Sung Kuk Hong, Taek Soo Kim, Kyoung Un Park, Jae-Seok Kim, Eui-Chong Kim
Ann Clin Microbiol 2013 June, 16(2): 53-60. Published on 20 June 2013.
Infections and outbreaks of antimicrobial-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE), have been increasing. Detection methods for antimicrobial-resistant bacteria have been changed from traditional culture methods to chromogenic media culture and molecular methods. Strain- typing methods using various molecular technologies are essential tools for epidemiologic surveillance. Furthermore, outbreak detection, using syndromic surveillance as well as passive and active surveillance, has been applied. However, it is difficult to establish effective and robust guidelines and systems for using these various methods to control antimicrobial-resistant bacteria. Therefore, clinical microbiologists and policy makers must possess expertise in the control of antimicrobial resistant bacteria, discuss the issue sufficiently, and, finally, create a system to accomplish this control.
[in Korean]
Chang-Ki Kim, Heungsup Sung, Yeon-Joon Park, Chulhun L . Chang
Ann Clin Microbiol 2013 June, 16(2): 61-68. Published on 20 June 2013.
There are several problems in mycobacterial detection and drug susceptibility testing. One problem is that some test results are unnecessarily delayed because the tests are postponed until patients revisit clinics and pay the cost of the tests. Another problem is that critical and important tests are not requested because patients do not agree with their necessity. These inefficient practices may be due to the fee-for-service policy that the Korean medical insurance system is adopting and because many test methods used for mycobacterial infection have each test codes. Therefore, we propose a new test code encompassing several test items necessary for laboratory diagnosis of mycobacterial infection. This new code enables all necessary tests to be performed sequentially without delay and also prevents performance of unnecessary tests. These changes will help control tuberculosis without any further medical insurance financial input.
[in Korean]
Yu Kyung Kim, Kyung-Min Lee, Won-Kil Lee
Ann Clin Microbiol 2013 June, 16(2): 69-74. Published on 20 June 2013.
Background: Hepatitis C virus (HCV) causes a chronic infection, resulting in progressive liver damage. Recent studies have described the protective effect of the apolipoprotein E (ApoE) genotype on liver damage in cases of HCV infection. Their findings were explained by the influence of the ApoE genotype on HCV pathology, which seems to be integrally linked to the process of HCV uptake into hepatocytes. We investigated whether specific ApoE genotypes were associated with the different clinical aspects of HCV infection in patients with chronic HCV.
Methods: From the whole blood of 196 chronic HCV hepatitis patients, the ApoE genotypes were determined by an allele-specific polymerase chain reaction. Several markers, including liver enzymes, platelet counts and HCV viral loads, as well as the radiologic findings, were investigated. In order to estimate the treatment outcome, the sustained virologic response (SVR), early virologic response (EVR) and end-of-treatment response (ETR) were determined according to the HCV viral loads.
Results: Based on genotyping, 15.8% (n=31) of the patients had the ApoE E4 allele (E2/E4, E3/E4, E4/E4), while 84.2% (n=165) were missing the ApoE E4 allele (E2/E2, E2/E3, E3/E3). Several clinical results of the E4-positive group, including liver enzymes, albumin, platelet counts, HCV viral loads and hepatic coarseness were not significantly different from those of E4-negative group. There were no differences in the SVR, EVR and ETR between patients with the ApoE E4 allele and those without the ApoE E4 allele.
Conclusion: There was no significant effect of the ApoE genotype on the clinical aspects of HCV infection and the anti-viral response, including SVR, EVR and ETR, in chronic HCV hepatitis patients.
[in Korean]
Ji Youn Sung, Sun Hoe Koo, Hye Hyun Cho, Kye Chul Kwon
Ann Clin Microbiol 2013 June, 16(2): 75-80. Published on 20 June 2013.
Background: Acinetobacter baumannii resistance islands (AbaRs) are transposons that have the role of important vehicles for the acquisition of antimicrobial resistance genes, and are associated with multidrug resistance (MDR). In this study, we aimed to determine the AbaRs in MDR A. baumannii global clone 2 (GC2) clinical isolates obtained from a university hospital in Daejeon, Korea.
