Expression of CD3 and CD11b antigens on blood and mammary gland leukocytes and bacterial survival in milk of cows with experimentally induced Staphylococcus aureus mastitis.

OBJECTIVES: To differentiate early (1 to 8 days) from late (9 to 14 days) inflammatory phases and assess relationships between leukocyte phenotype and bacterial recovery in cows with Staphylococcus aureus-induced mastitis. ANIMALS: 10 first-lactation Holstein cows. PROCEDURE: Blood and milk samples were collected from 4 or 6 cows before and after intramammary infusion of sterile broth or S. aureus, respectively. Flow cytometric expression of CD3 and CD11b antigens on blood and milk leukocytes, leukocyte differential counts, bacterial counts in milk, and somatic cell counts were determined longitudinally. RESULTS: Density of CD3 molecules decreased on blood lymphocytes and increased on milk lymphocytes after infusion of bacteria. Density of CD11b molecules on lymphocytes and phagocytes and percentage of CD11b+ lymphocytes in milk increased significantly after infusion; maximum values were achieved during the early inflammatory phase. Density of CD3 and CD11b molecules on milk lymphocytes and macrophages, respectively, 1 day after inoculation were negatively correlated with bacterial recovery on day 1 and days 9 to 14, respectively. Density of CD11b molecules on milk macrophages and the ratios of phagocyte to lymphocyte percentages and polymorphonuclear cell to macrophage percentages in milk differentiated the early from the late inflammatory phase. CONCLUSIONS AND CLINICAL RELEVANCE: Activation of bovine mammary gland macrophages and T cells in response to intramammary infusion of S. aureus was associated with an inability to culture this bacterium from milk. Identification of specific inflammatory phases of S. aureus-induced mastitis in cows may allow for the design of more efficacious treatment and control programs.     

Photochemical isomerization of fluazifop-butyl

Fluazifop-butyl, butyl (RS)-2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]propionate, as a thin film on glass, was photo-rearranged by ultraviolet irradiation at 254 nm to the isomer, butyl (RS)-2-[4-hydroxy-3-(5-trifluoromethyl-2-pyridyl)phenoxy]propionate. The reaction followed first-order kinetics. A mechanism that accounts for the formation of this product is proposed.     

Responses of shelter and pet dogs to an unknown human

Canine shelters frequently have inadequate living conditions that affect the behavior of dogs. This study compared fear-appeasement and sociability reactions in shelter and pet dogs when they are confronted by an unfamiliar experimenter. Results indicated that shelter dogs used for this study showed more fear-appeasement behavior—tail down, ears down, and crouching—as compared with pet dogs. In addition, shelter dogs quite frequently remained closer to the individual, despite showing signs of fear-appeasement, as compared with pet dogs. Finally, shelter dogs remained near the door of the enclosure less often when compared with pet dogs. This difference might be accounted for by the lack of any attachment bonds among shelter dogs toward their caretakers. These results may be associated to the usual stressful conditions and limited interactions with human beings that may be observed in shelters with scarce resources.     

Genetic diversity and erosion in lima bean (Phaseolus lunatus L.) in Northeast Brazil

Genetic Resources and Crop Evolution - Lima bean (Phaseolus lunatus L.) is a crop that stands out for its economic and social importance throughout the world, including in Northeast Brazil....     

Evaluation of different enzyme-linked immunosorbent assays for the diagnosis of brucellosis due to Brucella melitensis in sheep

Six serological assays for the diagnosis of ovine brucellosis, due to Brucella melitensis were evaluated. Reference serum samples from sheep of known B. melitensis infection status (n = 118) were assessed using the Rose Bengal test (RBT), complement fixation test (CFT) and four commercial enzyme-linked immunosorbent assays (ELISAs), including two indirect ELISAs (iELISAs), one competitive ELISA (cELISA) and one blocking ELISA (bELISA).The highest differential positive rates (DPR) were obtained with the cELISA and bELISA, while the lowest DPR was estimated using iELISAs. A latent class analysis was performed to estimate the accuracy of the CFT, RBT and bELISA using 1827 sera from sheep undergoing testing as part of a surveillance and control programme. Lower sensitivity and specificity were obtained for the three serological tests when the field samples were used. A higher DPR was achieved by the CFT, compared to bELISA and RBT. The results suggest that ELISAs, and particularly the bELISA, might be suitable for inclusion in the European Union legislation on intra-community trade for diagnosing B. melitensis infection in sheep, as it has a similar test performance compared to the RBT.     

