• Korean Journal of Clinical Laboratory Science
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• v.42 no.2
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• pp.71-80
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• 2010

Pseudomonas aeruginosa are important nosocomial pathogens. Their resistance to carbapenem is increasing and causing concerns in Korea. An increasing prevalence of carbapenem resistance mediated by acquired carbapenemase is being reported. Over a 10 month-period from July 2007 to April 2008, 32 strains of imipenem-nonsusceptible P. auruginosa were isolated from Kangwon National University Hospital. To determine the prevalence and genotypes of the carbapenemase-producing clinical isolates, the antibiotic susceptibility was determined by Microscan Walkaway 96 SI System and the carbapenem activity was detected by the modified Hodge test and the imipenem-EDTA-SMA double-disk synergy test. The metallo-${\beta}$-lactamase gene and OXA-type ${\beta}$-lactamase gene reported in Korea were detected by PCR. As for the result of PCR, 30 isolates of P. aeruginosa were found to have $bla_{IMP-1}$-like and 1 isolate was found to have $bla_{IMP-1}$-like and $bla_{IMP-2}$. No clinical isolates were found to have $bla_{SIM-1}$, $bla_{OXA-23}$-like and $bla_{OXA-24}$-like. Random amplified polymorphic DNA (RAPD)-PCR and dendrogram for genetical similarity to band patterns of each clinical isolates were examined. P. aeruginosa were grouped into 7 clusters of up to 50% of similarity index. In the P. aeruginosa group, PS3 was resistant to the most antibiotics, PS1 was susceptible to the most antibiotics. PS7 was resistant to aztreonam unlike other groups. This is the first report of prevalence of carbapenemase in Chuncheon.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.4
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• pp.136-139
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the severe nosocomial infectious agents. The traditional diagnostic methods including biochemical test, antibiotic susceptibility test and PCR amplification are time consuming and require much work. The Surface enhanced Raman spectroscopy (SERS) biosensor is a rapid and powerful tool for analyzing the chemical composition within a single living cell. To identify the biochemical and genetic characterization of clinical MRSA, all isolates from patients were performed with VITEK2 gram positive (GP) bacterial identification and Antibiotic Susceptibility Testing (AST). Virulence genes of MRSA also were identified by DNA based PCR using specific primers. All isolates, which were placed on a gold coated nanochip, were analyzed by a confocal Raman microscopy system. All isolates were identified as S. aureus by biochemical tests. MRSA, which exhibited antibiotic resistance, demonstrated to be positive gene expression of both femA and mecA. Furthermore, Raman shift of S. aureus and MRSA (n=20) was perfectly distinguished by a confocal Raman microscopy system. This novel technique explained that a SERS based confocal Raman microscopy system can selectively isolate MRSA from non-MRSA. The study recommends the SERS technique as a rapid and sensitive method to detect antibiotic resistant S. aureus in a single cell level.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.353-358
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• 1996

E. coli 11 and E. coli 101, clinical isolates of Escherichia coli were resistant to various quinolones, especially MICs to norfloxacin of both strains were higher than 100 mg/ml. In the presence of carbonyl cyanide m-chlorophenylhydrazone, a proton gradient uncoupler, norfloxacin uptake in both strains was increased, suggesting that an efflux system play an important role in the norfloxacin resistance. Outer membrane proteins of the susceptible and resistant strains which could affect the route of norfloxacin entry into cells were different. When quinolone resistance determining region(QRDR) of gyrA was amplified using PCR and cut with Hinf I, QRDR in the susceptible strain yielded two fragments while QRDRs in E. coli 11 and E. coli 101 yielded only one uncut fragment. When DNA sequence of QRDR was analyzed, there were two mutations as Ser-83 and Asp-87 in both resistant strains. these residues were changed to Leu-83 and Asn-87, respectively. These results showed that the norfloxacin resistance of E. coli 11 and E. coli 101 was resulted from multiple changes-an altered DNA gyrase A subunit, a change in route of drug entry, and reduction in quinolone concentration inside cells due to an efflux system.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.142-149
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• 2021

Objective: Bacteriospermia and urogenital infections are common problems in male infertility. This study aimed to evaluate the effects of bacteriospermia on sperm parameters and clinical outcomes in semen samples infected with two common bacteria (Staphylococcus saprophyticus and Escherichia coli) in northern Iran. Methods: Microbiological tests were performed to isolate and identify organisms from 435 semen samples from infertile couples. Semen samples were assessed according to the World Health Organization criteria. The protamine status, chromatin structure, chromatin condensation, and acrosome reaction of sperm and assisted reproductive outcomes were determined in couples with different male infertility factors. Results: Among the total cases, the two most prevalent pathogens were considered: S. saprophyticus (38.2%) and E. coli (52.9%). In the semen samples infected with E. coli, the spontaneous acrosome reaction and abnormal chromatin condensation were more common (p<0.05). Significant increases in abnormal chromatin condensation and deprotamination were seen in the presence of S. saprophyticus. In washed semen, tight adhesion between the sperm midpiece and S. saprophyticus was observed. There was also a significant decrease in the fertilization rate using semen samples infected with S. saprophyticus and E. coli during in vitro fertilization cycles (p<0.001). In addition, the presence of S. saprophyticus and E. coli in semen samples was associated with a lower likelihood of clinical pregnancy in couples with various factors of male infertility. Conclusion: Poor results of assisted reproductive techniques may be correlated with semen samples infected with two common bacteria in northern Iran.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.1
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• pp.15-21
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• 2016

Aspergillus is the most common opportunistic fungus causing infection. Aspergillus is the most morphologically identified in the laboratory. Recently, molecular genetic methods have been proposed for identification of fungi that unidentified morphologically or identified genus level. Of 475 cases of Aspergillus isolated from clinical specimens, there were Aspergillus fumigatus 257 (54.1%), A. niger 101 (21.3%), A. flavus 43 (9.1%), A. terreus 29 (6.1%), Aspergillus nidulans 2 (0.4%), Aspergillus clavatus 1 (0.2%), and the Aspergillus species 42 (8.8%). Eleven cases of unidentified or identified at the genus level included Aspergillus fumigatus 5, Aspergillus falvus 1, Aspergillus terreus 1, and Aspergillus lentulus 1 was identified in the sequencing of the strain level. It was identified as Aspergillus versicolor 2, and Emericella parvathecia 1. 92.2% of Aspergillus was identified as a possible morphological, 8.8% could not be identified at the species level. Sequence-based molecular analysis using the ITS and D1D2 is considered useful for identification of the species level.

