Differential amplification kinetics for point mutation analysis by PCR.
Explore the source record for details and available documents.
Alleles↗
Biomedical subjects
B Kaltenböck
Publications and source records attributed to B Kaltenböck.
Evidence for numerous omp1 alleles of porcine Chlamydia trachomatis and novel chlamydial species obtained by PCR.
A nested PCR for genus-specific amplification of the Chlamydia omp1 locus was established. This PCR detected single template molecules in 200-microl specimen aliquots. Amplified chlamydial omp1 alleles were typed by heminested species PCRs and allele PCRs. We applied this method to 407 specimens from several host animals with various clinical conditions, and we detected prevalences of chlamydiae from 6 to 50%. Amplicons from peacock enteritis and equine infertility specimens were not typeable according to present omp1 allelic criteria for the chlamydial species. DNA sequencing revealed novel omp1 alleles which were 29.9 and 47.6% divergent in the deduced peptide sequences from the most closely related chlamydiae. Phylogenetic reconstruction indicated segregation of these alleles from the current four chlamydial species (90 and 97% bootstrap support), thus strongly suggesting the existence of additional chlamydial species. Allele typing of amplicons from swine with intestinal, urogenital, and respiratory infections demonstrated several unique omp1 allelic variants of Chlamydia trachomatis. These novel alleles had deduced peptide sequences which were 11.6 to 19% divergent from porcine C. trachomatis S45. Mutations were clustered in the C-terminal region of variable segment IV of the omp1 locus encoding subspecies and serovar determinants of the chlamydial major outer membrane protein, thus implying that there are numerous serovars of porcine C. trachomatis. These results demonstrate the need for routine application of sensitive genus-specific detection of chlamydiae in animal specimens and suggest a more prominent role than anticipated for chlamydiae in animal diseases.
Alleles↗
Sex in Escherichia coli does not disrupt the clonal structure of the population: evidence from random amplified polymorphic DNA and restriction-fragment-length polymorphism.
Analysis of the Escherichia coli population by multilocus enzyme electrophoresis (MLEE) has established its clonal organization, but there is increasing evidence that horizontal DNA transfer occurs in E. coli. We have assessed the genetic structure of the species E. coli and determined the extent to which recombination can affect the clonal structure of bacteria. A panel of 72 E. coli strains from the ECOR collection was characterized by random amplified polymorphic DNA (RAPD) and restriction-fragment-length polymorphism (RFLP) of the ribosomal RNA gene (rrn) regions. These strains have been characterized by MLEE and are assumed to reflect the range of genotypic variation in the species as a whole. Statistical analysis, including factorial analysis of correspondence (FAC) and hierarchical classifications, established that the data obtained with the three genetic markers are mutually corroborative, thus providing compelling evidence that horizontal transfer does not disrupt the clonal organization of the population. However, there is a gradient of correlation between the different classifications which ranges from the highly clonal structure of B2 group strains causing extraintestinal infections in humans to the less-stringent structure of B1 group strains that came mainly from nonprimate mammals. This group (B1) appears to be the framework from which the remaining non-A group strains have emerged. These results indicate that RAPD analysis is well suited to intraspecies characterization of E. coli. Lastly, treating the RAPD data by FAC allowed description of subgroup-specific DNA fragments which can be used, in a strategy comparable to positional cloning, to isolate virulence genes.
Base Sequence↗
[Optimizing ruminant feed rations from the physiological aspect with FURAT, a personal computer program].
Health disorders caused by feeding are a common problem in cattle keeping. For this reason the personal computer program, FURAT, was developed for the calculation and optimization of ruminant feed rations with respect to physiological aspects. With this program, weighed feed rations selected from the feedstuff on the standard list or from a self-drawn up feedstuff list can be tested for their content of various nutrients and compared with the requirements of the animals to be fed. Subsequently in an optimization program using the same feedstuff rations can be worked out for various performance categories ensuring the best possible feeding from the health aspect. With a free choice within a feed range and taking into account the physiological limits of the rumen (maximum compound intake, minimum raw fiber amount in the dry matter, minimum structure in the raw fiber, maximum raw fat in the dry matter) the ration is calculated to achieve a balanced protein-energy ratio. One of the two main nutrients--protein or energy--must amount exactly to the target value in the ration, and the other has to be as close as possible to its target value. From among up to 12 different feedstuff the computer will choose the optimal ration which can be printed with a precise indication of all parameters. The rations worked out for the various performance categories are stored and, at the end of the program, are printed in short form in a letter addressed to the farmer that also lists necessary mineral supplements.
Animal Feed↗