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The genes erm (B), mef (A), and both erm (B) and mef (A) were identified in 42.6, 10.1, and 47.3%, respectively, of the erythromycin-resistant Streptococcus pneumoniae isolates. Of the strains, 3.8% were nonsusceptible to levofloxacin and had 1 to 6 amino acid changes in the quinolone resistance-determining region, including a new mutation, Asn94Ser, in the product of parC . Levofloxacin with reserpine was highly specific for efflux screening.

Five subspecies of Fusobacterium nucleatum have been classified: animalis , nucleatum , polymorphum , vincentii , and fusiforme . F. nucleatum subsp. animalis ChDC F324 (KCOM 1325) was isolated from a human subgingival plaque in the Republic of Korea. Here, we report the draft genome sequence of the strain.

Fusobacterium nucleatum is a Gram-negative, nonmotile, obligately anaerobic rod bacterium which might play an important role in the initiation and progression of periodontal diseases. F. nucleatum subsp. vincentii ChDC F8 (KCOM 1231) was isolated from a human gingivitis lesion. Here, we report the draft genome sequence of the strain.

Fusobacterium nucleatum is a Gram-negative anaerobe and is one of the causative agents of periodontal diseases, including peri-implantitis. Fusobacterium nucleatum subsp. nucleatum ChDC F316 (KCOM 1322) was isolated from a human peri-implantitis lesion. Here, we report the draft genome sequence of this strain.

The genus Peptoniphilus comprises butyrate-producing, nonsaccharolytic species that use peptone and amino acids as major energy sources. The novel Peptoniphilus sp. strain ChDC B134 (=KCOM 1628) was isolated from a human periapical abscess lesion. Here, we report the draft genome sequence of the strain.

The study aimed to investigate the prevalence of various serotypes and extended-spectrum β-lactamase-producing features of Salmonella strains and to determine the antimicrobial susceptibility of 256 Salmonella strains other than Salmonella serotype Typhi, which were isolated at 12 university hospitals in Korea. We identified 46 serotypes of Salmonella spp. Serogroup D was the most common (39.5%), followed by B (32.4%), C (22.7%), E (2.7%), A (2.3%), and G (0.4%). The three most common Salmonella serotypes were Enteritidis (36.3%), Typhimurium (16.8%), and Infantis (7.8%). Six strains that belonged to serotype Paratyphi A and nine that belonged to serotype Paratyphi B were also detected. The 256 Salmonella strains had a 38.7% rate of resistance to ampicillin, 23.0% to chloramphenicol, 8.2% to cefotaxime, 8.6% to ceftriaxone, and 6.3% to trimethoprim-sulfamethoxazole. The antimicrobial resistance rates of Salmonella serogroups B and D were higher than those of the other serogroups. Seven isolates carried blaCTX-M: four CTX-M-15, two CTX-M-14, and one CTX-M-3.

We present a case of acute myeloid leukemia (AML) with a balanced translocation between chromosomes 2q12 and 6q12, t(2;6)(q12;q12). This abnormality was defined by conventional cytogenetics and multicolor banding techniques using specific probes for chromosome 2. Blasts accounted for 2% of white blood cells in peripheral blood and approximately 30% of all nucleated cells in marrow aspirates. They were medium-to-large cells with fine nuclear chromatin, indistinct nucleoli and basophilic cytoplasm. Immunophenotyping indicated the blasts were of myeloid lineage with aberrant CD7 expression. Therefore, the patient was diagnosed as ‘Acute myeloid leukemia, NOS, AML with maturation’ according to the WHO classifications. In literature review, this case should be considered as the first report of AML with t(2;6)(q12;q12). Interestingly, a bone marrow smear showed dysmegakaryopoietic findings, such as multinucleated or mononucleated megakaryocytes and micromegakaryocytes. After diagnosis, the induction chemotherapy was given with idarubicin and cytosine arabinoside according to the protocol of intermediate-prognostic AML. After chemotherapy, the patient had been in remission for 13 months but relapsed with 54% blasts in marrow aspirates. The cytogenetic analysis revealed t(2;6)(q12;q12), which is same with karyotype shown at diagnosis. In this case report, the pathologic and clinical findings of AML with t(2;6)(q12;q12) were described, which are severe dysmegakaryopoiesis and poor prognosis. This report may be helpful for clinician to have a similar case treated

Point-of-care (POC) diagnostic testing of tuberculosis (TB) is a tremendous unmet need. In this study, four urinary mycobacterial antigens were identified through two independent approaches using IgG capture and immunodepletion methods. Among these, ModC was validated by a multiple reaction monitoring (MRM) method. As expected, the biomarkers elevated the clinical validity of TB diagnosis when combined with preexisting markers.

