Escherichia coli, but not Staphylococcus aureus triggers an early increased expression of factors contributing to the innate immune defense in the udder of the cow

The outcome of an udder infection is influenced by the pathogen species. We established a strictly defined infection model to better analyze the unknown molecular causes for these pathogen-specific effects, using Escherichia coli and Staphylococcus aureus strains previously asseverated from field cases of mastitis. Inoculation of quarters with 500 CFU of E. coli (n = 4) was performed 6 h, 12 h, and 24 h before culling. All animals showed signs of acute clinical mastitis 12 h after challenge: increased somatic cell count (SCC), decreased milk yield, leukopenia, fever, and udder swelling. Animals inoculated with 10 000 CFU of S. aureus for 24 h (n = 4) showed no or only modest clinical signs of mastitis. However, S. aureus caused clinical signs in animals, inoculated for 72 h-84 h. Real-time PCR proved that E. coli inoculation strongly and significantly upregulated the expression of beta-defensins, TLR2 and TLR4 in the pathogen inoculated udder quarters as well as in mammary lymph nodes. TLR3 and TLR6 were not significantly regulated by the infections. Immuno-histochemistry identified mammary epithelial cells as sites for the upregulated TLR2 and beta-defensin expression. S. aureus, in contrast, did not significantly regulate the expression of any of these genes during the first 24 h after pathogen inoculation. Only 84 h after inoculation, the expression of beta-defensins, but not of TLRs was significantly (> 20 fold) upregulated in five out of six pathogen inoculated quarters. Using the established mastitis model, the data clearly demonstrate a pathogen-dependent difference in the time kinetics of induced pathogen receptors and defense molecules.     

Association of carotenoids, tocopherols and vitamin C in plasma with allergic rhinitis and allergic sensitisation in adults

OBJECTIVES: Antioxidant nutrients like carotenoids, tocopherols and vitamin C have been suggested to protect against allergic rhinitis and allergic sensitisation but scientific evidence is scarce. The aims of the study were to measure the plasma concentration of six carotenoids, alpha- and gamma-tocopherol and vitamin C as biomarkers of the intake, absorption and subsequent metabolism of these nutrients, and to assess their association with allergic rhinitis and sensitisation. METHOD: Data from a cross-sectional study on representative dietary and lifestyle habits of the population of Bavaria, Germany, were analysed. The plasma levels of six carotenoids (alpha-carotene, beta-carotene, lycopene, lutein/zeaxanthin, canthaxanthin and cryptoxanthin) as well as of alpha-tocopherol, gamma-tocopherol and vitamin C were measured in 547 adults aged between 19 and 81 years. Participants with specific serum immunoglobulin E > or =700 U l(-1) were categorised as sensitised. The association of plasma antioxidant levels, allergic rhinitis and allergic sensitisation was assessed by means of unconditional logistic regression models. RESULTS: We observed a negative association between plasma total carotenoids and the prevalence of allergic rhinitis, with odds ratio (95% confidence interval) of 1.13 (0.54-2.39) for the second, 0.72 (0.33-1.58) for the third and 0.44 (0.19-1.03) for the fourth quartile of total carotenoids concentration (P for trend=0.0332); results for lycopene failed to reach statistical significance (P=0.0608). Other single carotenoids, tocopherols and vitamin C were unrelated to allergic rhinitis. Allergic sensitisation was negatively associated with plasma gamma-tocopherol, with odds ratio (95% confidence interval) of 0.92 (0.51-1.65) for the second, 1.00 (0.56-1.80) for the third and 0.45 (0.23-0.88) for the fourth quartile of plasma gamma-tocopherol concentration (P for trend=0.0410). No other antioxidant was significantly related to allergic sensitisation. CONCLUSIONS: High plasma carotenoid concentrations reflecting a diet high in various fruits and vegetables might have a protective effect on allergic rhinitis in adulthood.     

