Archive for July 24th, 2013

H5N1 vaccines in humans

24 July, 2013

See on Scoop.itVirology News

Highlights

 

2 Doses of unadjuvanted vaccine are necessary to elicit robust antibody titers.

Oil-in-water adjuvants permit antigen sparing.

Antibody titers decline rapidly but can be boosted with additional doses of vaccine.

High titers of antibody are associated with cross-reactivity against other clades.

Prime-boost strategies elicit a robust immune response.

 

 

 

Ed Rybicki‘s insight:

Thanks @MicrobeTweets!

See on www.sciencedirect.com

Antibiotic treatment expands the resistance reservoir and ecological network of the phage metagenome

24 July, 2013

See on Scoop.itVirology News

The mammalian gut ecosystem has considerable influence on host physiology1, 2, 3, 4, but the mechanisms that sustain this complex environment in the face of different stresses remain obscure. Perturbations to the gut ecosystem, such as through antibiotic treatment or diet, are at present interpreted at the level of bacterial phylogeny5, 6, 7. Less is known about the contributions of the abundant population of phages to this ecological network. Here we explore the phageome as a potential genetic reservoir for bacterial adaptation by sequencing murine faecal phage populations following antibiotic perturbation. We show that antibiotic treatment leads to the enrichment of phage-encoded genes that confer resistance via disparate mechanisms to the administered drug, as well as genes that confer resistance to antibiotics unrelated to the administered drug, and we demonstrate experimentally that phages from treated mice provide aerobically cultured naive microbiota with increased resistance. Systems-wide analyses uncovered post-treatment phage-encoded processes related to host colonization and growth adaptation, indicating that the phageome becomes broadly enriched for functionally beneficial genes under stress-related conditions. We also show that antibiotic treatment expands the interactions between phage and bacterial species, leading to a more highly connected phage–bacterial network for gene exchange. Our work implicates the phageome in the emergence of multidrug resistance, and indicates that the adaptive capacity of the phageome may represent a community-based mechanism for protecting the gut microflora, preserving its functional robustness during antibiotic stress.

  T4 phage graphic by Russell Kightley Media

Ed Rybicki‘s insight:

This is a fascinating finding, for a number of reasons: however, most importantly it means that the "phageome" – or bacterial virus metagenome in your gut – is a reservoir of genes that can confer survival advantage(s) on your microbial population when this population is stressed.

For example, by antibiotic therapy.

This alters our concept and understanding of phage-bacteria interactions quite significantly, as it can no longer be understood as a simple "predator/prey" relationship.  Rather, and while phages still regulate bacterial numbers by simply killing them, they also act as stewards or gamekeepers, by making it possible for bacteria to survive adverse events.

Quite a concept that: the virus as conserver!

See on www.nature.com

Close Relative of Human Middle East Respiratory Syndrome Coronavirus in Bat, South Africa

24 July, 2013

See on Scoop.itVirology and Bioinformatics from Virology.ca

The severe acute respiratory syndrome (SARS) outbreak of 2002–03 and the subsequent implication of bats as reservoir hosts of the causative agent, a coronavirus (CoV), prompted numerous studies of bats and the viruses they harbor. A novel clade 2c betacoronavirus, termed Middle East respiratory syndrome (MERS)–CoV, was recently identified as the causative agent of a severe respiratory disease that is mainly affecting humans on the Arabian Peninsula (1). Extending on previous work (2), we described European Pipistrellus bat–derived CoVs that are closely related to MERS-CoV (3). We now report the identification of a South Africa bat derived CoV that has an even closer phylogenetic relationship with MERS-CoV.

 

Coronavirus graphic courtesy of Russell Kightley Media

Ed Rybicki‘s insight:

This is interesting and timely work – for which notice, thanks Stephen Korsman! – out of various labs in South Africa and elsewhere.

This almost certainly means that, as with paramyxoviruses in bats, there are a LOT of CoVs out there with the potential to infect other mammals – including humans.

Of course, this one should be the REAL SARSCoV – for "South African respiratory syndrome virus.  Which would make all teh jokes about the SA Revenue Services even more pointed.

See on wwwnc.cdc.gov