Draft genome sequence of the Streptococcus pneumoniae Avery strain A66

We have used HiSeq 2000 technology to generate a draft genome sequence of Streptococcus pneumoniae strain A66. This is a common study strain used in investigations of pneumococcal bacterium-host interactions and was used in the seminal genetic studies of Avery et al

Identification and characterisation of novel pneumococcal virulence factors

The identification of four sortase homologues srtA-D in the pneumococcal genome prompted their investigation as candidate pneumococcal virulence factors. Not all of these sortase genes were present in both sequenced strains and so sortase gene distribution was investigated among a collection of clinical isolates. In contrast to srtB, C and D, srtA was found in all strains examined and so was selected for further study. It was subsequently found to contribute to pneumococcal virulence in mouse models of pneumonia, bacteraemia and colonisation. This is the first demonstration of a contribution of srtA to pneumococcal virulence. To complement this examination of srtA, some of the surface proteins known or likely to be anchored by SrtA were also investigated for a role in virulence in the animal model of pneumonia. In addition, two genes, annotated in the pneumococcal genomes as a macrophage infectivity potentiator protein and an exfoliative toxin A were also investigated and found to be novel pneumococcal virulence factors. However, it appears they have been incorrectly annotated and these genes do not represent a macrophage infectivity potentiator protein and exfoliative toxin A. Instead, one of them seems to be involved in the response to oxidative stress while no function for the other can yet be ascertained. Janus mutagenesis is a novel technique for manipulation of the pneumococcal genome allowing the creation of mutations that lack a selectable marker. This provides an accessible and potentially powerful method to easily alter the genome to make informative mutations. This thesis describes the first use, to our knowledge, of Janus mutagenesis to investigate pneumococcal virulence

Staphylococcal-produced bacteriocins and antimicrobial peptides: their potential as alternative treatments for Staphylococcus aureus infections

Staphylococcus aureus is an important pathogen of both humans and animals, implicated in a wide range of infections. The emergence of antibiotic resistance has resulted in S. aureus strains that are resistant to almost all available antibiotics, making treatment a clinical challenge. Development of novel antimicrobial approaches is now a priority worldwide. Bacteria produce a range of antimicrobial peptides; the most diverse of these being bacteriocins. Bacteriocins are ribosomally synthesised peptides, displaying potent antimicrobial activity usually against bacteria phylogenetically related to the producer strain. Several bacteriocins have been isolated from commensal coagulase-negative staphylococci, many of which display inhibitory activity against S. aureus in vitro and in vivo. The ability of these bacteriocins to target biofilm formation and their novel mechanisms of action with efficacy against antibiotic-resistant bacteria make them strong candidates as novel therapeutic antimicrobials. The use of genome-mining tools will help to advance identification and classification of bacteriocins. This review discusses the staphylococcal-derived antimicrobial peptides displaying promise as novel treatments for S. aureus infections

The emergence of mecC methicillin-resistant Staphylococcus aureus.

The report of methicillin-resistant Staphylococcus aureus (MRSA) encoding a divergent mecA gene in 2011 was highly significant. This homologue, designated mecC, poses diagnostic problems with the potential to be misdiagnosed as methicillin-sensitive S. aureus, with important potential consequences for individual patients and for the surveillance of MRSA. mecC MRSA have now been reported from 13 European countries and have been isolated from 14 different host species, with evidence of a recent increase in Denmark. The emergence of mecC MRSA is a topic of interest to human and veterinary microbiology, and we consider it timely to review here its discovery and subsequent investigation.Our work on S. aureus is supported by a Medical Research Council (MRC) Partnership Award to M.A.H and funding to G.K.P from PetPlan Charitable Trust, the British Society for Antimicrobial Chemotherapy, and the Cambridge–Africa Alborada Research Fund.This is the final published version distributed under a Creative Commons Attribution License 2.0, which can also be found on the publisher's website at: http://www.cell.com/trends/microbiology/abstract/S0966-842X(13)00226-

Accounting for Accountability: A Discourse Analysis of Psychiatric Nurses’ Experience of a Patient Suicide

Whilst the experience of a patient suicide is likely to have a significant impact upon the nurses who had been providing care, little work has actually explored this experience in any depth. In this article we explore how two psychiatric nurses construct and orient to accountability when talking of their experiences of a patient suicide. Discourse analysis was used to explore particular phases that the nurses oriented to in their accounts: scene setting; risk assessment; attributing for the suicide. Findings highlight the different, sometimes contradictory, ways the nurses attended to interactional concerns relating to implicit accountability and potential inferences of blame. Analysis of the nurses’ talk can make a valuable contribution to understanding the nature and the impact of ‘accountability’ in a mental health setting and so help nurses and other professionals gain an insight into their practice. The results from this study suggest that as a consequence of internalising fundamentally unrealisable expectations regarding suicide prevention, nurses can hold themselves to blame raising significant concerns around their needs in terms of support, which may not be recognised. This paper also makes a valuable contribution to our methodological understanding and the value of using discourse analysis in this setting