A family with severe insulin resistance and diabetes due to a mutation in AKT2

Inherited defects in signaling pathways downstream of the insulin receptor have long been suggested to contribute to human type 2 diabetes mellitus. Here we describe a mutation in the gene encoding the protein kinase AKT2/PKBbeta in a family that shows autosomal dominant inheritance of severe insulin resistance and diabetes mellitus. Expression of the mutant kinase in cultured cells disrupted insulin signaling to metabolic end points and inhibited the function of coexpressed, wild-type AKT. These findings demonstrate the central importance of AKT signaling to insulin sensitivity in humans.     

Cultivars Resulting From Cherry Breeding in Germany

In Germany the sweet and sour cherry breeding is concentrated at the Julius Kühn-Institut in Dresden-Pillnitz. The main breeding goals are directed on sweet cherries for fresh market and sour cherries for processing. The selection of new cultivars is focused on fruit quality, high and stable fruit set and tolerance to biotic and abiotic stress. In result of the breeding activities in sweet cherry four new cultivars, ‘Narana’, ‘Areko’, ‘Swing’, ‘Habunt’, were selected. ‘Narana’ is an early ripening cultivar with good fruit characteristics. ‘Areko’ ripens in the middle of the cherry season some days before cultivar ‘Kordia’ and has large, firm fruits. The both cultivars ‘Swing’ and ‘Habunt’ are self-compatible and more recommended for the use in house gardening. In sour cherry breeding four new cultivars, ‘Coralin’, ‘Spinell’, ‘Jachim’, ‘Boas’, were selected. The cultivar ‘Coralin’ shows good characteristics for processing and mechanical harvest and is tolerant to fungus diseases on leaves. With the large and tasty fruits, the cultivar ‘Spinell’ is mainly suitable for fresh consumption. The both other cultivars ‘Jachim’ and ‘Boas’ have a pillar growth habit.     

Localized cowpox infection in a 5‐month‐old Rottweiler

Cowpox virus (CPXV) infections are a sporadic cause of localized or disseminated skin disease in domestic animals and humans in Europe. Rodents are considered the primary reservoir host for CPXV. Cats can become infected by close contact with rodents and are the most important source of human infections. Recently, public awareness has also been drawn to CPXV infections by an outbreak of rat to human infections in central Europe. In dogs, CPXV infections are rare. Here we report a case of a 5‐month‐old Rottweiler with a focal nodule on the muzzle. The lesion was fully excised, and recovery was uneventful. The preliminary diagnosis of a CPXV infection was established by the characteristic inclusion bodies on histopathological examination. The diagnosis was confirmed by electron microscopy and polymerase chain reaction (PCR). Sequencing of the PCR product led to a 231 bp sequence of the orthopoxvirus HA gene that was identical to a CPXV strain previously isolated from a cat. This is the third documented case of a canine CPXV infection.     

What is the SMARTest way to breed plants and increase agrobiodiversity?

The evaluation and use of the vast diversity contained in plant genetic resources (PGR) is a main challenge for today’s plant breeding. The use of molecular markers has hugely increased the knowledge about genetic diversity and great hopes are raised about the potential of marker assisted selection [MAS; sometimes also termed SMART breeding (Selection with Markers and Advanced Reproductive Technologies)] to help increasing the use of PGR and maintaining crop genetic diversity. Another approach growing attention has been paid to over the past two decades and which also aims to increase variation in crops is evolutionary and participatory breeding (EPB). In this paper we discuss both the potential of marker-assisted breeding strategies and the potential of EPB breeding to contribute to the maintenance, increase and development of agrobiodiversity. The potentials of molecular markers in the evaluation and use of PGR and their documented contribution to agrobiodiversity are reviewed and results from guided interviews with scientists and breeders are given. Despite tremendous research efforts involving molecular markers, it is still difficult to obtain a clear picture how molecular markers contribute to the use of PGR in plant breeding. Minor and major crops do not benefit to the same degree from recent developments in marker technology. It therefore depends at least in part on economic considerations whether SMART breeding or EPB strategies or both are implemented in the breeding process of a crop. A general decision in favor or against MAS or EPB when breeding for diversity would not yield optimum results.     

