Immunochemical Cross-Reactivity of ß-Glucan in the Medicinal Plant, Sasa veitchii (Japanese Folk Medicine Kumazasa), and Medicinal Mushrooms.

Fungal ß-glucan is a representative pathogen-associated molecular pattern from mushroom, yeast, and fungi and stimulates innate as well as acquired immune systems. This ß-glucan is widely applied in functional food to enhance immunity. Humans and animals generally become sensitized to this ß-glucan and gradually produce specific antibodies to ß-glucans. The extracts of plants have been used as folk medicine and are reported to possess various biological activities that are beneficial for human health, such as antitumor, antiallergic, and anti-inflammatory activities. In the present study, the immunochemical cross-reactivity of Sasa extract and fungal ß-glucan was analyzed. We found that the anti-ß-glucan antibody in human sera strongly cross-reacted with the Sasa extract. This result strongly suggested that plant extracts modulate the immunostimulating effects of medicinal mushrooms. The cooperative effects of plants and mushrooms may be an important issue for functional foods.

Specificity of the Immunomodulating Activity of Sasa veitchii (Japanese Folk Medicine Kumazasa) to Fungal Polysaccharides.

Many plant extracts are used as well-known folk medicines and exhibit various biological activities that are beneficial to human health. These extracts contain polysaccharides, and some are pathogen-associated molecular patterns (PAMPs) that stimulate innate as well as acquired immune systems. In the present study, the cooperative effects of PAMPs and bamboo water-soluble methanol precipitation (BWMP) in a macromolecular fraction of the hot water extract of Sasa veitchii (in Japanese folk medicine, known as Kumazasa; family Poaceae) were analyzed in vitro using the spleen or bone marrow cells of mice. The splenocytes of male DBA/2 and C57BL/6 mice were cultured with BWMP in the presence or absence of PAMPs, and responses were assessed by measuring cytokines. BWMP inhibited the production of interferon gamma (IFN-γ) by not only toll like receptors (TLRs), but also the C-type lectin receptors (CLRs) dectin-1 and dectin-2. BWMP also inhibited the autologous production of IFN-γ in the splenocyte culture. These results suggested that BWMP may inhibit the signaling pathways of PAMPs, but not ligand-receptor interactions. In contrast, BWMP did not inhibit the production of cytokines by dendritic cells. These results indicated that the inhibition of IFN-γ by BWMP was mediated through the cell-to-cell interactions of splenic cells during cultivation.

Kinetic study of Sasa veitchii extract as a radical scavenger and an antioxidant.

UNLABELLED: We examined the free radical scavenging activity of Sasa veitchii extract (Hoshi's Striped Bamboo Extract(®), HSBE), well known in folk medicine as an efficient drug and antioxidant in detail. To evaluate the free radical scavenging activity of HSBE, its reactivity as hydrogen atom donor toward the 1, 1-diphenyl-2-picrylhydrazyl has been measured using stopped-flow spectrophotometry. It was found that the second-order rate constant, k(2), obtained at 25 °C was 1.4 (g/L)(-1) s(-1) for HSBE. To compare different chain-breaking antioxidants quantitatively, we obtained the second-order rate constant, k(2)', on the molar basis of active hydroxyl groups in the tested substances. As a result, the k(2)' values for HSBE, 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox), caffeic acid, and (+)-catechin were 2.6 × 10(3), 2.0 × 10(3), 2.3 × 10(2), and 6.0 × 10(2) M(-1) s(-1), respectively. These results show that HSBE and Trolox exerted the same free radical scavenging activity under these conditions. In addition, HSBE significantly inhibited the oxidation of methyl linoleate micelles in aqueous dispersions at 30 °C and its antioxidant activity (k(inh)) was more effective than those of caffeic acid and (+)-catechin. This is the first study on bamboo extracts in the context of radical scavenging activity that reports kinetic results. PRACTICAL APPLICATION: We determined the stoichiometric number and the rate constants of bamboo extracts using the method that was devised in determining the antioxidant activity of mixtures. This is the first study of bamboo extracts as an antioxidant that reports the stoichiometric and kinetic results.

