Complete Genome Sequence of Spiroplasma alleghenense PLHS-1T (ATCC 51752), a Bacterium Isolated from Scorpion Fly (Panorpa helena).

Spiroplasma alleghenense PLHS-1T (ATCC 51752) was isolated from the gut of a scorpion fly (Panorpa helena) collected in West Virginia. The complete genome sequence of this bacterium, which consists of a single 1,336,077-bp circular chromosome, is reported in this work.

Plant-Pathogenic Agrobacterium tumefaciens Strains Have Diverse Type VI Effector-Immunity Pairs and Vary in In-Planta Competitiveness.

The type VI secretion system (T6SS) is used by gram-negative bacteria to translocate effectors that can antagonize other bacterial cells. Models predict the variation in collections of effector and cognate immunity genes determine competitiveness and can affect the dynamics of populations and communities of bacteria. However, the outcomes of competition cannot be entirely explained by compatibility of effector-immunity (EI) pairs. Here, we characterized the diversity of T6SS loci of plant-pathogenic Agrobacterium tumefaciens and showed that factors other than EI pairs can impact interbacterial competition. All examined strains encode T6SS active in secretion and antagonism against Escherichia coli. The spectra of EI pairs as well as compositions of gene neighborhoods are diverse. Almost 30 in-planta competitions were tested between different genotypes of A. tumefaciens. Fifteen competitions between members of different species-level groups resulted in T6SS-dependent suppression in in-planta growth of prey genotypes. In contrast, ten competitions between members within species-level groups resulted in no significant effect on the growth of prey genotypes. One strain was an exceptional case and, despite encoding a functional T6SS and toxic effector protein, could not compromise the growth of the four tested prey genotypes. The data suggest T6SS-associated EI pairs can influence the competitiveness of strains of A. tumefaciens, but genetic features have a significant role on the efficacy of interbacterial antagonism.

Draft Genome Sequence of Vibrio vulnificus 86573B, a Bacterium Isolated from Diseased Tilapia in Taiwan.

Vibrio vulnificus 86573B is a biotype 1 strain isolated from a moribund tilapia collected in Kaohsiung, Taiwan, during an outbreak early in 1997. Here, we report the draft genome sequence of this bacterium to facilitate the investigation of its biology and future comparative genomic analysis.

Presence of an Agrobacterium-Type Tumor-Inducing Plasmid in Neorhizobium sp. NCHU2750 and the Link to Phytopathogenicity.

The genus Agrobacterium contains a group of plant-pathogenic bacteria that have been developed into an important tool for genetic transformation of eukaryotes. To further improve this biotechnology application, a better understanding of the natural genetic variation is critical. During the process of isolation and characterization of wild-type strains, we found a novel strain (i.e., NCHU2750) that resembles Agrobacterium phenotypically but exhibits high sequence divergence in several marker genes. For more comprehensive characterization of this strain, we determined its complete genome sequence for comparative analysis and performed pathogenicity assays on plants. The results demonstrated that this strain is closely related to Neorhizobium in chromosomal organization, gene content, and molecular phylogeny. However, unlike the characterized species within Neorhizobium, which all form root nodules with legume hosts and are potentially nitrogen-fixing mutualists, NCHU2750 is a gall-forming pathogen capable of infecting plant hosts across multiple families. Intriguingly, this pathogenicity phenotype could be attributed to the presence of an Agrobacterium-type tumor-inducing plasmid in the genome of NCHU2750. These findings suggest that these different lineages within the family Rhizobiaceae are capable of transitioning between ecological niches by having novel combinations of replicons. In summary, this work expanded the genomic resources available within Rhizobiaceae and provided a strong foundation for future studies of this novel lineage. With an infectivity profile that is different from several representative Agrobacterium strains, this strain may be useful for comparative analysis to better investigate the genetic determinants of host range among these bacteria.