From Linderiella baetica to gambilusa: Involving children in conservation by giving a new species a common name

1. The knowledge and awareness that the general public has about aquatic invertebrates is often poor, even when they are highly threatened. The frequent lack of popular names and the unattractiveness of the scientific ones may be among the factors hindering the knowledge of these organisms and, consequently, the awareness of their conservation status and the willingness to conserve them.
2. Linderiella baetica (Crustacea, Branchiopoda, Anostraca) was discovered in 2007 in southern Spain and is considered a critically endangered species. However, being a small invertebrate inhabiting generally unappreciated temporary ponds, this species was completely unknown by the general public, even in the area in which it occurs.
3. To increase the knowledge and awareness of L. baetica, 1,347 children from five schools within its distribution area participated in a contest to select a common name for this newly described taxon. The winning name, gambilusa (Andalusian shrimp), will be used in the future by the Spanish Ministry of Environment and hopefully by the general public to identify the species.
4. The contest was found to have increased the knowledge about the target species in a sustained manner, as 1 year later, 93% of the children recognized gambilusa as a crustacean, 75% remembered its typical habitat, and 89% broadly identified its geographical distribution.
5. This kind of name-choosing contest is applicable for different regions and taxa to raise awareness on the conservation of threatened but poorly known biota.

     

Temperature, the GacS/GacA system, and host metabolites regulate the type VI secretion system of Pseudomonas syringae pv. phaseolicola

The recently discovered type VI secretion system (T6SS) is implicated in the pathogenic and/or virulence processes of diverse bacteria. The expression pattern of the T6SS differs among different organisms and also depends on several environmental factors. We initiated a study of the conditions that influence T6SS gene expression in Pseudomonas syringae pv. phaseolicola NPS3121. Our results indicate that low temperatures and plant extracts impact the expression of T6SS genes and that the process is subject to regulation by the GacS/GacA two-component system.     

Comparative Study of Lead Accumulation in Different Organs of the Freshwater Crab <Emphasis Type="Italic">Zilchiopsis oronensis</Emphasis>

Lead (Pb) is known as an important aquatic contaminant with different toxic effects on various organisms. Until now, only few quantitative investigations have been published comparing Pb content in different organs of adult freshwater crabs. Their capacity to bioaccumulate other heavy metals is already known, and they can potentially transfer Pb to the terrestrial systems, as they are frequent trophic items of reptiles and birds, even humans. The objectives of this study were to assess Pb accumulation in the gills, carapace, digestive gland, and quela muscle of the freshwater crab Zilchiopsis oronensis, and to correlate bioaccumulation with morphometric data and sex. The crabs were manually caught in unpolluted ponds of the middle Paraná River alluvial valley (Santa Fe, Argentina). After the acclimation period, they were individually and randomly exposed per quadruplicate to three Pb experimental doses: 20, 40, and 80 mg Pb/L, in plastic cages during 15 days. After dissecting the crabs, the tissues were analyzed for lead in a Perkin Elmer Analyst 800 atomic absorption spectrometer. We found significant differences (p < 0.05) between the control and each one of the treatments but not between treatments (p > 0.05) and highly significant differences (p < 0.0001) between Pb concentration in organs. The Tukey posttest showed significant differences (p < 0.05) between gills–carapace, gills–digestive gland, and gills–quela muscle. The weight of the crabs only showed a negative correlation with Pb in the quela muscle (r = −0.53; p = 0.03). Pb in the carapace (but not in the other tissues) was positively correlated with the width (p = 0.571) and length (p = 0.616). Males accumulated more Pb than females, though not significantly. The present paper is aimed to contribute to our knowledge on Pb accumulation in freshwater crabs and select the better indicator organisms for biomonitoring.