Houttuynia cordata has a long history of use in indigenous systems of medicine as an antiseptic, febrifuge, diuretic, and deobstruant. It is frequently used in many traditional medicines for its antimicrobial, antiviral, and antiinflammatory properties. [1][2][3][4] H. cordata contains of methyl nonyl ketone, caryophyllene, bornyl acetate, a-pinene, b-pinene, limonene, and other components. These components have antibacterial properties against the Gram-positive bacteria Staphylococcus aureus and Sarcina ureae. 5) In experimental studies, H. cordata exhibited antibacterial activity, antileukemic activity, antiinflammatory activity, anaphylactic reaction and mast cell activation, and modulated nitric oxide (NO) production. [6][7][8][9][10] However, to date, studies to understand the other antibacterial effects, including the intracellularly replicating pathogens of these plants, are lacking.The mammalian immune response is divided broadly into the innate and adaptive responses. Innate immune responses of mammals involve the first line of defense against invading microorganisms, including the release of antimicrobial peptides at epithelial surfaces, phagocytosis, and intracellular killing of microorganisms by phagocytes and the activation of the complement cascade. In contrast, the adaptive immune response is antigen specific and modified by previous antigen exposure. 11) In the innate immune response, the reactive oxygen intermediates (ROIs) such as superoxide and reactive nitrogen intermediates (RNIs) such as NO have a key role in intracellular killing of microorganisms within phagocytes. 12)Several studies reported that RNIs are important for controlling Salmonella multiplication within macrophages. 13,14)Salmonellosis is a major bacterial zoonosis that causes a variety of disease syndromes, from self-limiting enteritis to fatal infection in animals and food-borne infection and typhoid fever in humans.15) The etiologic agents of salmonellosis are Salmonella sp. characterized by motile, Gram-negative, rod-shaped bacteria and facultative intracellular pathogens that can multiply within professional and nonprofessional phagocytes. Recently, the emergence of multidrugresistant strains of Salmonella sp. has caused more serious problems in public health.16) Multidrug resistance is a worldwide problem that does not recognize international borders and can indiscriminately affect the treatment and prevention of various diseases.To kill intracellular bacteria including Salmonella sp., Brucella sp., Listeria sp., Shigella sp., etc., much effort is needed to develop antibiotics, determine treatment duration, and resolve other issues.In this study, we examined the antibacterial effects, and macrophage activation of H. cordata water extract (HCWE) such as morphologic changes, NO production, phagocytic activity, and effects against the Salmonella enterica serovar Typhimurium in vitro and in vivo. Salmonellosis is a major bacterial zoonosis that causes a variety of disease syndromes, from self-limiting enteritis to fatal infec...
ABATRACT. Brucella spp. are Gram-negative, facultative, intracellular coccobacilli that are pathogenic to a variety of mammals, including ruminants and humans. The conventional serological test for diagnosing brucellosis in cattle in Korea is the standard tube agglutination test. However, agglutination tests sometimes give false-positive results due to cross-reactions with other pathogens. The outer membrane proteins of Brucella species have been extensively studied for their immunogenicity and serodiagnostic applications. However, an application of B. abortus OMPs for serodiagnosis has not been successfully established. In this study, cloning and expression of B. abortus Omp28, a group 3 antigen, were accomplished by PCR amplification cloning into a pMAL expression system, and purification of a recombinant Omp28 (rOmp28). The immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive bovine serum. To determine whether rOmp2 has a potential benefit for use in the serodiagnosis of bovine brucellosis, rOmp28-based ELISA and latex bead agglutination test were performed. B. abortus positive (n=122) or negative (n=88) Microorganisms belonging to the genus Brucella are Gram-negative, facultative, intracellular bacteria of zoonotic importance. Like other intracellular pathogens, Brucella spp. are virulent mainly because of their ability to avoid lysosomal degradation and proliferate within macrophages, leading to the establishment of a chronic infection in the host [6,7,14]. Brucella spp. may have either smooth or rough lipopolysaccharide (S-LPS or R-LPS), depending on the presence or absence of O-polysaccharide chains, respectively. Accordingly, the O-polysaccharide chains of LPS are thought to be necessary for the pathogenicity of Brucella strains bearing S-LPS [1,12,19,23]. The LPS of smooth Brucella species is by far the most immunostimulatory antigen when compared to other antigenic molecules. LPS elicits a long-lasting serological response in both vaccinated and infected animals [1,11,19,22]. These serological tests are mainly based on the detection of antibodies directed against the LPS portion of the bacterial cell membrane. For these reasons, it is difficult to differentiate between vaccinated and infected animals using LPS-based serological diagnosis [16,20]. In addition, serological tests based on anti-LPS antibodies give false positives because of cross-reactivity with other Gram-negative bacteria such as Yersinia enterocolitica O:9, Salmonella spp. and Escherichia coli [1]. Outer membrane proteins (OMPs) of Brucella, a non-LPS group of immunogens, have been the focus of vaccine development and the diagnosis of brucellosis [3,5,10,12]. The OMP antigens (Ags) of Brucella are categorized into three groups (1, 2 and 3) according to their molecular weights. Groups 1, 2 and 3 have approximate molecular masses of 94, 41 to 43, and 25 to 30 kDa, respectively [21]. In this study, the Omp28 coding gene of B. abortus was cloned and expressed using the pMAL expression system, and the rOmp...
The outer membrane proteins (OMPs) of Brucella (B.) abortus have been extensively studied, but their immunogenicity and protective ability against B. abortus infection are still unclear. In the present study, B. abortus Omp28, a group 3 antigen, was amplified by PCR and cloned into a maltose fusion protein expression system. Recombinant Omp28 (rOmp28) was expressed in Escherichia coli and was then purified. Immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive mouse serum. Furthermore, humoral- or cell-mediated immune responses measured by the production of IgG1 or IgG2a in rOmp28-immunized mice and the ability of rOmp28 immunization to protect against B. abortus infection were evaluated in a mouse model. In the immunogenicity analysis, the mean titers of IgG1 and IgG2a produced by rOmp28-immunized mice were 20-fold higher than those of PBS-treated mice throughout the entire experimental period. Furthermore, spleen proliferation and bacterial burden in the spleen of rOmp28-immunized mice were approximately 1.5-fold lower than those of PBS-treated mice when challenged with virulent B. abortus. These findings suggest that rOmp28 from B. abortus is a good candidate for manufacturing an effective subunit vaccine against B. abortus infection in animals.
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