Changing trends in mastitis     

RN Zadoks  JL Fitzpatrick 《Irish veterinary journal》2009,62(Z4):S59

The global dairy industry, the predominant pathogens causing mastitis, our understanding of mastitis pathogens and the host response to intramammary infection are changing rapidly. This paper aims to discuss changes in each of these aspects. Globalisation, energy demands, human population growth and climate change all affect the dairy industry. In many western countries, control programs for contagious mastitis have been in place for decades, resulting in a decrease in occurrence of Streptococcus agalactiae and Staphylococcus aureus mastitis and an increase in the relative impact of Streptococcus uberis and Escherichia coli mastitis. In some countries, Klebsiella spp. or Streptococcus dysgalactiae are appearing as important causes of mastitis. Differences between countries in legislation, veterinary and laboratory services and farmers' management practices affect the distribution and impact of mastitis pathogens. For pathogens that have traditionally been categorised as contagious, strain adaptation to human and bovine hosts has been recognised. For pathogens that are often categorised as environmental, strains causing transient and chronic infections are distinguished. The genetic basis underlying host adaptation and mechanisms of infection is being unravelled. Genomic information on pathogens and their hosts and improved knowledge of the host's innate and acquired immune responses to intramammary infections provide opportunities to expand our understanding of bovine mastitis. These developments will undoubtedly contribute to novel approaches to mastitis diagnostics and control.  相似文献   

Intensity and persistence profiles of flavor compounds in synthetic solutions. Simple model for explaining the intensity and persistence of their aftersmell     

Ferreira V  Pet'ka J  Cacho J 《Journal of agricultural and food chemistry》2006,54(2):489-496

Hydroalcoholic solutions containing a single aroma-active compound were evaluated by a sensory panel to determine the difference between ortho and retronasal odor intensities (DeltaI(ro)), buccal savoring, and aftersmell duration. Eight compounds were used. Buccal perception seems to be just a physiologically restricted form of retronasal perception. DeltaI(ro) values were dependent on the panel, although results from the two panels were significantly correlated. Such differences and the aftersmell persistence were also significantly correlated with different physicochemical parameters related to volatility. A simple model to explain such dependence is proposed. The model considers the mouth-throat system as a perfect mixing tank with a finite amount of odorants being progressively diluted by swallowing and purging (both taken as continuous processes). Retronasal intensity is modeled from the odor properties of the liquid in such a tank calculated from orthonasal odor intensity versus concentration (I/log C) curves. The model explains successfully experimental results and has also been successfully applied to instrumental data from other authors.  相似文献   

Ixodid ticks parasitizing Iberian red deer (Cervus elaphus hispanicus) and European wild boar (Sus scrofa) from Spain: geographical and temporal distribution     

Ruiz-Fons F  Fernández-de-Mera IG  Acevedo P  Höfle U  Vicente J  de la Fuente J  Gortazár C 《Veterinary parasitology》2006,140(1-2):133-142

Commercial hunting of Spanish wild ungulates has made them an important economic resource. Wild ungulates may have an important role in the maintenance of ixodid tick populations, and also as reservoirs of pathogens. We studied the ixodid ticks that parasitize Iberian red deer and European wild boar from Spain. Ixodid ticks (n=6,336) were collected from 431 Iberian red deer and 142 wild boar in different regions of Spain. We found 10 different ixodid tick species parasitizing Iberian red deer, mainly Hyalomma marginatum marginatum (63.7%), Rhipicephalus (Boophilus) annulatus (7.9%) and R. bursa (7.5%). R. (Boophilus) annulatus was only collected in the province of Cádiz (southern Spain). We found 8 ixodid tick species on the wild boar, mainly Hy. m. marginatum (68.7%), R. bursa (14.6%) and Dermacentor marginatus (9.3%). We found one adult Hy. marginatum rufipes and one adult Hy. anatolicum excavatum parasitizing wild boar from south-central Spain. Mean prevalence of ixodid ticks was 41.3+/-0.08% (n=475) and 31+/-0.09% (n=284) and intensity of parasitization was 13.9+/-0.2 (n=283) and 13.6+/-0.3 (n=130) ticks/animal for Iberian red deer and wild boar, respectively. Only 5 of the 13 ixodid tick species found were shared by Iberian red deer and wild boar. This finding could indicate a host preference when Iberian red deer and wild boar share common habitats. In both Iberian red deer and wild boar from south-central Spain the monthly relative frequencies of Hy. m. marginatum and R. bursa presented an inverse pattern. The highest Hy. m. marginatum relative frequencies coincided with the lowest R. bursa relative frequencies along the year. R. bursa and I. ricinus were present in areas from northern to southern Spain while Hyalomma sp. and D. marginatus were exclusively collected in the two southern thirds of Spain. Haemaphysalis sp. and D. reticulatus were collected in northern Spain. Hy. m. marginatum and R. bursa were present during the whole year in red deer and wild boar from south-central Spain, showing more than one life cycle per year. These results are important for understanding the role of wild ungulates in the maintenance of tick infestations and to improve tick control programmes.  相似文献   

