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

March, 2003. Vol. 6 No. 1.

Review article

Molecular Diagnostics for Detection of Microorganism

Sook Jin Jang

Ann Clin Microbiol 2003 March, 6(1): 1-6. Published on 20 March 2003.

진단에 유용한 미생물학적 검사의 기본목표는 특정 병원균을 신속히 검출하고 그 특징을 규명하여 환자가 잘 치료될 수 있도록 도와주는데에 있다.  지난 세기에 미생물의 동정은 배양한균의 형태와 생화학적 특징과 같은 표현형의 특성(phenotypic characteristics)에  근거를 두어 시행되어 왔으나 균성장에 근거를 둔 방법은 때로 시간이 많이 들거나 값이 비싸고 어떤 미생물에는 쉽게 이용할 수 있는 방법 이없다는 단점이 있다.

[in Korean]

Original article

Antibiotic Resistance and Its Mechanism of Group A Streptococci in School Children of Jinju

Soo Jin Park, Sunjoo Kim

Ann Clin Microbiol 2003 March, 6(1): 7-11. Published on 20 March 2003.

Background: Group A streptococci (GAS) is the most common cause of bacterial pharyngitis. Recently, a high frequency of resistance to erythromycin (EM), the drug of choice for penicillinallergic patients, has been reported, especially in countries where antibiotics are overused. Resistance is classified as constitutive, inducible, or M according to the sensitivity results with EM and clindamycin (CC). These EM resistance phenotype is attributable to the ermB, ermTR, and mefA genes, respectively. Although EM resistance of GAS is a serious problem in our country, there are very few reports regarding to its mechanism. 

Methods: GAS were isolated from elementary school children of Jinju in 2002. Antibiotic sensitivity testing by disk diffusion was performed against tetracycline (TC), ofloxacin, EM and CC, and the results were compared to the previous one in 1995 at the same area. The phenotypes of EM resistance were evaluated, and the frequency of ermB and mefA genes was determined by PCR. The resistance pattern was analyzed by each emm genotype. 

Results: The resistance rate to EM and CC was 51% and 34%, respectively, which is significantly higher than the rate of 25% and 9% recorded in 1995. Constitutive resistance was seen in 64% of the EM-resistant strains, the M phenotype in 34%, and inducible resistance in only 2%, compared to 38% of constitutive resistance and 62% of M phenotype in 1995. The ermB and mefA genes were present in 64% and 34% of strains, respectively. Most (88%) of the emm12 strains showed constitutive resistance, while emm18 and emm75 showed M phenotype. The organisms with most of the other emm genotypes were susceptible to EM. 

Conclusion: The EM and CC resistance rate had increased more than twofold. Constitutive resistance was twice as common as the M phenotype, whereas the mefA gene was more common in 1995. The resistance pattern was variable according to emm type, which suggests an association between the emm and resistance genes. Continuous microbiologic and epidemiological surveillance should be conducted and the seriousness of antibiotic resistance should be underscored in our community.

[in Korean]

Original article

Identification of Streptococcus viridans group Isolated from the Blood of Patients

Jongyoun Yi, Byoung-Wook Song, -Kyu Lee, Kyu-Sub Han, Myoung-Hee Park, and Eui-Chong Kim

Ann Clin Microbiol 2003 March, 6(1): 12-17. Published on 20 March 2003.

Background: Streptococcus viridans group (SVG) is the normal flora of the upper respiratory tract, skin and genitourinary tract, and is the major causative agent isolated in 30-40% of bacterial endocarditis patients. However, SVG has not been properly identified to the species level for lack of diagnostic system which enables the accurate identification of SVG. Poyart et al. have recently described the identification of SVG to the species level by DNA sequencing of superoxide dismutase gene (sodAint ). Using this method, we report here the identification of SVG isolated from the patients in Seoul National University Hospital within recent 2 years.

