Anthrax is caused by the spore-forming bacterium Bacillus anthracis, which has been used as a weapon for bioterrorism. Although current vaccines are effective, they involve prolonged dose regimens and often cause adverse reactions. High rates of mortality associated with anthrax have made the development of an improved vaccine a top priority.
View Article and Find Full Text PDFOsong Public Health Res Perspect
September 2012
Objective: Recombinant protective antigen (rPA) is the active pharmaceutical ingredient of a second generation anthrax vaccine undergoing clinical trials both in Korea and the USA. By using the rPA produced from Bacillus brevis pNU212 expression system, correlations of serological immune response to anthrax protection efficacy were analyzed in a guinea pig model.
Methods: Serological responses of rPA anthrax vaccine were investigated in guinea pigs that were given single or two injections (interval of 4 weeks) of various amounts of rPA combined with aluminumhydroxide adjuvant.
Influenza virus infects host cells through membrane fusion, a process mediated by the low pH-induced conformational change of the viral surface glycoprotein haemagglutinin (HA). We determined the structures and biochemical properties of the HA proteins from A/Korea/01/2009 (KR01), a 2009 pandemic strain, and A/Thailand/CU44/2006 (CU44), a seasonal strain. The crystal structure of KR01 HA revealed a V-shaped head-to-head arrangement, which is not seen in other HA proteins including CU44 HA.
View Article and Find Full Text PDFBacillus (B.) anthracis is the pathogen that causes fatal anthrax. Strain-specific detection of this bacterium using molecular approaches has enhanced our knowledge of microbial population genetics.
View Article and Find Full Text PDFObjective: To compare the characteristics and risk factors for surgical site infections (SSIs) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a nationwide survey, using shared case detection and recording systems.
Design: Retrospective cohort study.
Setting: Twenty-six hospitals participating in the Korean Nosocomial Infections Surveillance System (KONIS).
Transmission of influenza (H5N1) virus from birds to humans is a serious public health threat. In South Korea, serologic investigation among 2,512 poultry workers exposed during December 2003-March 2004 to poultry with confirmed or suspected influenza (H5N1) virus infection found antibodies in 9. Frequency of bird-to-human transmission was low.
View Article and Find Full Text PDFObjective: To evaluate the risk factors for surgical site infection (SSI) after gastric surgery in patients in Korea.
Design: A nationwide prospective multicenter study.
Setting: Twenty university-affiliated hospitals in Korea.
The poly-γ-D-glutamic acid (PGA) capsule is one of the major virulence factors of Bacillus anthracis, which causes a highly lethal infectious disease. The PGA capsule disguises B. anthracis from immune surveillance and allows its unimpeded growth in the host.
View Article and Find Full Text PDFOsong Public Health Res Perspect
June 2011
Objectives: We aimed to evaluate the pathogenesis and chronologic localization of human influenza A (H1N1) virus in experimentally infected cotton rats.
Methods: The animals were intranasally inoculated with 10(7) plaque-forming units of A/Solomon Islands/3/2006 (H1N1) influenza virus and evaluated for pathogenicity for a period of 28 days. Virus replication kinetics and pathological properties were assessed chronologically.
To identify oseltamivir resistance, we analyzed neuraminidase H275Y mutations in samples from 10 patients infected with pandemic (H1N1) 2009 virus in South Korea who had influenza that was refractory to antiviral treatment with this drug. A neuraminidase I117M mutation that might influence oseltamivir susceptibility was detected in sequential specimens from 1 patient.
View Article and Find Full Text PDFOsong Public Health Res Perspect
December 2010
Objectives: To characterise the genetic and serological diversity of pathogenic Escherichia coli, we tested 111 E coli strains isolated from diarrhoeal patients in Korea between 2003 and 2006.
Methods: The isolates were tested through polymerase chain reaction (PCR) and slide agglutination method for the detection of virulence genes and serotypes, respectively. To compare the expression of Shiga toxin (stx)-1 and stx2 genes, real-time quantitative reverse-transcriptase PCR and rapid exprssion assay, reversed-passive latex agglutination, were performed.
This study aimed to characterize the replication and pathogenic properties of a Korean pandemic (H1N1) 2009 influenza virus isolate in ferrets and mice. Ferrets infected with A/Korea/01/2009 (H1N1) virus showed mild clinical signs. The virus replicated well in lungs and slightly in brains with no replication in any other organs.