A probabilistic model for tropical tree seed desiccation tolerance and storage classification     

Fabieli Pelissari  Anderson Cleiton José  Marco Aurélio Leite Fontes  Antônio César Batista Matos  Wilson Vicente Souza Pereira  José Marcio Rocha Faria 《New Forests》2018,49(1):143-158

Knowledge of seed desiccation tolerance is fundamental for conservation and use of forest species. The protocol used for classification of seed desiccation tolerance and storage is time consuming and many times limited by the lack of information about optimum conditions for seed germination and treatments to overcome seed dormancy. This study evaluated 66 Brazilian tree species aiming to correlate seed characteristics with desiccation tolerance. For this purpose, a model was established to explain the relationship of tegument/seed mass ratio (SCR), seed mass, and water content of embryo + endosperm with desiccation tolerance. The principal component analysis showed the establishment of two groups, indicating the interaction between desiccation tolerance and seed characteristics. Recalcitrant seeds are more often associated with the water content of embryo + endosperm and water content of tegument + endocarp, while orthodox seeds are more associated with SCR and number of seeds per kilogram. The classification found using the model proposed was significantly correlated with desiccation tolerance and storage, with 92% confidence for the analyzed species. Seeds morphological characteristics can be used for prediction of desiccation tolerance and storage behavior; however, the use of a model that combines more variables increases the chance of accurate classification.  相似文献   

Local infection associated with vascular bundles: the colonization of coconut palm leaflets by two <Emphasis Type="Italic">Camarotella</Emphasis> species     

Kelly Lana Araújo  Silvaldo Felipe da Silveira  Vicente Mussi-Dias  Juan Manuel Anda Rocabado  Flavio Costa Miguens 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(2):413-422

Two Camarotella (Phyllachoraceae) species, C. torrendiella and C. acrocomiae are the causative agents of small (SV) and large verrucosis (LV), respectively, which are important diseases affecting Brazilian coconut palms. The small verrucosis produces necrotic lesions in coconut palm leaflets, whereas LV just produces chlorosis. Semi-thin sections of asymptomatic leaflets and of leaves presenting stromata in different development stages were compared through light microscopy in order to characterize the colonization process of these two coconut palm verrucosis agents. Camarotella torrendiella initially colonized the adaxial epidermal cells and the cells underlying the epidermis close to the vascular bundles. In latter colonization stages, the hyphae of C. torrendiella remained limited to the underlying necrotic tissue adjacent to the mature stromata, mostly in the intracellular spaces and in the collapsing cells of necrotized tissues around the vascular bundles. This species does not colonize intracellular intact fiber cells, xylem vessels or phloem sieve tube elements. In contrast, C. acrocomiae presented a typical biotrophic parasitism model such as that of some gramineous Phyllachora spp. High densities of C. acrocomiae hyphae were found inside intact sieve tube elements; however, with no evidence of cellular death. The extensive hyphal colonization by C. acrocomiae within sieve tube elements was also observed in tertiary and quaternary bundles, as well as in anastomosing vascular bundles. The dependence of both species on the colonization sites associated with vascular bundles indicates the need for additional studies about these intricate host-pathogen relationships. These studies could be important to define new strategies to control coconut palm verrucosis diseases.  相似文献   

First report of Peronospora sp. on sweet basil (Ocimum basilicum) in Cuba     

E. Martínez de la Parte  L. Pérez‐Vicente  B. Bernal  D. García 《Plant pathology》2010,59(4):800-800

  相似文献   

Development of a bioacoustic sensor for the early detection of Red Palm Weevil (Rhynchophorus ferrugineus Olivier)     

Abelardo Gutiérrez  Vicente Ruiz  Enrique Moltó  Gervasio Tapia  Maria del Mar Téllez 《Crop Protection》2010

The Red Palm Weevil (Rhynchophorus ferrugineus Olivier) is one of the worst pests for palms, since it can completely destroy the plant. Its early detection is very difficult and when the action of the pest is discovered, normally it is too late for recovering the plant. Bioacoustic sensors provide a good alternative for early detection of this pest because larvae activity is audible while they excavate tunnels to feed. This work describes the different stages for the development of an original electronic device based on acoustic sensors for early detection of Red Palm Weevil larvae in the interior of palms. This device is based on characteristic frequencies possibly related to their feeding activity. The performed tests have demonstrated that is possible to detect two week old larvae activity studying the sound intensity around 2250 Hz in palms infested only with 5 individuals under controlled environmental conditions. The activity of other insects artificially situated in the interior of palms did not affect the response of the device, possibly because they produce different frequencies (in the range 5–7 kHz). Future work will be aimed at assessing the infestation levels.  相似文献   