Methods: This study included 17 MDR A. baumannii strains isolated in Daejeon, Korea. The minimal inhibitory concentrations (MICs) were determined by Etest. A. baumannii isolates were characterized using 2 multiplex PCR assays and a multilocus sequence typing (MLST) scheme. To detect and characterize AbaRs, PCR and PCR mapping experiments were performed.
Results: All 17 MDR A. baumannii isolates tested in this study belonged to GC2 and contained 5 sequence types (STs): 75, 92, 137, 138, and 357. Tn6166 that contains antimicrobial resistance genes and is also known as AbaR4a was found in all 17 GC2 strains. This is the first report of Tn6166 in MDR A. baumannii GC2 isolates in Korea. In contrast, AbaR4 was not found in the GC2 isolates.
Conclusion: Tn6166 has been disseminated among MDR A. baumannii GC2 isolates in Korea. Further investigation is needed to recover the various types of AbaRs in MDR A. baumannii GC2 isolates in Korea are responsible for the multiple antimicrobial resistance mechanisms.
Eun-ha Koh, Sunjoo Kim, Dong-hyun Lee, Seong Chun Kim
Ann Clin Microbiol 2013 June, 16(2): 81-86. Published on 20 June 2013.
Background: Blood culture is essential for the diagnosis and management of bloodstream infections. Blood volume is a key parameter determining the success of blood cultures. Studies comparing compliance between physicians and phlebotomists regarding optimal blood culture procedure are very rare in Korea.
Methods: After educating physicians (interns) and phlebotomists about the correct procedure for blood culturing, the blood volumes of forty-three percent of randomly selected aerobic and anaerobic culture sets for adult patients (≥18 years old) were compared between these two groups over a period of three months. Physicians obtained blood from all admitted patients except those in the emergency department, where phlebotomists performed blood collection.
Results: The numbers of blood culture sets requested during the study period were 3,238 and 2,136 for the physician and phlebotomist groups, respectively. The blood volumes of blood culture sets were significantly higher for the phlebotomists (16.7 mL) than for the physicians (9.2 mL). The positive rate of blood culture was also higher for the phlebotomist group (10.3% vs. 7.9%). The contamination rates (0.8%) were the same for both groups.
Conclusion: Although the patients’ medical conditions, antibiotics prescriptions, or duration of hospitalization may have affected the positive rate of blood cultures, this rate might also have been influenced by the blood volume. The compliance of phlebotomists was greater than that of physicians regarding the blood volume collected for blood cultures.
Soie Chung, Sue Shin, Jong Hyun Yoon, Eun Youn Roh, Sung Jun Seoung, Gyoung Pyoung Kim, Eui-Chong Kim
Ann Clin Microbiol 2013 June, 16(2): 87-91. Published on 20 June 2013.
Background: The persistence of infection by high-risk human papillomavirus (HPV) may lead to cervical cancer. Recently, the American Society for Colposcopy and Cervical Pathology (ASCCP) announced that oncogenic HPV screening and the PAP smear are the main methods of screening for cervical cancer. The goal of this study was to investigate the prevalence and genotyping of HPV, as well as the risk of cervical dysplasia.
Methods: HPV genotyping was conducted by a commercial chip assay. Cervical dysplasia was retrospectively reviewed using electronic medical records. The study participants were grouped together according to cervical dysplasia status: ‘no dysplasia,’ ‘atypical squamous cells of undetermined significance (ASCUS),’ ‘low-grade squamous intraepithelial lesion (LSIL),’ and ‘high-grade squamous intraepithelial lesion (HSIL).’ The HPV prevalence and genotyping were analyzed according to the cervical dysplasia group.
Results: The overall prevalence of HPV was 17.6% (91 out of 518 patients). HPV-18 (2.3%), HPV-16 (2.1%), and HPV-58 (1.2%) were the three most frequent genotypes. The prevalence of HPV infection and the high-risk HPV positive rate was higher in the ASCUS, LSIL, and HSIL groups than in the no dysplasia group (P<0.05).
Conclusion: In this study, basic data regarding the prevalence and distribution of HPV genotypes were obtained. Since HPV vaccination has been actively encouraged among Korean women, a change in the prevalence of HPV and cervical dysplasia is expected in the future. This study provided basic data describing the prevalence of HPV and its genotypes in the pre-HPV vaccination era.