Effect of Sasa veitchii extract on immunostimulating activity of ß-glucan (SCG) from culinary-medicinal mushroom Sparassis crispa Wulf.:Fr. (higher Basidiomycetes).

Fungal ß-glucan is a representative pathogen-associated microbial pattern (PAMP) from mushroom, yeast, and fungi, and stimulates innate as well as acquired immune systems. It is a widely used functional food to enhance immunity. Such plant extracts have been known as folk medicines and reported to show various biological activities beneficial to human health, such as anti-tumor, anti-allergic, and anti-inflammatory activities. In the present study, the cooperative effect of bamboo water-soluble methanol precipitation (BWMP), a macromolecular fraction of the hot-water extract of Sasa veitchii (Japanese folk medicine Kumazasa), and the ß-glucan from the medicinal mushroom Sparassis crispa (SCG) was analyzed in vitro using DBA/2 mice. The splenocytes from male DBA/2 mice were cultured with BWMP in the presence of SCG, and the responses were assessed by measuring cytokines. BWMP suppressed IFN-γ and GM-CSF production by SCG, but not TNF-α production. To analyze the specificity of the reaction, similar experiments were conducted with BWMP in the presence of bacterial lipopolysaccharide (LPS); however, none of the cytokines were inhibited. Cytokine production of splenocytes by SCG was suggested to be largely dependent on the binding of lymphocytes with dendritic cells. Functions of BWMP were also analyzed by mixed lymphocyte reaction, and IFN-γ production was suppressed. These findings suggested that BWMP modulated the cell-to-cell contact induced by SCG and inhibited cytokine production. It is strongly suggested that the plant extracts modulate the immunostimulating effects of medicinal mushrooms. Cooperative effects of plants and mushrooms would be an important issue for functional foods.

KHM-1, a novel plasmid-mediated metallo-beta-lactamase from a Citrobacter freundii clinical isolate.

A novel gene, bla(KHM-1), encoding a metallo-beta-lactamase, KHM-1, was cloned from a clinical isolate of Citrobacter freundii resistant to most beta-lactam antibiotics. Escherichia coli expressing bla(KHM-1) was resistant to all broad-spectrum beta-lactams except for monobactams and showed reduced susceptibility to carbapenems. Recombinant KHM-1 exhibited EDTA-inhibitable hydrolytic activity against most beta-lactams, with an overall preference for cephalosporins.

[Cefotaxime-resistant shiga toxin-producing Escherichia coli O26 : H11 isolated from a patient with diarrhea].

A shiga toxin-producing Escherichia coli (STEC) O26 strain resistant to cefotaxime (CTX) and cefpodoxime (but not ceftazidime) was isolated from the faecal sample of a 17-year-old outpatient with diarrhea. The double disk synergy test, twin test, polymerase chain reaction and sequence analysis confirmed that the strain produced CTX-M-3 type extended-spectrum beta-lactamase (ESBL). Conjugation experiment results suggested that the CTX resistance in this strain was determined by an approximately 85kbp plasmid that was readily transferable to a susceptible recipient E. coli strain. This is the first report from Japan of CTX-M-3type ESBL-producing STEC O26.

Prevalence of viable Chlamydia pneumoniae in peripheral blood mononuclear cells of healthy blood donors.

