Species-specific DNA markers for identification of two root-knot nematodes of coffee: Meloidogyne arabicida and M. izalcoensis     

Valdir Ribeiro Correa  Marcilene Fernandes Almeida dos Santos  Maria Ritta Alves Almeida  José Ricardo Peixoto  Philippe Castagnone-Sereno  Regina Maria Dechechi Gomes Carneiro 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(2):305-313

Seven root-knot nematodes (RKN), including Meloidogyne exigua, M. incognita, M. paranaensis, M. enterolobii, M. arabicida, M. izalcoensis and M. arenaria are major pathogens of coffee crop in the Americas. Species-specific primers for their identification have been developed for five of them and constitute a fast and reliable method of identification. Here we report a PCR-based assay for specific detection of M. arabicida and M. izalcoensis. Random Amplified Polymorphic DNA fragments specific for these two species were converted into sequence characterized amplified region (SCAR) markers. PCR amplification using the SCAR primers produced a specific fragment of 300 bp and 670 bp for M. arabicida and M. izalcoensis, respectively, which were absent in other coffee-associated Meloidogyne spp. tested. SCAR primers also allowed successful amplification of DNA from single second-stage juveniles (J2), males and females. In addition, these primers were able to unambiguously detect the target species in nematode suspensions extracted from soil and roots samples, in different isolates of the same species or when used in multiplex PCR reactions containing mixtures of species. These results demonstrated the effectiveness of these SCAR markers and their multiplex use with those previously developed for M. exigua, M. incognita, M. paranaensis, M. enterolobii and M. arenaria constitute an essential detection tool. This diagnostic kit will contribute for specific J2 identification of the major RKN infecting coffee from field samples in the Americas.  相似文献   

Guava decline: effect of root exudates from Meloidogyne enterolobii-parasitized plants on Fusarium solani in vitro and on growth and development of guava seedlings under controlled conditions     

Vicente Martins Gomes  Ricardo Moreira Souza  Silvaldo Felipe da Silveira  Alexandre Macedo Almeida 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(2):393-401

In guava decline, Fusarium solani-immune guava trees become susceptible to extensive root rot caused by this fungus after parasitism by Meloidogyne enterolobii. To understand the mechanisms involved in this disease, root exudates were collected from nematode-inoculated (NI) or uninoculated (UN) guava plants cultivated in sand. After filtration through a Millipore® membrane, NI and UN exudates were used: i) to prepare media to assess their effect on mycelial growth and production of propagules of F. solani isolate UENF/CF 163, and ii) to incubate macro- and microconidia to assess their effect on germination. NI exudates promoted (P?<?0.05) more mycelial growth and production of propagules than UN exudates or water. NI and UN exudates were used to water guava seedlings laid over seed germination paper inside plastic boxes. Half of the seedlings had an agar plug colonized by the fungus positioned in the collar region. Upon watering with NI exudates the fungus caused (P?<?0.05) extensive rotting of the seedlings’ rootlets. NI and UN exudates, either unlyophilized or lyophilized and re-suspended to the original concentration, were used to water guava seedlings grown in sterile sand before being inoculated (or left uninoculated) as described before. Solely upon watering with NI exudates, in its unlyophilized form or after lyophilization, the fungus caused a reduction (P?<?0.05) of shoot and root biomass associated with rotting of roots. These results suggest that M. enterolobii induces chemical changes in the root exudates of guava trees, which are necessary for root invasion causing root rotting by F. solani.  相似文献   

Aromatic characterization of pot distilled kiwi spirits     

López-Vázquez C  García-Llobodanin L  Pérez-Correa JR  López F  Blanco P  Orriols I 《Journal of agricultural and food chemistry》2012,60(9):2242-2247

This study contributes fundamental knowledge that will help to develop a distillate of kiwi wine, made from kiwis of the Hayward variety grown in the southwest of Galicia (Spain). Two yeast strains, L1 (Saccharomyces cerevisiae ALB-6 from the EVEGA yeast collection) and L2 (S. cerevisiae Uvaferm BDX from Lallemand) were assessed to obtain a highly aromatic distillate. The kiwi spirits obtained were compared with other fruit spirits, in terms of higher alcohols, minor alcohols, monoterpenols, and other minor compounds, which are relevant in determining the quality and taste of the kiwi spirits. It was found that the kiwi juice fermented with yeast L1 produced a more aromatic distillate. In addition, kiwi distillates produced with both yeasts had the same ratio of trans-3-hexen-1-ol and cis-3-hexen-1-ol, which is lower than that found in other fruit distillates.  相似文献   