Fusobacterium nucleatum is classified into five subspecies. F. nucleatum ChDC F128 was isolated from a periodontitis lesion and proposed as a new subspecies based on the comparison of the nucleotide sequences of the RNA polymerase beta subunit and zinc protease genes. Here, we report the draft genome sequence of the strain.

Fusobacterium nucleatum , one of the major causative bacteria of periodontitis, is classified into five subspecies ( nucleatum , polymorphum , vincentii , animalis , and fusiforme ) on the basis of the several phenotypic characteristics and DNA homology. This is the first report of the draft genome sequence of F. nucleatum subsp. fusiforme ATCC 51190 T .

Chromosome 1q41q42 microdeletions have been classified as a syndrome consisting of significant developmental delay, seizures, and characteristic dysmorphic features. They harbor different breakpoints and their smallest region of overlap at 1q41q42 involves several genes, including DISP1. Deletion or variants of DISP1 have been proposed as a candidate for the midline defects in this syndrome but may not be responsible for its major features in some cases. We report here a patient with a 183-kb deletion in chromosome 1q41, representing the smallest deletion identified among cases of the 1q41q42 microdeletion syndrome. The involved genes are DISP1 and TLR5. This patient developed seizures and developmental delay but showed no facial dysmorphism or organ defects. This deleted region was inherited from a phenotypically normal parent. This case may help define the role of the DISP1 haploinsufficiency in phenotype and support the suggestion that DISP1 mutation or deletion may reveal incomplete penetrance.

Since thermostable Taq DNA polymerase was discovered in 1987, nucleic acid amplification techniques have made great strides and contributed greatly to progress in the life sciences. These techniques were introduced into the clinical laboratory and have produced great changes in diagnostic tools and tests. In particular, there have been many innovative molecular testing developments in the field of diagnostic microbiology.

A new Myroides species has been isolated from the urine of a patient with fever in spite of multiple antibiotic treatments who had undergone a radical hysterectomy for cervical cancer and percutaneous nephrostomies for hydronephrosis in the past. The isolate, Myroides injenensis M09-0166(T) (KCTC 23367(T)), showed a high level of resistance to multiple antibiotic agents. Here we provide the first report of the draft genome sequence of a novel species in the genus Myroides within the nonfermenting Gram-negative group.

The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) of Salmonella and their association with fluoroquinolone susceptibility in Korea.A total of 284 nonduplicated clinical isolates of Salmonella were collected from various clinical specimens at 12 tertiary-care hospitals in Korea. The qnrA, qnrB, and qnrS genes were detected by multiplex polymerase chain reaction (PCR). The qepA and aac(6')-Ib-cr genes were amplified by PCR. The QRDRs of gyrA, gyrB, parC, and parE were amplified by PCR from the DNA of selected nalidixic acid-resistant and qnr-positive isolates.We detected six qnr-positive Salmonella (four qnrS1 and two qnrB19) and one aac(6')-Ib-cr-positive strain. A mutation in the QRDR of gyrA only (N=46) was the most common, followed by gyrA+parC (N=9), parC (N=7), gyrA+parE (N=3), parC+parE (N=3), gyrA+gyrB (N=2), and parE (N=1). There were seven novel mutations in the QRDR regions of gyrB, parC, and parE. Six of seven PMQR-positive isolates had high-level resistance to nalidixic acid, and all six strains had reduced susceptibility to ciprofloxacin. One qnrS1-positive isolate was resistant to ciprofloxacin, norfloxacin, and nalidixic acid. The resistant rates to nalidixic acid, ciprofloxacin, norfloxacin, and levofloxacin were 49.3%, 1.1%, 0.7%, and 0.4%, respectively.We report the first detection of PMQR in Salmonella isolates from Korea. It is essential to continue surveillance and to watch for the spread of PMQR in Salmonella for public health control.

