Investigation of a severe SARS-CoV-2 outbreak in a long-term care home early in the pandemic.

BACKGROUND: The implementation of outbreak management measures has decreased the frequency and severity of SARS-CoV-2 outbreaks in Ontario long-term care homes. We describe the epidemiological and laboratory data from one of the first such outbreaks in Ontario to assess factors associated with its severity, and the impact of progressive interventions for infection control over the course of the outbreak. METHODS: We obtained line list and outbreak data from the public health unit to describe resident and staff cases, severity and distribution of cases over time and within the outbreak facility. Where available, we obtained data on laboratory specimens from the Public Health Ontario Laboratory and performed whole genome sequencing and phylogenetic analysis of viral specimens from the outbreak. RESULTS: Among 65 residents of the long-term care home, 61 (94%) contracted SARS-CoV-2, with a case fatality rate of 45% (28/61). Among 67 initial staff, 34 (51%) contracted the virus and none died. When the outbreak was declared, 12 staff, 2 visitors and 9 residents had symptoms. Resident cases were located in 3 of 4 areas of the home. Phylogenetic analysis showed tight clustering of cases, with only 1 additional strain of genetically distinct SARS-CoV-2 identified from a staff case in the third week of the outbreak. No cases were identified among 26 new staff brought into the home after full outbreak measures were implemented. INTERPRETATION: Rapid and undetected viral spread in a long-term care home led to high rates of infection among residents and staff. Progressive implementation of outbreak measures after the peak of cases prevented subsequent staff cases and are now part of long-term care outbreak policy in Ontario.

An Examination of Myers-Briggs Type Indicator Personality, Gender, and Career Interests of Ontario Veterinary College Students.

The objectives of this study were to describe the Myers-Briggs Type Indicator (MBTI) distribution of Ontario Veterinary College (OVC) veterinary students (n = 1,249), and to evaluate its associations with gender and career interests. This was achieved by collecting pre-matriculation data from 11 graduating classes. Overall, OVC veterinary students were diverse in their MBTI types and preferences, as well as career interests. Extraversion, Sensing, Thinking, and Judging were the most prevalent preferences. Female veterinary students were 2.96 (95% CI = 2.11-4.17) times more likely to demonstrate the Feeling preference and 1.89 (95% CI = 1.41-2.56) more likely to prefer Judging, compared to male students (who were more likely to prefer the Thinking and Perceiving preferences, respectively). At entry to the veterinary program, students who preferred Intuition (vs. Sensing) were 2.08 (95% CI = 1.33-3.33) times more likely to be interested in a veterinary career other than practice, and 1.92 (95% CI = 1.43-2.56) times more likely to be undecided about their future veterinary career path. Both at entry to the program and in their final-year stream choice, students of the Thinking preference were more likely to select equine or food animal, rather than small animal practice, compared to students of the Feeling preference. There were additional significant associations regarding MBTI preferences and career interests. This study highlights the diversity of veterinary students, and provides an opportunity for educators to potentially expand their teaching methods and career guidance resources to better reach students of all MBTI preferences.

Enquête sur une éclosion importante de SRAS-CoV-2 dans un établissement de soins de longue durée au début de la pandémie.

CONTEXTE: Le déploiement de mesures de gestion des éclosions de SRAS-CoV-2 dans les établissements de soins de longue durée en Ontario a permis d'en réduire la fréquence et la gravité. Nous décrivons ici les données épidémiologiques et de laboratoire d'une de ces premières éclosions en Ontario afin de déterminer les facteurs associés à son importance et les impacts des interventions progressives de lutte contre les infections appliquées pendant la durée de l'éclosion. MÉTHODES: Nous avons obtenu du bureau de santé la liste des cas et les données de l'éclosion afin de décrire les cas chez les résidents et le personnel, leur gravité et leur distribution dans le temps et à l'intérieur de l'établissement touché. Quand elles étaient disponibles, nous avons obtenu des données concernant les échantillons soumis au laboratoire de Santé publique Ontario et effectué un séquençage complet et une analyse phylogénétique des échantillons viraux de l'éclosion. RÉSULTATS: Sur les 65 résidents de l'établissement de soins de longue durée, 61 (94 %) ont contracté le SRAS-CoV-2, le taux de létalité étant de 45 % (28/61). Parmi les 67 employés initiaux, 34 (51 %) ont contracté le virus, et aucun n'est décédé. Lorsque l'éclosion a été déclarée, 12 employés, 2 visiteurs et 9 résidents présentaient des symptômes. Parmi les résidents, les cas se trouvaient dans 3 des 4 secteurs de l'établissement. L'analyse phylogénétique a montré une forte similitude des séquences; une seule autre souche de SRAS-CoV-2 génétiquement distincte a été identifiée chez un employé à la troisième semaine de l'éclosion. Après le déploiement de toutes les mesures de gestion de l'éclosion, aucun cas n'a été identifié parmi les 26 nouveaux employés appelés en renfort. INTERPRÉTATION: La propagation rapide et non détectée du virus dans un établissement de soins de longue durée a donné lieu à des taux élevés d'infection chez les résidents et le personnel. L'application progressive de mesures de gestion après le pic de l'éclosion a permis d'éviter la contamination du personnel appelé en renfort et fait désormais partie des politiques à long terme de prévention des éclosions en Ontario.