Impact of alternative respiration and target-site mutations on responses of germinating conidia of Magnaporthe grisea to Qo-inhibiting fungicides

Qo-inhibiting fungicides act as respiration inhibitors by binding to the Qo center of cytochrome b. Sensitivities of fungi to Qo inhibitors can be influenced by the induction of alternative respiration or by mutational changes of the cytochrome b target site. Previous studies on both mechanisms in Magnaporthe grisea (Hebert) Barr were focused on the mycelial stage of the pathogen. The present study describes the expression and impact of both resistance mechanisms during the stage of conidia germination. In the absence of a host, alternative respiration provided a >500-fold rescue from azoxystrobin during the germination of conidia derived from four wild-type isolates of M. grisea. This rescue potential during conidia gemination was substantially more pronounced than for mycelial growth. However, the pronounced effectiveness of alternative respiration during conidia germination was not apparent when barley leaves were protected with azoxystrobin prior to inoculation with conidia. In a comparison of a wild-type strain and an alternative respiration-deficient mutant, azoxystrobin efficacies in suppressing symptom development differed by a factor of two, with full disease control achieved for both genotypes at 1 microg ml(-1) azoxystrobin. In contrast, conidia derived from two QoI-resistant target site mutants were highly resistant to azoxystrobin and trifloxystrobin and fully capable of infecting leaf surfaces protected with 10 microg ml(-1) of azoxystrobin. Both target-site mutants had emerged spontaneously in the presence of high azoxystrobin doses when residual mycelial growth was supported by alternative respiration. The effective silencing of alternative respiration in protective applications of Qo-inhibiting fungicides might constitute a strategy of slowing the emergence of highly resistant target site mutants.     

Variable resistance factors of fungicides acting as sterol demethylation inhibitors

The ED₅₀ values and resistance factors of 20 fungicides that all act as inhibitors of the C-14 demethylation of 24-methylenedihydrolanosterol were determined for one wild-type and four resistant strains of Ustilago avenae. All fungicides were cross-resistant to each other; however, the resistance factors varied considerably, ranging from 50 (triadimenol) to 2·2 (miconazole). A tentative structural requirement for low resistant factors was the presence of two phenyl rings separated from each other by at least three atoms. Labeling of lipids with [¹⁴C]acetate in the absence and presence of the inhibitors and subsequent sterol analysis revealed that the variable resistance factors were not related to the presence of a second target site. In spite of reported second modes of action of fenarimol, tebuconazole or miconazole, accumulation of C-14 sterol precursors in both sensitive and resistant isolates was necessary to accomplish growth inhibition.     

Differential responses of germinating Venturia inaequalis conidia to kresoxim-methyl

A new class of agricultural fungicides derived from strobilurins act as respiration inhibitors by binding to mitochondrial cytochrome b. The effects of the strobilurin, kresoxim-methyl, on conidia germination, mycelial growth and the protection of apple leaves from scab development were investigated for two isolates of Venturia inaequalis randomly selected from a culture collection. Inhibition of mycelial growth required relatively high doses of kresoxim-methyl (ED₅₀=1 μg ml^-1) for both isolates. In comparison, germination of conidia was highly sensitive for one of the isolates (ED₅₀=0·005 μg ml^-1), while the level of inhibition achieved for the second isolate was 60-fold less (ED₅₀=0·3 μg ml^-1). As deduced from identical sequences of cytochrome b cDNAs prepared from both isolates, the different responses of germinating conidia to kresoxim-methyl were not caused by differences in the sequence of cytochrome b as the target site for strobilurin action. Strong synergistic effects of salicylhydroxamic acid on kresoxim-methyl inhibitory potency suggested that the reduced kresoxim-methyl sensitivity observed for germinating conidia was caused by interference of the alternative respiratory pathway with inhibitor action. However, this mechanism of target site circumvention in germinating conidia had no adverse effects on the protection of apple leaves from scab infection by kresoxim-methyl. © 1998 Society of Chemical Industry