Detection of the Bacterial Potato Pathogens Pectobacterium and Dickeya spp. Using Conventional and Real-Time PCR.

Blackleg and soft rot of potato, caused by Pectobacterium and Dickeya spp., are major production constraints in many potato-growing regions of the world. Despite advances in our understanding of the causative organisms, disease epidemiology, and control, blackleg remains the principal cause of down-grading and rejection of potato seed in classification schemes across Northern Europe and many other parts of the world.

Dickeya aquatica sp. nov., isolated from waterways.

Pectinolytic Gram-negative bacteria were isolated from different waterways in the UK and Finland. Three strains (174/2(T), 181/2 and Dw054) had the same 16S rRNA gene sequences which shared 99% sequence similarity to species of the genus Dickeya, and a phylogeny of related genera confirmed attribution to this genus. Fatty acid profile analysis of all three strains found a high proportion of C16 : 1ω7c/C16 : 1ω7c and C16 : 0 fatty acids, and library profile searches found closest matches to Dickeya chrysanthemi.

Dickeya solani sp. nov., a pectinolytic plant-pathogenic bacterium isolated from potato (Solanum tuberosum).

Pectinolytic bacteria have been recently isolated from diseased potato plants exhibiting blackleg and slow wilt symptoms found in a number of European countries and Israel. These Gram-reaction-negative, motile, rods were identified as belonging to the genus Dickeya, previously the Pectobacterium chrysanthemi complex (Erwinia chrysanthemi), on the basis of production of a PCR product with the pelADE primers, 16S rRNA gene sequence analysis, fatty acid methyl esterase analysis, the production of phosphatases and the ability to produce indole and acids from α-methylglucoside. Differential physiological assays used previously to differentiate between strains of E.

Application of variable-number tandem-repeat typing to discriminate Ralstonia solanacearum strains associated with English watercourses and disease outbreaks.

Variable-number tandem-repeat (VNTR) analysis was used for high-resolution discrimination among Ralstonia solanacearum phylotype IIB sequevar 1 (PIIB-1) isolates and further evaluated for use in source tracing. Five tandem-repeat-containing loci (comprising six tandem repeats) discriminated 17 different VNTR profiles among 75 isolates from potato, geranium, bittersweet (Solanum dulcamara), tomato, and the environment. R.

Proposal of Xanthomonas translucens pv. pistaciae pv. nov., pathogenic to pistachio (Pistacia vera).

Strains of Xanthomonas translucens have caused dieback in the Australian pistachio industry for the last 15 years. Such pathogenicity to a dicotyledonous woody host contrasts with that of other pathovars of X. translucens, which are characterized by their pathogenicity to monocotyledonous plant families.

Dickeya species relatedness and clade structure determined by comparison of recA sequences.

Using sequences from the recA locus, we have produced a phylogeny of 188 Dickeya strains from culture collections and identified species relatedness and subspecies clade structure within the genus. Of the six recognized species, Dickeya paradisiaca, D. chrysanthemi and D.

Phylogenetic structure of Xanthomonas determined by comparison of gyrB sequences.

Previously, we have produced a phylogeny of species type strains from the plant-pathogenic genus Xanthomonas based on gyrB sequences. To evaluate this locus further for species and infraspecies identification, we sequenced an additional 203 strains comprising all the pathovar reference strains (which have defined plant hosts), 67 poorly characterized pathovars, currently classified as Xanthomonas campestris, and 59 unidentified xanthomonads. The well-characterized pathovars grouped either in clades containing their respective species type strain or in clades containing species related to Xanthomonas axonopodis.

Phylogenetic analysis of Xanthomonas species by comparison of partial gyrase B gene sequences.

The genus Xanthomonas currently comprises 27 species with validly published names that are important crop and horticultural pathogens. We have constructed a phylogram from alignment of gyrase B (gyrB) sequences for all xanthomonad species, both to indicate inter-species relatedness and as an aid for rapid and accurate species-level identification. The phylogeny indicated a monophyletic group, with X.

Endotracheal tube and laryngeal mask airway cuff volume changes with altitude: a rule of thumb for aeromedical transport.

Background: Helicopters and light (unpressurised) aircraft are used increasingly for the transport of ventilated patients. Most of these patients are ventilated through endotracheal tubes (ETTs), others through laryngeal mask airways (LMAs). The cuffs of both ETTs and LMAs inflate with increases in altitude as barometric pressure decreases (30 mbar/1000 feet).

Towards a comprehensive view of the primary structure of venom proteins from the parasitoid wasp Pimpla hypochondriaca.

Venom from the parasitoid wasp Pimpla hypochondriaca has potent in vivo activity against insect haemocytes and disrupts host immune responses. Using hybridisation techniques, and more recently random sequence analysis, we had previously identified cDNAs encoding 10 venom proteins from this wasp and deduced their primary structures. We have now extended the random sequence analysis and discovered a further nine cDNAs encoding proteins with predicted signal sequences.

cDNAs encoding large venom proteins from the parasitoid wasp Pimpla hypochondriaca identified by random sequence analysis.

Venom from the parasitoid wasp Pimpla hypochondriaca contains numerous proteins, has potent in vitro anti-haemocytic properties, and disrupts host encapsulation responses. By sequencing 500 cDNAs randomly isolated from a venom gland library, we have identified 60 clones that encode proteins containing potential secretory signal sequences. To identify cDNAs encoding particular venom proteins, N-terminal amino acid sequences were determined for large (>30 kDa) venom proteins that had been separated using a combination of gel filtration and SDS-PAGE.