In modern medicine the resistance to conventional antibiotics is becoming a serious concern due to high instances of mortality. Several metallic nanoparticles are suggested as promising anti-microbial agents against multidrug-resistant bacteria and some viruses. Among the nanoparticles mentioned, we review the recent finding which demonstrate the impact of silver nanoparticles on antimicrobial activities and recommend them as a potential candidate for restraining infections.
Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; History, Modern 1601- ; Metal Nanoparticles ; Nanoparticles ; Silver

Neutrophils are the most abundant white blood cells in the peripheral blood and have long been recognized as the major phagocytes in acute infection by destroying extracellular pathogens. Although research on neutrophils hampered by intractability in the experiments, the newly discovered effector functions of neutrophils includes granular proteins, and cytokines, extracellular traps. With all effector mechanism neutrophils play a critical role in the pathogenesis of acute and chronic infection, autoimmunity and cancer.
Autoimmunity ; Cytokines ; Inflammation ; Leukocytes ; Neutrophils ; Phagocytes ; Proteins

To accelerate the molecular analysis of specifically induced antibacterial peptide against pathogen (E. coli), cDNA library prepared from the larvae fatbody of Bombyx mori was examined by the expressed sequence tag (EST) analysis. In a total of 722 clones, 653 clones were unique genes. Of 653 unique genes, 43.2% (282/653 ESTs) was identified as characterized genes, 38.1% (249/653 ESTs) as uncharacterized genes, and 18.7% (122/653 ESTs) as novel ESTs. According to the functional categorization of the characterized genes, 36.2% (102/282 ESTs) was antibacterial proteins. The highest expressed peptides, 78.4% of all the expressed antibacterial proteins (80/102 ESTs), belonged to the cecropin family. The antibacterial effect of selected clones representing novel ESTs based on a phylogenetic analysis was examined against various bacterial strains. None of the clones showed significant inhibitory effect to the bacteria tested. These results suggested that most of the novel molecules induced by E. coli may not act as immune-induced antibacterial peptides in the fatbody.
Bacteria ; Bombyx* ; Clone Cells ; Expressed Sequence Tags* ; Gene Library ; Humans ; Larva ; Peptides

Human T-cell lymphotrophic virus type I (HTLV-I) is a causative agent of adult T-cell leukemia (ATL). The viral transcriptional activator Tax encoded by the HTLV-I genome is thought to play critical roles in the activation of nuclear factor kappaB(NF-kappaB) as well as in the transformation of human T lymphocytes and the induction of tumor and leukemia. In this report, we suggest that RelA subunit of NF-kappaB might play an important role in Tax-induced p53 inactivation. Using antisense oligonucleotides, the ability of Tax inhibiting p53 transactivation was blocked by RelA, but not p50 or c-rel, antisense oligonucleotides in C81 HTLV-1-transfected cell line. The inability of p50 or c-rel antisense oligonucleotides in blocking the Tax-mediated inhibition of p53 function was not due lack of activity, since NF-kappaB activation was specifically blocked by these oligonucleotides. Also, we demonstrate by using co-immunoprecipitation assays that p53 interacts with RelA in HTLV-I transformed cells and their binding became stronger by the overexpression of Tax in 293T cells. These results suggest the possibility that the physical interaction between p53 and RelA correlates with Tax-induced p53 inhibition.
Cell Line ; Genome ; Human T-lymphotropic virus 1 ; Humans* ; Immunoprecipitation ; Leukemia ; Leukemia-Lymphoma, Adult T-Cell ; NF-kappa B* ; Oligonucleotides ; Oligonucleotides, Antisense ; T-Lymphocytes* ; Taxes ; Transcriptional Activation

