic non-A-E hepatitis or fulminant viral hepatitis.
HGV infection can be diagnosed by PCR assay to detect the viral RNA in serum. An enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to recombinant HGV putative envelope protein E2 was recently available. But antibodies to E2 appears to be a serological marker for diagnosing recovery from HGV infection. Since the role of HGV as a etiologic agent of liver disease is unclear, therapy is not recommended at this point.
[in Korean]
Won Kil Lee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 22-23. Published on 20 September 1998.
Tae Youn Choi, M.D.
Ann Clin Microbiol 1998 September, 1(1): 24-32. Published on 20 September 1998.
Wee Gyo Lee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 33-36. Published on 20 September 1998.
Jong Hee Shin, M.D.
Ann Clin Microbiol 1998 September, 1(1): 37-43. Published on 20 September 1998.
In the past decades there has been a dramatic increase in the number of opportunistic fungal infections. Establishing the diagnosis of opportunistic fungal infections in compromised patients is not simple. The laboratory diagnostic tests include microscopic examination, culture and serological tests. Although the most reliable method is the histologic examination, various opportunistic fungal agents can reveal similar histologic morphology. Culture should be attempted, however, the isolation of these organisms from cultures must be interpretated with caution, because the causing agents for opportunistic fungal infections are common laboratory contaminants. Serology for fungal infections has limited value except cryptococcal antigen: the usefulness of detection of antigenemia in invasive candidiasis and invasive aspergillosis has been limited by the rapid clearance of Candida mannan and Aspergillus galactomann from serum, which results in only moderate sensitivity for the disease. Therefore, it should be appreciated that every laboratory test, for the diagnosis of opportunistic infections, has its limitations and should be interpreted with caution.
[in Korean]
Mi Ae Lee, M.D. and Jung Won Huh, M.D.
Ann Clin Microbiol 1998 September, 1(1): 44-50. Published on 20 September 1998.
Backgrounds: Helicobacter pylori infection is now recognized as a cause of chronic gastritis, peptic ulcer disease, gastric carcinoma and lymphoma. Several diagnostic methods of H. pylori infection, such as histopathology, culture, rapid urease test, urea breath test, serologic test and polymerase chain reaction (PCR) have been used. This study aimed to compare different diagnostic methods of H. pylori infection and determined the appropriate cut-off value of IgG anti-H. pylori antibody using receiver operating characteristic (ROC) curve.
Methods: We compared sensitivities, specificities and efficiencies of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR using the ureC gene in gastric biopsy specimens from 112 H. pylori patients and 140 control group.
Results: The sensitivities of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 72%, 91%, 86%, 82% and 94%, respectively and the specificities of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 96%, 99%, 100%, 73% and 99%, respectively. The efficiencies of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 88%, 96%, 89%, 77% and 97%, respectively. From the ROC curve, the cut-off value of the anti-H. pylori Ab determined 10U/mL in which sensitivity was 82% and specificity was 82%.
Conclusions: These findings suggest that the PCR assay in gastric biopsy is the most sensitive and efficient diagnostic method of H. pylori infection and the cut-off value of the anti-H. pylori Ab determines 10U/mL showing highest efficiency.
[in Korean]
Chul Hun Chang, M.D., Jeong Whan Shin, M.D., Han Chul Son, M.D., Chul Min Kim, M.D. and Ju Hyun Lee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 51-56. Published on 20 September 1998.
Background: In the year 1996, there were some outbreaks of Salmonella typhi infection in Pusan and therefore, the incidence of S. typhi infection was markedly increased in comparison with the previous year. To differentiate the isolates epidemiologically, a random amplified polymorphic DNA (RAPD) fingerprinting method has been developed.
Methods: A total of 9 arbitrary primers were screened with S. typhi strains isolated in Pusan, 1996. This allowed selection of a panel of primers capable of detecting DNA polymorphisms among S. typhi isolates. This panel was used to examine 54 strains of S. typhi, which had been isolated in Pusan including the cases of outbreaks that was previously characterized by phage typing.