Modeling the Interfacial Interactions between CrtS and CrtR from Xanthophyllomyces dendrorhous , a P450 System Involved in Astaxanthin Production     

J Alcaı́no  M Fuentealba  R Cabrera  M Baeza  V Cifuentes 《Journal of agricultural and food chemistry》2012,60(35):8640-8647

Xanthophyllomyces dendrorhous is a natural source of astaxanthin, a carotenoid widely used in the food industry. In this yeast, astaxanthin is synthesized from β-carotene by a cytochrome P450, CrtS, which depends on CrtR, the four-domain cytochrome P450 reductase (CPR). Although Saccharomyces cerevisiae has an endogenous CPR (ScCPR), expression of CrtS does not result in astaxanthin production unless it is coexpressed with CrtR. Assuming that CrtS could interact with the FMN-binding domain of either CrtR or ScCPR (XdFMNbd and ScFMNbd, respectively), the aim of this work was to identify possible interaction differences between these alternative complexes by protein modeling and short molecular dynamics simulations. Considering the recently proposed membrane orientation of a mammalian P450, our CrtS-CrtR model predicts that both N-terminal ends stand adjacent to the membrane plane, allowing their anchoring. Compared with the possible interface between CrtS and both FMNbd, the Xanthophyllomyces system appears to be stabilized by more saline bridges.  相似文献   

Effect of fertilizer application on the yield,protein and fat content,and protein quality of raw and cooked grain of three amaranth species     

Ricardo Bressani  Jorge Mario Gonzalez  Luiz G. Elias  Mario Melgar 《Plant foods for human nutrition (Dordrecht, Netherlands)》1987,37(1):59-67

Four selections of three amaranth species were used in the study:A. cruentus (US Rodale 82S-1034),A. hypochondriacus (US Rodale 81S-1024).A. caudatus (Cusco, Peru CAC-2002) andA. cruentus (GUA-17). These were fertilized with levels of 0, 30, 60 and 90 kg/ha of a 12-24-12 fertilizer formulation applied to experimental plots 3×4m² in four replications. The harvested grain was used for protein and fat analysis, and for protein quality evaluations on raw and on heat processed samples.A. cruentus (US) andA. hypochondriacus flowered at 43–44 days at 60 and 43cm, respectively,A. caudatus (Peru) at 51 days and 65cm, andA. cruentus (Gua) at 50 days and 80cm height. Days at harvest varied from 100 to 129 days at heights of 125 to 180cm. Yield of grain fromA. hypochondriacus (US) andA. cruentus (Gua) was higher than forA. cruentus (US) andA. caudatus, but did not differ for each pair. although not influencing yield, the application of fertilizer increased protein content forA. caudatus (Peru) from 12.35 to 14.50%; but not the protein content of the other selections. The fat content was affected differently in all four selections. The application of fertilizer did not affect protein quality either in raw or processed grain. On the other hand, processing increased protein quality, food intake, and animal performance significantly most clearly seen withA. cruentus (US) andA. caudatus (Peru) and to a lesser extent forA. hypochondriacus (US) andA. cruentus (Gua)). The data obtained showed inconsistent effects on yield and chemical composition, and no effect on protein quality with fertilizer application.  相似文献   

Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle     

González-de-la-Vara Mdel R  Valdez RA  Lemus-Ramirez V  Vázquez-Chagoyán JC  Villa-Godoy A  Romano MC 《Canadian journal of veterinary research》2011,75(3):216-221

Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle.  相似文献   

Validation of an ELISA method for the serological diagnosis of canine brucellosis due to Brucella canis     

Maria Zoraida Daltro de Oliveira  Vera Vale  Lara Keid  Songeli Menezes Freire  Roberto Meyer  Ricardo Wagner Portela  Stella Maria Barrouin-Melo   《Research in veterinary science》2011,90(3):425-431

