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Y Kudoh

Publications and source records attributed to Y Kudoh.

At least 37 records · Page 2Linked to original sources
PubMed1997

Incidence and clinical symptoms of Aeromonas-associated travellers' diarrhoea in Tokyo.

In a survey examining the causes of travellers' diarrhoea treated in Tokyo between July 1986 and December 1995, Aeromonas species were isolated from 1265 (5.5%) of 23,215 travellers returning from developing countries. Aeromonas species were the fourth most frequent enteropathogen isolated, following enterotoxigenic E. coli (8.5%), Salmonella spp. (7.6%) and Plesiomonas shigelloides (5.6%). Aeromonas species were found in 1191 (5.6%) of 21,257 patients with diarrhoea and in 74 (3.8%) of 1958 healthy individuals without diarrhoea. Mixed infection was observed in 512 (40.5%) cases. No significant difference in the prevalence of Aeromonas by year, season, age distributions, or sex was observed, but a slight difference was noted depending on the country where the travellers visited. Of the 1265 Aeromonas isolates, 893 strains (70.6%) were A. veronii biovar sobria, 330 (26.1%) were A. hydrophila, and 42 (3.3%) were A. caviae. The clinical symptoms of patients from whom Aeromonas species was isolated as the only potential enteric pathogen were almost similar, which were watery diarrhoea (about 60%), abdominal cramps (43%), fever (around 15%), and nausea or vomiting (13%). Although the severity of illness was milder than that of enterotoxigenic E. coli alone, these data suggest that Aeromonas species are important enteric pathogens in travellers' diarrhoea.

Aeromonas↗
PubMed1997

[Sporadic diarrhea caused by Vibrio cholerae non-O1 and characteristics of the isolates].

In 1996, we examined five domestic and eight imported cases of sporadic diarrhea caused by Vibrio cholerae non-O1 in Tokyo. The domestic cases occurred during the summer, from June to September, while the imported cases were seen throughout the year. The major clinical symptoms of the patients were watery diarrhea (100%) with an average frequency of 5.5 times/day, abdominal pain (77%), vomiting (31%) and fever (15%). A total of 13 strains isolated from these 13 cases had the typical biochemical characteristics of Vibrio cholerae, and were classified into 11 kinds of serovars (O2, O5, O8, O9, O12, O14, O27, O51, O88, O97, and O161). All strains produced hemolysin, and two strains produced NAG-ST, while no strain produced cholera toxin.

Adult↗
PubMed1997

[Evaluation of a latex agglutination method for detecting and characterizing verotoxin (VT) produced by Escherichia coli].

The detection of VT produced by Escherichia coli is very important for the identification of verotoxin-producing Escherichia coli (VTEC). The latex agglutination reagents (Denka Seiken Co. Ltd, Tokyo) which was developed to detect VT was compared with the vero cell bioassay or polymerase chain reaction method. A total 147 VT-positive strains (109 serotype O157:H 7/- and 38 non-O157 serotype) and 31 VT-negative strains which were isolated from human were investigated. In addition, a total of 79 VT-positive strains (14 serotype O157:H7/- and 65 non-O157 serotype) and 79 VT-negative strains which were isolated from animals were also examined. The latex agglutination assay for the human isolates showed the 100% sensitivity, specificity and agreement. The assay for the animal isolates showed 94.9% sensitivity, 100% specificity and 97.5% agreement. Although 4 of 8 strains isolated from swine which produce VT2 variant toxin (VT2e) failed in detecting verotoxin by latex agglutination assay, VT2e was not related to human infections. We conclude that this latex agglutination reagent is highly sensitive and specific for detecting and characterizing VT of E. coli. The method is reliable, easy to perform at any laboratories.

Animals↗
PubMed1997

[Shigella dysenteriae strains possessing a new serovar isolated from imported diarrheal cases in Japan].

