Evaluation of the limitations and methods to improve rapid phage-based detection of viable Mycobacterium avium subsp. paratuberculosis in the blood of experimentally infected cattle

Background Disseminated infection and bacteraemia is an underreported and under-researched aspect of Johne’s disease. This is mainly due to the time it takes for Mycobacterium avium subsp. paratuberculosis (MAP) to grow and lack of sensitivity of culture. Viable MAP cells can be detected in the blood of cattle suffering from Johne’s disease within 48 h using peptide-mediated magnetic separation (PMMS) followed by bacteriophage amplification. The aim of this study was to demonstrate the first detection of MAP in the blood of experimentally exposed cattle using the PMMS-bacteriophage assay and to compare these results with the immune response of the animal based on serum ELISA and shedding of MAP by faecal culture. Results Using the PMMS-phage assay, seven out of the 19 (37 %) MAP-exposed animals that were tested were positive for viable MAP cells although very low numbers of MAP were detected. Two of these animals were positive by faecal culture and one was positive by serum ELISA. There was no correlation between PMMS-phage assay results and the faecal and serum ELISA results. None of the control animals (10) were positive for MAP using any of the four detection methods. Investigations carried out into the efficiency of the assay; found that the PMMS step was the limiting factor reducing the sensitivity of the phage assay. A modified method using the phage assay directly on isolated peripheral blood mononuclear cells (without PMMS) was found to be superior to the PMMS isolation step. Conclusions This proof of concept study has shown that viable MAP cells are present in the blood of MAP-exposed cattle prior to the onset of clinical signs. Although only one time point was tested, the ability to detect viable MAP in the blood of subclinically infected animals by the rapid phage-based method has the potential to increase the understanding of the pathogenesis of Johne’s disease progression by warranting further research on the presence of MAP in blood

Paratuberculosis sero-status and milk production, SCC and calving interval in Irish dairy herds

The objective of this study was to investigate the impact of paratuberculosis sero-status on milk yield, fat, protein, somatic cell count and calving interval in Irish dairy herds. Serum from all animals over 12 months of age (n = 2,602) in 34 dairy herds was tested for antibodies to Mycobacterium avium subsp. paratuberculosis using an ELISA. Herds were categorised by sero-status into positive, non-negative and negative, where a positive herd contained two or more positive cows, a non-negative herd contained only one positive cow and a negative herd contained no positive cows. Data at animal, parity and herd-level were analysed by multiple regression using general linear models. Positive herds (mean herd size = 129 cows) and non-negative herds (81 cows) were larger than negative herds (72 cows) (P < 0.01). Negative herds had the highest economic breeding index (EBI), while positive herds had the highest estimated breeding value (EBV) for milk yield. There was no significant effect of paratuberculosis sero-status at animal, parity or herd-level on milk yield, milk fat or protein production, somatic cell count score (SCCS) or calving interval. Negative herds tended to have a lower SCCS than positive and nonnegative herds (P = 0.087). This study only examined the effects of paratuberculosis sero-status but did not examine the clinical effects of Johne's disease at the farm or dairy industry levels

Integrating research and practice: A holistic, multi‐site and process‐oriented action research designed to build community disaster capacity

This presentation introduces a novel research design: an holistic, multi-site and processoriented action research designed to empower individuals and communities to build up their capacity for coping with natural disasters. This approach will seek both generic and specific solutions, applicable to hazards more broadly as well as the identification of solutions that appear to be hazard specific. In so doing the research design takes a multi-level perspective and investigates the influence of individuals within communities, and their reciprocal interactions. Based on a synergy of four theoretical frameworks paradigms (i.e., salutogenicparadigm, symbolic interactionism, narrative theory, systems theory), the research will merge three qualitative methodologies (i.e., grounded theory, multi-side ethnography, multi-side action research) to inform both theory and measurement of relevant constructs.In the first phase of the research, we will collect data with a combination of participant observation, episodic interviews, and surveys. The aim is to identify and describe similarities and differences between communities with respect to, for example, the influence networks, emergent community leadership characteristics and community proactivity. In the second phase, we will model differences between communities to identify statistically reliable effects with a view to develop effective and efficient interventions which will promote community proactivity, capacity and resilience. In the third phase, we will collaboratively with the communities identify, design and implement interventions based on the research findings. The outcomes of these interventions will be assessed and reflected onin phase four of the project. Throughout the project, the data from the case studies will be compared to identify thecharacteristics and processes that contribute to enhancing the resilience of individuals and communities

Information processing in the face of threat:A Multilevel Research Perspective

The lessons drawn from the 2003 Victorian bushfires suggest that community and socialcontext,information and its sources, and anxiety and emotional regulationcrucially influence preparing for and responding to bushfires(McLennan &amp; Elliott, 2010). This presentation discusses a three year research programthat will explore the combined and interactive role of these three factors in decision making.At the community level, individual behaviours in terms of preparing for and responding to an immediate threat are influenced by community characteristics. While large differences in community preparedness and responses are observed, as yet we appear to have no systematic account of how or why these differences exist.To address this gapa project entitled &ndash; &ldquo;Community level influence on individual behaviours with respect to bushfire readiness and decision making in the face of immediate threat.&rdquo; - aims at systematically identifying what factors and processes distinguish communities which are more prepared from those which areless prepared. It also endeavours to identify, implement, and assess interventions at the community level that improve preparedness and response.Prior to and during a disaster, individuals seek and/or receive information,process the information,and act. However, decisions made under stress are frequently impulsive, based on imperfect information, and rigid. In many instances fear interferes with the mitigationof danger, resulting in bad decisions. Accordingly, a second project - &ldquo;Information processing under stress: Community reactions&rdquo; - seeks to understand the role fear plays when community members process the information they receive in the lead up to, and during, the bushfire season, as well as during bushfire emergencies.It aims toidentify how individuals use information and warnings to guide their actions, what information should or should not be provided, how and when information is best delivered. How the community context moderates the effectiveness of these messages will be informed by findings from the community level project described previously.At the individual level, research in clinical settings has shown how people varysystematically with respect to their typical attentional responses to threat cues. Some people tend to deliberately avoid or ignore threat cues. Other people tend to be especially vigilant for threat cues. Both low and high levels of dispositional anxiety can impair decision-making and actiontaking capabilities. The goal ofthis project - &ldquo;Managing the threat through the modification of thought&rdquo; &ndash; is to develop an effective self administered cognitive bias modification program that trains adaptive attentional styles for specific stress inducing events such as bushfires