Mindfulness-and body-psychotherapy-based group treatment of chronic tinnitus: a randomized controlled pilot study.

BACKGROUND: Tinnitus, the perception of sound in absence of an external acoustic source, impairs the quality of life in 2% of the population. Since in most cases causal treatment is not possible, the majority of therapeutic attempts aim at developing and strengthening individual coping and habituation strategies. Therapeutic interventions that incorporate training in mindfulness meditation have become increasingly popular in the treatment of stress-related disorders. Here we conducted a randomized, controlled clinical study to investigate the efficacy of a specific mindfulness- and body-psychotherapy based program in patients suffering from chronic tinnitus. METHODS: Thirty-six patients were enrolled in this pilot study. The treatment was specifically developed for tinnitus patients and is based on mindfulness and body psychotherapy. Treatment was performed as group therapy at two training weekends that were separated by an interval of 7 weeks (eleven hours/weekend) and in four further two-hour sessions (week 2, 9, 18 and 22). Patients were randomized to receive treatment either immediately or after waiting time, which served as a control condition. The primary study outcome was the change in tinnitus complaints as measured by the German Version of the Tinnitus Questionnaire (TQ). RESULTS: ANOVA testing for the primary outcome showed a significant interaction effect time by group (F = 7.4; df = 1,33; p = 0.010). Post hoc t-tests indicated an amelioration of TQ scores from baseline to week 9 in both groups (intervention group: t = 6.2; df = 17; p < 0.001; control group: t = 2.5; df = 16; p = 0.023), but the intervention group improved more than the control group. Groups differed at week 7 and 9, but not at week 24 as far as the TQ score was concerned. CONCLUSIONS: Our results suggest that this mindfulness- and body-psychotherapy-based approach is feasible in the treatment of tinnitus and merits further evaluation in clinical studies with larger sample sizes.The study is registered with clinicaltrials.gov (NCT01540357).

Requirements for the import of neisserial Omp85 into the outer membrane of human mitochondria.

ß-Barrel proteins are present only in the outer membranes of Gram-negative bacteria, chloroplasts and mitochondria. Fungal mitochondria were shown to readily import and assemble bacterial ß-barrel proteins, but human mitochondria exhibit certain selectivity. Whereas enterobacterial ß-barrel proteins are not imported, neisserial ones are. Of those, solely neisserial Omp85 is integrated into the outer membrane of mitochondria. In this study, we wanted to identify the signal that targets neisserial ß-barrel proteins to mitochondria. We exchanged parts of neisserial Omp85 and PorB with their Escherichia coli homologues BamA and OmpC. For PorB, we could show that its C-terminal quarter can direct OmpC to mitochondria. In the case of Omp85, we could identify several amino acids of the C-terminal ß-sorting signal as crucial for mitochondrial targeting. Additionally, we found that at least two POTRA (polypeptide-transport associated) domains and not only the ß-sorting signal of Omp85 are needed for its membrane integration and function in human mitochondria. We conclude that the signal that directs neisserial ß-barrel proteins to mitochondria is not conserved between these proteins. Furthermore, a linear mitochondrial targeting signal probably does not exist. It is possible that the secondary structure of ß-barrel proteins plays a role in directing these proteins to mitochondria.

Interference of components of the phosphoenolpyruvate phosphotransferase system with the central virulence gene regulator PrfA of Listeria monocytogenes.

