Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.     

A femorotibial joint swelling with popliteal lymph node enlargement in a Rottweiler

A 9-year-old male Rottweiler was presented to the Veterinary Medical Hospital Montenegro, Porto, Portugal with a large mass medial to the left stifle and radiographic signs of bone lysis involving the proximal tibia, fibula, and distal femur. A fine-needle aspiration was obtained from left popliteal lymph node, which was markedly enlarged. Cytologic examination revealed a highly cellular sample consisting of pleomorphic cells with marked anisocytosis and anisokaryosis and other criteria of malignancy. Some cells contained intracytoplasmic, granular, dark brown material, consistent with hemosiderin. Histologic evaluation of the surgically-excised lymph node revealed a neoplastic proliferation of histiocytic cells, with marked pleomorphism; occasional cells were erythrophagocytic. Mitotic figures were frequently observed, and many were atypical. Histologic findings were consistent with malignant histiocytosis. Necropsy examination confirmed the diagnosis of malignant histiocytosis with systemic involvement affecting most organs examined. This case of malignant histiocytosis case had an atypical clinical presentation, mimicking a musculoskeletal disorder. It underlines the importance of cytology as a simple, inexpensive, rapid and noninvasive complementary exam in routine clinical practice that can permit early diagnosis of the disease and timely selection of the most adequate therapy.     

Astaxanthin Delivery Systems for Skin Application: A Review

Astaxanthin (AST) is a biomolecule known for its powerful antioxidant effect, which is considered of great importance in biochemical research and has great potential for application in cosmetics, as well as food products that are beneficial to human health and medicines. Unfortunately, its poor solubility in water, chemical instability, and low oral bioavailability make its applications in the cosmetic and pharmaceutical field a major challenge for the development of new products. To favor the search for alternatives to enhance and make possible the use of AST in formulations, this article aimed to review the scientific data on its application in delivery systems. The search was made in databases without time restriction, using keywords such as astaxanthin, delivery systems, skin, cosmetic, topical, and dermal. All delivery systems found, such as liposomes, particulate systems, inclusion complexes, emulsions, and films, presented peculiar advantages able to enhance AST properties, among which are stability, antioxidant potential, biological activities, and drug release. This survey showed that further studies are needed for the industrial development of new AST-containing cosmetics and topical formulations.     

Molecular biologic methods for epidemiological precision characterization of disease agents using Salmonella enteritidis from poultry as an example

The principles of molecular biological methods for epidemiological investigation of infectious bacteria are described. They were applied for differentiating S. enteritidis isolates originating from poultry. Among the methods described are the determination of the chromosomal DNA fingerprints (BRENDA), the methods of multilocus enzyme electrophoresis, plasmid profiles, and the outer membrane protein as well as lipopolysaccharide pattern. It turned out, that S. enteritidis strains isolated before 1987, in 1988 and the ones originating from Great Britain did not differ in anyone of these criteria. Consequently one has to assume, that the strains recently causing problems originate from the population of S. enteritidis which had existed in poultry before.     

Streptomycin resistance in Clavibacter michiganensis subsp. michiganensis strains from Chile is related to an rpsL gene mutation

Streptomycin has been used for decades in Chile to control Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of tomato bacterial canker. The aim of this work was to evaluate streptomycin resistance and to analyse the presence of resistance-related genes in Cmm strains from Chile. A collection of 25 Cmm strains isolated from different localities in central Chile between 1996 and 2015 was analysed. Minimum inhibitory concentration (MIC) of streptomycin was determined. A search of streptomycin resistance-related genes was carried out in Cmm genomes, and the presence of these genes was studied in all Chilean strains using PCR and sequencing techniques. MIC results showed that four of 25 strains were highly sensitive to streptomycin, with MIC values <2 μg mL⁻¹. The remaining 21 strains possessed MIC of streptomycin ≥100 μg mL⁻¹. The strB gene, encoding an aminoglycoside 6-phosphotransferase that inactivates streptomycin, was detected in all Chilean strains, including sensitive and resistant strains. In the 21 resistant strains, a mutation in codon 43 of the rpsL gene was determined, conferring high streptomycin resistance. Interestingly, the four streptomycin-sensitive Cmm strains did not possess this mutation. This study proposes that the continuous use of streptomycin leads to emergence of resistant Cmm strains, challenging researchers to look for novel alternatives to control this plant pathogenic bacterium.     

Study of the genetic variability and similarity among and within Arachis villosulicarpa, A. pietrarellii and A. hypogaea through isoenzyme analysis

Arachis villosulicarpa is a perennial species cultivated for its soft and tasty seeds by indigenous inhabitants of the Mato Grosso State, Brazil. Besides A. hypogaea, this species is considered as the only species of Arachis which represents a valuable food source for human consumption. Due to the lack of knowledge concerning the genetic diversity of A. villosulicarpa, this study was conducted to evaluate the genetic variability of the accessions from the Germplasm Collection of CENARGEN/EMBRAPA (Brasília, DF, Brazil) and Instituto Agrono^mico (IAC, Campinas, SP, Brazil). In addition, the genetic similarity between A. villosulicarpa, the related wild species A. pietrarellii, and the cultivated peanut A. hypogaea cv. Tatu was evaluated. From the entire sample analyzed of A. villosulicarpa, the accession from Instituto Agrono^mico showed the highest indices of diversity for both enzymatic systems analyzed, pointing this accession as a promising source of genetic variabil ity that must be preserved in the Germplasm Bank. A high level of genetic similarity was observed between A. pietrarellii and A. villosulicarpa, supporting previous suggestions that A. pietrarellii could be the ancestral progenitor species of A. villosulicarpa or that both species originated from a common ancestor.     

