Molecular diversity in <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> isolates from common bean fields in Brazil

The common bean (Phaseolus vulgaris L.) is widely cultivated in Brazil and is known as a very important crop for families in this country. Fusarium wilt severely harms common beans and has become a big issue for this crop. In order to assist the breeding programs that target resistance to this disease, the evaluation of genetic diversity of the pathogen and its molecular characterization are crucial. Thus, the present goal was to identify Fusarium isolates obtained from several places in Brazil using molecular tools; select molecular markers for these isolates; and analyze their diversity. All of isolates were molecularly identified as Fusarium oxysporum f. sp. phaseoli (Fop). By using seven selected SSR markers, the results of diversity obtained by the dendrogram and the Bayesian analysis formed four groups where a large diversity of this fungus was found within each state. However, the groups were more homogenous according to the collection source and the pathogenicity test. More specifically, group 2 was composed of the most virulent strains and originated from Minas Gerais State – UFV, and group 3 was mostly composed by isolates from Goias state. Group I was also more diverse in terms of location and virulence. The overall results indicated a positive correlation between Fusarium diversity and its virulence to common bean. Furthermore, the use of these markers was effective in molecular identification and in detecting polymorphism within F. oxysporum f. sp. phaseoli.     

Lipoid pneumonia in a rough collie dog

The incidence of lipoid pneumonia in dogs is not known and confirmed cases do not appear to have been reported. Three forms of lipoid pneumonia are recognised in mammalian species; exogenous lipoid pneumonia (ELP), endogenous lipoid pneumonia (EnLP), and post-obstructive endogenous lipoid pneumonia (PEnLP). All forms share similar microscopic characteristics of fat accumulation in the cytoplasm of alveolar macrophages and are otherwise clinically indistinct from other forms of pneumonia. A case of lipoid pneumonia in a seven-year-old rough collie dog which was presented with recurrent bronchopneumonia over several months is reported here. Diagnosis was made from biopsy of resected lung tissue and from detection of fat-containing vacuoles in macrophages obtained by bronchoalveolar lavage. ELP could not be differentiated from PEnLP in this dog, but a complete recovery followed removal of the affected right accessory and caudal lung lobes.     

Bovine and rabbit models for the study of a Staphylococcus aureus avirulent mutant strain, RC122

Staphylococcus aureus is the main etiological agent of bovine mastitis. Intramammary infections are difficult to cure and vaccination appears to be an alternative to prevent the disease. Research has focused on the development of mutants affected in the synthesis of pathogenicity determinants. We constructed a mutant strain (RC122) after chemical mutagenesis. In a mouse model, the strain was shown to be 1500 times less virulent, showed similar kinetics of disappearance in the kidney as its parental strain, and a good degree of protection against a challenge from homologous and heterologous strains.

The objective of the present report was to study the avirulent RC122 S. aureus mutant strain in rabbit and bovine infection models. The results clearly show that RC122 was less virulent than its parental strain in a rabbit skin model, and was also correlated with its avirulence as an udder pathogen. These traits make the RC122 mutant strain interesting as a potential strain for an experimental vaccine trial in dairy herds.

     

Arrangement of the Branches of the Aorta Abdominalis in the Wood Mouse (Apodemus sylvaticus)

Data on the distribution and variation of the abdominal arteries in the wood mouse, Apodemus sylvaticus, are given. Seventy specimens (44 males and 26 females) caught in the field were analyzed by injection of green latex solution and dissection. The general branching pattern of the aorta abdominalis is similar to those described in other rodents. There are certain differences, however, especially in the branching of the coeliac trunk, the origin of the genital arteries and the arrangement of the caudal mesenteric artery. Significant variability was detected in the distribution of the iliolumbar arteries about the testicular and ovaric arteries. Based on the observations and measurements carried out, some branching patterns of the aorta abdominalis are presented.     

Water stress and warming impact nutrient use efficiency of Mombasa grass (Megathyrsus maximus) in tropical conditions

Temperature and other abiotic factors, such water and nutrient availability, play an important role for plants in response to the changing environments. At this regard, both warming and drought might affect the nutrient use efficiency (NUE) and growth of Megathyrsus maximus a C4 forage grass of high interest for cattle feeding. However, the nutrient requirements of this species under climate change are unknown. Therefore, we aimed to evaluate the individual and combined effects of two levels of temperature: ambient and elevated temperature (2°C above ambient temperature), and two levels of soil water availability: irrigated plants and non‐irrigated plants on accumulation of leaf nutrients, NUE and biomass production of M. maximus. Temperature control was performed by a temperature free‐air‐controlled enhancement (T‐FACE) system under field conditions. In general, we observed that warming under well‐irrigated conditions increased the leaf accumulation of most nutrients, improving the NUE of N, P, K, Ca, Mg, Cu, Mn and Zn. Plant growth was also enhanced under warming effects, with higher leaf dry mass accumulation and root development. Meanwhile, drought decreased NUE of K, Ca, B and leaf dry biomass, while root growth was stimulated. The combined effects of warming and drought on nutrient accumulation, NUE and plant growth tended to be greater than the individual effects expected from a single factor; thus, warming mitigated the negative impacts of individual drought. In summary, our findings suggest that warming and drought, both as individual and combined factors, will change the nutrient requirements of M. maximus in tropical ecosystems.     

Comparison between tail and jugular venipuncture techniques for blood sample collection in common chameleons (Chamaeleo chamaeleon)

The most common technique used for collecting blood samples from chameleons, ventral tail caudal venipuncture (Reptile care. An Atlas of Diseases and Treatments, Vol. II, T.F.H. Publication, New Jersey, 1991) sometimes presents undesired effects. Here we compared tail versus jugular vein venipuncture techniques in the common chameleon. In the first experiment, we collected 0.25% of the chameleon's body mass in blood from either tail or jugular sites in size-matched pairs of animals to check for secondary effects. In a second experiment, we measured white blood cells (WBC), red blood cells (RBC), total plasma protein and uric acid in blood samples collected from both sites in the same individual. We found few secondary effects following the use of either venipuncture site although skin darkening was observed in few specimens when using the ventral tail vein. Blood profiles were similar between samples. The repeatability of measurements was similar in RBC and WBC counts and remarkably low (<0.90). Despite the few differences recorded, we recommend jugular venipunction in chameleons as skin darkening is unlikely, blood volumes are easily obtained and collection time is shorter.     

Changes induced by Trichoderma harzianum in suppressive compost controlling Fusarium wilt

The addition of species of Trichoderma to compost is a widespread technique used to control different plant diseases. The biological control activity of these species is mainly attributable to a combination of several mechanisms of action, which may affect the microbiota involved in the suppressiveness of compost. This study was therefore performed to determine the effect of inoculation of Trichoderma harzianum (T. harzianum) on compost, focusing on bacterial community structure (16S rRNA) and chitinase gene diversity. In addition, the ability of vineyard pruning waste compost, amended (GCTh) or not (GC) with T. harzianum, to suppress Fusarium wilt was evaluated. The addition of T. harzianum resulted in a high relative abundance of certain chitinolytic bacteria as well as in remarkable protection against Fusarium oxysporum comparable to that induced by compost GC. Moreover, variations in the abiotic characteristics of the media, such as pH, C, N and iron levels, were observed. Despite the lower diversity of chitinolytic bacteria found in GCTh, the high relative abundance of Streptomyces spp. may be involved in the suppressiveness of this growing media. The higher degree of compost suppressiveness achieved after the addition of T. harzianum may be due not only to its biocontrol ability, but also to changes promoted in both abiotic and biotic characteristics of the growing media.