Since 2011, massive new strandings of holopelagic Sargassum have been reported on the coasts of the Caribbean, northern Brazil, Guiana, and West Africa, causing severe economic and ecological damage. Three common morphotypes (S. fluitans III, S. natans I, and S. natans VIII) were identified as responsible for these catastrophic events, with dominance shifts between them over time. However, the taxonomic status of these holopelagic Sargassum morphotypes remains unclear. Using an integrative taxonomy framework, combining a morphological study and molecular analyses, this study aimed to clarify their taxonomic status. Morphological analyses of 54 characters revealed no intermediate form between the three morphotypes, with the overall shape, nature of the axis, and size and shape of blades and vesicles being the most discriminating. An analysis of mitochondrial (IGS, cox2, cox3, mt16S rRNA, and nad6) and plastid (rbcL) markers confirmed the genetic divergence among the three morphotypes, with a lower level of divergence between the two S. natans morphotypes. Without additional molecular characterization, these morphotypes cannot be classified as three distinct species. However, due to their distinct morphological characteristics and sympatry within drifting aggregations, a revision of holopelagic species names is proposed, with Sargassum fluitans var. fluitans (for S. fluitans III), Sargassum natans var. natans (for S. natans I), and S. natans var. wingei (for S. natans VIII). This revision provides necessary clarity on the species involved in inundations of the tropical Atlantic.

Teicoplanin is a key drug for the treatment of multiresistant staphylococcal bone and joint infections (BJI), yet can only be administered via a parenteral route. The objective of this study was to evaluate the safety and tolerability of subcutaneous (s.c.) teicoplanin for that indication over 42 days. Thirty patients with Gram-positive cocci BJI were included. Once the target of 25 to 40 mg/liter trough serum concentration was achieved, treatment was switched from an intravenous to an s.c. route. No discontinuation of teicoplanin related to injection site reaction and no severe local adverse event were observed. On multivariate analysis, better tolerability was observed at the beginning of treatment, in patients over 70 years old, and for dosages less than 600 mg. In conclusion, we recommend s.c. administration of teicoplanin when needed.