In the present study, the validation of an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of canine brucellosis is described. Two different antigenic extracts, obtained by heat or ultrasonic homogenization of microbial antigens from a wild isolate of Brucella canis bacteria, were compared by ELISA and Western blot (WB). A total of 145 canine sera were used to define sensitivity, specificity and accuracy of the ELISA as follows: (1) sera from 34 animals with natural B. canis infection, confirmed by blood culture and PCR, as well as 51 sera samples from healthy dogs with negative results by the agar–gel immunodiffusion (AGID) test for canine brucellosis, were used as the control panel for B. canis infection; and (2) to scrutinize the possibility of cross reactions with other common dog infections in the same geographical area in Brazil, 60 sera samples from dogs harboring known infections by Leptospira sp., Ehrlichia canis, canine distemper virus (CDV), Neospora caninum, Babesia canis and Leishmania chagasi (10 in each group) were included in the study. The ELISA using heat soluble bacterial extract (HE-antigen) as antigen showed the best values of sensitivity (91.18%), specificity (100%) and accuracy (96.47%). In the WB analyses, the HE-antigen showed no cross-reactivity with sera from dogs with different infections, while the B. canis sonicate had various protein bands identified by those sera. The performance of the ELISA standardized with the heat soluble B. canis antigen indicates that this assay can be used as a reliable and practical method to confirm infection by this microorganism, as well as a tool for seroepidemiological studies.  相似文献   

Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis   总被引：1，自引：0，他引：1  

Martin V  Zhou X  Marshall E  Jia B  Fusheng G  FrancoDixon MA  DeHaan N  Pfeiffer DU  Soares Magalhães RJ  Gilbert M 《Preventive veterinary medicine》2011,102(3):196-205

Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.  相似文献   

Cloning, characterization and diagnostic performance of the salivary lipocalin protein TSGP1 from Ornithodoros moubata     

Díaz-Martín V  Manzano-Román R  Siles-Lucas M  Oleaga A  Pérez-Sánchez R 《Veterinary parasitology》2011,178(1-2):163-172

The argasid tick Ornithodoros moubata is distributed throughout South and East Africa and Madagascar, where it colonizes wild and domestic habitats and feeds on warthogs, domestic swine, and humans. This argasid transmits the spirochete Borrelia duttonii, causing East African tick-borne relapsing fever in humans, and the African swine fever virus, which causes a highly lethal haemorrhagic disease in pigs. Tick surveillance and the elimination of O. moubata from synanthropic environments (human dwellings and pigsties) would facilitate the control and prevention of these two diseases. Since direct surveillance methods are impractical in this context, the development of an indirect method for the detection of specific antibodies against tick salivary proteins in samples taken from animal or human hosts living in the area under study would provide a more convenient surveillance and diagnostic tool. Previous work has indicated that the 20A1 salivary antigen of O. moubata could be an optimal candidate for the development of a specific serological test and identified it as an orthologue of the Ornithodoros savignyi TSGP1 lipocalin. The objectives of the present work were to clone, sequence, and molecularly characterize the O. moubata TSGP1, as well as its production as a recombinant protein in order to assess its usefulness as a diagnostic antigen in an ELISA test for tick surveillance. Our results show that O. moubata TSGP1 (OmTSGP1) conserves the tertiary structure of lipocalins and contains the biogenic amine-binding motif. We also show that OmTSGP1 shares 65% sequence identity with the O. savignyi TSGP1, demonstrating that they represent orthologous proteins and suggesting they share identical function as biogenic amine scavengers. A recombinant form of OmTSGP1 was produced, showing 100% sensitivity and 99.4% specificity in an ELISA test for the detection of anti-O. moubata antibodies in pig sera. This recombinant antigen represents a promising epidemiological tool for O. moubata surveillance that may help to implement control measures against O. moubata-borne diseases.  相似文献   

Acaricidal properties of the essential oil and precocene II obtained from Calea serrata (Asteraceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)     

Ribeiro VL  dos Santos JC  Martins JR  Schripsema J  Siqueira IR  von Poser GL  Apel MA 《Veterinary parasitology》2011,179(1-3):195-198

Calea serrata Less. (Asteraceae), an endemic species of south Brazil known as "quebra-tudo", is used in Afro-Brazilian religious rituals and in folk medicine for treating liver disorders. Phytochemical studies of the n-hexane extract of this plant demonstrated the presence of precocene II, a benzopyran derivative known for its insecticidal activity. The aim of this work was to isolate this benzopyran and determine the chemical composition of the essential oil of C. serrata and further to evaluate the acaricidal activity of the essential oil and precocene II against the larvae of Rhipicephalus (Boophilus) microplus. The LC(99.9) and LC(50) values obtained with the oil, which presents precocene II and sesquiterpenes, were 3.94 μL/mL and 0.28 μL/mL, respectively. For precocene II this values were 4.25mg/mL and 1.78 mg/mL, respectively. The results indicate a synergistic interaction between the components of the oil and precocene II.  相似文献