Subcuticular bacteria from the brittle star Ophiactis balli (Echinodermata: Ophiuroidea) represent a new lineage of extracellular marine symbionts in the alpha subdivision of the class Proteobacteria.

Many species of echinoderms, in all five extant classes, contain subcuticular bacterial symbionts (SCB). The role of these extracellular symbionts and the nature of the relationship remain unclear. We have sequenced 16S rRNA genes from symbionts to determine their phylogenetic affinities. Symbionts of an ophiuroid, Ophiactis balli, appear closely related to bacteria within the alpha group of the class Proteobacteria, including intracellular endosymbionts and pathogens. SCB are clearly of separate origin from other documented major groups of marine symbiotic bacteria.

Single versus double occlusive dressing technique to minimize infusion thrombophlebitis: Vialon and Teflon cannulae reassessed.

Infusion thrombophlebitis is the commonest complication of intravenous cannulation. This study was undertaken to prospectively evaluate a double-occlusive dressing technique and a new cannula, bismuth oxide-Teflon (Critikon Inc., Aust.), comparing it to Vialon (Deseret Medical Inc., Utah, USA). The study group of two hundred patients had a 16 gauge intravenous cannula inserted in theatre using a standard technique. The incidence of thrombophlebitis was determined on a daily basis. Cannula tips were sent for culture on removal. Vialon was found to be superior to Teflon after day 1. Although a double-occlusive dressing technique increased the duration of cannulation (50.9 vs. 41.9 hours, P less than 0.05), there was no difference in the incidence of thrombophlebitis. Neither cannula material nor dressing technique had an influence on the results of cannula tip culture (6% incidence). There was no evidence of bacteraemia in any case.