Nectar volume and floral entomofauna as a tool for the implementation of sustainable apicultural management plans in <Emphasis Type="Italic">Quillaja saponaria</Emphasis> Mol.

The objective of the present study was to quantify nectar volume and secretion dynamics in Quillaja saponaria Mol. and the entomofauna associated with its flowers, as a tool for the implementation of sustainable apicultural management plans. Nectar was collected daily throughout the flowers’ lifetime, three times per day at 4-h intervals. For the identification of insects associated with flowers, 5-min observation periods were carried out for 170 min in total, and a list of registered species was prepared. Within the inflorescence, central hermaphrodite flowers and lateral male flowers lived 12.3 ± 0.26 and 5.8 ± 0.26 days on average, respectively. Nectar production increased from day 1 to day 11, and then decreased until day 15. The average volume of nectar secreted per tree was 5.3 l, which would be equivalent to 4.2 kg of honey. Forty-one species of flower visitors were registered in total.     

Dynamics of infections with gastrointestinal parasites and Dictyocaulus viviparus in dairy and beef cattle from Costa Rica

A longitudinal survey was carried out to determine and describe the prevalence and intensity of gastrointestinal parasite infections and Dictyocaulus viviparus in a dairy and a beef cattle farm of two different ecological zones in Costa Rica. The influence of anthelmintic treatment, age and meteorological factors (rainfall, minimum and maximum temperatures) on gastrointestinal nematodes and D. viviparus counts was determined. Calves were subjected to monthly sampling of feces and blood between April 2002 and March 2003. Coprological techniques were used to detect gastrointestinal helminthes, protozoan and D. viviparus. Blood samples were analyzed for antibodies to D. viviparus by ELISA. The most prevalent gastrointestinal parasites detected on both farms (dairy cattle, A; beef cattle, B) were Eimeria spp. (94.7%, 93.7%), Strongylidae (75.0%, 81.4%), Buxtonella sulcata (38.0%, 21.6%) and Strongyloides papillosus (29.8%, 31.7%), whereas Moniezia benedeni (4.8%, 9.1%), Trichuris spp. (7.3%, 13.2%), Toxocara vitulorum (0.0%, 1.8%) and Entamoeba bovis (2.5%, 1.1%) were less prevalent. Mean fecal egg counts (FEC) showed highest values of Strongylidae in April, May and July (>335.3 eggs/g feces) on farm A, and April, May and August (>304.3 eggs/g feces) on farm B. S. papillosus presented low FEC throughout the year on farm A, on farm B the highest values were obtained in April (303.0 eggs/g feces). Trichuris spp. presented maximum FEC values in May (328.6 eggs/g feces) on farm A and in June (157.5 eggs/g feces) on farm B. Treatment and age had significant influence on infection intensity of Strongylidae (farms A and B), S. papillosus (farms A and B) and Trichuris spp. (farm A). Rainfall had significant effect on S. papillosus (farms A and B) and Trichuris spp. (farm B). Maximum temperature showed significant effect on S. papillosus (farm A) and Trichuris spp. (farms A and B). Minimum temperature had significant influence on Strongylidae (farm A), S. papillosus (farms A and B) and Trichuris spp. (farm B). Haemonchus spp. (57%, 66%) and Cooperia spp. (30.0%, 30.7%) were the most prevalent genera identified by coproculture on both farms, in contrast, Trichostrongylus spp. and Oesophagostomum spp. were less frequent. Patent lungworm infections were low on both farms (10.8%, 1.8%). On farm A, high prevalence of antibodies against D. viviparus was determined only at the beginning of the study, in contrast, on farm B the seroprevalence fluctuated throughout the year. Treatment, age and maximum temperature had significant effect on D. viviparus counts on farm A, but not on farm B.     

Diversity of vegetative compatibility types,distribution of mating types and occurrence of hypovirulence of Cryphonectria parasitica in chestnut stands in NW Spain

An extensive survey on chestnut stands in NW Spain was carried out to study the population biology of Cryphonectria parasitica in order to design future biological control programmes of chestnut blight based on the field introduction of native hypovirulent strains. Five hundred and thirty-nine Cryphonectria parasitica isolates, belonging to five populations (A Coruña, Lugo, Ourense, Pontevedra and León), were obtained. The diversity of vegetative compatibility was very low. Six vc types were found, each population showing only from 2 to 4 vc types. Two vc types were the known European testers EU1 and EU66, and the other four were undescribed vc types that were named E1, E2, E3 and E4. E1 was the dominant vc type in Lugo and Ourense populations, and EU1 in Pontevedra and León. Hypovirulent isolates (a total of 15) were only detected in the León population, all but one being compatible with the vc type EU1. Hypovirulent strains belonged to the French subtype F1 of the Cryphonectria hypovirus-1 (CHV1).