Use of RAD sequencing for delimiting species.

RAD-tag sequencing is a promising method for conducting genome-wide evolutionary studies. However, to date, only a handful of studies empirically tested its applicability above the species level. In this communication, we use RAD tags to contribute to the delimitation of species within a diverse genus of deep-sea octocorals, Chrysogorgia, for which few classical genetic markers have proved informative. Previous studies have hypothesized that single mitochondrial haplotypes can be used to delimit Chrysogorgia species. On the basis of two lanes of Illumina sequencing, we inferred phylogenetic relationships among 12 putative species that were delimited using mitochondrial data, comparing two RAD analysis pipelines (Stacks and PyRAD). The number of homologous RAD loci decreased dramatically with increasing divergence, as >70% of loci are lost when comparing specimens separated by two mutations on the 700-nt long mitochondrial phylogeny. Species delimitation hypotheses based on the mitochondrial mtMutS gene are largely supported, as six out of nine putative species represented by more than one colony were recovered as discrete, well-supported clades. Significant genetic structure (correlating with geography) was detected within one putative species, suggesting that individuals characterized by the same mtMutS haplotype may belong to distinct species. Conversely, three mtMutS haplotypes formed one well-supported clade within which no population structure was detected, also suggesting that intraspecific variation exists at mtMutS in Chrysogorgia. Despite an impressive decrease in the number of homologous loci across clades, RAD data helped us to fine-tune our interpretations of classical mitochondrial markers used in octocoral species delimitation, and discover previously undetected diversity.

[Syphilis--diagnosis, treatment and characteristics in HIV-infected patients]. / Syphilis und HIV-Infektion. Dem Duo möglichst fruh den Kampf ansagen.

Venereal syphilis is a chronic cyclic infectious disease that, if untreated, runs a decades-long course. The responsible pathogen is Treponema pallidum. Clinically, a differentiation is made into early (primary) syphilis (up to 1 year following infection, syphilis I), during which disease manifestations are localized, secondary syphilis (syphilis II) with generalized manifestations, and late, or tertiary syphilis (syphilis III). Clinical manifestations that have been observed in HIV patients are syphilis maligna and neurosyphilis. Treatment of choice continues to be penicillin. Instead of only a single injection of penicillin, HIV infected patients with early syphilis should be given three injections, with an interval of 1 week between them, to prevent the development of neurosyphilis.