Antimicrobial susceptibilities, serogroups, and molecular characterization of avian pathogenic Escherichia coli isolates in Japan     

Ozawa M  Harada K  Kojima A  Asai T  Sameshima T 《Avian diseases》2008,52(3):392-397

In total, 83 avian pathogenic Escherichia coli (APEC) isolates from avian colibacillosis during a period from 2001 to 2006 in Japan were investigated for serogroups, typical virulence factors, antimicrobial susceptibility, and genetic relatedness. The most common serogroup was O78 (30.1%); 80.7% of isolates harbored the iss gene and 55.4% of isolates harbored the tsh gene. Antimicrobial resistance of the isolates was found for ampicillin (77.1%), oxytetracycline (75.9%), kanamycin (36.1%), fradiomycin (33.7%), trimethoprim (25.3%), enrofloxacin (21.7%), and florfenicol (6.0%). Although multiple antimicrobial-resistant phenotypes (three or more antimicrobials) accounted for 54.2% of isolates, no isolate exhibited resistance to all agents tested. The fluoroquinolone-resistant isolates had point mutations in GyrA (Ser83 --> Leu, Asp87 --> Asn) and ParC (Ser80 --> Ile, Glu84 --> Gly). Of 18 enrofloxacin-resistant E. coli isolates, nine isolates belonged to serotype O78. In PFGE analysis, eight of the nine enrofloxacin-resistant O78 isolates were classified into an identical cluster. This suggests that a specific genotype of fluoroquinolone-resistant O78 APEC may be widely distributed in Japan.  相似文献   

Formation of detached tail and coiled tail of sperm in a beagle dog     

Kawakami E  Ozawa T  Hirano T  Hori T  Tsutsui T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(1):83-85

The right testis and epididymis were excised from a Beagle dog that ejaculated high percentages of sperm with detached tails and with coiled tails. Cross sections of the organs were stamped on glass slides and histological examination of the organs was performed to find the portion where sperm with the abnormal tails appear. Many sperm with tails whose axoneme was exposed near the neck region were observed in the testis and they decreased in order from the caput, to the corpus, and the cauda epididymis. Sperm with detached tails and sperm with coiled tails gradually increased in the epididymis. These findings indicate that the tails of sperm with an exposed axoneme detached in the epididymis.  相似文献   

Identification and characterization of peptides binding to newcastle disease virus by phage display     

Ozawa M  Ohashi K  Onuma M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(12):1237-1241

Three individual peptide sequences, EVSHPKVG, WVTTSNQW, and SGGSNRSP, which have potentials to bind to Newcastle disease virus (NDV), were identified by the biopanning method using phage display technology. The binding specificities of these peptides presented on phages were confirmed by ELISA competition assay using chicken anti-NDV antiserum. The synthetic peptides designed based on these results partially neutralized the infection of NDV in vitro. The peptide-motives identified here have the potential to lead to the identification of novel molecules that inhibit the NDV infection independent of the immune system.  相似文献   

Usefulness of an early diagnosis for the favorable prognosis of fibrocartilaginous embolism diagnosed by magnetic resonance imaging in 10 Small- to Middle-Sized Dogs     

Nakamoto Y  Ozawa T  Katakabe K  Nishiya K  Mashita T  Morita Y  Yasuda N  Ishii Y  Nakaichi M  Itamoto K 《Veterinary research communications》2008,32(8):609-617

Fibrocartilaginous embolism (FCE), a disorder of rapid onset featured by nonprogressive paralysis and paresis of four legs, shows clinical symptoms very similar to those of other disorders, e.g., disk herniation. We examined 10 animals diagnosed with FCE based on clinical symptoms and magnetic resonance imaging (MRI) findings in a retrospective study to examine the relationship between onset-to-diagnosis/treatment initiation time and prognosis of FCE. Statistical procedures, including Fisher’s exact probability test, were conducted. All animals in a group, in which the diagnosis was made and treatment was initiated after an elapse of <15 days after onset, showed improved symptoms; the group showed a positive correlation (r = 0.76) between “onset-to-symptom improvement time” and “onset-to-diagnosis/treatment initiation time”. Furthermore, the mean onset-to-diagnosis/ treatment initiation times were 2.67 days and 10.25 days in groups without and with sequelae, respectively; the time was significantly (P < 0.02) shorter in the group without sequelae. A significant difference was found between the groups in early diagnosis and treatment initiation. Our study indicates that the early precise diagnosis for acutely developed paralysis and paresis of four legs through testings including MRI, as well as the early onset of their treatment are important to obtain a favorable prognosis.  相似文献   

