• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.73-77
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• 1985

Haemophilus aphrophilus is a fastidious gram-negative bacillus found in mouth of normal individuals. Though H. aphrophilus infection is quite rate, it includes such serious ones as endocarditis and brain abscess. The authors isolated H. aphrophilus from five patients with the diagnosis of lung abscess, conjunctivitis, brain abscess and facial masticator space abscess. Two of the patients died. Three of the patients also yielded other species of bacteria from the same specimens. One of the isolate was intermediately susceptible to amikacin and resistant to tobramycin, indicating the necessity of a routine susceptibility test in order to select the proper antimicrobial agents. Since H. aphrophilus can be differentiated from other similar organisms by morphological and biochemical characteristics, one should determie the possibility of this organism when fastidious gram-negative bacilli are isolated from blood or from sites adjacent to upper respiratory tract.

• Restorative Dentistry and Endodontics
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• v.49 no.3
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• pp.23.1-23.10
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• 2024

Objectives: Previous in vitro studies determined the whitening effects of bleaching products on stained resin composite surfaces. This in vitro study aimed to verify the effectiveness of a whitening system on composite resin previously subjected to pigmentation, specifically examining the depth of whitening effectiveness within the material structure. Materials and Methods: A commercially available nano-filled composite resin was used. Specimens were stained using a coffee-based solution and a 10% carbamide peroxide-based gel was employed as the whitening agent. The pigment's penetration and the effect of the bleaching gel were evaluated by measuring color (CieLab values) from the outer edge to the inner part of the specimens. Color measurements were taken at 14 points, starting from 0.1 mm from the external perimeter up to 3.0 mm. Results: Analysis of variance tests showed a statistically significant difference between the Control Group (CG), Pigmentation Group, and Whitening Group. The whitening agent was effective up to 1.5 mm in depth, with Whiteness index (W) values not statistically different from those of CG up to 0.5 mm in depth. Conclusions: Whitening agents on nano-filled resin composite previously pigmented appear effective in restoring the W to values similar to the original, particularly in the superficial layers of the sample.

• Biomedical Science Letters
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• v.29 no.4
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• pp.249-255
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• 2023

Transporting clinical samples for microbiological testing requires a proper transport medium that guarantees the survival of microorganisms. Therefore, the aim of the study was to determine the ability of Amies Transport Medium (ATM) to maintain the viability of microorganisms in clinical specimens and its suitability as a transport medium for microbiological testing. This study evaluated the performance of swab provided by KS Co., Ltd. for three groups of bacteria comprising aerobic and facultative anaerobic bacteria, anaerobic bacteria, and fastidious bacteria, according to the Clinical and Laboratory Standard Institute (CLSI) 8.11.2. The ATM stability test was conducted by dividing the medium into two groups based on the product expiration date of use. All tested media, A and B (the date of manufacture and expiration date are different) showed ≥5 CFU, and there was no significant difference in the result values of Category A and Category B with different serial numbers for each test. The results of this experiment when cross-checked with the guidelines suggest that ATM is a suitable transport medium for microbiological testing, as it maintains the viability of microorganisms and is suitable for overgrowth trials. In addition, compared to the number of CFUs at the origin, the number of CFUs did not increase by more than 1 log after storage. These results have important implications for the development of transport media that can guarantee the survival of microorganisms in clinical specimens.

• Tuberculosis and Respiratory Diseases
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• v.76 no.4
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• pp.163-168
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• 2014

Background: Mycobacterial identification in active pulmonary tuberculosis (APTB) is confirmative, even though successful rates using self-expectorated sputum are limited. Sputum specimens collected by hypertonic saline nebulization showed higher bacteriologic diagnostic sensitivities over those of self-expectoration, mostly studied in smear-negative or sputum-scarce patients. The efficacy of induced sputum was rarely assessed in real clinical settings. Methods: A prospective randomized case-control study was performed in one hospital. The subjects highly suspicious of APTB were asked to provide 3 pairs of sputum specimens in 3 consecutive days. The first pairs of the specimens were obtained either by self-expectoration (ES) from the next day of the visit or sputum induction with 7% saline nebulization in clinic (SI), and the other specimens were collected in the same way. The samples were tested in microscopy, culture, and polymerase chain reaction (PCR). The outcomes of the bacteriological diagnosis were compared. Results: Seventy six patients were assigned to either ES (38 subjects, median age of 51, 65.8% male) or SI (38 subjects, median age of 55, 52.6% male). APTB was clinically confirmed in 51 patients (70.8%), 27 in ES and 24 in SI. Among the APTB, more adequate specimens were collected from SI (41/65, 63.1%) than ES (34/80, 42.5%) (p=0.01). Bacteriological confirmation was achieved in 14 (58.3%) patients in SI, and 13 (48.1%) in ES (p=0.46). In the same-day bacteriological diagnosis with microscopy and PCR, there were positive results for 9 patients (37.5%) in SI and 7 patients (25.9%) in ES (p=0.37). Conclusion: Sputum induction improves sputum specimen adequacy. It may be useful for the same-day bacteriological diagnosis with microscopic examination and PCR.

• Journal of Microbiology
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• v.40 no.2
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• pp.166-169
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• 2002

Twenty strains of Cryptococcus neoformams isolated from environmental and clinical sources in Korea were examined for their serotypes. Two environmental isolates from pigeon excreta belonged to C. neoformans var. neoformans serotypes A. Of the 18 isolates from clinical specimens, 17 belonged to C. neoformans vats, neoiomans (serotype A : 16, serotype D : 1) and one belonged to C. neoformans vats, gattii serotype B, which was culturally unusual, producing mucous colonies. This is the first report of the identification of C. neoformans roar, gattii serotype B from a patient in Korea.

