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Yukio Morita

Publications and source records attributed to Yukio Morita.

16 recordsLinked to original sources
PubMed2006

Immunohistological findings of suppurative granulomas of Yersinia enterocolitica appendicitis: a report of two cases.

We report on the histopathologic and immunohistologic findings of two cases of suppurative granulomatous appendicitis of Yersinia enterocolitica (Y. ent.). Using formalin-fixed, paraffin-embedded materials, polymerase chain reaction revealed Y. ent. in both cases. Histologically, the epithelioid cell granulomas (EPGs) were transmural in both cases. The EPGs were predominantly nonsuppurative, and were surrounded by a lymphoid cuff composed of small lymphocytes. A portion of EPGs contained suppuration of the centers of the granulomas (central microabscesses). The EPGs were composed of numerous histiocytes with or without epithelioid cell features, along with scattered small T-lymphocytes and plasmacytoid monocytes. None of the EPGs contained monocytoid B-cells. Immunohistochemical study demonstrated that EPGs were usually surrounded by surface IgM/D+ small mantle zone lymphocytes. Moreover, CNA.42 immunostaining occasionally demonstrated residual follicular dendritic cells in the center of the EPGs. The overall histomorphologic and immunohistochemical findings demonstrated that the EPGs with Y. ent. are of the B-cell negative hypersensitivity type and occur in reactive germinal centers. In one case, regional lymph nodes contained EPGs showing the same histologic and immunohistologic findings as those of the appendix. The present study indicates that among abscesses forming epithelioid granulomatous lesions, EPGs with Y. ent. were B-cell negative granulomas, and it demonstrates histopathologic and immunohistochemical findings different from those of cat scratch disease and lymphogranuloma venerum, which contain numerous monocytoid B-cells.

Abdominal Abscess↗
PubMed2006

Antimicrobial resistance in Campylobacter isolated from food animals and humans in northern Thailand.

A study was conducted to determine the prevalence of Campylobacter with antimicrobial resistance from chickens, pigs, dairy cows, healthy farm workers, and children hospitalized with diarrhea in northern Thailand. Resistance was highest in pig samples and lowest in healthy farm workers. Resistance to fluoroquinolones and tetracycline was high in all study populations. The increased prevalence of resistant isolates from meat samples collected at markets, compared to isolates collected from animals on the farm or the slaughterhouse, suggests that contamination after carcasses leave the slaughterhouse is an important factor in the spread of resistant bacteria into the human food chain.

Animal Diseases↗
PubMed2005

Plasmacytoid monocytes in cat scratch disease with special reference to the histological diversity of suppurative lesions.

It has been suggested that plasmacytoid monocytes (PMOs) play an essential role in T-cell-dependent immune response. Indeed, numerous PMOs are found in close topographical association with epithelioid cell granulomas in hypersensitivity-type granulomas, such as tuberculosis and sarcoidosis. The key pathologic process in cat scratch disease (CSD) usually involves a B-cell-associated granulomatous reaction. Histologically, CSD appears to exhibit a histopathologic diversity, including suppurative lesions without epithelioid cell granulomas (early lesion), in which the microabscesses were surrounded by monocytoid B-cells (MBCs), suppurative granulomas containing MBCs (intermediate lesion), and suppurative granulomas without MBCs (late lesion). However, the presence or absence of PMO in CSD has not been studied previously. We examined 14 cases of CSD. In early lesions, numerous clusters of PMO were detected in the MBCs. In intermediate lesions, both MBCs and PMOs were found to be decreased in number, while late lesions contained no or only a few MBCs and PMOs. Overall, these findings suggest that PMOs may play a role in MBC-associated granulomatous response and in hypersensitivity granulomatous response. Moreover, the association with MBCs and PMOs indicates a functional relationship of MBCs with PMOs in the formation of suppurative lesions in CSD.

Abscess↗
PubMed2005

Detection and sequence analysis of DNA polymerase and major envelope protein genes in koi herpesviruses derived from Cyprinus carpio in Gunma prefecture, Japan.

Koi herpesvirus (KHV), which is believed to be an emerging virus, causes fatal diseases in carps. Since the 1990s, the presence of KHV has been confirmed in several countries. In Japan, from 2003 to 2004, large outbreaks of KHV infection in farmed carps resulted in the death of numerous fishes. From April to May 2004, we collected 43 dead or dying carps exhibiting typical symptoms of KHV infection in Gunma prefecture. To conduct a molecular epidemiologic study of KHV in our prefecture, we amplified DNA polymerase and the major envelope protein genes of KHV derived from carp gills using newly designed primers. We also performed sequence analysis of both genes of KHV. Sensitivity of our PCR method for amplification of DNA polymerase and the major envelope protein genes of KHV was 3 x 10(2) (100 fg) and 3 x 10(3) (1000 fg) copies of KHV genome, respectively. We detected both DNA polymerase and major envelope protein genes in 37 of 43 carps (86%). No mutation was found in both the genes sequenced from 11 strains, which included two foreign strains and one domestic strain. The results suggested that KHV strains derived from carps in our prefecture were closely related genetically to the other KHV strains.

Animals↗
PubMed2005

Serotypes and antimicrobial resistance of Campylobacter jejuni isolated from humans and animals in Thailand.