Two Shigella strains (93-119 and 95-619) isolated from stool cultures of imported diarrheal cases in Japan, did not react to any antisera of the established SHigella serovars. These strains had the typical biochemical characteristics of Shigella dysenteriae, and were biochemically identical to each other. Both strains were positive in the Serény test and other tests for invasiveness; these indicate that they can cause shigellosis in humans. The results of antigenic analysis showed that they did not belong to any of the recognized or provisional serovars, and were serologically indistinguishable. Strain 93-119 is designated as the test strain for this new serovar.

Animals↗
PubMed1997

[Biochemical and molecular characterization of Salmonella serovar enteritidis phage type 4 isolated from food poisoning outbreaks in Tokyo].

Since 1989, outbreaks of Salmonella ser. Enteritidis (S. Enteritidis) food poisoning have dramatically increased in Tokyo, and a total of 31 outbreaks has been reported in 1989. Twenty-one of these 31 outbreaks were caused by S. Enteritidis PT34, but 8 outbreaks were caused by S. Enteritidis PT4. After 1990 instead of SE PT34, food poisoning due to PT4, which was a very common phage type in the UK, has increased in Tokyo. Between 1989 and 1995, there were 144 food poisoning outbreaks caused by S. Enteritidis, and 64 of these outbreaks were by due to S. Enteritidis PT4, which was one of the main phage types in Tokyo. To characterize these strains of phage type (PT) 4,293 isolates from patients, and vehicle foods, eggs and environment in Tokyo were examined for plasmid DNA profiles, acid productivity from glycols (propylene and ethylene) and antimicrobial resistance patterns. Plasmid DNA was extracted by Kado's method, and analyzed by agarose gel electrophoresis. The acid productivity from propylene glycol or ethylene glycol were tested using Barsicow medium with 1% propylene glycol or ethylene glycol. Antimicrobial susceptibility to AM, CP, TC, SM, KM, NA, ST, FOM and NFLX was tested by the K-B disc method. The strains of PT4 were further subdivided into 9 types by those epidemiologic marker analysis. The prevalent pattern of PT4 strains was type A plasmid profile carrying only one plasmid (60 kb) and there were 2 kinds of antibiograms. One was SM resistant, while the other was susceptible. A total of 56 (87.5%) of 64 outbreaks was found to have been caused by these types of S. Enteritidis. Several kinds of egg-related foods were suspected as the vehicles of transmission among 24 outbreaks. Especially, in 5 outbreaks, S. Enteritidis strains were isolated both from patients and suspected food which were cooked with egg. This strongly suggests that these foods may be the potential source of infection in S. Enteritidis PT4 outbreaks.

Anti-Bacterial Agents↗
PubMed1997

[Serological diagnosis of enterohaemorrhagic Escherichia coli(EHEC) infection by passive hemagglutination assay].

The passive hemagglutination(PHA) assay was developed to diagnose enterohaemorrhagic Escherichia coli(EHEC) infections serologically and was evaluated for the utility. The PHA assay was done using formalinized sheep erythrocytes sensitized with 2 kinds of antigens; soluble native and heat-treated antigens, by a microtiter method. A total of 63 serum samples from 33 HUS patients and 30 sporadic hemorrhagic colitis were subjected to the assay. For the control, 30 serum samples from 20 healthy adults and 10 healthy children were used. Thirty-two of 33 HUS patients had the antibody against soluble native antigen and/or heat-treated antigen of EHEC O157. These response was also observed in 14 HC cases with stool culture positive for EHEC O157. Good antibody response was observed against soluble native antigen than that against heat-treated antigen. The PHA titers distributed between 1:100 and 1:8,100 were observed in the samples taken in about 1 week or more after the onset of diarrhea, and the higher titer were observed in HUS patients than in HC patients. All of control sera were negative. The PHA assay described here is highly sensitive, simple and rapid method, and is recommended for the serological diagnosis of EHEC infections.

Adult↗
PubMed1997

[Current status of gastrointestinal infection in Japan--with special reference to enterohaemorrhagic Escherichia coli infection].

