Higher atypical enteropathogenic Escherichia coli (a-EPEC) bacterial loads in children with diarrhea are associated with PCR detection of the EHEC factor for adherence 1/lymphocyte inhibitory factor A (efa1/lifa) gene

Background

Typical enteropathogenic Escherichia coli (t-EPEC) are known to cause diarrhea in children but it is uncertain whether atypical EPEC (a-EPEC) do, since a-EPEC lack the bundle-forming pilus (bfp) gene that encodes a key adherence factor in t-EPEC. In culture-based studies of a-EPEC, the presence of another adherence factor, called EHEC factor for adherence/lymphocyte activation inhibitor (efa1/lifA), was strongly associated with diarrhea. Since a-EPEC culture is not feasible in clinical laboratories, we designed an efa1/lifA quantitative PCR assay and examined whether the presence of efa1/lifA was associated with higher a-EPEC bacterial loads in pediatric diarrheal stool samples.

Methods

Fecal samples from children with diarrhea were tested by qPCR for EPEC (presence of eae gene) and for shiga toxin genes to exclude enterohemorrhagic E. coli, which also contain the eae gene. EPEC containing samples were then tested for the bundle-forming pilus gene found in t-EPEC and efa1/lifA. The eae gene quantity in efa1/lifA-positive and negative samples was compared.

Results

Thirty-nine of 320 (12%) fecal samples tested positive for EPEC and 38/39 (97%) contained a-EPEC. The efa1/lifA gene was detected in 16/38 (42%) a-EPEC samples. The median eae concentration for efa1/lifA positive samples was significantly higher than for efa1/lifA negative samples (median 16,745 vs. 1183 copies/µL, respectively, p = 0.006).

Conclusions

Atypical enteropathogenic E. coli-positive diarrheal stool samples containing the efa1/lifA gene had significantly higher bacterial loads than samples lacking this gene. This supports the idea that efa1/lifA contributes to diarrheal pathogenesis and suggests that, in EPEC-positive samples, efa/lifA may be a useful additional molecular biomarker.

Transformational leadership, well-being, morale, and readiness: The mediating role of empowerment

Transformational leadership is embedded in the value system of the Canadian military ethos. Research suggests that transformational leadership can be viewed as a form of empowering leadership facilitating empowered psychological states among their followers, which in turn, enhances their performance, wellbeing, and engagement. The current study examined the associations between transformational leadership and Canadian Armed Forces members' psychological distress, morale, and pre-deployment readiness and the mediating role of psychological empowerment in these relationships. A path analysis model of the data collected through a pre-deployment survey completed by Canadian Armed Force (CAF) members (N = 2,391) revealed that transformational leadership was associated with lower psychological distress and greater morale and these relationships were partly explained by increased feelings of empowerment, namely higher levels of autonomy, competence, and meaning. Furthermore, transformational leadership was also associated with higher perceptions of pre-deployment readiness, and this was partly explained by increased feelings of meaning and competence. The results of this research suggest that transformational leadership is an effective strategy to bolster psychological resources and readiness in the CAF.