Horizontal Gene Acquisitions Contributed to Genome Expansion in Insect-Symbiotic Spiroplasma clarkii.

Genome reduction is a recurring theme of symbiont evolution. The genus Spiroplasma contains species that are mostly facultative insect symbionts. The typical genome sizes of those species within the Apis clade were estimated to be ∼1.0-1.4 Mb. Intriguingly, Spiroplasma clarkii was found to have a genome size that is >30% larger than the median of other species within the same clade. To investigate the molecular evolution events that led to the genome expansion of this bacterium, we determined its complete genome sequence and inferred the evolutionary origin of each protein-coding gene based on the phylogenetic distribution of homologs. Among the 1,346 annotated protein-coding genes, 641 were originated from within the Apis clade while 233 were putatively acquired from outside of the clade (including 91 high-confidence candidates). Additionally, 472 were specific to S. clarkii without homologs in the current database (i.e., the origins remained unknown). The acquisition of protein-coding genes, rather than mobile genetic elements, appeared to be a major contributing factor of genome expansion. Notably, >50% of the high-confidence acquired genes are related to carbohydrate transport and metabolism, suggesting that these acquired genes contributed to the expansion of both genome size and metabolic capability. The findings of this work provided an interesting case against the general evolutionary trend observed among symbiotic bacteria and further demonstrated the flexibility of Spiroplasma genomes. For future studies, investigation on the functional integration of these acquired genes, as well as the inference of their contribution to fitness could improve our knowledge of symbiont evolution.

Complete Genome Sequence of Spiroplasma monobiae MQ-1T (ATCC 33825), a Bacterium Isolated from the Vespid Wasp (Monobia quadridens).

Spiroplasma monobiae MQ-1T (ATCC 33825) was isolated from the hemolymph of an adult vespid wasp (Monobia quadridens) collected in Maryland. Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its biology and the comparative genomics among Spiroplasma species.

Complete Genome Sequence of Spiroplasma floricola 23-6T (ATCC 29989), a Bacterium Isolated from a Tulip Tree (Liriodendron tulipifera L.).

Spiroplasma floricola 23-6T (ATCC 29989) was isolated from the flower surface of a tulip tree (Liriodendron tulipifera L.). Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its biology and the comparative genomics among Spiroplasma species.

Complete Genome Sequence of Spiroplasma corruscae EC-1T (DSM 19793), a Bacterium Isolated from a Lampyrid Beetle (Ellychnia corrusca).

Spiroplasma corruscae EC-1T (DSM 19793) was isolated from the gut of a lampryid beetle (Ellychnia corrusca) collected in Beltsville, MD, USA, in 1983. Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its biology and the comparative genomics among Spiroplasma species.

Effect of resistance exercise on dehydroepiandrosterone sulfate concentrations during a 72-h recovery: relation to glucose tolerance and insulin response.

Serum dehydroepiandrosterone sulfate (DHEA-S) concentration is known to be associated with the whole-body insulin sensitivity. The main purpose of the study was to investigate the effect of resistance exercise on DHEA-S concentration during a 72 h post-exercise recovery, and its relation to glucose tolerance and insulin sensitivity. Morning fasted serum samples was obtained from 19 male volunteers (aged 21.1+/-0.4 years) 24 h before the onset of exercise and 24 h, 48 h, and 72 h following exercise for measurements of DHEA-S, cortisol, and TNF-alpha. Oral glucose tolerance test (OGTT) and insulin response were determined 24 h before and 48 h after exercise. We found that resistance exercise causes a delayed suppression in serum DHEA-S levels during recovery (48 h and 72 h). This exercise challenge did not affect glucose tolerance, but insulin response during OGTT was significantly elevated. The increased insulin level was not associated with serum levels of cortisol and TNF-alpha. In conclusion, the present study found that resistance exercise has a DHEA-S lowering effect that persisted for 72 h. This change could be related to the elevated insulin concentrations during OGTT.