Methods: According to the method by Poyart et al., a set of two oligonucleotides, D1 (5’-CCI TAY ICI TAY GAY GCI YTI GAR CC-3’) and D2 (5’-ARR TAR TAI GCR TGY TCC CAI ACR TC-3’) were used as PCR primers, and PCR products of 480-bp size were obtained. The PCR products purified by MicroSpin S-400 HR Column were sequenced using ABI-PRISM 3700 Sequence Analyzer. D1 and D2 were used as sequencing primers. The clinical isolates were respectively identified as the species showing the greatest sequence homology which was demonstrated by the BLAST program provided by NCBI(USA).

Results: Clinical strains isolated from 26 patients who had shown two or more positive blood cultures were analyzed by DNA sequencing of superoxide dismutase gene, which showed 6 strains of S. salivarius, five S. oralis, four S. sanguis, three S. pasteuri, three S. equisimilis, two S. gordonii, one S. constellatus, one S. luteciae, and one S. mitis. S. salivarius and S. sanguis were clearly discriminated, while S. equisimilis and S. pyogenes were not. Species identification results by conventional method seldom corresponded to those by DNA sequencing. Among 7 patients suspected to have bacterial endocarditis, S. sanguis were isolated in 4 patients, and S. gordonii, S. oralis, S. pasteuri in one, respectively. Among 17 patients with liver cirrhosis or cancer, S. salivarius were isolated in 6 patients, and S. oralis in four.

Conclusions: In this study, we could identify the species of SVG isolated from the patients with bacteremia; S. sanguis were frequently isolated from patients with bacterial endocarditis, while S. salivarius from ones with malignancy. These results imply that a different group of underlying diseases could show correspondingly different group of SVG species which cause bacteremia, and we suggest that further pathophysiological study on the correlations between underlying disease and the species of SVG be performed.

[in Korean]

Original article

Glycopeptide and Aminoglycoside Resistance of Vancomycin-resistant Enterococcus faeciumin Korea

Wee Gyo Lee, Young Sun Kim, Ji Young Huh

Ann Clin Microbiol 2003 March, 6(1): 18-22. Published on 20 March 2003.

Background:Nosocomial infections caused by vancomycin-resistant enterococci (VRE) are increasing problem in Korea. Until now, no nationwide study has been performed. The aim of the present study was to monitor the antimicrobial resistance of vancomycin-resistant Enterococcus faecium (VREF).

Methods: Two hundred and two E. faecium isolated in 10 teaching hospital were studied. To detect VRE, the brain heart infusion agar containing 6 μg /mL vancomycin was used as the screening agar. The MIC was determined using agar dilution test. The vancomycin resistance genes (vanA, vanB & vanD)and genes (aac(6’)Ie-aph(2”) Ia & ant(6’) Ia encoding the aminoglycoside-modifying enzymes were detected by multiplex PCR using specific primers. 

Results:Thirty-nine VREF were detected from 202 isolates. All had vancomycin MICs ≥256 μg /mL and harboured vanA gene. No isolates revealed positive results for the vanB or vanD gene. However, the MIC range for teicoplanin was 2 to ≥256 μg/mL. All isolates with gentamicin MIC ≥ 500 μg/mL gave positive results for the aac(6’) Ieaph(2”) Ia genes and with streptomycin ≥2000 μg /mL gave positive results for the ant(6’)Ia gene. 

Conclusions:All VREF harboured vanA gene. According to MIC tests, 7 isolates(18%) showed intermediate or susceptible to teicoplanin. Therefore we need a study concerning the clinical meaning. The VREF in Korea contain at least one of genes encoding the aminoglycoside-modifying enzymes. This means there are only limited numbers of antibiotics to choose.

[in Korean]

Original article

Urinary Tract Infection Due to Coagulase-negative Staphylococci : Species Identification, Antimicrobial Resistance and Clinical Characteristics

Hee Won Moon, and Mi Ae Lee

Ann Clin Microbiol 2003 March, 6(1): 23-28. Published on 20 March 2003.

Background: Previously considered as nonpathogenic contaminants, coagulase-negative staphylococci (CoNS) are now a major cause of nosocomial infections as increased use of prosthetic devices, intravascular catheters, and other invasive technology in more immunosuppressed patients and urinary tract infections (UTI) due to CoNS have been reported. In present study, species frequency, antimicrobial susceptability and clinical characteristics of CoNS UTI were evaluated. 