Results: Four single primers and one combination of two primers were selected to discriminate the S. typhi isolates. RAPD analysis resolved the 54 strains into 20 different subtypes. At least two outbreaks were found by RAPD analysis. The isolates of E1 phage type, which are the most common in Korea, were perfectly differentiated with each other, except the strains isolated within the outbreaks.
Conclusion: The RAPD approach is the useful epidemiologic tool to S. typhi subtyping, which is providing high discriminatory power. There were at least two outbreaks when the epidemic Salmonella infections of Pusan in 1996 had been occurred. The primers or their combination capable to discriminate the S. typhi isolates were described.
[in Korean]
Eun Gyung Ko, M.D., Chang Jung Kim, M.D., Key Earn Lee, M.D., Jihyun Cho, M.D., and Young Hoe Moon, M.D.
Ann Clin Microbiol 1998 September, 1(1): 57-62. Published on 20 September 1998.
Background: In developed countries, food-borne diseases have decreased and hospital laboratory have taken more simple method rather than complex enrichment-selective methods. But detection rate of pathogenic bacteria in stool culture was not so high.
Methods: We mixed 4 pathogenic bacteria (S. typhi, S. flexneri, V. cholerae and Y. enterocolitica) with 3 stool specimens from healthy persons (for Y. enterocolitica, 5 specimens) and inoculated directly or after enrichment (10^5 bacteria/plate). After proper incubation, we counted suspected colonies and calculated true positive rate after identification of each colonies.
Results: For S. typhi, in the case of direct innoculation on the MacConkey, XLD and SS agar, positive rate of selected colonies were below 36.6%. After enrichment in SF broth for 8 hours, the rate were 80.0%, 83.0% and 70.0% respectively. For S. flexneri, the rates were 86.7%, 100%, 93.3% in direct innoculation, and were highest after enrichment in GN broth for two hours (93.3% in MacConkey and 100.0% in both XLD and SS agar). For V. cholerae, inspite of screening by catalase and oxidase tests, positive rate of selected colonies were 0% (0/7 colonies) in direct innoculation on the MacConkey. After enrichment in APW about 1 day and on TCBS agar, the rate were 100%. For Y. enterocolitica, after incubation at room temperature for 2 days, most selected colonies were Y. enterocolitica on CIN media.
Conclusion: For more efficient detection of pathogenic bacteria in stool culture, combination of direct innoculation on MacConkey agar and on one or two selective media after proper enrichment process, should be considered.
[in Korean]
Yong Kohn Cho, M.D., Dal Sik Kim, M.D., Sam Im Choi M.D., and Hye Soo Lee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 63-67. Published on 20 September 1998.
Background：Blood culture has been used for finding the etiology of bacteremia. The results of its susceptibility test can be an important tool for deciding the direction of treatment. However, the rate of positive blood culture is very low; it, most of all, is because of the abuse of antimicrobials. Especially under the condition which allows anyone to get antimicrobials at any pharmacies and hospitals without antimicrobial susceptibility test as in Korea, the abuse of antimicrobials be brought about, but there is no concrete information about it.
Methods：The rate of antimicrobial abuse and the serum antimicrobial activities of 106 patients, whose blood was requested for diagnosis of bacteremia, were investigated, and the results were compared with blood culture results. Thirteen mililiters of blood was aseptically extracted; 10 ml out of it was used for blood culture and the serum separated from 3ml of blood was used for serum antibacterial activities. For the test of serum antimicrobial activities, standard strain of bacteria, Staphylococcus aureus ATCC 25923, which are susceptible to every antibiotics was used. And for the blood culture, blood samples were inoculated to aerobic and anaerobic culture broth, and incubated in the automated blood culture system. The abuse of antimicrobials were investigated by the interview with patients and the medical records at admission.
Results：The antimicrobial abuse rate was 78.3%(83/106), and the rate of positive blood culture was as low as 6.6%(7/106). The rate of positive serum antibacterial activity was 47.2%(50/106). The rate of positive blood culture in the group of positive serum antimicrobial activity was only 4%(2/50) and that in the group of negative serum antimicrobial activity was 8.9%(5/56). And in the group of positive blood culture, the rate of positive serum antimicrobial activity was 28.6%(2/7) and the rate of negative activity was 71.4%(5/7).