Rapid and reliable diagnosis of measles is important to establish an appropriate therapy and to monitor the epidemic. However, classical ELISA methods using purified virus or virus-infected cells as antigens are not only difficult to determine optimal condition for diagnosis but also highly expensive to establish routine and appropriate diagnostic systems. Nucleoprotein of measles virus is one of the major antigens of measles virus that evoke initial IgM responses. It can be used as an attractive antigen for sero-diagnosis of measles during early infection. To develop simple and inexpensive diagnostic method for measles, we expressed a recombinant nucleoprotein (60-kDa) and a fragmented portion of the nucleoprotein (50-kDa) in E. coli and evaluated their appropriateness as diagnostic antigens. The proteins strongly reacted with sera from measles patients but not with normal control sera. Efficiency of recombinant nucleoprotein-ELISA (rN-ELISA) to detect IgM was compared that of whole measles virus-ELISA (MV-ELISA) on the basis of a clinical diagnosis. In rN-ELISA, sensitivity was 73.8% and agreement was above 76.4%. In MV-ELISA, sensitivity was 76.9% and agreement was 79.2%. Therefore, efficacy of rN-ELISA seemed to be similar to that of MV-ELISA. In addition, we compared with Edmonston rN-ELISA and Korean isolate rN-ELISA on the basis of commercial MV-ELISA. In Edmonston rN-ELISA, sensitivity was 94.0% and agreement was 98.4%. In the case of Korean isolate rN-ELISA, sensitivity was 96.0% and agreement was 96.9%. Thus, there was no significant difference in the efficacy between Edmonston rN-ELISA and Korean isolate rN-ELISA. Furthermore, the correlation coefficient (R2) between Edmonston rN-ELISA and Korean isolate rN-ELISA was 0.9925. These results suggest both Edmonston and Korean isolate rN-ELISA may be useful to diagnose measles.
Diagnosis ; Enzyme-Linked Immunosorbent Assay* ; Humans ; Immunoglobulin M* ; Immunoglobulins* ; Measles virus* ; Measles* ; Nucleoproteins*

Insect cell-derived biotechnological products have a potential for viral contamination from cell line sources themselves or from adventitious introduction of virus during production. The objective of this study was to establish techniques for viral clearance validation of insect cell-derived recombinant human papillomavirus (HPV)-16 type L1 virus-like particles (VLPs) using Japanese encephalitis virus (JEV) and bovine viral diarrhea virus (BVDV) as relevant viruses. The downstream process for the production of recombinant HPV-16 L1 VLPs was sequentially carried out employing detergent lysis (NP-40/PBS), sonication, sucrose cushion centrifugation, and cesium chloride (CsCl) equilibrium density centrifugation. Recombinant HPV-16 L1 capsid protein (56 kD) expressed in Sf9 cell culture was clearly detected by SDS-PAGE and Western blotting analysis. Each purification step was evaluated to determine reduction factor for viral clearance by infectivity assay. In individual purification steps, detergent treatment (0.50% v/v, NP-40/PBS) and CsCl equilibrium density centrifugation were found to be effective in JEV and BVDV clearance. Overall cumulative reduction factors of JEV and BVDV infectivity titer for the purification procedure implemented in this study were 12.53 and 10.05 log TCID(50)/pool, respectively. The results suggest that the purification procedure employed in this study for the HPV-16 L1 VLPs produced from recombinant baculovirus-infected Sf9 cells will be effective over 10 log TCID(50)/pool reduction factor in the clearance of enveloped, adventitious viruses with a buoyant density lower than approximately 1.23 g/ml.
Blotting, Western ; Capsid Proteins ; Cell Line ; Centrifugation ; Cesium ; Detergents ; Diarrhea ; Electrophoresis, Polyacrylamide Gel ; Encephalitis Virus, Japanese ; Human papillomavirus 16* ; Humans ; Insects ; Sf9 Cells ; Sonication ; Sucrose

A porcine parvovirus, designated as VRI-1, was isolated from a 30-day-old piglet. Replicative form of viral DNA from ST cells infected with VRI-1 was directly cloned into pUC19. The cloned DNA fragment contained the entire nonstructural and structural protein genes, covering approximately 85% of the viral genome. The nucleotide sequence of VRI-1 showed 99.4~99.5% identity in the nonstructural protein (NS) and 99.0~99.2% identity in the structural protein with previously reported PPV strains, respectively. Among the cloned genes, two types of defective genomes with deletion of 100 and 247 nucleotides at almost similar location of 3' region within NS gene were also identified in this study.
Base Sequence* ; Clone Cells ; DNA ; DNA, Viral ; Genome* ; Genome, Viral ; Nucleotides ; Parvovirus, Porcine*

