-
[show abstract]
[hide abstract]
ABSTRACT: Plasmid profiles, Southern blot hybridization, and conjugation assays revealed that the blaCMY-11 gene, responsible for beta-lactam resistance, was located on a noble complex class 1 integron within a conjugative plasmid. A sul1-type class 1 integron, harboring dfrA12, orfF, and aadA2a gene cassettes, was identified upstream of an ISCR1 element and ended with a truncated 3' conserved segment. The nucleotide sequence analyses of blaCMY-1, blaCMY-8, blaCMY-9, and blaCMY-11 genes indicate that there might be past transposition events by the ISCR1 element upstream of blaCMY-11. For the first time, a unique gene (yqgF-yqgE-gshB-orf97-orf105) array was detected between blaCMY-11 and a duplicate of the 3' conserved segment.
Journal of Medical Microbiology 10/2009; 59(Pt 1):132-4. · 2.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The dissemination of many antibiotic resistance genes has arisen among members of the family Enterobacteriaceae. The dissemination mechanism of these antibiotic resistance genes is closely linked with insertion sequence common region 1 (ISCRl). Thus, caution must be taken in clinical settings to prevent further dissemination of these antibiotic resistance genes. A nomenclature system of ISCRl variants, important for the antibiotic resistance dissemination, was proposed. The proposed system can designate all ISCRl variants on the basis of the detection time and by considering amino-acid substitution(s) compared with ISCRla. This nomenclature system of ISCRl variants can be applied to 19 groups (ISCRl to ISCR19) of the ISCR family and help some researchers to correctly designate new ISCR subgroups.
The Journal of Microbiology 08/2009; 47(4):514-6. · 1.10 Impact Factor
-
Mingai Huang,
Seong-Jin Choi,
Dong-Won Kim,
Na-Young Kim,
Choong-Hee Park,
Seung-Do Yu,
Dae-Seon Kim,
Kyung-Su Park, Jae-Seok Song,
Heon Kim,
Byung-Sun Choi,
Il-Je Yu,
Jung-Duck Park
[show abstract]
[hide abstract]
ABSTRACT: Cadmium (Cd) and arsenic (As) are widely distributed in the environment and are known human carcinogens. Several studies reported that chronic exposure to Cd and As produced renal injuries in humans. As one of the mechanisms, oxidative stress was suggested to play a role in the early process of Cd- and/or As-induced tubular damage in the kidney. This study was performed to evaluate the significance of urinary biomarkers, role of oxidative stress, and effect of coexposure to environmental low-level exposure to Cd and/or As in the general population. Urine samples were collected from 290 adults (86 males and 204 females). Urinary concentrations of Cd and As were measured, and kidney biomarkers of toxicity such as beta(2)-microglobulin and N-acetyl-beta-D-glucosaminidase (NAG) activity determined in urine. Urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were measured as oxidative stress indices. The mean concentration of Cd was 1.21 microg/L, 0.84 microg/g creatinine, and As was 5.7 microg/L, 3.95 microg/g creatinine in urine. NAG, MDA, and 8-OHdG were positively correlated with both Cd and As in urine. Positive correlations were also observed between NAG and oxidative indices. The effects of coexposure to Cd and As on biomarkers are more pronounced than for exposure to each metal alone. These findings suggest that chronic exposure to low levels of Cd and/or As might produce tubular damage in the kidney through oxidative stress in humans.
Journal of Toxicology and Environmental Health Part A 01/2009; 72(21-22):1493-8. · 1.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine prevalence and genotypes of β-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pi determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced β-lactamases and had the high genetic diversity. According to minimum inhibitory concentration patterns, we found that five (16.7%) of thirty clones produced an extended-spectrum β-lactamase. Banding patterns of PCR amplification with the designed primers showed that 837- and 259-bp fragments specific to blaTEM genes were amplified. TEM-1 was the most prevalent β-lactamase and conferred the resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type β-lactamases were essentially the same as the resistance levels conferred by the TEM -type alleles that had been isolated from clinically resistant strains of bacteria after antibiotic era. Our first report on the TEM -type β-lactamases before the antibiotic era indicates that TEM -type β-lactamases paint a picture in which most of the diversity of the enzymes may not the result of recent evolution but that of ancient evolution.
02/2008: pages 33 - 41; , ISBN: 9783527611904
-
[show abstract]
[hide abstract]
ABSTRACT: The present study evaluated the possible role of interleukin (IL)-10 promoter polymorphisms in children with atopic dermatitis (AD). IL-10 promoter polymorphisms are associated with the phenotype of AD in children.