Conclusions：The antimicrobial abuse rate in Korea was considerably high, and the rate of positive blood culture was very low. The rate of positive blood culture in the group of positive serum antibacterial activity was conspicuously lower than that in the group of negative ones. According to these results, the use of antimicrobials before blood culture should be carefully considered for the diagnosis and treatment of bacterial infection.
[in Korean]
Jeong Hwan Shin, M.D., Chul Hun Chang, M.D., Han Chul Son, M.D., and Kwang Ok Park, M.D.
Ann Clin Microbiol 1998 September, 1(1): 68-74. Published on 20 September 1998.
Background：Several risk factors related with vancomycin-resistant Enterococcus (VRE) colonization are well known, but the direct relatedness of the use of glycopeptides with VRE colonization is not confirmed yet. So we evaluated the influence of the use of glycopeptides and other variables, as risk factors on intestinal colonization with VRE.
Methods：In glycopeptide-administered inpatients group, multiple stool specimens were collected on the day of glycopeptides administration, and weekly after that, until VRE were detected. In the inpatients and outpatients control groups, stool were obtained with point survey. The specimens were inoculated on m-enterococcus agar with 6mg/L vancomycin. The phenotypes and genotypes of resistance of the VRE isolates were confirmed by disk diffusion and agar dilution tests, and polymerase chain reaction.
Results：Of the 361 patients(530 specimens), twelve VRE(3.3%) were isolated. The rates of intestinal colonizations were not significantly differed between the inpatients groups with or without glycopeptides administration, which are 5.1 and 4.1%, respectively. The colonization rates were significantly higher in the patients with 30 or more hospital stay, and in those with three or more antimicrobial administrations. vanA and vanC genes were amplified in the isolates.
Conclusions：It is demonstrated that the use of glycopeptides is not a direct risk factor of intestinal colonization of VRE in Pusan National University Hospital, in which the prescription of glycopeptides is rigidly controlled. But, a shortened stay in the hospital will diminish the intestinal colonization of VRE.
[in Korean]
Chang-Seok Ki, M.D., Seong Kyu Lee, M.D., Jang Ho Lee, M.T., and Nam Yong Lee, M.D.
Ann Clin Microbiol 1998 September, 1(1): 75-81. Published on 20 September 1998.
Background: We tried to evaluate the incidence and clinical significance of coagulase-negative staphylococci (CoNS) with reduced susceptibilities to glycopeptides. In addition, the ability of disk diffusion and Vitek system to detect CoNS with reduced susceptibilities to glycopeptides were compared with the standard agar dilution method.
Methods: One hundred and nineteen clinical isolates of CoNS were recovered at Samsung Medical Center from June to July 1998 and were examined for their susceptibilities to vancomycin and teicoplanin by disk diffusion method (30-µg disk), Vitek system with GPS-AA card, and agar dilution for the determination of MICs. The records of all patients, from whom CoNS with decreased susceptibility to glycopeptide was isolated, were reviewed.
Results: All CoNS showed uniform susceptibility to vancomycin by all three methods but 11 strains (9.2%) exhibited reduced susceptibilities to teicoplanin (MICs, 16 to 32 µg/mL). All but suspected colonized strains were nosocomially acquired and were isolated from 7 different wards. None were previously treated with teicoplanin. The concordance rates of disk diffusion method and Vitek system with agar dilution method were 94.1% and 84%, respectively. However, the sensitivity of disk diffusion method and Vitek system were only 50.0% and 62.5%, respectively.
Conclusions: This study demonstrates that CoNS with reduced susceptibilities to glycopeptides is not uncommon and may cause true infections in clinical settings. However, neither disk diffusion method nor Vitek system could differentiate these strains from more susceptible isolates.