Bacillus anthracis is generally accepted as the most potent biological warfare agent because of its highly pathogenic nature and transmission efficiency. Identification of chromosomal markers for the rapid detection of B. anthracis is difficult since significant chromosomal homology exists among B. anthracis, B. cereus and B. thuringiensis. In this study, we tested whether the gyrB sequence could be used as the target for the PCR detection of B. anthracis. The gyrB sequence, composed of 1,923 bp, was identical in 17 Korean B. anthracis isolates. The comparison of gyrB sequence between B. anthracis and B. cereus type strain showed 8.8% difference (105 bp among 1,194 bp), and the gyrB sequence similarities of B. cereus, B. thuringiensis and B. mycoides with B. anthracis were 92.3%, 86.9% and 86.1%, respectively. When polymerase chain reaction was designed and performed based on the gyrB sequence, a specific amplicon (351 bp) could be amplified. These results indicate that gyrB could be useful as a chromosomal marker for the rapid screening of B. anthracis by PCR or differentiation of B. anthracis from other related species by multiplex PCR with other plasmid markers.
Bacillus anthracis* ; Bacillus* ; Biological Warfare Agents ; Mass Screening ; Multiplex Polymerase Chain Reaction ; Plasmids ; Polymerase Chain Reaction

Many antibiotic resistance genes found in gram-negative clinical isolates are a part of a gene cassette inserted into an integron. Incidence of the integron carriage in extended-spectrum beta-lactamases (ESBLs)-producing clinical isolates is considerably high. In this study, the presence of class 1 integron was investigated among ESBL-producing K. pneumoniae, and the genetic location of the integron and bla(ESBL) was determined to elucidate the genetic linkage of the integron and bla(ESBL) gene. Thirty-nine clinical isolates of ESBL-producing K. pneumoniae and 36 transconjugants were used. The presence of class 1 integron was examined by PCR and Southern hybridization, and the location of ESBL gene and integron was studied by Southern hybridization with the probes for bla(TEM), bla(SHV), bla(CMY-1), and integron. PCR and Southern blot hybridization studies showed that 31 of 39 (79.5%) clinical isolates and 21 of 36 (58.3%) transconjugants carried integrons. Furthermore, integron was found to be on the same conjugative plasmid on which bla(SHV-ESBL) or bla(CMY-1) gene was located, suggesting high genetic linkage of integron and blaESBL genes. A sequencing study showed that PCR-amplified inserted gene cassettes contained aminoglycoside resistance genes (aadA2, aadA5, aacA4, aadB) as well as catB5, dfrA12, dfrA17, OXA-1, and OXA-2 variant. Notably, aacA4, which had been rarely found in previous studies, was the most predominant gene cassette. In conclusion, the coincidence of an ESBL gene and class 1 integron/ gene cassette on the same conjugative plasmid has potential implications for the spread of ESBL-mediated drug resistance and may be responsible for the multi-drug resistance in these isolates.
beta-Lactamases ; Blotting, Southern ; Drug Resistance ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Genes, vif ; Genetic Linkage ; Incidence ; Integrons* ; Plasmids ; Pneumonia* ; Polymerase Chain Reaction

The cag7 gene of Korean H. pylori strains was analyzed by RFLP to develop a discriminatory tool for genotyping clinical isolates. For this study, a total of 82 H. pylori strains were isolated from the patients; 27 strains from the patients with chronic gastritis, 26 from duodenal ulcer, and 29 from gastric cancer. Genomic DNA was isolated and subjected to PCR targeting entire ORF or the repeat regions I and II of cag7 gene. PCR products from entire ORF or repeat region I of cag7 gene were divided into two types. However, there was no difference in the length of PCR products from the repeat region II. By the PCR genotyping of the entire cag7 gene, genotypes A and B were established, which showed approximately 5,100 and 5,500 bp PCR products, respectively. The repeat region I showed approximately 600 or 1,000 bp DNA fragments by PCR. The length of cag7 gene was determined by the size variation in the repeat region I. In addition, RFLP analysis of the PCR products of cag7 gene showed 11 subtypes, based on the major bands. These findings illustrate that the genetic diversity of the repeat region I would serve a reliable target for the genotyping of the cag7 gene.
Animals ; DNA ; Duodenal Ulcer ; Ecthyma, Contagious ; Gastritis ; Genetic Variation ; Genotype ; Helicobacter pylori* ; Helicobacter* ; Humans ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length* ; Stomach Neoplasms