Tsuneo MAEGAWA | Kanazawa University (original) (raw)
Papers by Tsuneo MAEGAWA
Microbial Pathogenesis, Oct 1, 2002
The neurotoxin of Clostridium butyricum strain LCL155 (BuNT/LCL155) associated with type E food-b... more The neurotoxin of Clostridium butyricum strain LCL155 (BuNT/LCL155) associated with type E food-borne botulism showed antigenic and biological properties different from those of C. botulinum type E (BoNT/E) and C. butyricum strain BL5262 (BuNT/BL5262). The speci®c toxicity of BuNT/ LCL155 was found to be about 10% those of BoNT/E and BuNT/BL5262. Immunological analysis with monoclonal antibodies against BoNT/E showed that the heavy chain of BuNT/LCL155 differs partially from those of BoNT/E and BuNT/BL5262. Binding experiments with rat brain synaptic membrane revealed that BuNT/LCL155 possesses a binding activity lower than either BoNT/E or BuNT/BL5262. There was no difference in the catalytic activity of the three neurotoxins, which had been determined with a recombinant of the intracellular target protein SNAP-25. These data suggest that the BuNT/LCL155 shares the receptor-recognition site structurally different from BoNT/E and BuNT/BL5262, perhaps causing a decreased speci®c toxicity.
Journal of Medical Microbiology, 2001
Healthy adults who had not been exposed to antimicrobial agents for the preceding 4 weeks were ex... more Healthy adults who had not been exposed to antimicrobial agents for the preceding 4 weeks were examined for intestinal carriage of Clostridium dif®cile. The 1234 individuals examined were composed of seven groups: three classes of university students, hospital workers at two hospitals, employees of a company and self-defence force personnel at a local station. Overall, 94 (7.6%) individuals were positive for C. dif®cile by faecal culture but carriage rates among the study groups ranged from 4.2% to 15.3%. Typing by PCR ribotyping and pulsed-®eld gel electrophoresis demonstrated clusters of carriers colonised by a single type in each of three groups, indicating that cross-transmission of C. dif®cile can occur in community settings. Follow-up culture was performed on 38 C. dif®cile-positive individuals and C. dif®cile was isolated again from 12 (32%) of them 5± 7 months after the initial culture; six (50%) of these 12 individuals had a new strain on repeat culture. Two or more family members were C. dif®cile-positive in ®ve of 22 families examined. C. dif®cile with an identical type was isolated from persons within a family in only one family. These results suggest that intestinal carriage by healthy adults may play a role as a reservoir for community-acquired C. dif®cile-associated diarrhoea, but that cross-transmission of C. dif®cile does not occur frequently among family members at home.
Infection and Immunity, Feb 1, 2003
The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histi... more The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histidinetagged (His-tag) protein, and the protein was purified to compare its enzymatic and biological activities with those of Clostridium perfringens phospholipase C (Cpa) and Clostridium bifermentans phospholipase C (Cbp). Csp was found to consist of 371 amino acid residues in the mature form and to be more homologous to Cbp than to Cpa. The egg yolk phospholipid hydrolysis activity of the His-tag Csp was about one-third of that of His-tag Cpa, but the hemolytic activity was less than 1% of that of His-tag Cpa. His-tag Csp was nontoxic to mice. Immunization of mice with His-tag Cbp or His-tag Csp did not provide effective protection against the lethal activity of His-tag Cpa. These results indicate that Csp possesses similar molecular properties to Cbp and suggest that comparative analysis of toxic and nontoxic clostridial phospholipases is helpful for characterization of the toxic properties of clostridial phospholipases. Clostridium perfringens elaborates lecithinase, known as alpha-toxin (Cpa), which is the best characterized of all clostridial lecithinases (10, 29, 30). Cpa is a phospholipase C enzyme (30). It is toxic to mammals and is considered to be one of the major virulence factors produced by C. perfringens (25, 29, 30). However, there are still many lecithinases produced by other clostridia that are poorly characterized, and their roles in the pathogenesis of disease have not yet been determined (29, 30). Clostridial lecithinases whose primary structures have been determined are