Simple and sensitive BIO-PCR detection of potato blackleg pathogens from stem,tuber, and soil samples     

Aono  Yoshiyuki  Nakayama  Takato  Ozawa  Takahiro  Ushio  Yutaka  Yasuoka  Shinji  Fujimoto  Taketo  Ohki  Takehiro  Oka  Norikuni  Maoka  Tetsuo 《Journal of General Plant Pathology》2021,87(4):209-218

Journal of General Plant Pathology - A BIO-PCR was developed for the detection of potato blackleg pathogens, including Pectobacterium wasabiae (Pw), P. atrosepticum (Pa), P. carotovorum subsp....  相似文献   

Changes in circulating and testicular levels of inhibin A and B during postnatal development in bulls     

Kaneko H  Matsuzaki M  Noguchi J  Kikuchi K  Ohnuma K  Ozawa M 《The Journal of reproduction and development》2006,52(6):741-749

We investigated testicular and circulating levels of dimeric inhibins in Holstein bulls from the infantile to postpubertal periods (5 to 50 weeks of age) and examined the relationship between the profiles of circulating dimeric inhibins and FSH. Concentrations of total inhibin and inhibin B in the testis were highest at 4 to 5 weeks of age but decreased gradually as the bulls aged. Testicular inhibin A levels showed a gradual decline to a nadir at 15 to 26 weeks of age, but by 39 weeks, they were high again. The contents of total inhibin, inhibin A, and inhibin B per testis generally increased with age. Fractionation of testicular homogenates obtained from 15-week-old bulls by a combination of immunoaffinity chromatography and SDS-PAGE confirmed the presence of two major molecular weight forms (32 and 45 kDa) of dimeric inhibins in the testes. Circulating levels of total inhibin and inhibin A showed a significant increase in bulls at around 10 to 14 weeks of age compared to the levels between 5 and 7 weeks of age but decreased thereafter. However, immunoreactivity for inhibin B was not detected in the peripheral circulation, probably because of low sensitivity of the inhibin B assays. The concentrations of plasma FSH were high at 5 weeks of age but declined to lower levels between 11 and 40 weeks, and then increased from 41 weeks onward. There was no significant correlation between the plasma levels of FSH and inhibin A or total inhibin. The results clearly indicate that the bull testis produces inhibin A and B and secretes at least inhibin A into the circulation during postnatal development. However, the profile of circulating FSH in bulls shows no reciprocal relationship with the inhibin A or total inhibin profile during the postnatal period.  相似文献   

Successful long term culture of immature porcine sertoli cells in the reconstructed testicular cell cord     

Noguchi J  Ohnuma K  Ozawa M  Karja NW  Fahrudin M  Somfai T  Kikuchi K  Kaneko H 《The Journal of reproduction and development》2006,52(3):383-389

