Peer Support and Crisis-Focused Psychological Interventions Designed to Mitigate Post-Traumatic Stress Injuries among Public Safety and Frontline Healthcare Personnel: A Systematic Review

Public safety personnel (PSP) and frontline healthcare professionals (FHP) are frequently exposed to potentially psychologically traumatic events (PPTEs), and report increased rates of post-traumatic stress injuries (PTSIs). Despite widespread implementation and repeated calls for research, effectiveness evidence for organizational post-exposure PTSI mitigation services remains lacking. The current systematic review synthesized and appraised recent (2008-December 2019) empirical research from 22 electronic databases following a population-intervention-comparison-outcome framework. Eligible studies investigated the effectiveness of organizational peer support and crisis-focused psychological interventions designed to mitigate PTSIs among PSP, FHP, and other PPTE-exposed workers. The review included 14 eligible studies (n = 18,849 participants) that were synthesized with qualitative narrative analyses. The absence of pre-post-evaluations and the use of inconsistent outcome measures precluded quantitative meta-analysis. Thematic services included diverse programming for critical incident stress debriefing, critical incident stress management, peer support, psychological first aid, and trauma risk management. Designs included randomized control trials, retrospective cohort studies, and cross-sectional studies. Outcome measures included PPTE impacts, absenteeism, substance use, suicide rates, psychiatric symptoms, risk assessments, stigma, and global assessments of functioning. Quality assessment indicated limited strength of evidence and failures to control for pre-existing PTSIs, which would significantly bias program effectiveness evaluations for reducing PTSIs post-PPTE.

Sulfur Respiration in a Group of Facultatively Anaerobic Natronoarchaea Ubiquitous in Hypersaline Soda Lakes

The ubiquity of strictly anaerobic sulfur-respiring haloarchaea in hypersaline systems with circumneutral pH has shaken a traditional concept of this group as predominantly aerobic heterotrophs. Here, we demonstrated that this functional group of haloarchaea also has its representatives in hypersaline alkaline lakes. Sediments from various hypersaline soda lakes showed high activity of sulfur reduction only partially inhibited by antibiotics. Eight pure cultures of sulfur-reducing natronoarchaea were isolated from such sediments using formate and butyrate as electron donors and sulfur as an electron acceptor. Unlike strict anaerobic haloarchaea, these novel sulfur-reducing natronoarchaea are facultative anaerobes, whose metabolic capabilities were inferred from cultivation experiments and genomic/proteomic reconstruction. While sharing many physiological traits with strict anaerobic haloarchaea, following metabolic distinctions make these new organisms be successful in both anoxic and aerobic habitats: the recruiting of heme-copper quinol oxidases as terminal electron sink in aerobic respiratory chain and the utilization of formate, hydrogen or short-chain fatty acids as electron donors during anaerobic growth with elemental sulfur. Obtained results significantly advance the emerging concept of halo(natrono)archaea as important players in the anaerobic sulfur and carbon cycling in various salt-saturated habitats.

Structural composition of alternative complex III: variations on the same theme

Alternative complex III forms a recently identified family of enzymes with quinol:electron acceptor oxidoreductase activity. First biochemical and genomic analyses showed that ACIII is composed of six to eight subunits, most of which homologous to different proteins or domains already observed in other known enzymatic complexes. The increasing number of completely sequenced genomes led us to perform a new search for the genes coding for the different ACIII subunits. We have identified a larger number of gene clusters coding for ACIII, still confined to the bacterial domain, but extended to classes in which it was not observed before. We also found an unanticipated diversity in gene clusters, both in terms of its constitution and organization. The several unexpected gene arrangements brought new perspectives to the role of the different subunits of ACIII, namely in quinone binding and in proton translocation. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.