Method: We performed species identification and antimicrobial susceptibility of 109 CoNS strains isolated from urine in Ewha Womans University hospital from January 1998 to December 2002 and analysed clinical characteristics of 57 cases with CoNS UTI cases, retrospectively. 

Results: Among 13,336 strains isolated from urine, 109 strains were CoNS showing 0.8%. The most common species of CoNS from urine were S. epidermidis (49.5%) followed by S. haemolyticus (16.5%), S. saprophyticus (13.8%), S. auricularis (1.8%), S. simulans (0.9%) and unidentified CoNS represented 17.4%. The antimicrobial susceptibility showed high resistance to multiple drugs. Among CoNS, S. haemolyticus showed the highest resistance whereas S. saprophyticus showed the highest susceptibility to multiple drugs. The patients isolated S. saprophyticus were younger (mean age: 41 yrs) than those isolated other CoNS (mean age: 53 yrs) and more frequently female (9/14 vs 19/43). The hospitalized patients (74.4% vs 21.4%), bacteriuria more than 105 CFU/ml (83.7% vs 64.3%), indwelling catheter (34.9% vs 7.1%) and other risk factors (48.8% vs 35.7%) were more common in patients isolated other CoNS than those isolated S. saprophyticus and no significant differences were noted in pyuria (51.2% vs 57.1%). The symptomatic presentations were more common in patients isolated S. saprophyticus than those isolated other CoNS (71.4% vs 9.3%) and so were treatment (85.7% vs 44.2%).

Conclusions: When CoNS other than S. saprophyticus isolated from urine in hospitalized patientes with risk factors, identification and antimicrobial susceptability test is necessary for proper management.

[in Korean]

Original article

Antimicrobial Resistance of Clinically Important Bacteria Isolated from Hospitals Located in Representative Provinces of Korea

Seong Geun Hong, Dongeun Yong, Kyungwon Lee, Eui-Chong Kim, Wee Kyo Lee, Seok Hoon Jeong, Won Keun Song, Yeon Jun Park, Mi-Na Kim, Young Uh, Jong Hee Shin, Jongwook Lee, Ji Young Ahn, Sun Wha Lee, Jae Seok Kim, Hee Bong Shin

Ann Clin Microbiol 2003 March, 6(1): 29-36. Published on 20 March 2003.

Background: A rapid increase of antimicrobial-resistant bacteria has become a serious problem in many countries. The aim of this study was to determine the prevalence of resistance among frequently isolated gram-positive and -negative bacteria in Korea. 

Methods: Data of routine antimicrobial susceptibility test for medically important bacteria, isolated during 3 months of 2002, were collected from 12 university and 1 commercial laboratories in Korea. 

Results: The proportions of methicillin-resistant Staphylococcus aureus (MRSA) were 60-88%, but vancomycin-resistant S. aureus was not detected. Among the Enterococcus faecium isolates, the resistance rate to vancomycin was 29%. The resistance rates of Escherichia coli and Klebsiella pneumoniae: 11% and 24% to cefotaxime, respectively, and 12% and 21% to cefoxitin, respectively. The resistance rates of Citrobacter freundii, Enterobacter cloacae, and Serratia marcescens: 28%, 34% and 21% to cefotaxime, respectively, <1%, 8% and 14% to cefepime, respectively. The resistance rates of Acinetobacter baumannii and Pseudomonas aeruginosa were: 65% and 37% to piperacillin, 64% and 19% to ceftazidime, 13% and 20% to imipenem, respectively. The resistant rates varied according to the hospital size. The resistance rates were generally higher among the isolates in the hospitals with more than 1,000 beds. The rates of penicillin-nonsusceptible Streptococcus pneumoniae were 58-90%. Among the Haemophilus influenzae isolates, 55-68% were resistant to ampicillin. 

Conclusions: Antimicrobial resistant strains were prevalent among the medically important clinical isolates, especially, MRSA, vancomycin-resistant enterococci, extended-spectrum β-lactamase- or AmpC β-lactamase-producing E. coli and K. pneumoniae, third generation cephalosporin-resistant C. freundii, E. cloacae and S. marcescens, imipenem-resistant A. baumannii and P. aeruginosa, penicillinnonsusceptible S. pneumoniae and ampicillin-resistant H. influenzae. The antimicrobial resistance has become a serious problem in Korea.