The aims of the current study were to investigate the prevalence and molecular characteristics of plasmid-mediated quinolone resistance (PMQR) genes from colonizing fecal organisms and to compare the incidence and subtype of these genes according to bacterial species and hospital at five tertiary-care hospitals in Korea. A total of 500 nonduplicated clinical isolates of Enterobacteriaceae were obtained from fecal specimens at five tertiary-care hospitals between March and May 2008. The PMQR genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) were amplified by PCR and confirmed by direct sequencing of the PCR products. A total of 83 (16.6%) qnr-positive isolates were detected. The prevalence rates of qnrA, qnrB, and qnrS were 1.4%, 13.6%, and 1.6%, respectively. The species distributions of qnrB-positive isolates were Klebsiella pneumoniae (37/109; 33.9%), Citrobacter freundii (10/34; 29.4%), Citrobacter braakii (8/13; 61.5%), and Escherichia coli (8/275; 2.9%). Sixteen subtypes of qnrB were detected, including seven novel variants. The prevalences of aac(6')-Ib-cr and qepA were 15.6% (n=78) and 0.6% (n=3), respectively. The aac(6')-Ib-cr gene was detected in 39 (47.0%) of 83 qnr-positive isolates and 39 (9.4%) of 417 qnr-negative isolates There was one qepA variant containing a novel mutation (Ala231Val). The prevalence of PMQR genes was high in Enterobacteriaceae from stool specimens in Korea, and there was a close relation between qnr and aac(6')-Ib-cr.

Background: Several previous studies have suggested the improvement of atopic dermatitis (AD) in response to special fabrics. In particular, beneficial effects have been reported, following the use of anion textiles. Objective: The purpose of this study is to evaluate the effectiveness and safety of an anion textile in patients suffering from AD. Methods: We compared an anion textile with a pure cotton textile. Fifty-two atopic patients (n=52) were enrolled and divided into two groups. The patients in the test (n=25) and control (n=19) groups wore undergarments made of an anion textile or pure cotton over a period of 4 weeks. The overall severity of disease was evaluated using the SCORing atopic dermatitis (SCORAD) index, whereas, the treatment efficacy was measured using a Tewameter® (Courage & Khazaka, Cologne, Germany), Mexameter® (Courage & Khazaka) and Corneo meter® (Courage & Khazaka). Results: At the end of the study, a significant decrease in the SCORAD index was observed among the patients with AD in the test group (mean SCORAD decreased from 47.2 to 36.1). Similarly, improvements in the mean transepidermal water loss, skin erythema and stratum corneum hydration were significantly greater among the patients with AD in the test group than in the control group. Conclusion: Anion textiles may be used to significantly improve the objective and subjective symptoms of AD, and are similar in terms of comfort to cotton textiles. The use of anion textiles may be beneficial in the management of patients with AD. (Ann Dermatol 24(4) 438∼443, 2012)

Background The aims of this study were to compare several DNA extraction methods and 16S rDNA primers and to evaluate the clinical utility of broad-range PCR in continuous ambulatory peritoneal dialysis (CAPD) culture fluids. Methods Six type strains were used as model organisms in dilutions from 108 to 100 colony-forming units (CFU)/mL for the evaluation of 5 DNA extraction methods and 5 PCR primer pairs. Broad-range PCR was applied to 100 CAPD culture fluids, and the results were compared with conventional culture results. Results There were some differences between the various DNA extraction methods and primer sets with regard to the detection limits. The InstaGene Matrix (Bio-Rad Laboratories, USA) and Exgene Clinic SV kits (GeneAll Biotechnology Co. Ltd, Korea) seem to have higher sensitivities than the others. The results of broad-range PCR were concordant with the results from culture in 97% of all cases (97/100). Two culture-positive cases that were broad-range PCR-negative were identified as Candida albicans, and 1 PCR-positive but culture-negative sample was identified as Bacillus circulans by sequencing. Two samples among 54 broad-range PCR-positive products could not be sequenced. Conclusions There were differences in the analytical sensitivity of various DNA extraction methods and primers for broad-range PCR. The broad-range PCR assay can be used to detect bacterial pathogens in CAPD culture fluid as a supplement to culture methods.