[in Korean]
Young Uh, M.D., Jeong Seog Son, M.D., Gyu Yel Hwang, M.D., In Ho Jang, M.D., Kap Jun Yoon, M.D., and Dong Min Seo, M.D.
Ann Clin Microbiol 1998 September, 1(1): 82-96. Published on 20 September 1998.
Background: In clinical microbiology the accurate and rapid identification of members of the family Enterobacteriaceae is essential for diagnostic and therapeutic purposes and for epidemiologic studies. Accuracy of identification system depends mainly on data base such as positive rate of biochemical reactions, relative frequency of occurrence of biotype, and isolation frequency of microorganisms. The purpose of this study was to analyze the isolation rate and biotype frequency of the family Enterobacteriaceae isolated from tertiary care hospital in Korea.
Methods: Isolation frequency of the family Enterobacteriaceae isolated from clinical specimens during the period of January 1998 to June 1998 were analyzed. And biochemical phenotypes of 2,022 isolates tested by 10 tube system consisting of 14 conventional biochemical tests were also analyzed.
Results: Isolation rate of the family Enterobacteriaceae to the genus level in order of decreasing frequency were Escherichia (37.0%), Serratia (15.9%), Klebsiella (14.9%), Enterobacter (11.1%), Providencia (8.1%), Citrobacter (2.8%), Proteus (2.5%), Morganella (2.4%), Salmonella (2.4%), and Cedeca (1.0%). Among the genus of the family Enterobacteriaceae, Budvicia, Edwardsiella, Erwinia, Hafnia, Kluyvera, Leineriella, Moellerella, Shigella, Tatumella, Xenorhabdus, Yersinia, and Yokenella were not isolated. The number of species and genus of the family Enterobacteriaceae by this study were 48 and 12, respectively. Over 95% of all clinical isolates belonged to only 25 species.
Conclusions: Although these data about frequency of relative isolation rate and biotype frequency of the family Enterobacteriaceae is inadequate according to species and genus, yet these data will be utilized for the application and development of identification method of the family Enterobacteriaceae.
[in Korean]
Bo-Moon Shin M.D. and Seung-Ok Paik, M.T.
Ann Clin Microbiol 1998 September, 1(1): 97-103. Published on 20 September 1998.
Background : Continuous monitoring blood culture systems (CMBCS) reduce the time and false negative rates of bacterial growth compared with the traditional manual blood culture systems which have been used in many hospitals yet. The purpose of this study is to evaluate the terminal subcultures monitored by Vital system compared with the manual system and to determine the guideline of terminal subcultures.
Methods : A retrospective study was conducted over a period of one year (from January to December 1995) with manual blood culture system and and sixteen months (from February 1996 to May 1997) with Vital system. All of the positive and negative blood bottles were done Gram staining and subcultured aerobically and anaerobically with 7-day terminal subculture protocol. All of the isolates were identified with API systems or ATB systems.
Results : Among 3,344 cases with the manual system, 305 cases (9.1%) were declared positive and 424 cases (8.8%) out of 4,822 cases with Vital system were positive. The terminal subcultures detected 48 cases (1.44%) in manual system and 9 cases (0.19%) in Vital system according to 7-day protocol. No statistical differences were observed in results among 5 day, 7 day and terminal subcultures. Those of false negative organisms were gram positive cocci (22 cases), Enterobacteriaceae (13 cases), non-fermenters (12 cases) and gram positive rod (1 case) with the manual system and gram positive cocci (4 cases), Entrobacteriaceae (1 case), non-fermenter (1 case) and yeasts (3 cases) with Vital system.
Conclusions : These results suggest that terminal subculture of Vital system-negative blood culture bottles is not necessary except S. aureus and fungus bacteremia on the basis of clinical situation.
[in Korean]
Mi Yeon Choi, M.D., Seong Soo Jang, M.D., Jung Oak Kang, M.D., and Myung Ju Ahn, M.D.
Ann Clin Microbiol 1998 September, 1(1): 104-108. Published on 20 September 1998.