[in Korean]

Original article

In Vitro Antimicrobial Activity of Cefroxadine, an Oral Cephalosporin, Against Major Clinical Isolates

Jongyoun Yi, Jae-Kyu Lee, Eui-Chong Kim

Ann Clin Microbiol 2003 March, 6(1): 37-40. Published on 20 March 2003.

Background: Cefroxadine is an oral first-generation cephalosporin, which has been used for several years. But, the susceptibility data of cefroxadine were rarely reported in Korea. The current study attempted to determine the antibacterial activity of cefroxadine against the major clinical isolates.

Methods: According to the NCCLS recommendations, antibacterial activities of cefroxadine were measured against total 500 major clinical isolates. MICs were determined by the agar dilution method, a series of doubling dilutions from 128 to 0.03μg /mL, on Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, Proteus mirabilis, and Staphylococcus spp. In case of Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis, broth microdilution method, a series of doubling dilutions from 16 to 0.015μg /mL, was performed.

Results: Cefroxadine had variable activity against Enterobacteriaceae. MIC cumulative curves showed that cefroxadine had relatively low MIC distributions against E. coli, K. pneumoniae and P. mirabilis, showing MIC50 were 4, 4, and 8μg/mL, respectively. Against E. cloacae, C. freundii, and S. marcescens, cefroxadine’s MIC50 values ranged from 128 to >128μg /mL. For clinical isolates of methicillin-susceptible Staphylococcus aureus and methicillin-susceptible Staphylococcus epidermidis, cefroxadine had MIC90 values were 4μg /mL and 8μg /mL, respectively. Cefroxadine had MIC50 values of 1 μg/mL and >16μg /mL for penicillin-susceptible and penicillin-not-susceptible strains of S. pneumoniae, respectively. Cefroxadine had MIC50 values of 8μg /mL and 4 μg/mL against H. influenzae and M. catarrhalis, respectively.

Conclusion: Cefroxadine had good activity against gram-positive bacteria, except penicillinresistant S. pneumoniae, and showed moderate antimicrobial activity against M. catarrhalis, E. coli, P. mirabilis, and K. pneumonaie. Cefroxadine had variable activity against Enterobacteriaceae other than the above-mentioned species.

[in Korean]

Original article

Comparison of MicroScan and Vitek ESBL test with NCCLS ESBL Confirmatory Test

Myung Hee Lee

Ann Clin Microbiol 2003 March, 6(1): 41-46. Published on 20 March 2003.

Background: This study was designed to evaluate the ability of the Vitek and MicroScan ESBL test by comparing with NCCLS ESBL phenotypic confirmatory test by disk diffusion and to know the frequency of ESBL producers in the Seoul Veterans Hospital.

Methods: A total of 1,261 isolates(Escherichia coli 705, Klebsiella pneumoniae 502, K. oxytoca 54) from 883 patients were included in ESBL screening test by Vitek (494 strains) and MicroScan (767 strains). After excluding repetitive isolates from same patients, NCCLS ESBL confirmatory test was performed for 197 ESBL screening positives and 184 ESBL screening negatives.

Results:The overall frequency of ESBL screening positives was 22.3% (by MicroScan 26.2%, by Vitek 15.6%), and that of NCCLS ESBL positives was 18.9%(18.3% in E. coli, 21% in K. pneumoniae). MicroScan and Vitek ESBL test showed 100% and 92.3% sensitivity, 77.1% and 95.5% specificity, respectively. Among the 158 NCCLS ESBL positives, 17.7% showed clavulanic acid effect in cefotaxime only, 10.1% in ceftazidime only, and 72.2% in both. MicroScan Neg ComboPanel Type 21 test revealed that 91.4% of suspicious ESBL producers flagged by one or two antimicrobials were erroneous. In contrast, 96.2% of strains flagged by all five antimicrobials were correct.

Conclusion: Suspicious ESBL producers by MicroScan showing three or four antimicrobial flags should be retested by NCCLS ESBLconfirmatory test. But strains with two or less flags and strains with all 5 flags can be reported as Non-ESBL producers and ESBL producers, respectively.