The annual incidence of gastrointestinal infections such as bacillary dysentery, typhoid fever and paratyphoid fever has declined markedly since the early 1960s. However, in parallel with the increase of international travel, the incidence of imported cases from abroad has recently tended to increase. Moreover, similar to North America and Europe, food-borne infections such as Salmonella food poisoning due to serovar Enteritidis and enterohaemorrhagic Escherichia coli infection has increased dramatically recently. In this paper, the current trend of gastrointestinal infections in Japan was discussed from the epidemiologic and bacteriologic view points.

Cholera↗
PubMed1997

Propylthiouracil-induced rapidly progressive glomerulonephritis associated with antineutrophil cytoplasmic autoantibodies.

We present a case study of a 52-year-old female patient with hyperthyroidism which had been diagnosed at the age of 35. However, the malfunction of thyroid had been poorly controlled. Thyroid function was returning to normal after the administration of propylthiouracil (PTU) 300 mg/day, however purpura appeared in both lower extremities. Renal function deteriorated rapidly, and the patient was admitted to our hospital. According to the biopsies, leukocytoclastic vasculitis in the skin was apparent, and crescent formation was observed in the glomerulus. Serological examination revealed positive antineutrophil cytoplasmic autoantibodies (ANCA) against proteinase 3 (Pr3) and myeloperoxidase (MPO). Antinuclear autoantibody was positive. After cessation of PTU and administration of prednisolone, the purpura disappeared and ANCA were becoming negative. Renal function recovered gradually. Thyroid function was kept within normal range using iodine solution. Thus, it is strongly suggested that PTU-induced rapidly progressive glomerulonephritis associated with ANCA.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1996

[Characteristics of Salmonella strains isolated from sporadic diarrheal cases during 1992-1994 in the Philippines].

A total of 263 Salmonella strains isolated in Metro Manila, the Philippines from 1992 to 1994, were examined for their serovar-distribution and drug-resistance. Salmonella serovar Typhi (S. Typhi) and S. Enteritidis phage type was also tested. The serological typing results showed that the strains were classified into 10 O-groups and 32 serovars. S. Weltevreden, S. Enteritidis, S. Typhi, S. Typhimurium, and S. Derby were predominant in the serovars identified. The drug-resistance test using nine drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 95 strains (36.1%) were resistant to any of the seven drugs except FOM and NFLX. The serovars of a high resistant rate were S. Ruiru (100%), S. Typhimurium (87.0%), S. Senftenberg (80.0%), S. Derby (66.7%), and S. Agona (50.0%). Drug-resistance patterns of the resistant strains varied to 21 types, and 80 of them were multidrug-resistant. Phage types of 37 S. Typhi strains were B1 (27 strains), E2 (6 strains), and others (4 strains). Phage types of 38 S. Enteritidis strains were 4 (32 strains), 7 (3 strains), and others (3 strains).

Ampicillin Resistance↗
PubMed1996

[Evolution of susceptibilities of Campylobacter jejuni isolated from diarrhoeal cases to fluoroquinolones in Tokyo].

Recently, the increase in the number of resistant strains of Campylobacter jejuni to fluoroquinolone has been reported in European countries. We also studied antimicrobial susceptibilities of 600 clinical isolates of Campylobacter jejuni isolated during a 6 year period from 1989 through 1994 in four Tokyo Metropolitan Hospitals. The susceptibility to 6 antimicrobial agents, norfloxacin (NFLX), ofloxacin (OFLX), ciprofloxacin (CPFX), nalidixic acid (NA), erythromycin (EM) and tetracycline (TC) were examined. The overall resistant rates were as follows: NFLX, 45 strains (7.5%); OFLX, 45 strains (7.5%); CPFX, 44 strains (7.3%); NA, 62 strains (10.3%); EM, 4 strains (0.6%) and TC, 259 strains (43.2%). The number of resistant strains to fluoroquinolones and NA has increased significantly since 1993 in Japan, but the susceptibility to erythromycin has still remained the same level during the past 6 years. The susceptibility to TC was variable, and MICs gave a bimobal distribution, as pointed out previously. The resistance pattern of NFLX, OFLX, CPFX and NA were observed most frequently in those isolates.