BACKGROUND: Demonstration of viable Chlamydia (Chlamydophila) pneumoniae in peripheral blood mononuclear cells (PBMNCs) is essential to understand the involvement of C. pneumoniae in atherosclerosis. Nevertheless, the prevalence of viable C. pneumoniae in the blood of healthy donors has not yet been studied. STUDY DESIGN AND METHODS: The presence of C. pneumoniae transcript in PBMNCs from blood of healthy human donors was assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR) with primers for C. pneumoniae 16S rRNA, which is more sensitive than genomic-DNA-based analysis, and by the use of staining with fluorescein isothiocyanate-conjugated chlamydia monoclonal antibody (MoAb). RESULTS: Thirteen of 70 donors (18.5%) showed the presence of bacterial transcript in cultured PBMNCs. The prevalence of bacterial detection and bacterial numbers was significantly increased in PBMNC cultures incubated with cycloheximide. Immunostaining of PBMNCs with antichlamydial MoAb also revealed the presence of bacterial antigen in the PBMNCs judged as positive. Nevertheless, cultivation of C. pneumoniae from all PCR-positive donors was unsuccessful. There was no significant correlation between the presence of chlamydia and either sex or current smoking habits. A possible age variation, however, in the presence of chlamydia in blood of healthy donors was suggested by the results obtained. CONCLUSION: The bacterial transcripts in PBMNCs obtained from healthy donors were detected by the RT-PCR method. Viable C. pneumoniae may be present in healthy human PBMNCs.

Sequence analysis of amplified DNA fragments containing the region encoding the putative lipase substrate-binding domain and genotyping of Aeromonas hydrophila.

DNA fragments were amplified by PCR from all tested strains of Aeromonas hydrophila, A. caviae, and A. sobria with primers designed based on sequence alignment of all lipase, phospholipase C, and phospholipase A1 genes and the cytotonic enterotoxin gene, all of which have been reported to have the consensus region of the putative lipase substrate-binding domain. All strains showed lipase activity, and all amplified DNA fragments contained a nucleotide sequence corresponding to the substrate-binding domain. Thirty-five distinct nucleotide sequence patterns and 15 distinct deduced amino acid sequence patterns were found in the amplified DNA fragments from 59 A. hydrophila strains. The deduced amino acid sequences of the amplified DNA fragments from A. caviae and A. sobria strains had distinctive amino acids, suggesting a species-specific sequence in each organism. Furthermore, the amino acid sequence patterns appear to differ between clinical and environmental isolates among A. hydrophila strains. Some strains whose nucleotide sequences were identical to one another in the amplified region showed an identical DNA fingerprinting pattern by repetitive extragenic palindromic sequence-PCR genotyping. These results suggest that A. hydrophila, and also A. caviae and A. sobria strains, have a gene encoding a protein with lipase activity. Homologs of the gene appear to be widely distributed in Aeromonas strains, probably associating with the evolutionary genetic difference between clinical and environmental isolates of A. hydrophila. Additionally, the distinctive nucleotide sequences of the genes could be attributed to the genotype of each strain, suggesting that their analysis may be helpful in elucidating the genetic heterogeneity of Aeromonas.

[Increasing drug resistance in Vibrio cholerae O1 and non-O1 strains isolated from diarrheal cases in Japan].

Drug resistance trends were investigated for 271 Vibrio cholerae O1 (V.c O1) and 401 V. cholerae non-O1 (V.c non-O1) strains isolated from mainly imported diarrheal cases during 1981-2001 in Japan. The results of drug resistance test using 8 drugs (CP, TC, SM, KM, ABPC, ST, NA, and NFLX) showed that 34.7% of the V. c O1 strains and 15.7% of V.c non-O1 strains were multi-drug or mono-drug resistant. The incidence of drug resistant strains has increased since 1991, and it has been remarkable in V.c O1 strains that increased from 1.2% in 1981-1985 to 70.8% in 1996-2001. The drug resistance patterns of the resistant strains classified into 6 types in V.c O1 and 21 types in V.c non-O1. The prevalent patterns recognized were SM (75.5%), CP.TC.SM.ST (10.6%) and CP.SM.ST (8.5%) in V.c O1, and SM (25.4%) and ABPC (25.4%) in V.c non-O1. Ten V.c O1 strains (3.7%) and 10 V.c non-O1 strains (2.5%) were multi-drug resistant including TC. Among those, 13 strains were isolated from travelers who returned to Japan from Thailand. One V.c O1 strain (0.4%) and 6 V.c non-O1 strains (1.5%) were NA high-resistant and fluoroquinolones low-sensitive. Among those, 4 strains were isolated from travelers who returned to Japan from India.