[in Korean]

Original article

Antibiogram of Escherichia coli and Klebsiella spp. Detected by Vitek ESBL Test

Eun Hae Cho, Nam Yong Lee

Ann Clin Microbiol 2003 March, 6(1): 47-51. Published on 20 March 2003.

Background:Extended-spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella spp. isolates are clinically resistant to all the β-lactams except carapenems and cephamycins. This study was to determine the prevalence of ESBL producing E. coli and Klebsiella spp. and the rates and trends of resistance to extended-spectrum β-lactams and other antimicrobial agents in ESBL producing E. coli and Klebsiella spp.. 

Methods:During the periods of 2002, a total 2,551 clinical isolates of E. coli & Klebsiella spp. were collected from patients of the Samsung medical center, Seoul, Korea. Antimicrobial susceptibility test and determination of ESBL production were performed by Vitek GNS-433 card. 

Results:151/1,594 (9.5%) of E. coli isolates, 128/896 (14.3%) of K. pneumoniaeisolates and 11/61 (18.0%) of K. oxytica were ESBL producing strains. Resistance to cefoxitin and cefepime were 2.4% and 13.4% in ESBL producing isolates. Imipenem had excellent activity against E .coli and Klebsiella spp. (100% susceptible). 

Conclusion: In this study, ESBL-producing E. coli and Klebsiella spp were more resistant to β-lactams including cefepime than ESBL non-producing E. coli and Klebsiella spp.. ESBL producing E. coli and Klebsiella spp. showed a high level of co-resistance with aminoglycosides and fluoroquinolones. Imipenem showed the highest level of activity against E. coli and Klebsiella spp..

[in Korean]

Original article

A Prospective, Comparative Study of Two Methods of Ascitic Fluid Culture to Diagnose Spontaneous Bacterial Peritonitis

In Sook Kim, Nam Yong Lee

Ann Clin Microbiol 2003 March, 6(1): 52-55. Published on 20 March 2003.

Background: Inoculation of ascitic fluid into blood culture bottles is known to be more efficient than conventional culture method to diagnose spontaneous bacterial peritonitis. The aim of this study is to evaluate recovery and early detection of peritonitis-causing bacteria from ascitic fluid by using the BACTEC blood culture system with bedside inoculation. The results were compared to those of conventional culture method. 

Methods: Ascitic fluid specimens from 345 patients suspicious of spontaneous bacterial peritonitis were prospectively evaluated between January 1999 and March 2002. In all cases, 5 to 10 mL of ascitic fluid were inoculated at the bedside into a pair of BACTEC blood culture bottles (BC method), and simultaneously an aliquot of ascitic fluid was sent to microbiology laboratory for conventional culture. Isolated microorganisms and the time elapsed for final report were compared between the two methods. 

Results:BC method was positive in 66/345 ascitic fluid specimens (19.1%) and conventional culture method in 48/345 (13.9%) (P=0.065). Time elapsed for final report was 82±20.5 hours for blood culture method and 107±42.4 hours for conventional culture method (P=0.002). 

Conclusion:BC method using BACTEC system provides an earlier microbiologic diagnosis of spontaneous bacterial peritonitis than conventional culture method with higher sensitivity.

[in Korean]

Original article

Quality Assurance for Commercially Prepared Microbiological Culture Media

Tae Yeal Choi

Ann Clin Microbiol 2003 March, 6(1): 56-62. Published on 20 March 2003.

Background:Culture media that perform as intended are crucial to accurate work by a clinical microbiology laboratory. The author evaluated commercially prepared microbiological culture media for quality assurance. 

Material and methods:Five types of commercially prepared media from Shin Yang Chemical Co., Ltd. were evaluated in Hanyang University Hospital for one year. Five types included blood agar media, chocolate agar, MacConkey agar, Salmonella-Shigella agar and Mueller-Hinton agar. All media were evaluated by NCCLS M22-A2 (Quality assurance for commercially prepared microbiological culture media-second edition; approved standard, 1996). 