limited to only Cpa (13, 22, 23, 26, 32), Clostridium bifermentans phospholipase C (Cbp) (32), and Clostridium novyi type A phospholipase C (Cnp) (33). Additionally, clostridial lecithinases that have been purified and characterized are limited to Cpa and Cbp. C. bifermentans and C. sordellii resemble each other in their cultural and biological properties, but they have been determined to be genetically different species (19). C. sordellii lecithinase is one of the clostridial lecithinases whose molecular properties are not yet understood (28). Here we report the cloning of the C. sordellii lecithinase (Csp) gene, expression of its product using purified histidine-tagged (His-tag) proteins, and comparison of the enzymatic and biological activities of Csp with those of Cpa and Cbp. MATERIALS AND METHODS Bacterial strains, plasmids, and culture. C. sordellii NCIB10717 (ATCC 9714), C. perfringens KZ 221 (33), and C. bifermentans KZ 1012 (SJ2) were used to isolate the lecithinase genes. To investigate the occurrence of the csp gene, 23 C. sordellii strains kept at our laboratory were used. Esherichia coli TOP10F' (Invitrogen) was used for transformation. PCRII-TOPO (Invitrogen) and pKF3
Annals of Tropical Medicine & Parasitology, 2000
Clostridium botulinum, the aetiological agent of botulism, is currently split into seven types, d... more Clostridium botulinum, the aetiological agent of botulism, is currently split into seven types, designated by the letters A-G, according to differences in the neurotoxin produced. Types A, B, E, F and G are mostly found in soil or freshwater sediments, but types C and D seem to be commensals in mammals and birds and are, consequently, more widely dist:·ibuted in the environment (Popoff and Marvaud, 1999). There have been few surveys of the distribution of C. botulinum in the soils of Africa. Clostridium botulinum type-B and type-D botulinum toxins have been detected in soil samples from South Africa (Knock, 1952; Mason, 1968), and the type-A and type-C toxins have been demonstrated in Kenyan soil (Yamakawa et al., 1990). Although there have been at least two surveys of clostridia in Zambia (Munang'andu et al., 1996; Hang'ombe et al., 2000), the distribution of the seven types of C. botulinum in Zambian soils has not been described. The botulinum toxins in the 46 soil samples collected by Hang'ombe et al. (2000) were therefore investigated. These samples had been collected, 10-15 cm below ground level, from five sites in Zambia during the 1999 rainy season (i.e. January-March; see Fig.). Each of five, 1-g subsamples of each sample was inoculated into a tube containing 10 ml of chopped-meat-glucose medium (Holdeman et al., 1978; Yamakawa et al., 1988; Yamakawa and Nakamura, 1992), or of commercial, cooked-meat medium (Becton and Dickinson, Cockeysville, MD). The tubes were incubated anaerobically at 30°C for 5 days. The culture supernatants were then frozen and thawed before being checked for the presence of botulinum toxin, using the mouse assay (Yamakawa et al., 1988; Yamakawa and Nakamura, 1992). The antisera used for neutralization tests were purchased
Journal of the Japanese Association for Infectious Diseases, 1992
This article cites 34 articles, 14 of which can be accessed free
Journal of medical …, 2002
The production of toxins A and B by Clostridium dif®cile was greatly enhanced under biotin-limite... more The production of toxins A and B by Clostridium dif®cile was greatly enhanced under biotin-limited conditions, in which a 140-kDa protein was expressed strongly. Gene cloning revealed that this protein was a homologue of formylglycinamidine ribonucleotide synthetase (FGAM synthetase, EC 6.3.5.3), which is known as PurL in Escherichia coli and catalyses the fourth step of the de novo purine biosynthesis pathway. This enzyme consisted of a single polypeptide, although FGAM synthetases of gram-positive bacteria usually consist of two subunits. Inhibition of the enzymic activity of C. dif®cile PurL by O-diazoacetyl-L-serine (azaserine) resulted in enhanced toxin B production even in biotin-suf®cient conditions. In contrast, blockade of the preceding step of the PurL catalysing step by sulfamethoxazole inhibited toxin B production almost completely. These results suggest that accumulation of formylglycinamide ribonucleotide (FGAR), a substrate of FGAM synthetase, enhances toxin production by C. dif®cile and depletion of FGAR reduces toxin production.
