Biomedical subjects

Sang-Jong Kim

Publications and source records attributed to Sang-Jong Kim.

5 recordsLinked to original sources

PubMed2006

Physiological, biochemical, and genetic characterization of an alicyclic amine-degrading Mycobacterium sp. strain THO100 isolated from a morpholine-containing culture of activated sewage sludge.

Mycobacterium sp. strain THO100 was isolated from a morpholine-containing culture of activated sewage sludge. This strain was able to utilize pyrrolidine, morpholine, piperidine, piperazine, and 1,2,3,6-tetrahydropyridine as the sole sources of carbon, nitrogen, and energy. The degradation pathway of pyrrolidine as the best substrate for cellular growth was proposed based on the assays of substrate-induced cytochrome P450 and constitutive enzyme activities toward 4-aminobutyric acid (GABA) and succinic semialdehyde (SSA). Its 16S ribosomal RNA gene sequence (16S rDNA) was identical to that of Mycobacterium tokaiense ATCC 27282(T). The morABC genes responsible for alicyclic amine degradation were nearly identical among different species of Mycobacteria. Remarkably, repetitive sequences at the intergenic spacer (IGS) region between morC and orf1' were detected by comparison of the nearly identical mor gene cluster regions. Considering the strain activity for alicyclic amine degradation, the deleted 65-bp DNA segment did not significantly alter the open reading frames, and the expression and functions of the P450(mor) system remained unaltered. In addition, we found a spontaneous deletion of P450(mor) from another strain HE5 containing the archetypal mor gene cluster, which indicated a possible occurrence of DNA recombination to rearrange the DNA.

Amines↗

PubMed2006

Detection of human adenoviruses and enteroviruses in Korean oysters using cell culture, integrated cell culture-PCR, and direct PCR.

Oysters are known to be carriers of food-born diseases, but research on viruses in Korean oysters is scarce despite its importance for public health. We therefore tested oysters cultivated in Goheung, Seosan, Chungmu, and Tongyeong, for viral contamination using cell culture and integrated cell culture PCR (ICC-PCR) with Buffalo green monkey kidney (BGMK) and human lung epithelial (A549) cells. Additional screens via PCR, amplifying viral nucleic acids extracted from oysters supplemented our analysis. Our methods found 23.6%, 50.9%, and 89.1% of all oysters to be positive for adenoviruses when cell culture, ICC-PCR, and direct PCR, respectively, was used to conduct the screen. The same methodology identified enteroviruses in 5.45%, 30.9%, and 10.9% of all cases. Most of the detected enteroviruses (81.3%) were similar to poliovirus type 1; the remainder resembled coxsackievirus type A1. A homology search with the adenoviral sequences revealed similarities to adenovirus subgenera C (type 2, 5, and 6), D (type 44), and F (enteric type 40 and 41). Adenovirus-positive samples were more abundant in A549 cells (47.3%) than in BGMK cells (18.2%), while the reverse was true for enteroviruses (21.8% vs. 14.5%). Our data demonstrate that Korean oysters are heavily contaminated with enteric viruses, which is readily detectable via ICC-PCR using a combination of A549 and BGMK cells.

Adenoviridae↗

PubMed2004

A novel continuous toxicity test system using a luminously modified freshwater bacterium.

An automated continuous toxicity test system was developed using a recombinant bioluminescent freshwater bacterium. The groundwater-borne bacterium, Janthinobacterium lividum YH9-RC, was modified with luxAB and optimized for toxicity tests using different kinds of organic carbon compounds and heavy metals. luxAB-marked YH9-RC cells were much more sensitive (average 7.3-8.6 times) to chemicals used for toxicity detection than marine Vibrio fischeri cells used in the Microtox assay. Toxicity tests for wastewater samples using the YH9-RC-based toxicity assay showed that EC50-5 min values in an untreated raw wastewater sample (23.9 +/- 12.8%) were the lowest, while those in an effluent sample (76.7 +/- 14.9%) were the highest. Lyophilization conditions were optimized in 384-multiwell plates containing bioluminescent bacteria that were pre-incubated for 15 min in 0.16 M of trehalose prior to freeze-drying, increasing the recovery of bioluminescence and viability by 50%. Luminously modified cells exposed to continuous phenol or wastewater stream showed a rapid decrease in bioluminescence, which fell below detectable range within 1 min. An advanced toxicity test system, featuring automated real-time toxicity monitoring and alerting functions, was designed and finely tuned. This novel continuous toxicity test system can be used for real-time biomonitoring of water toxicity, and can potentially be used as a biological early warning system.

Biological Assay↗

PubMed2004

Use of cell culture-PCR assay based on combination of A549 and BGMK cell lines and molecular identification as a tool to monitor infectious adenoviruses and enteroviruses in river water.

Viral contamination in environmental samples can be underestimated because a single cell line might reproduce only some enteric viruses and some enteric viruses do not exhibit apparent cytopathic effects in cell culture. To overcome this problem, we evaluated a cell culture-PCR assay based on a combination of A549 and Buffalo green monkey kidney (BGMK) cell lines as a tool to monitor infectious adenoviruses and enteroviruses in river water. Water samples were collected 10 times at each of four rivers located in Gyeonggi Province, South Korea, and then cultured on group 1 cells (BGMK cells alone) and group 2 cells (BGMK and A549 cells). Reverse transcription and multiplex PCR were performed, followed by phylogenetic analysis of the amplicons. Thirty (75.0%) of the 40 samples were positive for viruses based on cell culture, and the frequency of positive samples grown on group 2 cells (65.0%) was higher than the frequency of positive samples grown on group 1 cells (50.0%). The number of samples positive for adenoviruses was higher with A549 cells (13 samples) than with BGMK cells (one sample); the numbers of samples positive for enteroviruses were similar with both types of cells. By using phylogenetic analysis, adenoviral amplicons were grouped into subgenera A, C, D, and F, and enteroviral amplicons were grouped into coxsackieviruses B3 and B4 and echoviruses 6, 7, and 30, indicating that A549 and BGMK cells were suitable for recovering a wide range of adenoviral and enteroviral types. The cell culture-PCR assay with a combination of A549 and BGMK cells and molecular identification could be a useful tool for monitoring infectious adenoviruses and enteroviruses in aquatic environments.

Adenoviruses, Human↗

PubMed2002

Detection of infectious enteroviruses and adenoviruses in tap water in urban areas in Korea.

We investigated the viral contamination of tap water at 11 urban sites in Korea between 1997 and 1998 over a period of 11 months. A total of 23 tap water samples were examined for infectious enteroviruses and adenoviruses by a cell culture technique followed by polymerase chain reaction (PCR) amplification. To identify the recovered viruses, sequence analysis of PCR products was performed. Infectious enteroviruses and adenoviruses were detected in 11 (47.8%) and 9 (39.1%) of the samples, respectively. Both enteroviruses and adenoviruses were detected in five samples (21.7%). The level of viral contamination was quite high, ranging from 2 x 10(-3) to 2.9 x 10(-2) Most Probable Number of Infectious Unit L(-1), far above the recommended virus level in drinking water set by the US EPA. Poliovirus type I derived from vaccine was frequently detected and the remainder comprised coxsackievirus B type or echovirus type 6, which were causative agents of aseptic meningitis in Korea in 1997 and 1998, respectively. Several types of adenovirus were detected in tap water samples and some water samples were found to contain adenoviruses which were closely related to enteric adenovirus types 40 and 41.

Adenoviridae↗