Analysis of Listeria monocytogenes ptsH, hprK, and ccpA mutants defective in carbon catabolite repression (CCR) control revealed significant alterations in the expression of PrfA-dependent genes. The hprK mutant showed high up-regulation of PrfA-dependent virulence genes upon growth in glucose-containing medium whereas expression of these genes was even slightly down-regulated in the ccpA mutant compared to the wild-type strain. The ptsH mutant could only grow in a rich culture medium, and here the PrfA-dependent genes were up-regulated as in the hprK mutant. As expected, HPr-Ser-P was not produced in the hprK and ptsH mutants and synthesized at a similar level in the ccpA mutant as in the wild-type strain. However, no direct correlation was found between the level of HPr-Ser-P or HPr-His-P and PrfA activity when L. monocytogenes was grown in minimal medium with different phosphotransferase system (PTS) carbohydrates. Comparison of the transcript profiles of the hprK and ccpA mutants with that of the wild-type strain indicates that the up-regulation of the PrfA-dependent virulence genes in the hprK mutant correlates with the down-regulation of genes known to be controlled by the efficiency of PTS-mediated glucose transport. Furthermore, growth in the presence of the non-PTS substrate glycerol results in high PrfA activity. These data suggest that it is not the component(s) of the CCR or the common PTS pathway but, rather, the component(s) of subsequent steps that seem to be involved in the modulation of PrfA activity.

Inefficient replication of Listeria innocua in the cytosol of mammalian cells.

The efficiency of adherence to, internalization by, and replication in the cytosol of J774 macrophages and HEp-2 epithelial cells was compared between a nonspreading Listeria monocytogenes actA mutant and L. innocua. The studied L. innocua strains were equipped either with listeriolysin alone or with listeriolysin O (LLO) and the recently identified hexose-phosphate transporter of L. monocytogenes. All listerial strains expressed green fluorescent protein (GFP) under the control of the PrfA-dependent actA promoter. GFP expression was observed exclusively in the cytosol of host cells. Escape from the phagosome of LLO-expressing L. innocua strains was as efficient as that from L. monocytogenes. hpt-positive L. innocua showed significantly enhanced adherence to HEp-2 cells, but internalization was only slightly increased, compared with hpt-negative L. innocua. Subsequent replication of L. monocytogenes in the cytosol of the host cells proceeded within the next 6 h in most infected host cells, with a generation time <40 min. L. innocua prfA hly replicated more slowly (with a generation time of 60-90 min), and, in most host cells, bacterial replication stopped after 2-3 rounds of replication. In some cells, bacterial replication did not occur. Twenty-four hours after infection, the majority of J774 cells (>90%) infected with L. monocytogenes actA were dead, whereas most host cells infected with L. innocua were still alive. L. innocua equipped with the prfA, hly, and hpt genes of L. monocytogenes did not show significantly increased cytosolic replication, which indicates that expression of this sugar phosphate uptake system is not sufficient for extensive listerial replication in the cytosol of host cells.

InlA- but not InlB-mediated internalization of Listeria monocytogenes by non-phagocytic mammalian cells needs the support of other internalins.

To determine the contribution of the previously identified internalins, InlA, InlB, InlC, InlE, InlG, and InlH, to internalization of Listeria monocytogenes by non-professional phagocytic mammalian cells, we constructed mutants with various combinations of deletions in the respective inl genes. Internalization of these mutants into the epithelial-like Caco-2 and the microvascular endothelial HBMEC cell lines were studied. Deletion of the inlGHE gene cluster, or of the single genes, led to a two to fourfold increased internalization by HBMEC and other non-phagocytic mammalian cells. Invasion into HBMEC was totally blocked in the absence of InlB, and InlB-dependent internalization did not require the presence of any of the other internalins. Internalization by Caco-2 cells was reduced to a level of about 1% in the absence of InlA and InlB, and was most efficient in the presence of InlA, InlB and InlC and in the absence of InlG, InlH and InlE. InlB and InlA, in each case in the absence of the other internalins, led (compared with the wild-type strain) to reduced internalization of about 20% and less than 10% respectively. InlA-dependent internalization (in the absence of InlB) required the additional function of InlC and InlGHE. The deletion of inlGHE enhanced the expression of InlA and InlB. The increased amount of InlA led to an increase in early association of L. monocytogenes with Caco-2 cells without enhancing its uptake in the absence of the other internalins, whereas the larger amount of InlB did not enhance early association of L. monocytogenes with HBMEC but led to an increase in internalization of L. monocytogenes. The results suggest that InlB is able to induce phagocytosis in HBMEC and (at a lower efficiency) in Caco-2 cells by itself, but InlA needs the supportive functions of the other internalins to trigger phagocytosis. None of these internalins seems to be required for cell-to-cell spread by L. monocytogenes, as shown by microinjection of Caco-2 cells with appropriate inl mutants.