Acta microbiologica Polonica, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
ABSTRACT Neurotoxigenic Clostridium butyricum has been identified as occurring in the natural env... more ABSTRACT Neurotoxigenic Clostridium butyricum has been identified as occurring in the natural environment. Nontoxigenic and neurotoxigenic C. butyricum strains were comparatively analyzed by PCR assay and Southern blot hybridization for the type E botulinum toxin gene (bont/E), random amplified polymorphic DNA (RAPD) assay, and pulsed-field gel electrophoresis (PFGE). With the PCR assay and Southern blot hybridization, the bont/E gene was detected in all seven strains of neurotoxigenic C. butyricum (BL 5262, BL 6340, LCL 155, LCL 063, LCL 095, KZ 1886, and KZ 1887), but not in nontoxigenic strains (MIYAIRI 588, MIYAIRI 595, MIYAIRI 630, SI 293-2, RU 063-3, GU-2, ATCC 19398, and IFO 3315), indicating that there were no partial bont/E gene fragments in the nontoxigenic C. butyricum strains. All strains were successfully analyzed by RAPD assay. In contrast to the RAPD assay, two strains of nontoxigenic C. butyricum could not be analyzed by PFGE, probably due to the DNase activity. Nontoxigenic strains SI 293-2 and GU-2 shared an identical RAPD or PFGE pattern. The other nontoxigenic strains showed unique RAPD and PFGE patterns, and these patterns differed from those of all neurotoxigenic C. butyricum strains. The present results are discussed in relation to the transfer of the bont/E gene.
The Journal of the Korean Society for Microbiology, 2000
Acta Microbiologica Polonica, Feb 1, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
The Journal of Immunology, 2004
Journal of immunology (Baltimore, Md. : 1950), 2004
Clostridium difficile has emerged as the important causative agent of antibiotics-associated pseu... more Clostridium difficile has emerged as the important causative agent of antibiotics-associated pseudomembranous colitis; especially its toxin A is presumed to be responsible for the colitis. We examined the pathophysiological roles of IFN-gamma in toxin A-induced enteritis using IFN-gamma knockout (KO) mice. When toxin A of C. difficile was injected into the ileal loops of BALB/c wild-type (WT) mice, massive fluid secretion, disruption of intestinal epithelial structure, and massive neutrophil infiltration developed within 4 h after the injection. IFN-gamma protein was faintly detected in some CD3-positive lymphocytes in the lamina propria and submucosa of the ileum of untreated WT mice. On the contrary, at 2 and 4 h after toxin A injection, IFN-gamma protein was detected in infiltrating neutrophils and to a lesser degree in CD3-positive lymphocytes. In the ileum of WT mice, toxin A treatment markedly enhanced the gene expression of TNF-alpha, macrophage inflammatory protein-1alpha an...
Acta microbiologica Polonica, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
Microbiology and Immunology, 1997
Twenty strains of Clostridium difficile were examined for the effect of arginine on toxin product... more Twenty strains of Clostridium difficile were examined for the effect of arginine on toxin production in a defined medium. In three strains, the production of toxins A and B was greatly enhanced in the absence of arginine. These strains showed distinctively poorer growth in the absence of arginine in comparison with the remaining 17 strains, indicating that the presence of arginine is required for good growth among the three strains. From the present results, test strains were divided into two groups: a group in which arginine insufficiency caused distinctly poor growth and enhanced toxin production, and another group in which there was neither distinctly poor growth nor enhanced toxin production. The phenomenon is discussed in relation to the biosynthesis and catabolism of arginine.
The Journal of Immunology, 2004
The Journal of Immunology, 2004
Fems Microbiology Letters, 1999
The repeating sequences of the toxin A gene from toxin A-negative, toxin B-positive (toxin A3, to... more The repeating sequences of the toxin A gene from toxin A-negative, toxin B-positive (toxin A3, toxin B+) strains of Clostridium difficile which were isolated in geographically separated facilities in Japan and Indonesia were determined. All six strains tested had identical repeating sequences with two deletions (1548 and 273 nucleotides in size) in the toxin A gene. A PCR method was designed to detect the deletions and the deletions were confirmed in all 50 toxin A3, toxin B+ strains examined by this method. Western immunoblot analysis revealed that polyclonal antiserum against native toxin A did not react with the concentrated culture filtrates of the toxin A3, toxin B+ strains. These results may suggest that toxin A3, toxin B+ strains have deletions of the two thirds of the repeating regions of the toxin A gene, which encodes the epitopes fully responsible for the reaction with the polyclonal antiserum. z
Microbial Pathogenesis, Oct 1, 2002
The neurotoxin of Clostridium butyricum strain LCL155 (BuNT/LCL155) associated with type E food-b... more The neurotoxin of Clostridium butyricum strain LCL155 (BuNT/LCL155) associated with type E food-borne botulism showed antigenic and biological properties different from those of C. botulinum type E (BoNT/E) and C. butyricum strain BL5262 (BuNT/BL5262). The speci®c toxicity of BuNT/ LCL155 was found to be about 10% those of BoNT/E and BuNT/BL5262. Immunological analysis with monoclonal antibodies against BoNT/E showed that the heavy chain of BuNT/LCL155 differs partially from those of BoNT/E and BuNT/BL5262. Binding experiments with rat brain synaptic membrane revealed that BuNT/LCL155 possesses a binding activity lower than either BoNT/E or BuNT/BL5262. There was no difference in the catalytic activity of the three neurotoxins, which had been determined with a recombinant of the intracellular target protein SNAP-25. These data suggest that the BuNT/LCL155 shares the receptor-recognition site structurally different from BoNT/E and BuNT/BL5262, perhaps causing a decreased speci®c toxicity.