Results:Blood agar media provided luxuriant growth of many bacteria-especially the fastidious streptococci and pneumococci, as shown by early colonial development and clear hemolytic reactions with S. pyogeses. Chocolate agar supported growth of fastidious bacteria such as N. gonorrheaeand H. influenzae. MacConkey agar gave excellent differentiation between coliforms and non-lactose fermenters with inhibition of Gram-positive micrococci. Salmonella-Shigella agar was a good differential selective medium for the isolation of Salmonella and some Shigella species from clinical specimens. Mueller-Hinton agar showed good reproducibility for antimicrobial susceptibility test by the disk diffusion method. 

Conclusion:The five types of commercially prepared culture media have demonstrated competence and integrity for bacterial culture in clinical trial. Theses media could be used without performance quality assurance test by user.

[in Korean]

Original article

Direct Detection of Clostridium difficile Toxin B Gene by Nested PCR in Human Stool Specimens

Hee Kyung Park, Young Mi Lee, Hyun Jung Jang, Cheol Min Kim, Kyungwon Lee, Seok Hoon Jeong, Mooin Park

Ann Clin Microbiol 2003 March, 6(1): 63-68. Published on 20 March 2003.

Background: Clostridium difficile is the major cause of antibiotic-associated diarrhea (AAD) and pseudomembranous colitis (PMC). The aim of this study was to develop the nested PCR assay for direct detection of toxigenic C. difficile in stool specimens and to evaluate the usefulness of the method.

Methods: Specificity of newly designed primers are tested with 36 reference strains of intestinal flora. Lower detection limit of nested PCR for B toxin gene in C. difficile was determined using 10-fold serial dilutions of C. difficile ATCC 9689. One hundred and two clinical stool samples were cultured for detection of C. difficile on cycloserine-cefoxitin- fructose agar and the PCR assay for detection of toxin B gene in C. difficile isolates was performed. Nested PCR assay for direct detection of toxin B gene in clinical samples was also performed.

Results: Nested PCR assay showed negative amplification results in intestinal floras except C. difficile ATCC 9689. Lower detection limit of nested PCR for toxin B gene was 104 CFU/mL. Sensitivity of nested PCR assay compared to culture method was 100% (29/29), and the specificity was 68% (50/73).

Conclusion: Nested PCR assay showed high sensitivity in direct detection of toxin B gene in C. difficile isolates even after administration of metronidazole, so the assay could be used in initial diagnosis and follow-up tests of AAD and PMC.

[in Korean]

Original article

Evaluation of MGIT 960 System for Recovery of Mycobacteria from Body Fluids

Youn Mi Choi

Ann Clin Microbiol 2003 March, 6(1): 69-73. Published on 20 March 2003.

Background: In this study, we evaluated the BACTEC MGIT 960 system (Becton Dickinson Microbiology Systems, Sparks, Md, USA), which is fully automated, noninvasive and nonradiometric fluorescent indicator broth detection system, for the growth and detection of mycobacteria with body fluid specimens. 

Methods:Total of 1,891 body fluid specimens were included (pleural fluid 752, ascitic fluid 629, cerebrospinal fluid 214, joint fluid 79, peritozol 54, others 163). Specimens were inoculated into MGIT and solid media (3% ogawa, Japan). Polymerase chain reaction was performed for the discrimination of Mycobacterium tuberculosis from Mycobacterium other than tuberculosis (MOTT). 

Results:A total of 62 isolates of mycobacteria were recovered from all culture system. With MGIT system, 56 isolates were recovered, compared with solid system recovered 33 isolates. 29 isolates were recovered with MGIT only and 6 isolates recovered with solid media only. Among 62 isolates recovered, 11 isolates were positive in acid fast stain. 10 isolates were recovered with MGIT. One isolate was recovered with solid system. 51 isolates were negative in acid fast stain. Among this, 46 isolates were recovered with MGIT. The mean detection time was 14.2 days with MGIT system, and 38.2 days with solid media. Contamination rate for each system with body fluid specimens were 4.1% for MGIT and 1.7% for solid media. 

Conclusion: In body fluid, the MGIT system has the advantages of improved detection rate and rapid recovery than solid media to recover mycobacteria.