Among 222 Proteus mirabilis clinical isolates collected from 17 hospitals in Korea in 2008, 28 (12.6%) and 8 (3.6%) isolates exhibited extended-spectrum β-lactamase (ESBL) and AmpC phenotypes, respectively. The most common type of ESBL gene identified by PCR and sequencing experiments was bla CTX-M-14a ( n = 12). The bla CTX-M-90 ( n = 4), bla CTX-M-15 ( n = 3), bla CTX-M-12 ( n = 3), bla CTX-M-2 ( n = 2), bla CTX-M-14b ( n = 1), bla TEM-52 ( n = 5), and bla SHV-12 ( n = 1) genes were also detected. Eight isolates carried an AmpC β-lactamase gene, such as bla CMY-2 ( n = 6) or bla DHA-1 ( n = 2). All bla genes encoding CTX-M-1- and CTX-M-9-type enzymes and all bla CMY-2 genes were preceded by IS Ecp1 -like elements. The bla CTX-M-2 gene found in two isolates was located on a complex class 1 integron. The bla DHA-1 gene was preceded by a transcriptional regulator gene and was followed by phage shock protein genes. The bla CTX-M genes were located on the chromosome in 21 isolates. A plasmid location for the bla CTX-M gene was found in only four isolates: the bla CTX-M-14a gene was located on ∼150-kbp IncA/C plasmids in three isolates and on a ∼50-kbp IncN plasmid in one isolate. The bla TEM-52 gene was located on ∼50-kbp IncN plasmids in all five isolates. The AmpC β-lactamase genes were located on the chromosome in seven of eight isolates; one isolate carried the bla CMY-2 gene on a ∼150-kbp IncA/C plasmid. Our results show that a chromosomal location of CTX-M ESBL and AmpC β-lactamase genes in P. mirabilis is no longer an unusual phenomenon in hospital environments.

Leuconostoc infections are rare and usually occur in immunocompromised patients. This report describes a case of Leuconostoc lactis bacteremia in a patient with coexisting rheumatoid arthritis and tuberculosis arthritis. A disrupted gastrointestinal barrier due to gastrointestinal amyloidosis in long-standing rheumatoid arthritis and tuberculosis arthritis could be a risk factor for Leuconostoc bacteremia. Despite aggressive antibiotic treatment, the patient progressed to septic shock and multi-organ failure. The fatal course might have been caused by rapid progression of gastrointestinal pathology, which could be a risk factor for Leuconostoc bacteremia.

The rapid, accurate diagnosis of Plasmodium spp. is essential for the effective control of malaria, especially in asymptomatic infections. In this study, we developed a sensitive, genus-specific, real-time quantitative PCR assay. It was compared with the microscopic examination of Giemsa-stained blood smears and two different molecular diagnostic techniques: nested PCR and multiplex PCR. For the effective quantitative detection of malaria parasites, all reagents were designed with a lyophilized format in one tube. Plasmodium was detected successfully in all 112 clinically suspected malaria patients, including 32 individuals with low parasitemia (1–100 parasites/μl). The sensitivity threshold was 0.2 parasites/μl and no PCR-positive reaction occurred when malaria parasites were not present. This may be a useful method for detecting malaria parasites in endemic areas.

Translocation (10;17)(p13-15;q12-21) in acute leukemia is rarely reported in the literature. Here, we present both a novel t(10;17) case study and a review of relevant literature on t(10;17) in acute leukemia (10 cases). In summary, we came to the following preliminary conclusions: t(10;17) is associated with poorly differentiated acute leukemia subtype [90%; eight cases of acute myeloid leukemia (AML M0, M1) and one case of acute undifferentiated leukemia], phagocytic activity by blasts occurs (30%), and the survival time was short in three of the seven t(10;17) cases for whom follow-up data were available (median, 8 months). More clinical studies concerning the prognosis, treatment response, and survival of patients with t(10;17) are necessary.

This paper proposes a new decoding algorithm for raptor codes which are widely used rateless channel codes in the area of multimedia broadcast services such as 3GPP MBMS, DVB-H etc. The decoding algorithms for raptor codes can be categorized into two groups. One is the Maximum Likelihood (ML) decoding which shows good performance with very high computational complexity. The other is the Message Passing (MP) decoding with very low computational complexity but the performance is very poor. In this paper, we propose a modified MP decoding which can achieves much better performance with a little increase of complexity compared to the conventional MP decoding.

