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41.
Kobayashi S Tsutsui T Yamamoto T Nishiguchi A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(12):1255-1258
Epidemiologic indicators associated with within-farm infection of Johne's disease in dairy farms in Japan were determined through a nationwide investigation of infected farms. We assumed that subsequent detection of the disease within one year after the first detection could represent the occurrence of within-farm spread occurring before the first detection. Of 594 infected farms, 158 farms (27%) had at least one additional detection. Logistic regression analysis using epidemiologic information obtained from infected farms at the time of the first detection revealed three epidemiologic indicators associated with subsequent detection. Farms at which the first cases included cattle with clinical signs were 3.8 (95% confidence interval: 2.2, 6.8) times more likely to have additional detections than those with cattle without clinical signs. Similarly, farms where two or more cattle were detected at the time of first detection and where cattle were held in a loose housing system were 2.8 (95% CI: 1.8, 4.5) and 2.0 (95% CI: 1.1, 3.6) times more likely to have additional detections than those where only one animal was detected and a tied-up housing system was used, respectively. These epidemiologic indicators are likely important determinants in the selection of farms requiring more intensive on-farm control measures. 相似文献
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Francis Shahada Haruhisa Sugiyama Takehisa Chuma Masuo Sueyoshi Karoku Okamoto 《Veterinary microbiology》2010,140(1-2):136-141
An epidemiologic study was conducted to investigate the incidence and characterize the antimicrobial resistance determinants, analyzing plasmid profiles, and establishing the genetic relationship among β-lactam-resistant isolates of Salmonella Infantis from broilers in Southern Japan. A total of 120 isolates were recovered from 56 flocks belonging to 44 holdings during 2004–2006. The percentages of resistance were as follows: ampicillin (24%), cephalothin (23%), cefoxitin (0%), ceftazidime (11%), cefotaxime (11%), chloramphenicol (0%), kanamycin (7.5%), ofloxacin (20%), oxytetracycline, streptomycin and sulfamethoxazole (100%) and trimethoprim (75%). The incidence of blaTEM-encoded β-lactam resistance in 2004–2006 was significantly higher than in 1998–2003 (P < 0.001). BlnI-digested PFGE patterns generated two related clusters implicated in the dissemination of β-lactam resistance. Two types of plasmid profiles were observed and two plasmids of ca. 50 and 180-kb size were carried by β-lactam-resistant isolates. Streptomycin resistance was conferred by aadA1 (n = 116), aadA1-aadA2 (n = 1), and aadA1-strA-strB (n = 3). Resistances to kanamycin, oxytetracycline, sulfamethoxazole and trimethoprim were conferred by aphA1 (n = 9, 100%), tetA (n = 120, 100%) sul1 (n = 120, 100%) and dfrA5 (n = 90, 100%), respectively. Two types of class 1 integrons were detected: 1.0 kb (n = 120) and, 1.0/1.5 kb (n = 3). Integrons of 1.0/1.5 kb were found in isolates with the aadA1-strA-strB gene combination. For the first time, all S. Infantis isolates showed resistance to at least three classes of antimicrobial agents; and the intestinal tract of healthy poultry was a reservoir of the extended-spectrum cephalosporin-resistant isolates of serovar Infantis. 相似文献
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Trinh Thi Phuong Vy Gang-Su Hyon Nguyen Thi Thanh Nga Yoshihiro Inoue Izumi Chuma Yukio Tosa 《Journal of General Plant Pathology》2014,80(1):59-65
Lolium isolate TP2 of Pyricularia oryzae, causal agent of gray leaf spot of perennial ryegrass (Lolium perenne), is virulent on perennial ryegrass, but avirulent on wheat cultivars. Genetic analysis of wheat F2 populations revealed that the resistance of wheat cultivars Chinese Spring, Shin-chunaga, and Norin 4 to TP2 was conditioned by two genes, R1 and R2. R1 was highly effective, while R2 was less effective. The strong resistance gene R1, designated Rmg6, was mapped on chromosome 1D using microsatellite markers. For revealing genetic mechanisms of avirulence, TP2 was crossed with Triticum isolate Br48. Segregation analysis of their F1 progenies revealed that the avirulence of TP2 on the three wheat cultivars was conditioned by two unlinked genes, one (A1) highly effective and the other (A2) less effective. These results suggest that the incompatibility between TP2 and the common wheat cultivars is conditioned by two gene pairs; the Rmg6–A1 interaction results in strong resistance, and the R2–A2 interaction results in moderate resistance. 相似文献
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输液器污染微生物辐射抗性频率分布的研究 总被引：2，自引：1，他引：1
从 5 6套输液器分离得到 3 0 3 2株分离菌 ,系统地研究了输液器上污染微生物的辐射抗性。用辐射处理获得了较高抗辐射的微生物 98株 ,测定了它们的辐射抗性D10 。分离菌株的D10 是在 0 8～ 4 0kGy之间 ,主要集中在 1 2～ 1 6kGy。D10 ≤1 6kGy占全部污染菌的 99%。所有辐射筛选菌株是革兰氏阳性菌 ,其中 84株是Bacillussp .,1 4株是micrococcussp .。在输液器外壁获得了 1株桔红色的菌株 ,其D10 为 4 0kGy。 相似文献
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Marc Cotter Folkard Asch Bayuh Belay Abera Boshuwenda Andre Chuma Kalimuthu Senthilkumar Arisoa Rajaona Ando Razafindrazaka Kazuki Saito Sabine Stuerz 《Journal of Agronomy and Crop Science》2020,206(4):423-432