Anti-Infective Agents↗
PubMed1996

[Serovar-distribution and drug-resistance of Salmonella strains isolated from domestic and imported cases in 1990-1994 in Tokyo].

A total of 3,647 non-typhoidal Salmonella strains consisting of 2,655 domestic strains and 992 imported strains isolated in Tokyo from 1990 to 1994, were examined for their serovar-distribution and their drug-resistance. The serological typing results showed that the domestic strains were classified into 15 O-groups and 96 serovars, and the imported strains were classified into 13 O-groups and 73 serovars. Among the serovars identified, Salmonella serovar Enteritidis (S. Enteritidis), S. Thompson, S. Hadar, S. Litchfield, and S. Tennessee were predominant in the domestic strains, whereas S. Hadar, S. Enteritidis, S. Anatum, S. Derby, and S. Blockley were predominant in the imported strains. The drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 30.5% of the domestic strains and 40.5% of the imported strains were resistant to any of the drugs examined. The serovars of a high resistant rate during this period were S. Hadar (96.2%), S. Blockley (88.7%), S. Enteritidis (63.4%), S. Virchow (54.3%), and S. Typhimurium (51.3%) in the domestic strains and S. Krefeld (100%), S. Hadar (98.9%), S. Blockley (98.2%), S. Emek (83.3%), S. Kentucky (76.5%), S. Panama (69.2%), S. Derby (63.8%), S. Typhimurium (57.1%), S. Rissen (55.6%), and S. Agona (53.7%) in the imported strains. Drug-resistance patterns of the resistant isolates varied to 62 types. Prevalent patterns recognized were SM, TC.SM, TC.SM.KM, TC, TC.SM.KM.ABPC and CP.TC.SM.KM in the domestic strains and TC.SM, TC, CP.TC.SM.ST, TC.SM.KM, and CP.TC.SM.KM in the imported strains.

Diarrhea↗
PubMed1996

[Analysis of verotoxin-producing Escherichia coli (O157:H7) strains isolated in the Fukuoka area in 1994 by pulsed-field gel electrophoresis].

Nine verotoxin-producing Escherichia coli O157:H7 strains were isolated from 9 pediatric patients with sporadic enteritis between July and September 1994 at four clinics in the Fukuoka area. The patients included two families with two cases each. These strains were analyzed by pulsed-field gel electrophoresis for Xba I-digested DNA fragments. The restriction patterns were identical between each two strains within the two family outbreaks, but different among the seven strains of the distinct seven sporadic cases. It is strongly suggested that the seven sporadic cases were infected through distinct sources, and that the two family cases were due to a common source of infection or person to person infection.

Bacterial Toxins↗
PubMed1996

[Characterization of Salmonella ser. enteritidis phage type 34 isolated from food poisoning outbreaks in Tokyo by epidemiological makers].

Since 1989, outbreaks of Salmonella ser. Enteritidis food poisoning has dramatically increased in Tokyo, and a total of 95 outbreaks has been reported between 1989 and 1993. As the results of examination of phage type by the method of Ward, et al., strains isolated from 31 (32.6%) of 95 outbreaks were phage type 34 which is a very rare type in Europe and America. To characterize these unique strains of phage type (PT) 34, 302 isolates obtained from patients and vehicle foods of the outbreaks, eggs and environments in Tokyo were examined for plasmid DNA profiles and antimicrobial resistance patterns. Plasmid DNA was extracted by the Kado's method, and analysed by agalose gel electrophoresis. Antimicrobial susceptibility was tested for CP, TC, SM, KM, ABPC, NA, SXT, FOM and NFLX by the K-B disc method. The strains of PT 34 were further subdivided to 4 types by plasmid profile and antibiogram. The prevalent pattern of PT 34 strains was type plasmid profile which carried 2 different plasmids (> 250 and 60 kb) and was streptomysin-resistant. A total of 28 (90.3%) of 31 outbreaks were found to be caused by this specific type of Salmonella ser. Enteritidis. Several kinds of egg-related foods were suspected for the vehicles of transmission among 12 outbreaks. Especially, in 5 outbreaks, this specific type (type B plasmid profile and streptomysin resistant) of Salmonella ser. Enteritidis strains were isolated both from patients and incriminated food which were cooked with eggs. The phase type of Salmonella ser. Enteritidis strains isolated from raw egg and poultry or environmental specimens from poultry farm showed that the prevailing phage types were almost the same as those of foods poisoning outbreaks. This strongly suggests that these foods may be considered as a source of infection in Salmonella ser. Enteritidis outbreaks.