• Tuberculosis and Respiratory Diseases
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• v.64 no.6
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• pp.422-426
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• 2008

Background: Mycobacterium abscessus is the most pathogenic and drug-resistant rapid-growing mycobacterium. Clarithromycin or azithromycin are the only regular oral antimycobacterial agents that have an effect on M. abscessus. We tried to detect the clarithromycin-resistant strains from the clinical isolates of M. abscessus. Methods: We tried to isolate the clarithromycin-resistant strains from 220 clinical isolates of M. abscessus by performing using reverse hybridization assay (RHA) and the broth microdilution test (BMT). Results: Seven resistant strains (3.2%) from all the tested clinical isolates were detected by BMT. Three of these resistant strains were also detected by RHA and it was confirmed that they had point mutants. Conclusion: These results showed that clarithromycin resistance in M. abscessus clinical isolates is related to a point mutation and other unknown mechanisms.

• ETRI Journal
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• v.37 no.2
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• pp.233-240
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• 2015

The novelty of this study resides in a 6"-wafer-level microfabrication protocol for a microdevice with a fluidic control system for the separation of circulating tumor cells (CTCs) from human whole blood cells. The microdevice utilizes a lateral magnetophoresis method based on immunomagnetic nanobeads with anti-epithelial cell adhesive molecule antibodies that selectively bind to epithelial cancer cells. The device consists of a top polydimethylsiloxane substrate for microfluidic control and a bottom substrate for lateral magnetophoretic force generation with embedded v-shaped soft magnetic microwires. The microdevice can isolate about 93% of the spiked cancer cells (MCF-7, a breast cancer cell line) at a flow rate of 40/100 mL/min with respect to a whole human blood/buffer solution. For all isolation, it takes only 10 min to process 400 mL of whole human blood. The fabrication method is sufficiently simple and easy, allowing the microdevice to be a mass-producible clinical tool for cancer diagnosis, prognosis, and personalized medicine.

• KSBB Journal
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• v.26 no.6
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• pp.543-551
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• 2011

Bacterial antibiotic resistance is a real and growing problem for both Gram positive and Gram negative bacterial pathogens in the hospital setting. Among Gram negative bacteria, the ubiquitous bacterium Pseudomonas aeruginosa is a particular concern in immunocompromised and burn patients. The present study evaluated antibacterial activity and efficacy of a Korean herbal medicine against eight multi-drug resistant clinical isolates of P. aeruginosa (0225, 0254, 0347, 0826, 1113, 1378, 1731, and 2492) isolated at Daegu Catholic University Hospital. Methanol extracts of Galla rhois (5 and 10 mg/mL) displayed inhibition diameters for isolate 2492 of 10 and 12 mm, respectively, in a conventional disc diffusion assay. In seven kinds of Korean herbal medicines, increased inhibitory power of Lonicera japonica, Gardenia jasminoides, Galla rhois, and Scultellaria baicalensis was evident with the fermentation of six kinds of lactic acid bacteria. Three lactic acid bacteria (Lactobacillus plantarum subsp. plantarum KCTC 3108, L. casei KCTC 3109, and L. fermentum KCTC 3112) were identified as excellent strains for the production of antibacterial materials. In the six Korean herbal medicine extracts, strong inhibitory activity of fermented Forsythia suspensa, Glycyrrhizae radix, Lycium chinense, Platycodon grum, and Schizandra chinensis with five kinds of lactic acid bacteria was evident for seven multi-drug resistant P. aeruginosa isolates.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.149-158
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• 2003

The purpose of this study was to isolate and characterize the Fusohacrerium nucleatum (F. nucleatum) from subgingival plaque in Korean periodontitis patients. The subgingival plaque samples of periodontitis patient were collected with sterilized paper point. The paper point was put into reduced transfer medium and then immediately transferred to laboratory. The subgingival samples were diluted by 10,000 folds and plated on F. nucleatum-selective media agar plate. The plates were incubated at 37$^{\circ}C$ in an anaerobic chamber for 3 days. The violet-colored colonies were selected and subjected to further verification whether those are F. nucleatum or not. For further confirmation, 16S rRNA genes (rDNA) were cloned from each of bacterial clones and determined sequence of 16S rDNA. In this study, we found 17 distinct clinical isolates of F. nucleatum from subgingival plaque. The clinical isolates will be a useful in various studies in periodontology.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.138-144
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• 2000

This study was carried out to investigate the pathogenicity of Korea N caninum isolates, KBA-1 and KBA-2 on SCID mouse following 3 different routes of infection. NC-1 was served as reference isolate. The pathogenecity was evaluated by progression of clinical signs, histopathology and immunohistochemistry. Pathogenicity of KBA-2 appears to be stronger than that of KBA-1 but weaker than that of NC-1. Progress of clinical signs and lesion distribution and pattern of each isolates were similar when the isolates were infected either subcatareously or intraperitoneally. However, oral inoculation of tachyzoites failed to induce the infection.