Background : There is no guideline for the appropriate wavelength at which to measure the optical density (OD) value in broth microdilution antifungal susceptibility testing, although a spectrophotometric reading method is commonly used. The present study aimed to analyze the difference in the OD values over the range of visible light and to ascertain the optimal wavelength for the spectrophotometric method of microdilution testing. Methods : We measured the OD of background blank controls of broth medium, antifungal agents, and inocula of five type strains using a Synergy HT multi-detection microplate reader at 5-nm intervals from 380 nm to 760 nm. We also estimated the OD differences between the 50% of growth control and blank control. Results : The OD of the blank control showed a parabola shape with two peaks and steadily decreased at longer wavelengths. The curves of the antifungal agent were similar to those of blank controls, and the influence of each antifungal agent on the OD was minimal. For the difference in OD between 50% of growth control and the blank control, the curve was the opposite of the blank control, and the OD increased steadily at the wavelengths above 600 nm. Conclusions : The range between 600 nm and 700 nm was the optimal wavelength for broth microdilution antifungal susceptibility testing, although any wavelength within the visible light spectrum can be used.

Kocuria spp. are members of the Micrococcaceae family that are frequently found in the environment and on human skin. Few human infections have been reported. We describe what appear to be the first two cases of Kocuria marina peritonitis in patients undergoing continuous ambulatory peritoneal dialysis.

In previous works, density evolution schemes have been used to design an irregular low-density parity-check (LDPC) code for the multi-input multi-output (MIMO) systems. However the code design based on the density evolution can be used only for simple code structure like LDPC codes and repeat-accumulate (RA) codes. Recently simple and accurate irregular LDPC code design method based on the extrinsic information transfer (EXIT) chart was introduced for an AWGN channel. This code design scheme is much flexible, therefore it can be used for any kind of code structure like turbo codes. In this paper we design an irregular LDPC code for a MIMO system using the EXIT chart based scheme. The EXIT charts are used to obtain the optimal edge degree distribution of the irregular LDPC code combined with the MMSE-SIC MIMO detector. This scheme can be generalized for designing the optimal iterative MIMO detector combined with any kind of channel codes including turbo codes.

We consider the challenges of finding good puncturing patterns for rate-compatible LDPC codes over additive white Gaussian noise (AWGN) channel. In previous works, the role of survived check nodes in puncturing patterns was considered with the limitations such as single survived check node assumption and simulation-based verification. In this paper, we analyze the performance according to the role of multiple survived check nodes and multiple dead check nodes. Based on theses analyses, we propose new algorithm to find good puncturing pattern for LDPC codes over additive white Gaussian noise (AWGN) channel.

The aims of this study were to investigate the prevalence of qnrA, qnrB, and qnrS determinants and their molecular characteristics in ciprofloxacin-resistant isolates of Escherichia coli and Klebsiella pneumoniae from urinary tract infections (UTI) in Korea. A total of 202 nonduplicated clinical isolates of ciprofloxacin-resistant E. coli (n = 143) and K. pneumoniae (n = 59) were collected between July 2005 and August 2006. The qnr determinant screening was carried out by PCR amplification of qnrA, qnrB, and qnrS, and all positive results were confirmed by direct sequencing of the PCR products. For qnr-positive strains and their conjugants, antimicrobial susceptibility tests and pulsed-field gel electrophoresis (PFGE) were performed. The qnrB gene was detected in 41 of the 202 isolates. Among 33 of 59 (55.9%) K. pneumoniae isolates showing qnrB, 29 isolates contained the qnrB4 gene, 3 isolates had the qnrB2 gene, and 1 isolate had the qnrB6 gene. All 8 (5.6%) of the qnrB-positive isolates among the 143 E. coli strains possessed the qnrB4 gene. The minimum inhibitory concentrations (MICs) of ciprofloxacin for the transconjugants were 0.03-2 mug/ml, representing an increase of 4- to 256-fold relative to the recipient, E. coli J53Az(r). Resistances to various other antimicrobial agents also were transferred with the plasmid. The PFGE analysis revealed indistinguishable or closely related patterns in several strains and highly diverse patterns in general. QnrB variants, especially the qnrB4 subtype, are highly prevalent in ciprofloxacin-resistant E. coli and K. pneumoniae from UTI in Korea. The emergence of plasmid-mediated quinolone resistance may contribute by several means to the rapid increase in bacterial resistance to these drugs.