The Journal of pediatrics 02/2007; 150(1):106-8. · 4.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study confirms that Taq DNA polymerase could be contaminated with the blaTEM-1(a) gene. It also proposes two different methods that could be used to overcome DNA contamination: (i) DNase I treatment prior to PCR amplification; and (ii) the use of a highly purified Taq DNA polymerase which was devoid of detectable contamination.
The Journal of Microbiology 03/2006; 44(1):126-8. · 1.10 Impact Factor
-
Antimicrobial Agents and Chemotherapy 12/2005; 49(11):4809-10. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated an outbreak of Acinetobacter baumannii in an intensive care unit and in the surgery, medicine, neurology, and urology wards of the Kosin University Gospel Hospital in Busan, Korea. The outbreak involved 36 cases of infection by A. baumannii producing the OXA-23 beta-lactamase over an 8-month period and was caused by a single pulsed-field gel electrophoresis clone. The epidemic isolates were characterized by a modified cloverleaf synergy test. Isoelectric focusing of crude bacterial extracts detected one nitrocefin-positive band with a pI value of 6.65. PCR amplification and characterization of the amplicons by direct sequencing indicated that the epidemic isolates carried a bla(OXA-23) determinant. The epidemic isolates were characterized by a multidrug resistance phenotype that remained unchanged over the outbreak, including penicillins, cephamycins, extended-spectrum cephalosporins, carbapenems, monobactams, and aminoglycosides. This study shows that the bla(OXA-23) resistance determinant may become an emerging therapeutic problem.
Journal of Clinical Microbiology 06/2005; 43(5):2241-5. · 4.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the prevalence and genotypes of beta-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced beta-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five (16.7%) of thirty clones produced an extended-spectrum beta-lactamase. 837- and 259-bp fragments specific to blaTEM genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM-1 was the most prevalent beta-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type beta-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type beta-lactamases of the pre-antibiotic era indicates that TEM-type beta-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.
The Journal of Microbiology 05/2005; 43(2):172-8. · 1.10 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Among the 51 clinical isolates collected from a university hospital in Korea, nine isolates were resistant to cephamycins. Nine isolates were shown to produce CMY-11 and these also included three isolates producing TEM-1. The results from ERIC-PCR revealed that dissemination of CMY-11 was due to outbreaks of resistant species and to the intra-species spread of resistance to cephamycins in Korea. CMY-11 beta-lactamase genes from nine clinical isolates that were responsible for resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin and amoxicillin-clavulanic acid, were cloned and characterised. A sequence identical to the common regions in In6, In7 and a novel integron from pSAL-1 was found upstream from bla(CMY-11) gene at nucleotide 1-71. Eighteen nucleotides between position 71 and 72 were inserted into the bla(CMY-11) gene.
International Journal of Antimicrobial Agents 11/2004; 24(4):320-6. · 4.13 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Alkyl cellosolves include ethylene glycol monomethylether, ethylene glycol monoethylether, ethylene glycol monobuthylether. And their urine metabolites are methoxyacetic acid, ethoxyacetic acid and butoxyacetic acid. The current analytical method for urinary alkoxyacetic acid is liquid-liquid phase extraction. But the liquid-liquid phase extraction method needs a more complex pre-treatment process and has a low recovery rate. We determined the appropriate extraction solvent and its flow rate. We also evaluated the non-absorptive rate and recovery rate according to particle size. Finally we developed a convenient solid phase extraction method for the analysis of urine cellosolve metabolites. As a result, the recovery rates for methoxyacetic acid, ethoxyacetic acid and butoxyacetic acid were 100.4 +/- 1.6%, 100.2 +/- 1.8% and 100.7 +/- 10.0% respectively, when acetone was used as the extraction solution. The most appropriate flow rate was 0.1 ml/min. At a particle size of 140-200 mesh, non-absorption percentages for methoxyacetic acid, ethoxyacetic acid, butoxyacetic acid were 3.2 +/- 0.3%, 1.0 +/- 0.1% and 1.1 +/- 0.1%, and the recovery rates according to particle size were similar. Further evaluation of the recovery rate and non-absorptive rate according to the mini column shape, stationary phase and recovery rate with various extracting solutions is required.
Journal of Occupational Health 08/2004; 46(4):260-5. · 1.55 Impact Factor
