Genetic diversity of Actinobacillus lignieresii isolates from different hosts

Genetic diversity detected by analysis of amplified fragment length polymorphisms (AFLPs) of 54 Actinobacilus lignieresii isolates from different hosts and geographic localities is described. On the basis of variances in AFLP profiles, the strains were grouped in two major clusters; one comprising strains isolated from horses and infected wounds of humans bitten by horses and another consisting of strains isolated from bovine and ovine hosts. The present data indicate a comparatively higher degree of genetic diversity among strains isolated from equine hosts and confirm the existence of a separate genomospecies for A. lignieresi-like isolates from horses. Among the isolates from bovine and ovine hosts some clonal lines appear to be genetically stable over time and could be detected at very distant geographic localities. Although all ovine strains investigated grouped in a single cluster, the existence of distinct genetic lineages that have evolved specificity for ovine hosts is not obvious and needs to be confirmed in other studies

Pathotyping the Zoonotic Pathogen Streptococcus suis: Novel Genetic Markers To Differentiate Invasive Disease-Associated Isolates from Non-Disease-Associated Isolates from England and Wales.

Streptococcus suis is one of the most important zoonotic bacterial pathogens of pigs, causing significant economic losses to the global swine industry. S. suis is also a very successful colonizer of mucosal surfaces, and commensal strains can be found in almost all pig populations worldwide, making detection of the S. suis species in asymptomatic carrier herds of little practical value in predicting the likelihood of future clinical relevance. The value of future molecular tools for surveillance and preventative health management lies in the detection of strains that genetically have increased potential to cause disease in presently healthy animals. Here we describe the use of genome-wide association studies to identify genetic markers associated with the observed clinical phenotypes (i) invasive disease and (ii) asymptomatic carriage on the palatine tonsils of pigs on UK farms. Subsequently, we designed a multiplex PCR to target three genetic markers that differentiated 115 S. suis isolates into disease-associated and non-disease-associated groups, that performed with a sensitivity of 0.91, a specificity of 0.79, a negative predictive value of 0.91, and a positive predictive value of 0.79 in comparison to observed clinical phenotypes. We describe evaluation of our pathotyping tool, using an out-of-sample collection of 50 previously uncharacterized S. suis isolates, in comparison to existing methods used to characterize and subtype S. suis isolates. In doing so, we show our pathotyping approach to be a competitive method to characterize S. suis isolates recovered from pigs on UK farms and one that can easily be updated to incorporate global strain collections.This work was supported by a Biotechnology and Biological Sciences Research Council (BBSRC) Knowledge Transfer Network CASE studentship co-funded by Zoetis (previously Pfizer Animal Health UK) and with significant contribution from BQP Ltd (Award Reference: BB/L502479/1). Funding bodies provided scholarship support but had no part in study design, data collection, analysis and interpretation of data or in writing the manuscript. AWT is supported by a BBSRC Longer and Larger (LoLa) grant (Award Reference: BB/G019274/1). LAW is supported by a Dorothy Hodgkin Fellowship funded by the Royal Society (Grant Number: DH140195) and a Sir Henry Dale Fellowship co-funded by the Royal Society and Wellcome Trust (Grant Number: 109385/Z/15/Z)

Generation and evaluation of a glaesserella (Haemophilus) parasuis capsular mutant

Glaesserella (Haemophilus) parasuis is a commensal bacterium of the upper respiratory tract in pigs and also the causative agent of Glässer’s disease, which causes significant morbidity and mortality in pigs worldwide. Isolates are characterized into 15 serovars by their capsular polysaccharide, which has shown a correlation with isolate pathogenicity. To investigate the role the capsule plays in G. parasuis virulence and host interaction, a capsule mutant of the serovar 5 strain HS069 was generated (HS069Δcap) through allelic exchange following natural transformation. HS069Δcap was unable to cause signs of systemic disease during a pig challenge study and had increased sensitivity to complement killing and phagocytosis by alveolar macrophages. Compared with the parent strain, HS069Δcap produced more robust biofilm and adhered equivalently to 3D4/31 cells; however, it was unable to persistently colonize the nasal cavity of inoculated pigs, with all pigs clearing HS069Δcap by 5 days postchallenge. Our results indicate the importance of the capsular polysaccharide to G. parasuis virulence as well as nasal colonization in pigs

The N-linking glycosylation system from Actinobacillus pleuropneumoniae is required for adhesion and has potential use in glycoengineering.