Although coagulase-negative staphylococci (CNS) have been considered part of the resident flora on the human skin, Staphylococcus lugdunensis is an unusually virulent CNS and can cause many types of infection. We report a rare case of acute lymphadenitis with cellulitis in the right infraauricular region caused by S. lugdunensis. A 62-yr-old woman visited the Department of Otolaryngology of Busan Paik university hospital. She had a palpable mass and swelling in the right infraauricular region and complained of aggressive pain and a febrile sensation in the region for 5 days. On the suspicion of abscess with infection, percutaneous aspiration was performed and smooth, flat, white, opaque colonies grew on a blood agar plate as a pure culture. The biochemical test results showed the organism to be catalase positive, tube coagulase negative, ornithine decarboxylase positive, slide coagulase positive, and latex agglutination tests for coagulase positive. The API Staph Kit was used to identify the isolate to the species level as S. lugdunensis with a 64.6% probability (profile 6716152). We confirmed the species identification of this strain by 16S rDNA sequence analysis. The patient's clinical condition improved with appropriate antimicrobial therapy and pus drainage.

We evaluated the clinical usefulness of simultaneous LISS/Coombs and NaCl/Enzyme testing using the gel method for screening and identification of unexpected antibodies in 15,014 samples. When unexpected antibodies were detected by either screening test, those antibodies were identified using both the LISS/Coombs and the NaCl/ Enzyme gel test. The positive screening rates of the LISS/Coombs, NaCl/Enzyme, and combined tests (excluding 25 autoantibody cases) were 0.48%, 1.29%, and 1.39%, respectively. Among the 57 samples positive by both screening methods, the antibodies in 19.3% could be identified only by the NaCl/Enzyme method. Among the 137 samples positive only by NaCl/Enzyme screening, 74.5% showed positive results in antibody identification only by the NaCl/Enzyme test, although 7.3% were also positive in the LISS/Coombs test. The NaCl/Enzyme method thus showed about threefold higher detection rates than the LISS/Coombs method, especially in screening for Rh antibodies, and higher exact identification rates and discriminatory power for identifying mixed antibodies. Addition of the NaCl/Enzyme method to routine laboratory procedures may detect and identify considerable numbers of significant antibodies that might be missed if only the LISS/Coombs method is used.

Vibrio fluvialis is a Gram-negative, oxidase-producing, halophilic bacterium that, as a pathogen, has been implicated mainly as a cause of gastroenteritis. We describe a case of V. fluvialis peritonitis after a traffic accident that is, to our knowledge, the 1st report of non-continuous ambulatory peritoneal dialysis-related acute peritonitis caused by this organism.

Staphylococcus lugdunensis is an unusually virulent coagulase-negative staphylococcus (CoNS) that can cause many types of infection. All culture specimens were collected from patients at Inje University Busan Paik Hospital between October 2005 and March 2006. S. lugdunensis was identified using the phenotypic biochemical tests and 16S rDNA sequencing. Among 358 CoNS, three strains were identified as S. lugdunensis. All three isolates showed positive results in the clumping factor testing, but the L-pyrrolidonyl-beta-naphthylamide hydrolysis test was positive in only one and the ornithine decarboxylase test in two. Two of the three isolates were correctly identified by API Staph, but none of them was identified correctly by the Vitek I system. All three strains were penicillin resistant secondary to beta-lactamase production. S. lugdunensis was an unrecognized but infrequent cause of infection.

