The habu genome reveals accelerated evolution of venom protein genes

Evolution of novel traits is a challenging subject in biological research. Several snake lineages developed elaborate venom systems to deliver complex protein mixtures for prey capture. To understand mechanisms involved in snake venom evolution, we decoded here the ~1.4-Gb genome of a habu, Protobothrops flavoviridis. We identified 60 snake venom protein genes (SV) and 224 non-venom paralogs (NV), belonging to 18 gene families. Molecular phylogeny reveals early divergence of SV and NV genes, suggesting that one of the four copies generated through two rounds of whole-genome duplication was modified for use as a toxin. Among them, both SV and NV genes in four major components were extensively duplicated after their diversification, but accelerated evolution is evident exclusively in the SV genes. Both venom-related SV and NV genes are significantly enriched in microchromosomes. The present study thus provides a genetic background for evolution of snake venom composition

A case of relapsed lung abscess caused by Eubacterium brachy infection following an initial diagnosis of pulmonary actinomycosis

We report a rare case of lung abscess due to Eubacterium brachy. In this case, an analysis of the aspirate from frank pus revealed Gram-positive coccobacilli. We initially strongly suspected lung abscess associated with actinomycosis because of the chronic/recurrent clinical course and radio-pathological findings such as a granuloma lesion. Although a biochemical analysis revealed Actinomyces sp., 16S rRNA gene sequencing and a phylogenetic tree analysis of the isolated strain confirmed the presence of E. brachy. Some cases previously diagnosed as actinomycosis might be correctly diagnosed as E. brachy infection. Clinicians should be aware that additional studies using 16S rRNA gene sequencing are needed to clarify whether pulmonary infection associated with E. brachy is a similar entity to that of chronic granulomatous infection disease in pulmonary actinomycosis