Actinobacillus pleuropneumoniae is a mucosal respiratory pathogen causing contagious porcine pleuropneumonia. Pathogenesis studies have demonstrated a major role for the capsule, exotoxins and outer membrane proteins. Actinobacillus pleuropneumoniae can also glycosylate proteins, using a cytoplasmic N-linked glycosylating enzyme designated NGT, but its transcriptional arrangement and role in virulence remains unknown. We investigated the NGT locus and demonstrated that the putative transcriptional unit consists of rimO, ngt and a glycosyltransferase termed agt. From this information we used the A. pleuropneumoniae glycosylation locus to decorate an acceptor protein, within Escherichia coli, with a hexose polymer that reacted with an anti-dextran antibody. Mass spectrometry analysis of a truncated protein revealed that this operon could add up to 29 repeat units to the appropriate sequon. We demonstrated the importance of NGT in virulence, by creating deletion mutants and testing them in a novel respiratory cell line adhesion model. This study demonstrates the importance of the NGT glycosylation system for pathogenesis and its potential biotechnological application for glycoengineering.This work was supported by a Longer and Larger (LoLa) grant from the UK Biotechnology and Biological Sciences Research Council (grant nos BB/G020744/1, BB/G019177/1, BB/G019274/1 and BB/G003203/1) and The Wellcome Trust (grant no. 102979/Z/13/Z)

The Emergency Department Action in Smoking Cessation (EDASC) Trial: Impact on Delivery of Smoking Cessation Counseling

Objectives:  The focus on acute care, time pressure, and lack of resources hamper the delivery of smoking cessation interventions in the emergency department (ED). The aim of this study was to 1) determine the effect of an emergency nurse–initiated intervention on delivery of smoking cessation counseling based on the 5As framework (ask–advise–assess–assist–arrange) and 2) assess ED nurses’ and physicians’ perceptions of smoking cessation counseling. Methods:  The authors conducted a pre–post trial in 789 adult smokers (five or more cigarettes/day) who presented to two EDs. The intervention focused on improving delivery of the 5As by ED nurses and physicians and included face‐to‐face training and an online tutorial, use of a charting/reminder tool, fax referral of motivated smokers to the state tobacco quitline for proactive telephone counseling, and group feedback to ED staff. To assess ED performance of cessation counseling, a telephone interview of subjects was conducted shortly after the ED visit. Nurses’ and physicians’ self‐efficacy, role satisfaction, and attitudes toward smoking cessation counseling were assessed by survey. Multivariable logistic regression was used to assess the effect of the intervention on performance of the 5As, while adjusting for key covariates. Results:  Of 650 smokers who completed the post‐ED interview, a greater proportion had been asked about smoking by an ED nurse (68% vs. 53%, adjusted odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.3 to 2.9), assessed for willingness to quit (31% vs. 9%, adjusted OR= 4.9, 95% CI = 2.9 to 7.9), and assisted in quitting (23% vs. 6%, adjusted OR = 5.1, 95% CI = 2.7 to 9.5) and had arrangements for follow‐up cessation counseling (7% vs. 1%, adjusted OR = 7.1, 95% CI = 2.3 to 21) during the intervention compared to the baseline period. A similar increase was observed for emergency physicians (EPs). ED nurses’ self‐efficacy and role satisfaction in cessation counseling significantly improved following the intervention; however, there was no change in “pros” and “cons” attitudes toward smoking cessation in either ED nurses or physicians. Conclusions:  Emergency department nurses and physicians can effectively deliver smoking cessation counseling to smokers in a time‐efficient manner. This trial also provides empirical support for expert recommendations that call for nursing staff to play a larger role in delivering public health interventions in the ED.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91133/1/ACEM_1331_sm_DataSupplementS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91133/2/j.1553-2712.2012.01331.x.pd

A before-after implementation trial of smoking cessation guidelines in hospitalized veterans

Abstract Background Although most hospitalized smokers receive some form of cessation counseling during hospitalization, few receive outpatient cessation counseling and/or pharmacotherapy following discharge, which are key factors associated with long-term cessation. US Department of Veterans Affairs (VA) hospitals are challenged to find resources to implement and maintain the kind of high intensity cessation programs that have been shown to be effective in research studies. Few studies have applied the Chronic Care Model (CCM) to improve inpatient smoking cessation. Specific objectives The primary objective of this protocol is to determine the effect of a nurse-initiated intervention, which couples low-intensity inpatient counseling with sustained proactive telephone counseling, on smoking abstinence in hospitalized patients. Key secondary aims are to determine the impact of the intervention on staff nurses' attitudes toward providing smoking cessation counseling; to identify barriers and facilitators to implementation of smoking cessation guidelines in VA hospitals; and to determine the short-term cost-effectiveness of implementing the intervention. Design Pre-post study design in four VA hospitals Participants Hospitalized patients, aged 18 or older, who smoke at least one cigarette per day. Intervention The intervention will include: nurse training in delivery of bedside cessation counseling, electronic medical record tools (to streamline nursing assessment and documentation, to facilitate prescription of pharmacotherapy), computerized referral of motivated inpatients for proactive telephone counseling, and use of internal nursing facilitators to provide coaching to staff nurses practicing in non-critical care inpatient units. Outcomes The primary endpoint is seven-day point prevalence abstinence at six months following hospital admission and prolonged abstinence after a one-month grace period. To compare abstinence rates during the intervention and baseline periods, we will use random effects logistic regression models, which take the clustered nature of the data within nurses and hospitals into account. We will assess attitudes of staff nurses toward cessation counseling by questionnaire and will identify barriers and facilitators to implementation by using clinician focus groups. To determine the short-term incremental cost per quitter from the perspective of the VA health care system, we will calculate cessation-related costs incurred during the initial hospitalization and six-month follow-up period. Trial number NCT00816036http://deepblue.lib.umich.edu/bitstream/2027.42/112349/1/13012_2009_Article_190.pd