Background: There have been steady changes and improvements in diagnostic tests for Mycobacterium tuberculosis, so it is necessary to carry out periodic surveys to understand the current situation. The aims of this study were to investigate the changes in principal practices and quality control for M. tuberculosis using a nationwide survey in the Republic of Korea. Methods: We constructed a questionnaire composed of four subseries with 42 items. We e-mailed this survey to members of the Korean Society of Clinical Microbiology from April to September 2014 and analyzed the replies. Results: Employees at a total of 65 hospital laboratories and 5 commercial laboratories participated in the survey. AFB staining was reportedly performed in all 70 institutions, and fluorescent staining was used as the primary detection method in 59 (84.3%) laboratories. Solid and liquid culture methods for Mycobacterium were performed at 62 (88.6%) and 59 (84.3%) laboratories, respectively. There were 57 laboratories (90.5%) that identified strains growing on primary culture media using a rapid antigen kit or molecular method. The mean values of positive and contamination rates for solid culture media were 8.2% (range 3.7-19.9%) and 4.0% (0.4-8.4%), respectively. In liquid culture, the mean values of positive and contamination rates were 11.5% (4.8-22.3%) and 6.8% (0.3-18.7%), respectively. Conclusion: There have been significant changes and improvements in overall mycobacterial testing, especially in the numbers of laboratories using fluorescent staining, liquid culture, and identification of M. tuberculosis cultured media compared with previous surveys in Korea. (Ann Clin Microbiol 2015;18:69-75)

손종애*·김시현*·신정환·전가원·신종범·이자영·김혜란·전경란·이정녀·송새암 Jong Ae Son, M.D.*, Si Hyun Kim, Ph.D.*, Jeong Hwan Shin, M.D., Ga Won Jeon, M.D., Jong Beom Sin, M.D., Ja Young Lee, M.D., Hye Ran Kim, M.D., Kyung Ran Jun, M.D., Jeong Nyeo Lee, M.D., Sae Am Song, M.D. 인제대학교 의과대학 진단검사의학교실·소아청소년과학교실, 인제대학교 의과대학 백인제기념임상의학연구소 Departments of Laboratory Medicine, and Pediatrics, Inje University College of Medicine, Busan; Paik Institute for Clinical Research, Inje University College of Medicine, Busan, Korea 원저 Lab Med Online Vol. 5, No. 1: 27-32, January 2015 http://dx.doi.org/10.3343/lmo.2015.5.1.27 임상미생물학

Background/Aims We evaluated the trend in the rates of drug-resistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) at a private referral center in South Korea. Methods All patients with culture-confirmed TB from 2006 to 2013 were included. Results In total, 1,745 patients were included: 1,431 (82.0%) were new cases, and 314 (18.0%) were cases treated previously; 1,610 (92.3%) were diagnosed with PTB, and 135 (7.7%) were diagnosed with EPTB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB were detected in 5.8% and 2.0% of new cases and in 20.1% and 8.6% of previously treated cases, respectively. The MDR TB rate during the study period decreased remarkably, whereas the MDR and XDR TB rates decreased significantly in previously treated cases. No difference in the drug-resistance rate was detected between PTB and EPTB. Conclusions The TB drug-resistance rate, particularly that of MDR TB, remained high at a private referral hospital, and the drug-resistance rate did not decrease significantly from 2006 to 2013. This finding underscores the need for a national survey regarding the prevalence of drug-resistant TB to obtain the most accurate and current drug-resistance status in South Korea, including the private sector.

이자영·송새암·오승환·신정환·김혜란·전경란·이정녀 Ja Young Lee, M.D., Sae Am Song, M.D., Seung Hwan Oh, M.D., Jeong Hwan Shin, M.D., Hye Ran Kim, M.D., Kyung Ran Jun, M.D., Jeong Nyeo Lee, M.D. 인제대학교 의과대학 부산백병원 진단검사의학과·해운대백병원 진단검사의학과 Department of Laboratory Medicine, Busan Paik Hospital, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea 원저 Lab Med Online Vol. 5, No. 4: 188-195, October 2015 http://dx.doi.org/10.3343/lmo.2015.5.4.188 진단면역학

An oligonucleotide chip (Combichip Mycobacteria chip) detecting specific mutations in the rpoB , katG , and inhA genes of Mycobacterium tuberculosis was compared with conventional antimicrobial susceptibility results. The probes detecting drug resistance were as follows: 7 wild-type and 13 mutant probes for rifampin and 2 wild-type and 3 mutant probes for isoniazid. Target DNA of M. tuberculosis was amplified by PCR, followed by hybridization and scanning. Direct sequencing was performed to verify the results of the oligonucleotide chip. One-hundred seven of 115 rifampin-resistant strains (93%) had mutations in the rpoB gene. Eighty-five of 119 isoniazid-resistant strains (71%) had mutations in the katG gene or inhA gene. The diagnostic oligonucleotide chip with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of resistance against rifampin and isoniazid in M. tuberculosis isolates.