We investigated the serotypes, distributions, and antimicrobial resistance of Campylobacter jejuni isolates from humans and animals as a source of infection in poultry between 2002 and 2003. A total of 50 C. jejuni isolates from humans and 29 C. jejuni isolates from poultry were studied for serotype using the Penner serotyping scheme and the drug susceptibilities of the isolates which were determined for 7 antimicrobial drugs using the disk diffusion method. Serotype B (10%), serotype E (8%) and serotype R (8%) were found in humans isolates, while serotype A (27%) was most freguently isolated from poultry, followed by serotype K (21%) and serotype C (13%). Resistance in human isolates to cephalothin was high (100%). Resistance to trimethoprim/sulfamethoxazole, ciprofloxacin, and nalidixic acid were observed in 90, 82 and 78% of isolates, respectively. Most of the isolates (88%) were susceptible to erythromycin. High levels of resistance to drugs (ciprofloxacin and nalidixic acid) were observed in the isolates from poultry. These results indicate the importance of poultry as a reservoir of C. jejuni infection in Thailand is limited. In addition, a high proportion of the isolates were resistant to antimicrobial drugs, particularly the quinolone group.

Animals↗
PubMed2004

Prevalence of Arcobacter species in retail meats and antimicrobial susceptibility of the isolates in Japan.

A survey was conducted to examine the prevalence of Arcobacter species among meat samples and to investigate the antimicrobial susceptibility of the isolates in Japan. In 1998 and 1999, samples of beef (n=90), pork (n=100) and chicken meat (n=100) were purchased from seven retail shops. Arcobacter species were isolated from 2.2%, 7.0% and 23.0% of beef, pork and chicken meat samples, respectively. The rate of isolations in chicken meats was shown to be significantly higher than those of beef and pork. Species-specific polymerase chain reaction (PCR) demonstrated that the most dominant Arcobacter species was Arcobacter butzleri among the isolates examined. Multiple contaminations with different Arcobacter species were observed in 5% of the chicken samples. Almost all the strains tested showed resistance to vancomycin (100%) and methicillin (97.5%). Strains resistant to cephalothin, sulfamethoxazole-trimethoprim, nalidixic acid and chloramphenicol were detected at the rate of 81.1%, 67.2%, 53.5% and 24.6%, respectively. All Arcobacter strains examined were susceptible to ampicillin, tetracycline, streptomycin and kanamycin.

Animals↗
PubMed2004

Genetic diversity of the dnaJ gene in the Mycobacterium avium complex.

The Mycobacterium avium complex (MAC) is associated with various diseases in humans as a zoonosis. The dnaJ gene was partially sequenced in Schaefer's 28 reference strains of MAC, 14 human MAC isolates and 22 veterinary isolates. From substitutions affecting 21-32 nucleotides, all strains could be classified into 14 groups. Most nucleotide substitutions did not alter amino acid sequences. Approximately 8 % genetic diversity was seen in these strains, which divided into two clusters: cluster I (0.8 % genetic diversity), comprising the reference strain serotypes 1-6, 8-11 and 21 and all isolates; and cluster II (7 % genetic diversity), comprising the remaining reference strains. Analysis of the dnaJ gene in MAC may be useful in epidemiological studies.

Animals↗
PubMed2004

Isolation and phylogenetic analysis of arcobacter spp. in ground chicken meat and environmental water in Japan and Thailand.

Prevalence of Arcobacter spp. in chicken meat samples and environmental water samples in Japan and Thailand was investigated. Arcobacter was isolated from 48% of chicken meat samples (20/41) and 23% of river water samples (4/17) from Japan, and 100% of chicken meat samples (10/10) and 100% of canal water samples (7/7) from Thailand. A. butzleri was among the species isolated from all positive samples. About 10% genetic diversity was seen in the rpoB-rpoC in Arcobacters, and phylogenetic trees were divided into two clusters. In both countries, the results suggested that chicken and environmental water were highly contaminated with a genetically diverse population of Arcobacter.

Animals↗
PubMed2004

A highly effective method for removing suspended poliovirus from water using a positively-charged carbon felt electrode.

We developed an effective system to eliminate poliovirus from modified tap water using a positively-charged carbon felt electrode. The zeta potential of polioviruses was measured using laser microscopic electrophoresis. Poliovirus adsorption to the electrode was examined by indirect immunofluorescence. The tissue culture infective dose (TCID) of poliovirus type 2 (Sabin strain) was determined using human rhabdomyosarcoma cells (RD cells). Poliovirus VP2 gene copy numbers were assessed by reverse transcription followed by a quantitative real-time polymerase chain reaction. The mean zeta potential of the viruses was -20 mV. Relatively large numbers of polioviruses (10(3) or 4 x 10(3) TCID(50)/0.1 ml) could be removed by adsorption to the electrode, drastically decreasing TCID and copy numbers of poliovirus genome in the water. Virus elimination was dependent on electric current and time. Thus, the positively-charged carbon felt electrode effectively adsorbed polioviruses. The system may prove applicable to the elimination of certain viruses from water.

Adsorption↗
PubMed2003

Distribution of Arcobacter species among livestock in Japan.

A survey was conducted to examine the distribution of Arcobacter species among livestock in Japan. During May 1999 and May 2000, fecal samples from cattle (n=332) and swine (n=250), chicken cloacal swabs (n=234), and vaginal swabs of cattle (n=61) and swine (n=15) were submitted for the isolation of Arcobacter species. Arcobacter species were isolated from 3.6 and 10.0% of the cattle and swine fecal samples, respectively, along with 14.5% of chicken cloacal swabs. No significant seasonal differences were observed. Species-specific polymerase chain reaction assay showed that A. butzleri was the most prevalent species (83.3, 60.0 and 47.1% of the cattle, swine and chicken isolates, respectively), followed by A. cryaerophilus 1B (16.7, 36.0 and 55.9% of the cattle, swine and chicken isolates, respectively). Of the samples from vaginal swabs, 8.1 and 13.3% were positive for Arcobacter in cattle and swine, respectively. This is the first report demonstrating the distribution of Arcobacter species among livestock in Japan.

Animals↗