[in Korean]
Eun Jeong Won, Jong Hee Shin, Won-Kil Lee, Sun Hoe Koo, Shine Young Kim, Yeon-Joon Park, Wee Gyo Lee, Soo-Hyun Kim, Young Uh, Mi-Kyung Lee, Mi-Na Kim, Hye-Soo Lee, Kyungwon Lee
Ann Clin Microbiol 2013 June, 16(2): 92-100. Published on 20 June 2013.
Background: The incidence of fungal infections varies among hospitals and between different time periods. We performed a nationwide survey in Korea to investigate the distribution of yeast and mold species recovered from clinical specimens.
Methods: The distributions of clinical isolates of yeast and mold species obtained from 12 university hospitals between January and December 2011 were evaluated relative to the hospital and specimen type.
Results: A total of 39,533 fungal isolates (37,847 yeast and 1,686 mold isolates) were obtained. C. albicans was the predominant species (49.4%) among the yeast isolates from all clinical specimens, followed by C. glabrata (7.2%) and C. tropicalis (6.5%). For 5,248 yeast isolates from sterile body fluids, blood was the most common source of yeasts (71.1%), followed by peritoneal fluid (9.4%). Although C. albicans was the predominant species at all but two hospitals, the rate of non-albicans Candida species varied from 71.2% to 40.1%, depending on the hospital. The yeast species recovered most frequently from the sterile body fluids was C. albicans (41.7%), followed by C. parapsilosis (17.8%) and C. glabrata (14.4%), while that from non-sterile sites was C. albicans (50.7%), followed by C. glabrata (6.0%) and C. tropicalis (5.5%). For mold-forming fungi, Aspergillus species (62.3%) were most common, followed by Trichophyton species (15.4%). Respiratory specimens were the most common source of molds (39.6%), followed by abscesses/wounds (28.4%) and tissues (17.5%).
Conclusion: The rank order of distribution for different fungal species varied among hospitals and specimen types. Continual national surveillance programs are essential for identifying possible changes in fungal infection patterns.
[in Korean]
Seon Joo Kang, Heungsoo Kim, Kyoung Un Park, Young Ae Lim, Wee Gyo Lee
Ann Clin Microbiol 2013 June, 16(2): 101-104. Published on 20 June 2013.
Mycobacterium is an uncommon cause of peritonitis in patients receiving peritoneal dialysis (PD), and the incidence of nontuberculous mycobacterium (NTM) peritonitis is even rarer since the majority of mycobacterial peritonitis cases are caused by Mycobacterium tuberculosis. However, NTM peritonitis has been known to result in a high mortality rate with delayed diagnosis and treatment. In this study, we report a case of Mycobacterium abscessus peritonitis in a 52- year-old male under continuous ambulatory peritoneal dialysis (CAPD).
[in Korean]
Hee Jae Huh, Jang Ho Lee, Kyung Sun Park, Tae-Gook Jun, I-Seok Kang, Yae-Jean Kim, Chang-Seok Ki, Nam Yong Lee
Ann Clin Microbiol 2013 June, 16(2): 105-109. Published on 20 June 2013.
We report a case of the isolation of the Aspergillus versicolor complex, initially misidentified by morphological characteristics as the Scopulariopsis species, from a homograft with a bicuspidalized pulmonary valve. An eighteen-month-old female, who had critical pulmonary stenosis, underwent pulmonary valve replacement. On postoperative day 8, she developed a fever, which did not respond to empiric broad-spectrum antibiotics. While no definitive source was identified, a filamentous fungus was isolated from the thawed homograft tissue culture prior to implantation on the operation day. The colonies were powdery green with white edges on Sabouraud dextrose agar. Microscopic examination showed septate hyphae with branched conidiophores and chains of spiny conidia, which suggested Scopulariopsis species. After direct sequencing of the internal transcribed spacer (ITS) regions, the fungus was identified as the A. versicolor complex. To our knowledge, the isolation of the A. versicolor complex from a homograft valve has not been previously described. This case shows that laboratory staff should be aware that microscopic morphology of the A. versicolor complex can resemble that of a number of other genera, including Scopulariopsis species.