Investigating the Diversity of Marine Bacteriophage in Contrasting Water Masses Associated with the East Australian Current (EAC) System

Virus- and bacteriophage-induced mortality can have a significant impact on marine productivity and alter the flux of nutrients in marine microbial food-webs. Viral mediated horizontal gene transfer can also influence host fitness and community composition. However, there are very few studies of marine viral diversity in the Southern Hemisphere, which hampers our ability to fully understand the complex interplay of biotic and abiotic factors that shape microbial communities. We carried out the first genetic study of bacteriophage communities within a dynamic western boundary current (WBC) system, the east Australian current (EAC). Virus DNA sequences were extracted from 63 assembled metagenomes and six metaviromes obtained from various depths at 24 different locations. More than 1700 bacteriophage genomic fragments (>9 kbps) were recovered from the assembled sequences. Bacteriophage diversity displayed distinct depth and regional patterns. There were clear differences in the bacteriophage populations associated with the EAC and Tasman Sea euphotic zones, at both the taxonomic and functional level. In contrast, bathypelagic phages were similar across the two oceanic regions. These data provide the first characterisation of viral diversity across a dynamic western boundary current, which is an emerging model for studying the response of microbial communities to climate change.

Network meta-analysis of topical haemostatic agents in thyroid surgery

Background

The objective of this study was to investigate the potential benefit of local haemostatic agents for the prevention of postoperative bleeding after thyroidectomy.

Methods

A systematic literature search was performed, and RCTs involving adult patients who underwent thyroid surgery using either active (AHA) or passive (PHA) haemostatic agents were included in the review. The main outcome was the rate of cervical haematoma that required reoperation. A Bayesian random-effects model was used for network meta-analysis with minimally informative prior distributions.

Results

Thirteen RCTs were included. The rate of cervical haematoma requiring reoperation ranged from 0 to 9·1 per cent, and was not reduced by haemostatic agents: AHA versus control (odds ratio (OR) 1·53, 95 per cent credibility interval 0·21 to 10·77); PHA versus control (OR 2·74, 0·41 to 16·62) and AHA versus PHA (OR 1·77, 0·12 to 25·06). No difference was observed in the time required for drain removal, duration of hospital stay, and the rate of postoperative hypocalcaemia or recurrent nerve palsy. AHA led to a significantly lower total postoperative blood loss and reduced operating time in comparison with both the control and PHA groups.

Conclusion

The general use of local haemostatic agents has not been shown to reduce the rate of clinically relevant bleeding.