[in Korean]

Original article

Detection of Ureaplasma urealyticum and Mycoplasma hominis in Pregnant Women Using MYCOFAST®️ Evolution 2 and PCR

Hye Gyung Bae, Woon Bo Heo, Nang Young Lee, Won Kil Lee, Tae Bon Koo

Ann Clin Microbiol 2003 March, 6(1): 74-80. Published on 20 March 2003.

Background: The associations between preterm labor or premature rupture of membrane (PROM) and urogenital infections of pregnant women are reported. Ureaplasma urealyticum and Mycoplasma hominis are well known as important pathogens of urogenital infections in pregnant women. In routine clinical laboratory, conventional culture for these microorganisms has not been made generally because of the requirements for strict growth condition. MYCOFAST®️ Evolution 2 is an easy and rapid liquid microculture method using metabolism of these microorganisms. Author investigated the relationship between U. urealyticum or M. hominis infections and preterm labor or PROM by MYCOFAST Evolution 2 and PCR. Also it was reviewed that the possibility of substitution of MYCOFAST Evolution 2 for conventional culture method by comparing with PCR methods.

Methods: This study was done on 91 pregnant women. They were composed of two groups; group Ⅰ(n=48) had full-term delivery and group Ⅱ(n=43) had preterm labor or PROM before the 37th week.Two cervical swabs were made each time. One was used for MYCOFAST®️ Evolution 2 and the other for PCR.

Results: The positivity of U. urealyticum was 39.6% in group Ⅰ and 58.1% in group Ⅱ by MYCOFAST®️ Evolution 2 and 39.6% and 58.1% by PCR method, respectively. The positivity of M. hominis was 4.2% in group Ⅰ and 11.6% in group Ⅱ by MYCOFAST Evolution 2 and 4.2% and 7.0% by PCR method, respectively. The positivity of U. urealyticum and M. hominis in group Ⅱ was higher than that in group Ⅰ but was not significant statistically. The concordance rates between two methods were 86.8% for U. urealyticum and 97.8% for M. hominis. It showed good correlation between two methods (U. urealyticum, r=0.736; M. hominis, r=0.835).

Conclusions: The infections of U. urealyticum and M. hominis were related to preterm labor or PROM. Considering vertical transmission to fetus or neonates resulting in perinatal morbidity or mortality, the detection of these microorganisms is important. MYCOFAST®️ Evolution 2 was an easy, rapid and reliable method substituting conventional culture method.

[in Korean]

Original article

Detection of Chlamydophila pneumoniae in Acute Myocardial Infarction

Won-Kil Lee, Eun-Hee Kwon, Hye-Gyung Bae, Jang Soo Suh, Kyung Eun Song, Nan Young Lee, Dong Il Won, Jung Bum Lee

Ann Clin Microbiol 2003 March, 6(1): 81-87. Published on 20 March 2003.

Background: There is growing evidence linking infection with Chlamydophila pneumoniae with vascular diseases, such as atherosclerosis and myocardial infarction. However, the data remain inconclusive and the clinical importance of C. pneumoniae as vasculopathic is unclear. So, we intend to detect C. pneumoniae in acute myocardial infarction patients by microimmunofluorescence (mIF) and polymerase chain reaction (PCR).

Methods:Blood and peripheral mononuclear cells (PMNCs) of 24 myocardial infarction patients and 100 normal controls were collected. Serum were used in mIF and PMNCs in PCR. PMNC sample were tested for C. pneumoniae by ‘touchdown’nested PCR. The first round PCR amplified DNA from both C. pneumoniae and Chlamydophila psittaci, while the second round specially targeted C. pneumoniae allowing the two species to be differentiated.

Results: Seropositivity of IgG and IgM anti-Chlamydophila pneumoniae antibody titers were 95.8% and 25% in myocardial infarction patients and 61% and 16% in control group, respectively. Positive rates of PCR of PMNCs were 8.3% in the patients and 15% in control group.

Conclusion:The results of mIF show that mIF positive rate in myocardial infarction was much higher than control group. So an association between C. pneumoniae and myocardial infarction can be concluded. But the opposite results of PCR of PMNCs needed further studies.

[in Korean]