• Biomedical Science Letters
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• v.6 no.1
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• pp.55-63
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• 2000

This study has been carried out to investigate the sensitivity of polymerase chain reaction (PCR) method over conventional acid-fast bacilli (AFB) staining and/culture methods for the detection of Mycobacterium tuberculosis from trace body fluid and paraffin-embedded tissues (PET) specimens. A total of 65 cases were employed for the AFB staining and culture test, and a total of 50 cases were subjected to PCR and histopathological analysis. Among the specimen showing negative reaction to AFB staining, 12.1% were positive to PCR and 3.7% of the specimen representing negative result to culture test showed positive reaction to PCR. In addition, 20.0% of the specimen with AFB negative showed positive reaction to PCR. From these results, it could be concluded that PCR method overwhelms AFB staining and culture tests in sensitivity and specificity to M tuberculosis detection.

• Biomedical Science Letters
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• v.16 no.2
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• pp.127-131
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• 2010

Mycobacterium leprae detection is difficult even with molecular biological techniques due to the low sensitivity of current methodologies. In this report, real-time PCR targeting the M. leprae-specific repetitive element (RLEP) sequence was developed as a new diagnostic tool and evaluated using clinical specimens. For this, M. leprae DNAs were extracted from skin biopsy specimens from 80 patients and analyzed by real-time PCR using TaqMan probe. Then, the detection efficiency of the real-time PCR was compared with that of standard PCR. In brief, the rate of positive detection by the standard PCR and real-time PCR was 32.50% and 66.25%, respectively. The results seemed to clearly show that the TaqMan real-time PCR developed in this study may be a useful tool for sensitive detection of M. leprae from clinical specimens.

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.432-437
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• 2006

Objective : In order to establish the index of degeneration, the authors performed a histochemical study with Safranin-O staining and investigated the occurrence of apoptosis in the human intervertebral disc. Methods : Eighteen intervertebral disc specimens surgically extracted from the patients and two additional specimens from the autopsied cases were stained with Safranin-O for proteoglycan according to a standard protocol. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate- biotin nick end labeling[TUNEL] was used to detect the fragmented DNA known to be associated with apoptotic cell death and classification scheme was formulated for categorization of the degree of Safranin-O staining [normal, moderate reduction, faint] by modification of Makin's histological-histochemical grading. The Kruskal-Wallis H test and Chi-square test were used for statistical analysis. Results : The statistical results showed a significant difference in the mean age between "normal" Safranin-O staining group and the others [19.3 versus 55, 43.4, p=0021]. However, there was no statistically significant correlation between Safranin-O staining and MR grading of disc degeneration. Only six of eighteen surgical specimens and none in autopsies showed positive apoptotic cells in TUNEL staining. Conclusion : The determination of the degree of degeneration in surgically obtained disc tissue per se by histochemical staining or by the degree of apoptosis that corresponds to its morphologic change was not feasible.

• Korean Journal of Veterinary Research
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• v.61 no.3
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• pp.26.1-26.8
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• 2021

Acinetobacter is a bacteria found in the environment and clinical specimens, causing nosocomial infection and antimicrobial resistance (AMR) threats. This study examined the prevalence, species, and AMR characteristics of Acinetobacter isolated from surgical practice and the laboratory dog husbandry room environments (n = 235) at Rajamangala University of Technology Tawan-ok veterinary hospital during 2018-2019. The prevalence of Acinetobacter in the laboratory dog husbandry room and veterinary belongings were 2.55% and 0.43%, respectively. Species determination was Acinetobacter hemolyticus (2.13%) and Acinetobacter baumannii (0.43%) from environments in the laboratory dog husbandry room, and Acinetobacter junii (0.43%) from the shoes used in the surgical practice room. AMR was observed in both study environments and the specimens sent to the Veterinary Diagnostic Center. These isolates had a high resistant percentage to amoxicillin-clavulanic acid (84.62%), sulfamethoxazole-trimethoprim (61.54%), and cephalexin (53.85%) but were susceptible to imipenem. Compared to the isolates recovered from the clinical specimens, most isolates derived from environments exhibited multidrug resistance and shared correlated resistance patterns. These results highlight the need for sanitization in the dog husbandry room. Furthermore, the AMR results can be used as a preliminary baseline for studying AMR Acinetobacter contamination in animals and their environments.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.123-126
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• 2023

The prevalence of candidiasis, a contagious disease with high morbidity and mortality, has sharply increased globally over the last two decades. Candida albicans can cause serious infections in patients with weak immunity and in recipients of prolonged antibiotic treatment. Consequently, rapid and accurate identification of species can play an important role in the treatment of candidiasis. Here, we investigated the positive rate and infection trend of C. albicans according to age, specimen type, and sex using multiplex real-time polymerase chain reaction-based testing of samples collected for the diagnosis of sexually transmitted diseases in Korea between 2018 and 2020. When the type of specimen collected was a swab, the positive rate of C. albicans was higher among younger women, and tended to decrease with age. Analysis of swab samples revealed higher positive rates than urinalysis. The reduction trend in positive rates by age was comparable between the overall samples and urine specimens. Among male patients, the positive rate did not differ substantially across the various types of specimens collected. Previous studies have shown a higher prevalence of non-albicans Candida species than C. albicans in clinical specimens, and exclusion of the former from our analysis may be a limitation of this study. However, our findings contribute significantly to the literature because globally, there is a paucity of epidemiological studies using molecular techniques to detect C. albicans in sexually transmitted disease test samples.