Journal of Medical Microbiology, 2001
Healthy adults who had not been exposed to antimicrobial agents for the preceding 4 weeks were ex... more Healthy adults who had not been exposed to antimicrobial agents for the preceding 4 weeks were examined for intestinal carriage of Clostridium dif®cile. The 1234 individuals examined were composed of seven groups: three classes of university students, hospital workers at two hospitals, employees of a company and self-defence force personnel at a local station. Overall, 94 (7.6%) individuals were positive for C. dif®cile by faecal culture but carriage rates among the study groups ranged from 4.2% to 15.3%. Typing by PCR ribotyping and pulsed-®eld gel electrophoresis demonstrated clusters of carriers colonised by a single type in each of three groups, indicating that cross-transmission of C. dif®cile can occur in community settings. Follow-up culture was performed on 38 C. dif®cile-positive individuals and C. dif®cile was isolated again from 12 (32%) of them 5± 7 months after the initial culture; six (50%) of these 12 individuals had a new strain on repeat culture. Two or more family members were C. dif®cile-positive in ®ve of 22 families examined. C. dif®cile with an identical type was isolated from persons within a family in only one family. These results suggest that intestinal carriage by healthy adults may play a role as a reservoir for community-acquired C. dif®cile-associated diarrhoea, but that cross-transmission of C. dif®cile does not occur frequently among family members at home.
Infection and Immunity, Feb 1, 2003
The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histi... more The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histidinetagged (His-tag) protein, and the protein was purified to compare its enzymatic and biological activities with those of Clostridium perfringens phospholipase C (Cpa) and Clostridium bifermentans phospholipase C (Cbp). Csp was found to consist of 371 amino acid residues in the mature form and to be more homologous to Cbp than to Cpa. The egg yolk phospholipid hydrolysis activity of the His-tag Csp was about one-third of that of His-tag Cpa, but the hemolytic activity was less than 1% of that of His-tag Cpa. His-tag Csp was nontoxic to mice. Immunization of mice with His-tag Cbp or His-tag Csp did not provide effective protection against the lethal activity of His-tag Cpa. These results indicate that Csp possesses similar molecular properties to Cbp and suggest that comparative analysis of toxic and nontoxic clostridial phospholipases is helpful for characterization of the toxic properties of clostridial phospholipases. Clostridium perfringens elaborates lecithinase, known as alpha-toxin (Cpa), which is the best characterized of all clostridial lecithinases (10, 29, 30). Cpa is a phospholipase C enzyme (30). It is toxic to mammals and is considered to be one of the major virulence factors produced by C. perfringens (25, 29, 30). However, there are still many lecithinases produced by other clostridia that are poorly characterized, and their roles in the pathogenesis of disease have not yet been determined (29, 30). Clostridial lecithinases whose primary structures have been determined are limited to only Cpa (13, 22, 23, 26, 32), Clostridium bifermentans phospholipase C (Cbp) (32), and Clostridium novyi type A phospholipase C (Cnp) (33). Additionally, clostridial lecithinases that have been purified and characterized are limited to Cpa and Cbp. C. bifermentans and C. sordellii resemble each other in their cultural and biological properties, but they have been determined to be genetically different species (19). C. sordellii lecithinase is one of the clostridial lecithinases whose molecular properties are not yet understood (28). Here we report the cloning of the C. sordellii lecithinase (Csp) gene, expression of its product using purified histidine-tagged (His-tag) proteins, and comparison of the enzymatic and biological activities of Csp with those of Cpa and Cbp. MATERIALS AND METHODS Bacterial strains, plasmids, and culture. C. sordellii NCIB10717 (ATCC 9714), C. perfringens KZ 221 (33), and C. bifermentans KZ 1012 (SJ2) were used to isolate the lecithinase genes. To investigate the occurrence of the csp gene, 23 C. sordellii strains kept at our laboratory were used. Esherichia coli TOP10F' (Invitrogen) was used for transformation. PCRII-TOPO (Invitrogen) and pKF3
Annals of Tropical Medicine & Parasitology, 2000
Clostridium botulinum, the aetiological agent of botulism, is currently split into seven types, d... more Clostridium botulinum, the aetiological agent of botulism, is currently split into seven types, designated by the letters A-G, according to differences in the neurotoxin produced. Types A, B, E, F and G are mostly found in soil or freshwater sediments, but types C and D seem to be commensals in mammals and birds and are, consequently, more widely dist:·ibuted in the environment (Popoff and Marvaud, 1999). There have been few surveys of the distribution of C. botulinum in the soils of Africa. Clostridium botulinum type-B and type-D botulinum toxins have been detected in soil samples from South Africa (Knock, 1952; Mason, 1968), and the type-A and type-C toxins have been demonstrated in Kenyan soil (Yamakawa et al., 1990). Although there have been at least two surveys of clostridia in Zambia (Munang'andu et al., 1996; Hang'ombe et al., 2000), the distribution of the seven types of C. botulinum in Zambian soils has not been described. The botulinum toxins in the 46 soil samples collected by Hang'ombe et al. (2000) were therefore investigated. These samples had been collected, 10-15 cm below ground level, from five sites in Zambia during the 1999 rainy season (i.e. January-March; see Fig.). Each of five, 1-g subsamples of each sample was inoculated into a tube containing 10 ml of chopped-meat-glucose medium (Holdeman et al., 1978; Yamakawa et al., 1988; Yamakawa and Nakamura, 1992), or of commercial, cooked-meat medium (Becton and Dickinson, Cockeysville, MD). The tubes were incubated anaerobically at 30°C for 5 days. The culture supernatants were then frozen and thawed before being checked for the presence of botulinum toxin, using the mouse assay (Yamakawa et al., 1988; Yamakawa and Nakamura, 1992). The antisera used for neutralization tests were purchased
Journal of the Japanese Association for Infectious Diseases, 1992
This article cites 34 articles, 14 of which can be accessed free
Journal of medical …, 2002
The production of toxins A and B by Clostridium dif®cile was greatly enhanced under biotin-limite... more The production of toxins A and B by Clostridium dif®cile was greatly enhanced under biotin-limited conditions, in which a 140-kDa protein was expressed strongly. Gene cloning revealed that this protein was a homologue of formylglycinamidine ribonucleotide synthetase (FGAM synthetase, EC 6.3.5.3), which is known as PurL in Escherichia coli and catalyses the fourth step of the de novo purine biosynthesis pathway. This enzyme consisted of a single polypeptide, although FGAM synthetases of gram-positive bacteria usually consist of two subunits. Inhibition of the enzymic activity of C. dif®cile PurL by O-diazoacetyl-L-serine (azaserine) resulted in enhanced toxin B production even in biotin-suf®cient conditions. In contrast, blockade of the preceding step of the PurL catalysing step by sulfamethoxazole inhibited toxin B production almost completely. These results suggest that accumulation of formylglycinamide ribonucleotide (FGAR), a substrate of FGAM synthetase, enhances toxin production by C. dif®cile and depletion of FGAR reduces toxin production.