Anti-Bacterial Agents↗
PubMed1996

[Detection of the trh gene in Vibrio parahaemolyticus isolated from overseas travellers' diarrhea and their biochemical characteristics].

A total of 478 Vibrio parahaemolyticus strains isolated from overseas travellers' diarrhea during the last 7 years of 1989 to 1995 were examined for the production of Kanagawa hemolysin by reversed passive latex agglutination (RPLA) test. Three hundred-seventy (77.4%) out of 478 strains were positive for Kanagawa hemolysin, whereas 108 strains were weakly positive or negative. For those Kanagawa hemolysin-weakly positive or negative strains, the tdh and trh genes associated with the production of TDH (thermostable direct hemolysin) and TRH (TDH-related hemolysin), respectively, were studied by the polymerase chain reaction method. The trh gene was detected in 98 (90.7%) out of 108 strains. In 35 strains belonging to 13 serotypes such as O3: K6, O1:K33, O3:K59, the trh gene alone was detected. On the other hand, both trh and tdh genes were detected in 63 strains of 17 serotypes including O1:K69, O3:K72, O6:K46. Among the strains of 4 serotypes including O1:K56, O1:KUT, O3:KUT and O5:KUT, two types of the trh positive alone and the trh and tdh positive were observed. Of interest, all of the 98 trh-positive strains were positive for the urease hydrolysis, whereas all Kanagawa hemolysin-positive strains were not. Furthermore, the strains of serotype O6:K18 (4 strains) were positive for the fermentation of dulcitol, and the strains of serotype O1:K1 (5 strains) were indole negative. These characteristics of the strains were completely different from those of typical V. parahaemolyticus strains.

Diarrhea↗
PubMed1996

[Preliminary screening for antiviral AIDS drugs. VII. Report for fiscal year 1994].

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 246 samples of different origin tested, six were shown to inhibit the growth of HIV in vitro. Two of the positive samples have hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.

Anti-HIV Agents↗
PubMed1996

Surface reaction between titanium castings and investments.

The selection of investments suitable for titanium castings is critical because the surface-reacted layer greatly affects their mechanical properties. This study analyzed the interfacial zone of titanium castings obtained from various commercial investments and examined the relationship between the surface-reacted layer and the hardness. CP titanium disks (20 mm diameter, 1 mm thick, n = 5) were cast using eight commercial casting systems and investments for titanium casting: two alumina-based investments (T-invest, CD-titan investment), two spinel-based investments (Titanmold, Titavest MZ), three zirconia-based investments (Asahivest-D, Titaniumvest EX, Tycast investment TM), and a magnesia-based investment (Selevest CB). The Vickers hardness of cast disks in cross-section was tested at 50 microns intervals from the surface to 0.5 mm in depth. The cross-section was observed metallurgically, and an elemental mapping measurement of the reacted layer was conducted under the EPMA. The Vickers hardnesses at 50 microns from the surface of the specimens ranged 312 to 624 and were significantly different among the investments (p < 0.01). The thickness of the reacted layer, rich in O, Si, Al, Zr, Mg, and P, ranged from 10 to 60 microns. No correlation was seen between the thickness of reacted layer and the hardness (p > 0.05). However, the specimens cast with alumina-based and zirconia-based investments were harder than the spinel-based and magnesia-based investments at 500 microns. Although the free energies of metal oxide formation of alumina and zirconia were lower than titania, these data suggest that silica, alumina and zirconia were reduced by contact with molten titanium. Accordingly, silicon, aluminum and zirconium diffused to the interior of the titanium castings and changed their mechanical properties.

Aluminum Oxide↗