Increasing demand for land to ensure human food security in the future has already impelled agricultural production into marginal areas. The environmental conditions found there have a more pronounced impact on agricultural productivity than in the systems used so far under favourable conditions. In addition to this challenge, climate change is expected to increase the unreliability of weather conditions (through increased variability and occurrence of extremes) for farmers considerably. This unreliability is even more serious in developing countries’ farming system where food security is vulnerable. Current efforts in digitalization offer great possibilities to improve farmers` decision-making processes. A wide range of online tools and smartphone applications is available to support both agricultural extension services and smallholder farmers alike. These apps are often parameterized and validated to certain environments and are troubled when applied to new geographical locations and different environmental conditions. We have conducted field trials to demonstrate potential methods to close knowledge gaps in the data background for one of these apps, RiceAdvice, concerning three key aspects: shifting of cropping calendar, adjustment of fertilizer management and genotype selection. Sites in Ethiopia, Madagascar and Rwanda were selected to represent altitudinal gradients, with overlapping elevations reflecting differences in temperature to enable cross-country comparisons. Planting dates were distributed throughout three calendar years, with continuous iterative planting dates taking place in Madagascar, in- and off-season planting dates in Rwanda with different fertilizer applications, and one planting date during each rainy season in Ethiopia with different management options. With these trials, we have been able to identify key data sets needed for the adaptation of agricultural decision support tools to new environments. These include the assessment of climatic constraints on innovations to cropping calendars (e.g. double cropping), informed selection of alternative varieties able to complete crucial parts of their phenological development to avoid temperature-related stress inducing, for example spikelet sterility in rice in late development stages and the effectivity of potential innovations in fertilizer management strategies. 相似文献
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Sota KOBAYASHI Toshiyuki TSUTSUI Takehisa YAMAMOTO Yoko HAYAMA Norihiko MUROGA Misako KONISHI Ken-ichiro KAMEYAMA Kenji MURAKAMI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):861-863
A cohort study was conducted to evaluate the risk of bovine leukemia virus (BLV)
transmission to uninfected cattle by adjacent infected cattle in 6 dairy farms. Animals
were initially tested in 2010–2011 using a commercial ELISA kit. Uninfected cattle were
repeatedly tested every 4 to 6 months until fall of 2012. The Cox proportional hazard
model with frailty showed that uninfected cattle neighboring to infected cattle (n=53) had
a significant higher risk of seroconversion than those without any infected neighbors
(n=81) (hazard ratio: 12.4, P=0.001), implying that neighboring infected
cattle were a significant risk factor for BLV transmission. This finding provides
scientific support for animal health authorities and farmers to segregate infected cattle
on farms to prevent spread of BLV. 相似文献
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Yoko HAYAMA Takehisa YAMAMOTO Sota KOBAYASHI Norihiko MUROGA Toshiyuki TSUTSUI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):13-22
The characteristics of a livestock area, including farm density and animal species,
influence the spread of foot-and-mouth disease (FMD). In this study, the impact of
livestock area on FMD epidemics was examined using an FMD transmission model. For this
simulation, three major livestock areas were selected: the 2010 FMD epidemic area in Japan
as the baseline area (BS), a cattle and pig mixed production area (CP) and a cattle
production area (C). Simulation results demonstrated that under the 24-hr culling policy,
only 12% of epidemics among 1,000 simulations were abated within 100 days in the CP area,
whereas 90% of the epidemics ceased in the BS area. In the C area, all epidemics were
successfully contained within 100 days. Evaluation of additional control measures in the
CP area showed that the 0.5-km pre-emptive culling, even when only targeting pig farms,
raised the potential for successful containment to 94%. A 10-km vaccination on day 7 or 14
after initial detection was also effective in halting the epidemics (80%), but accompanied
a large number of culled or vaccinated farms. The combined strategy of 10-km vaccination
and 0.5-km pre-emptive culling targeting pig farms succeeded in containing all epidemics
within 100 days. The present study suggests the importance of preparedness for the 24-hr
culling policy and additional control measures when an FMD outbreak occurs in a densely
populated area. Considering the characteristics of the livestock area is important in
planning FMD control strategies. 相似文献