The ultimate goal of this study was to establish an in vitro system to produce sperms. To pursue this goal, immature porcine testicular cells were cultured in stereostructural form and cultured testicular cord was investigated morphologically. At 4 weeks of age, the seminiferous tubules of the porcine testes consisted of undifferentiated germ cells (gonocytes and undifferentiated spermatogonia) and immature Sertoli cells. The interstitial tissue was largely occupied by Leydig cells. The testes were enzymatically digested, and the dispersed cells were encapsulated with alginate either immediately or after freeze-thawing. The resulting testicular cell cords were cultured for up to 10 weeks. After 2 weeks of culture, Sertoli cells, which were identified by their inhibin-positive reaction in immunohistochemistry, and Leydig cells, which were identified by their morphological characteristics, were observed in the cords. Neither undifferentiated nor differentiated types of germ cells were detected. The number of cells in the cords progressively decreased during the culture period. In order to discover the fate of the Sertoli cells, the level of inhibin in the spent media was determined. Inhibin in the media was at a detectable level after 2 days of culture. The levels increased and peaked at 2 weeks. When frozen-thawed testicular cells were applied to the culture, the peak level was maintained for over 8 weeks, in contrast to the gradual decrease of inhibin level when fresh cells were cultured. These results indicate that the culture conditions can sustain the survival of Sertoli cells. Further improvement is required for proliferation and differentiation of germ cells.  相似文献   

Identificaiton of a clubroot resistance locus conferring resistance to a Plasmodiophora brassicae classified into pathotype group 3 in Chinese cabbage (Brassica rapa L.)     

Takeyuki Kato  Katsunori Hatakeyama  Nobuko Fukino  Satoru Matsumoto 《Breeding Science》2012,62(3):282-287

In Chinese cabbage (Brassica rapa), the clubroot resistance (CR) genes Crr1 and Crr2 are effective against the mild Plasmodiophora brassicae isolate Ano-01 and the more virulent isolate Wakayama-01, but not against isolate No. 14, classified into pathotype group 3. ‘Akiriso’, a clubroot-resistant F₁ cultivar, showed resistance to isolate No. 14. To increase the durability of resistance, we attempted to identify the CR locus in ‘Akiriso’. CR in ‘Akiriso’ segregated as a single dominant gene and was linked to several molecular markers that were also linked to CRb, a CR locus from cultivar ‘CR Shinki’. We developed additional markers around CRb and constructed partial genetic maps of this region in ‘Akiriso’ and ‘CR Shinki’. The positions and order of markers in the genetic maps of the two cultivars were very similar. The segregation ratios for resistance to isolate No. 14 in F₂ populations derived from each of the two cultivars were also very similar. These results suggest that the CR locus in ‘Akiriso’ is CRb or a tightly linked locus. The newly developed markers in this study were more closely linked to CRb than previously reported markers and will be useful for marker-assisted selection of CRb in Chinese cabbage breeding.  相似文献   

Transgenic rice containing human CYP2B6 detoxifies various classes of herbicides   总被引：7，自引：0，他引：7  

Hirose S  Kawahigashi H  Ozawa K  Shiota N  Inui H  Ohkawa H  Ohkawa Y 《Journal of agricultural and food chemistry》2005,53(9):3461-3467

The human gene for CYP2B6, a cytochrome P450 monooxygenase that inactivates xenobiotic chemicals, was introduced into Oryza sativa cv. Nipponbare by Agrobacterium-mediated transformation. At germination, R(1) seeds of transgenic rice plants expressing CYP2B6 (CYP2B6 rice) showed a high tolerance to 5 microM metolachlor, a preemergence herbicide that is degraded by CYP2B6. Thin-layer chromatography after culture with (14)C-labeled metolachlor revealed that the amounts of residual metolachlor decreased in plant tissues and the medium of CYP2B6 rice faster than those of untransformed Nipponbare. CYP2B6 rice plants were able to grow in the presence of 13 out of 17 herbicides: five chloroacetamides and mefenacet, pyributicarb, amiprofos-methyl, trifluralin, pendimethalin, norflurazon, and chlorotoluron. These herbicides differ in their modes of action and chemical structures. Transgenic rice expressing a xenobiotic-degrading human CYP2B6, which has broad substrate specificity, should be good not only for developing herbicide tolerant rice but also for reducing the environmental impact of agrochemicals.  相似文献   

Effect of vegetation on the convection of ponded water in a paddy field   总被引：1，自引：0，他引：1  

Susumu HANAYAMA  Motoyasu NATSUGA  Takeyuki ANNAKA  Tatsuaki KASUBUCHI 《Soil Science and Plant Nutrition》2006,52(5):579-583

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