Assignment of Reference 5’-end 16S rDNA Sequences and Species-Specific Sequence Polymorphisms Improves Species Identification of Nocardia

16S rDNA sequence analysis is the most accurate method for definitive species identification of nocardiae. However, conflicting results can be found due to sequence errors in gene databases. This study tested the feasibility of species identification of Nocardia by partial (5’-end 606-bp) 16S rDNA sequencing, based on sequence comparison with “reference” sequences of well-annotated strains. This new approach was evaluated using 96 American Type Culture Collection (n=6), and clinical (n=90) Nocardia isolates. Nucleotide sequence-based polymorphisms within species were indicative of “sequence types” for that species. Sequences were compared with those in the GenBank, Bioinformatics Bacteria Identification and Ribosomal Database Project databases. Compared with the reference sequence set, all 96 isolates were correctly identified using the criterion of ≥99% sequence similarity. Seventy-eight (81.3%) were speciated by database comparison; alignment with reference sequences resolved the identity of 14 (15%) isolates whose sequences yielded 100% similarity to sequences in GenBank under >1 species designation. Of 90 clinical isolates, the commonest species was Nocardia nova (33.3%) followed by Nocardia cyriacigeorgica (26.7%). Recently-described or uncommon species included Nocardia veterana (4.4%), Nocarida bejingensis (2.2%) and, Nocardia abscessus and Nocardia arthriditis (each n=1). Nocardia asteroides sensu stricto was rare (n=1). There were nine sequence types of N. nova, three of Nocardia brasiliensis with two each of N. cyriacigeorgica and Nocardia farcinica. Thirteen novel sequences were identified. Alignment of sequences with reference sequences facilitated species identification of Nocardia and allowed delineation of sequence types within species, suggesting that such a barcoding approach can be clinically useful for identification of bacteria

Molecular Typing of Australian Scedosporium Isolates Showing Genetic Variability and Numerous S. aurantiacum

Molecular typing showed genetic diversity, dismissed 2 suspected outbreaks of scedosporiosis, and identified multiple strains of the newly described species S. aurantiacum

Tensor Polarization of the phi meson Photoproduced at High t

As part of a measurement of the cross section of $\phi$ meson photoproduction to high momentum transfer, we measured the polar angular decay distribution of the outgoing $K^+$ in the channel $\phi \to K^+K^-$ in the $\phi$ center-of-mass frame (the helicity frame). We find that s-channel helicity conservation (SCHC) holds in the kinematical range where $t$-channel exchange dominates (up to $-t \sim 2.5$ GeV$^2$ for $E_{\gamma}$=3.6 GeV). Above this momentum, $u$-channel production of a $\phi$ meson dominates and induces a violation of SCHC. The deduced value of the $\phi NN$ coupling constant lies in the upper range of previously reported values.Comment: 6 pages; 5 figure

Effects of conditioners (standard, long term, and expander) on pellet quality and growth performance in nursery pigs

In our first experiment, digestibilities for DM, N, and GE were greater and F/G was better for pigs fed pelleted diets than for pigs fed meal diets. However, we observed no advantages in ADG or F/G with long-term conditioning. In a second experiment, pelleting once again improved nutrient digestibility and F/G. Expander conditioning improved digestibilities of DM, N, and GE but not growth performance compared to standard conditioning

Effects of expander conditioning of corn- and sorghum-based diets on pellet quality and performance in finishing pigs and lactating sows

Pellet durability index was similar for sorghum- vs com-based diets but was greater for expander-conditioned pellets than standard-conditioned pellets. For finishing pigs, ADG, F/G, and carcass measurenlents were similar for pigs fed sorghum vs com. Efficiency of gain was 6% better for pigs fed pelleted diets compared to those given meal diets but was sinlilar for pigs fed the conventional- and expander-conditioned diets. For sows, the com- and sorghumbased diets supported similar litter performance. Our data indicate that sorghum is an excellent feedstuff: comparable to corn, in diets for finishing pigs and sows

Le burn-out : état des connaissances et perspectives de prévention dans le milieu sportif

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