Effect of Cooling Rate to 5°C,Straw Size and Farm on Fertilizing Ability of Cryopreserved Rabbit Sperm     

E Mocé  R Lavara  JS Vicente 《Reproduction in domestic animals》2010,45(5):e1-e7

High fertility and prolificacy in rabbits are currently only achieved using fresh sperm. This study was conducted to determine if the cooling rate to 5°C, the straw size and the farm where artificial inseminations are performed have an impact on the fertilizing ability of rabbit sperm cryopreserved with an extender containing dimethyl sulphoxide (DMSO; 1.75 m ) and sucrose (0.05 m ). Slow cooling to 5°C improved neither fertility rate (58 vs 56% kindling rate for fast and slow cooling, respectively) nor prolificacy (6.5 vs 8.7 total born for slow and fast cooling, respectively; p < 0.05) compared to fast cooling rate to 5°C. The straw size did not have an effect on either fertility or prolificacy (47 vs 57% kindling rate and 6.3 vs 6.8 total born for sperm loaded into 0.25 and 0.5 ml straws, respectively). In addition, similar results were obtained between farms (46–57% kindling rate and 4.9–6.7 total born), although this effect should be studied further. In conclusion, with this extender, slow cooling does not present a beneficial effect on sperm fertilizing ability and either 0.25 or 0.5 ml straws can be used to freeze the sperm, obtaining similar results after artificial insemination. In addition, similar results were obtained between farms when using cryopreserved sperm, and these results were lower than those obtained after artificial insemination with fresh semen. Therefore, new approaches are needed to improve the results obtained when cryopreserved sperms are used before this type of sperm can be used for commercial purposes.  相似文献   

Effect of quercetin on platelet spreading on collagen and fibrinogen and on multiple platelet kinases     

Leyre Navarro-Núñez  María L. Lozano  Constantino Martínez  Vicente Vicente  José Rivera 《Fitoterapia》2010

α₂β₁ and α_IIbβ₃ integrins, that support platelet adhesion to collagen and fibrinogen, respectively, share common signaling molecules. The effect of quercetin on platelet static adhesion to collagen and fibrinogen was assessed and correlated with its kinase inhibitory activity. Quercetin strongly abrogated PI3K and Src kinases, mildly inhibited Akt1/2, and slightly affected PKC, p38 and ERK1/2. Quercetin or the combined use of adenosine diphosphate and thromboxane A₂ inhibitors abrogated platelet spreading on these surfaces to a similar extent. We suggest that the inhibitory effect of quercetin on platelet kinases blocks early signaling events preventing a complete platelet spreading.  相似文献   

Characterization,genetic diversity and distribution of Xanthomonas campestris pv. campestris races causing black rot disease in cruciferous crops of India          下载免费PDF全文

D. Singh  P. S. Rathaur  J. G. Vicente 《Plant pathology》2016,65(9):1411-1418

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is a disease of crucifer crops. The objective of this study was to characterize races of Xcc, their distribution and genetic diversity in India. Two hundred and seventeen isolates of bacteria were obtained from 12 different black rot‐infected crucifer crops from 19 states of India; these were identified as Xcc based on morphology, hrpF gene and 16S rRNA gene based molecular markers and pathogenicity tests. Characterization of races was performed by using a set of seven differential crucifer hosts, comprising two cultivars of turnip (Brassica rapa var. rapa) and cultivars of Indian mustard (B. juncea), Ethiopian mustard (B. carinata), rapeseed mustard (B. napus), cauliflower (B. oleracea) and Savoy cabbage (B. oleracea var. sabauda). Races 1, 4 and 6 of Xcc were identified and, among these races, race 1 followed by race 4 dominated most of the states of India. Genetic diversity of the Indian isolates of Xcc was analysed using repetitive sequence‐based PCR (rep‐PCR) including primers for REP (repetitive extragenic palindromic), ERIC (enterobacterial repetitive intergenic consensus) and BOX (amplifying with BOX A1 R primer) repetitive elements. This method of fingerprinting grouped the isolates into 56 different DNA types (clusters) with a 75% similarity coefficient. Among these clusters, DNA types 22 and 53 contained two different races 1 and 4, whereas DNA type 12 contained races 1, 4 and 6. However, no clear relationship was observed between fingerprints and races, hosts or geographical origin.  相似文献