Suitability of SSCP-PCR analysis for molecular detection of quinolone resistance in Campylobacter jejuni

Foodborne infections with Campylobacter spp. are increasing, especially antibiotic resistant strains are emerging. Quinolone resistant isolates can cause failure of therapy in severe clinical infections. Molecular characterisation is needed for the detection of resistant variants of C. jejuni. Therefore 23 isolates from poultry and human medicine as well as three control strains were tested for their minimal inhibitory concentration, their Single-Strand-Conformation-Polymorphism (SSCP)-PCR pattern (a method for the detection of resistance determining point mutations), and their sequence of the quinolone resistance determining region (QRDR). Six different SSCP types could be identified: two types for quinolone resistant isolates and other types containing so called silent mutations without influence on the resistance. A genotypic monitoring of the quinolone resistance in C. jejuni can be useful for the early detection of new resistance variants. As a screening method for detection of point mutations in the QRDR the SSCP-PCR can be applied. Compared to other genotypic methods the SSCP-PCR is less time and cost consuming and needs only standard technical equipment.     

Association between frost tolerance and the alleles of high molecular weight glutenin subunits present in Polish winter wheats

Subunits of high molecular weight glutenins strongly influence wheat bread making quality and can be associated with important agronomic traits. Polish winter wheats show a significant quantitative dominance of the null allele over the coding alleles of the Glu-A1 locus. To identify the causes of such skewed distribution, 116 F₅ lines obtained from six cross combinations were analyzed for their HMW glutenin subunits and 11 agronomic characteristics, such as plant height and uniformity, leaf blotch and leaf rust resistance, grain yield per plot, number of grains per ear, grain yield per ear, 1000 kernel weight, frost tolerance, total protein content and the SDS-sedimentation value. The SDS-sedimentation value, resistance to leaf blotch and frost tolerance showed statistically significant associations with the status of the Glu-A1 locus. It appears that chromosome 1A with the null allele at Glu-A1 carries a closely linked locus responsible for frost tolerance. With early strong selection for winter hardiness, the null allele of Glu-A1 becomes fixed in advanced breeding materials despite its strong negative impact on the end use quality.     

Störungen bei der Kokonbildung von Neodiprion sertifer Geoffr. (Hym., Diprionidae) nach Aufnahme des Häutungshemmstoffs SIR Bay 8514 durch die Altlarven

Old larvae ofN. sertifer treated with SIR Bay 8514, an insect growth regulator similar to Diflubenzuron produced partly (17–24%) abnormal cocoons showing a hole or a broad fissure in their middle region. Such phenomenon was not known hitherto.     

How deforestation drives stream habitat changes and the functional structure of fish assemblages in different tropical regions

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