View Article and Find Full Text PDFWe evaluated a new rapid influenza diagnostic test for the pandemic (H1N1) 2009 influenza virus by using real-time reverse transcription-PCR (rRT-PCR) and viral culture. The sensitivities were 68.5% and 64.
View Article and Find Full Text PDFRecent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea.
View Article and Find Full Text PDFInfluenza epidemics arise through the accumulation of viral genetic changes, culminating in a novel antigenic type that is able to escape host immunity. Following an outbreak of the A/Fujian/411/2002-like strains in Asia, including China, Japan, and South Korea, in 2002, Australia and New Zealand experienced substantial outbreaks of the same strains in 2003, and subsequently worldwide outbreaks occurred in the 2003-2004 season. The emergence of A/Fujian/411/2002-like strains coincided with a higher level of influenza-like illness in South Korea than what is seen at the peak of a normal season, and there was at least a year's difference between South Korea and the United States.
View Article and Find Full Text PDFThe poly-gamma-d-glutamic acid (PGA) capsule is one of the major virulence factors of Bacillus anthracis, which causes a highly lethal infection. The antiphagocytic PGA capsule disguises the bacilli from immune surveillance and allows unimpeded growth of bacilli in the host. Recently, efforts have been made to include PGA as a component of anthrax vaccine; however, the innate immune response of PGA itself has been poorly investigated.
View Article and Find Full Text PDFAnthrax is a lethal infectious disease caused by the spore-forming Bacillus anthracis. The two major virulence factors of B. anthracis are exotoxin and the poly-gamma-d-glutamic acid (PGA) capsule.
View Article and Find Full Text PDFLethal toxin (LT), produced by the gram-positive bacterium Bacillus anthracis, was identified as a major etiologic agent causing anthrax due to its strong immunotoxicity. Gram-positive bacteria express lipoteichoic acid (LTA), which is considered as a counterpart to lipopolysaccharide (LPS) of gram-negative bacteria, but differs from LPS in the structure and function. Since dendritic cells (DCs) are essential for the appropriate initiation of immune response, we investigated the effect of LT on LTA-induced DC maturation using immature DCs prepared by differentiation of C57BL/6 mouse bone marrow cells.
View Article and Find Full Text PDFTo investigate the frequency of amantadine resistance among influenza A viruses isolated in Korea during the 2003-2009 seasons, 369 (16.8%) 2199 A/H1N1 viruses and 780 (14.8%) of 5263 A/H3N2 viruses were randomly selected.
View Article and Find Full Text PDFInfluenza epidemics arise through the acquisition of viral genetic changes to overcome immunity from previous infections. An increasing number of complete genomes of influenza viruses have been sequenced in Asia in recent years. Knowledge about the genomes of the seasonal influenza viruses from different countries in Asia is valuable for monitoring and understanding of the emergence, migration and evolution of strains.
View Article and Find Full Text PDFNeisseria gonorrhoeae is an obligate human pathogen that is the etiological agent of gonorrhea. We explored variations in the genes of a multidrug-resistant N. gonorrhoeae isolate from a Korean patient in an effort to understand the prevalence, antibiotic resistance, and importance of horizontal gene transfer within this important, naturally competent organism.
View Article and Find Full Text PDFBackground: Human bocavirus (HBoV) is a parvovirus that has been recently detected in patients with respiratory illness.
Objectives: We developed a sensitive, specific, and quantitative real-time PCR assay based on the TaqMan method for HBoV detection and quantification in respiratory specimens.
Study Design: Three individual real-time PCR assays were designed to amplify HBoV NS1, NP-1, and VP1 genes.
An enrichment semi-nested PCR procedure was developed for detection of Clostridium botulinum types A, B, E, and F. It was applied to sediment samples to examine the prevalence of C. botulinum in the Korean environment.
View Article and Find Full Text PDFAntimicrobial-resistant gonococcus has been a major problem in sexually transmitted disease control . Outer membrane proteins (OMPs) of Neisseria gonorrhoeae were suggested to have influence on its resistance to antibiotics. So, in this work, we provide a proteomic analysis tool for examining the OMPs of N.
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