Weissella confusa is gram-positive, catalase-negative, short rod or coccobacillus that has been isolated from a wide variety of habitats. We describe a rare, severe infective endocarditis of native valves caused by W. confusa that was detected incidentally on echocardiography. The patient recovered completely with valvular replacement plus antibiotic therapy.

In recent years, non-tuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections but there is little known about the isolation and identification of NTM in Korea. The aim of this study was to assess the prevalence of NTM in the hospital environment and identify the species. A total of 150 samples were collected from different parts of the hospital. NTM were isolated and identified by restriction fragment length polymorphism analysis of the gene encoding rpoB and partial sequencing analysis of hsp65 and rpoB. In this study, 60 strains of NTM were isolated from 50 of the 150 samples. Half of the tap water samples (50 of 100) were positive for mycobacteria. An estimated 73.3% of the isolates were saprophytic, 21.7% were potentially pathogenic and 5% were unidentified. The presence of NTM in hospital tap water is not uncommon. Such water isolates might cause true nosocomial infection in immunocompromised patients, in addition to the risk of false-positive culture results.

A colorimetric antifungal susceptibility test was performed using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride. Among 24 strains of Candida species, no trailing growth was found. In 22 and 20 strains, the MICs obtained in the colorimetric assay were within two dilutions of those obtained by the National Committee for Clinical Laboratory Standards method for ketoconazole and itraconazole, respectively.

Rothia dentocariosa , a gram-positive coccoid- to rod-shaped bacterium with irregular morphology, is a rare cause of bacteremia in patients without endocarditis. We report the first case of R. dentocariosa septicemia without endocarditis, which occurred in a neonatal infant with meconium aspiration syndrome.

김지현·이자영·손종애·송새암·오승환·신정환·김혜란·전경란·이정녀 Ji Hyun Kim, M.D., Ja Young Lee, M.D., Jong Ae Son, M.D., Sae Am Song, M.D., Seung Hwan Oh, M.D., Jeong Hwan Shin, M.D., Hye Ran Kim, M.D., Kyung Ran Jun, M.D., Jeong Nyeo Lee, M.D. 인제대학교 의과대학 부산백병원·해운대백병원 진단검사의학과 Department of Laboratory Medicine, Busan Paik Hospital, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea 원저 Lab Med Online Vol. 4, No. 3: 125-131, July 2014 http://dx.doi.org/10.3343/lmo.2014.4.3.125 진단혈액학

Background: Blood culture for diagnosis of bacter- emia and fungemia comprises aerobic and anaerobic cultures. The clinical utility of routine anaerobic blood culture has been questioned for a long time and was evaluated in this study. Methods: A total of 9,028 positive blood cultures were collected...

This paper presents an on-chip integrated reverse transcriptase polymerase chain reaction (RT-PCR) microchip, which integrates the genetic functionalities of messenger ribonucleic acid (mRNA) extraction, complementary deoxyribonucleic acid (cDNA) synthesis, and gene amplification. The proposed RT-PCR microchip consists of a RNA microchannel for extracting mRNA from lysate biological samples, and a DNA microchamber for synthesizing cDNA and amplifying the target gene. As magnetic oligo-dT beads are passed through the RNA microchannel, mRNA bound to the beads was extracted within 1 min by a ferromagnetic wire array inlaid in the RNA microchannel. In the DNA microchamber, the extracted bound mRNA was used for direct synthesis of cDNA followed by amplification of the target gene. To evaluate the performance of the RT-PCR microchip, RT-PCR analyses were performed using various volumes of blood and numbers of breast cancer cells. Additionally, to verify the feasibility of the RT-PCR microchip for clinical applications, it was used for detection of virus-specific genes from specimens of patients infected with respiratory viruses. The continuous and integrated mRNA extraction, cDNA synthesis, and gene amplification process enabled by the proposed RT-PCR microchip suggests its use for high-precision genetic assays with small sample quantities.