Acta microbiologica Polonica, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
ABSTRACT Neurotoxigenic Clostridium butyricum has been identified as occurring in the natural env... more ABSTRACT Neurotoxigenic Clostridium butyricum has been identified as occurring in the natural environment. Nontoxigenic and neurotoxigenic C. butyricum strains were comparatively analyzed by PCR assay and Southern blot hybridization for the type E botulinum toxin gene (bont/E), random amplified polymorphic DNA (RAPD) assay, and pulsed-field gel electrophoresis (PFGE). With the PCR assay and Southern blot hybridization, the bont/E gene was detected in all seven strains of neurotoxigenic C. butyricum (BL 5262, BL 6340, LCL 155, LCL 063, LCL 095, KZ 1886, and KZ 1887), but not in nontoxigenic strains (MIYAIRI 588, MIYAIRI 595, MIYAIRI 630, SI 293-2, RU 063-3, GU-2, ATCC 19398, and IFO 3315), indicating that there were no partial bont/E gene fragments in the nontoxigenic C. butyricum strains. All strains were successfully analyzed by RAPD assay. In contrast to the RAPD assay, two strains of nontoxigenic C. butyricum could not be analyzed by PFGE, probably due to the DNase activity. Nontoxigenic strains SI 293-2 and GU-2 shared an identical RAPD or PFGE pattern. The other nontoxigenic strains showed unique RAPD and PFGE patterns, and these patterns differed from those of all neurotoxigenic C. butyricum strains. The present results are discussed in relation to the transfer of the bont/E gene.
The Journal of the Korean Society for Microbiology, 2000
Acta Microbiologica Polonica, Feb 1, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
The Journal of Immunology, 2004
Journal of immunology (Baltimore, Md. : 1950), 2004
Clostridium difficile has emerged as the important causative agent of antibiotics-associated pseu... more Clostridium difficile has emerged as the important causative agent of antibiotics-associated pseudomembranous colitis; especially its toxin A is presumed to be responsible for the colitis. We examined the pathophysiological roles of IFN-gamma in toxin A-induced enteritis using IFN-gamma knockout (KO) mice. When toxin A of C. difficile was injected into the ileal loops of BALB/c wild-type (WT) mice, massive fluid secretion, disruption of intestinal epithelial structure, and massive neutrophil infiltration developed within 4 h after the injection. IFN-gamma protein was faintly detected in some CD3-positive lymphocytes in the lamina propria and submucosa of the ileum of untreated WT mice. On the contrary, at 2 and 4 h after toxin A injection, IFN-gamma protein was detected in infiltrating neutrophils and to a lesser degree in CD3-positive lymphocytes. In the ileum of WT mice, toxin A treatment markedly enhanced the gene expression of TNF-alpha, macrophage inflammatory protein-1alpha an...
Acta microbiologica Polonica, 2002
We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice ind... more We report that the intraperitoneal injection of Clostridium perfringens alpha-toxin into mice induces ascites. This phenomenon was monitored by measuring fluid volume and analyzing hematologic data. The mouse toxicity test provides a simple and useful model for examining C. perfringens alpha-toxin-induced vascular permeability.
Microbiology and Immunology, 1997
Twenty strains of Clostridium difficile were examined for the effect of arginine on toxin product... more Twenty strains of Clostridium difficile were examined for the effect of arginine on toxin production in a defined medium. In three strains, the production of toxins A and B was greatly enhanced in the absence of arginine. These strains showed distinctively poorer growth in the absence of arginine in comparison with the remaining 17 strains, indicating that the presence of arginine is required for good growth among the three strains. From the present results, test strains were divided into two groups: a group in which arginine insufficiency caused distinctly poor growth and enhanced toxin production, and another group in which there was neither distinctly poor growth nor enhanced toxin production. The phenomenon is discussed in relation to the biosynthesis and catabolism of arginine.
The Journal of Immunology, 2004
The Journal of Immunology, 2004
Fems Microbiology Letters, 1999
The repeating sequences of the toxin A gene from toxin A-negative, toxin B-positive (toxin A3, to... more The repeating sequences of the toxin A gene from toxin A-negative, toxin B-positive (toxin A3, toxin B+) strains of Clostridium difficile which were isolated in geographically separated facilities in Japan and Indonesia were determined. All six strains tested had identical repeating sequences with two deletions (1548 and 273 nucleotides in size) in the toxin A gene. A PCR method was designed to detect the deletions and the deletions were confirmed in all 50 toxin A3, toxin B+ strains examined by this method. Western immunoblot analysis revealed that polyclonal antiserum against native toxin A did not react with the concentrated culture filtrates of the toxin A3, toxin B+ strains. These results may suggest that toxin A3, toxin B+ strains have deletions of the two thirds of the repeating regions of the toxin A gene, which encodes the epitopes fully responsible for the reaction with the polyclonal antiserum. z