The major cause of pseudomembranous colitis is known to be Clostridium difficile (C. difficile). There are few reports that Clostridium species other than C. difficile has caused pseudomembranous colitis. We report a case of pseudomembranous colitis caused by Clostridium glycolicum (C. glycolicum).
A 47-year-old woman who had operational history for rectal cancer 3 months ago, was readmitted with diarrhea of 3 days duration. Seven weeks before admission, she had received ornidazole and ceftriaxone due to diarrhea and abdominal pain, and her symptoms were improved. She had received additional radiation therapy for rectal cancer during six weeks before the recent onset of diarrhea. On admission, she complained of watery diarrhea ten times a day and abdominal pain. She had tenderness on both lower abdomen. Pseudomembrane was observed by colonoscopic and histologic examination. VIDAS C. difficile toxin A II assay was positive and C. glycolicum was isolated in the stool. She recovered after receiving oral metronidazole treatment.
[in Korean]
Soo Youn Lee, M.D., Jung Soo Lee, M.D., Mi Ae Lee, M.D., Wha Soon Chung, M.D. and Seon Ju Kim, M.D.
Ann Clin Microbiol 1998 September, 1(1): 109-112. Published on 20 September 1998.
The group A streptococcus is capable of producing exotoxins that have been linked to a toxic shock-like syndrome. Streptococcal toxic shock syndrome is a rapidly progressive associated with injury to multiple organ systems and a 30-60% mortality rate. These cases are very rare in Korea. We present a case of 32-year-old pregnant woman who developed streptococcal toxic shock syndrome following intrauterine fetal death. She manifested hypotension, shock, increased level of creatinine, disseminated intravascular coagulopathy, liver impairment, renal failure, pulmonary edema and adult respiratory distress syndrome. Blood cultures yielded Streptococcus pyogenes. After 17 hours on admission, she died in spite of massive transfusion, antibiotics therapy and ventilatory support. Clinicians should be alert to the importance of early diagnosis and treatment of this lethal infection.
[in Korean]
Hyun Yong Hwang, M.D., Seok Hoon Jeong, M.D., Hark Rim, M.D., Mi Hyang Kim, M.D., Tae Jeon Jeong, M.T., Byeong Gil Choi, M.T.
Ann Clin Microbiol 1998 September, 1(1): 113-116. Published on 20 September 1998.
A 60-year-old male with continuous ambulatory peritoneal dialysis was admitted because of abdominal discomfort and turbid dialysate. He had a history of chronic renal failure due to diabetic nephropathy. His WBC count of peripheral blood was 8,500/mm³ (neutrophil 92%), and that of dialysate was 1,400/mm³ (polymorphonuclear leukocyte 69%, lymphocyte 31%). Pure growth of Leclercia adecarboxylata was isolated from dialysate. The L. adecarboxylata isolate was susceptible to ampicillin, ampicillin/sulbactam, cephalothin, cefoperazone, cefoxitin, cefotaxime, ceftazidime, aztreonam, imipenem, gentamicin, tobramycin, amikacin, tetracycline, trimethoprim-sulfamethoxazole and ciprofloxacin. Cephalothin & amikacin were added into dialysate, and his clinical symptoms and turbidity of dialysate were resolved. L. adecarboxylata has been rarely isolated from clinical specimens. To our knowledge, this is the first report of L. adecarboxylata isolated from clinical specimen in Korea. On review of the world literature, we found only 7 cases of L. adecarboxylata infections. This microorganism has been isolated from lower extremity wounds and sputum as part of a mixed flora in 3 cases and 1 case, respectively, but it was the only microorganism isolated from cultures of blood in 3 cases. These 3 patients with bacteremia due to L. adecarboxylata had severe underlying diseases, and clinical symptoms were developed after invasive procedures. All of the L. adecarboxylata isolates from clinical specimens were susceptible to antimicrobial agents tested, and the responses to antibiotic therapy were excellent. It is difficult to identify this organism because its biochemical reactions are similar to those of Escherichia coli, therefore careful identification is required. And additional studies are necessary to determine the pathogenic potential and route of infection of this organism.
[in Korean]
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