Whole-genome Sequencing to Track Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission in Nosocomial Outbreaks.

BACKGROUND: During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in healthcare institutions posed a significant problem. Due to limited evidence, guidance on appropriate infection prevention and control (IPC) measures such as the wearing of face masks varied. Here, we applied whole virus genome sequencing (WvGS) to analyze transmission routes of SARS-CoV-2 in hospital-acquired (HA) COVID-19. METHODS: An investigation was undertaken for all HA cases of COVID-19 from March to April 2020. Fifty SARS-CoV-2 samples were analysed by WvGS and their phylogenetic relationship established. RESULTS: WvGS identified transmission events previously undetected by epidemiological analysis and provided evidence for SARS-CoV-2 transmission between healthcare workers (HCW) and patients and among HCW themselves. The majority of HA COVID-19 cases occurred in patients highly dependent on nursing care, suggesting the likely route of transmission was by close contact or droplet, rather than aerosol, transmission. Mortality among HA COVID-19 infections was recorded as 33%. CONCLUSIONS: This study provides evidence that SARS-CoV-2 transmission occurs from symptomatic and asymptomatic HCWs to patients. Interventions including comprehensive screening of HCWs for COVID-19 symptoms, PCR testing of asymptomatic HCWs upon identification of HA cases and implementation of universal use of surgical masks for all clinical care is indicated to prevent viral transmission. Our study highlights the importance of close collaboration between guidance bodies and frontline IPC experts for developing control measures in an emergency pandemic situation caused by a virus with undefined transmission modus.

Bifidobacteriumbreve Bif195 Protects Against Small-Intestinal Damage Caused by Acetylsalicylic Acid in Healthy Volunteers.

BACKGROUND & AIMS: Enteropathy and small-intestinal ulcers are common adverse effects of nonsteroidal anti-inflammatory drugs such as acetylsalicylic acid (ASA). Safe, cytoprotective strategies are needed to reduce this risk. Specific bifidobacteria might have cytoprotective activities, but little is known about these effects in humans. We used serial video capsule endoscopy (VCE) to assess the efficacy of a specific Bifidobacterium strain in healthy volunteers exposed to ASA. METHODS: We performed a single-site, double-blind, parallel-group, proof-of-concept analysis of 75 heathy volunteers given ASA (300 mg) daily for 6 weeks, from July 31 through October 24, 2017. The participants were randomly assigned (1:1) to groups given oral capsules of Bifidobacterium breve (Bif195) (≥5 × 1010 colony-forming units) or placebo daily for 8 weeks. Small-intestinal damage was analyzed by serial VCE at 6 visits. The area under the curve (AUC) for intestinal damage (Lewis score) and the AUC value for ulcers were the primary and first-ranked secondary end points of the trial, respectively. RESULTS: Efficacy data were obtained from 35 participants given Bif195 and 31 given placebo. The AUC for Lewis score was significantly lower in the Bif195 group (3040 ± 1340 arbitrary units) than the placebo group (4351 ± 3195) (P = .0376). The AUC for ulcer number was significantly lower in the Bif195 group (50.4 ± 53.1 arbitrary units) than in the placebo group (75.2 ± 85.3 arbitrary units) (P = .0258). Twelve adverse events were reported from the Bif195 group and 20 from the placebo group. None of the events was determined to be related to Bif195 intake. CONCLUSIONS: In a randomized, double-blind trial of healthy volunteers, we found oral Bif195 to safely reduce the risk of small-intestinal enteropathy caused by ASA. ClinicalTrials.gov no: NCT03228589.

A universal stress protein upregulated by hypoxia has a role in Burkholderia cenocepacia intramacrophage survival: Implications for chronic infection in cystic fibrosis.

Universal stress proteins (USPs) are ubiquitously expressed in bacteria, archaea, and eukaryotes and play a lead role in adaptation to environmental conditions. They enable adaptation of bacterial pathogens to the conditions encountered in the human niche, including hypoxia, oxidative stress, osmotic stress, nutrient deficiency, or acid stress, thereby facilitating colonization. We previously reported that all six USP proteins encoded within a low-oxygen activated (lxa) locus in Burkholderia cenocepacia showed increased abundance during chronic colonization of the cystic fibrosis (CF) lung. However, the role of USPs in chronic cystic fibrosis infection is not well understood. Structural modeling identified surface arginines on one lxa-encoded USP, USP76, which suggested it mediated interactions with heparan sulfate. Using mutants derived from the B. cenocepacia strain, K56-2, we show that USP76 is involved in host cell attachment. Pretreatment of lung epithelial cells with heparanase reduced the binding of the wild-type and complement strains but not the Δusp76 mutant strain, indicating that USP76 is directly or indirectly involved in receptor recognition on the surface of epithelial cells. We also show that USP76 is required for growth and survival in many conditions associated with the CF lung, including acidic conditions and oxidative stress. Moreover, USP76 also has a role in survival in macrophages isolated from people with CF. Overall, while further elucidation of the exact mechanism(s) is required, we can conclude that USP76, which is upregulated during chronic infection, is involved in bacterial survival within CF macrophages, a hallmark of Burkholderia infection.

Case of recurrent Achromobacter xylosoxidans bacteraemia and PICC (peripherally-inserted central catheter) line infection in an immunocompromised patient.

BACKGROUND: This report describes recurrent A. xylosoxidans bloodstream and PICC (peripherally-inserted central catheter) line infection in an immunocompromised patient. PRESENTATION OF CASE: A 64-year-old female with acute promyelocytic leukaemia presented during a non-neutropenic febrile episode, and A. xylosoxidans was isolated from multiple PICC and peripheral blood cultures, and from the tip of the line on removal. The patient was treated with meropenem and a new PICC line was inserted after sterile blood cultures. Six weeks later, she represented with A. xylosoxidans from multiple cultures from the line. She was treated with piperacillin-tazobactam and the line was removed. There was no evidence of deep-seated infection. Further discussion revealed that the patient was using a sponge to clean, and a sleeve to cover her PICC-line while bathing. A. xylosoxidans was cultured from both the sponge and the swab. Whole Genome Sequencing performed on two blood culture isolated and both environmental isolates confirmed all four isolates were indistinguishable. The patient was advised not to use the sponge/sleeve in future and we have incorporated specific advice in this regard into our patient information. DISCUSSION: Achromobacter xylosoxidans is an aerobic, non-lactose fermenting gram-negative bacillus usually considered an opportunistic pathogen. It is associated with infection in immunocompromised patients, and is an emerging pathogen in catheter-related infections, sometimes associated with contaminated water. CONCLUSION: This case of recurrent A. xylosoxidans line infection highlights diagnostic and management challenges associated with catheter-related infections. Treatment is challenging because of intrinsic and acquired resistance mechanisms. Empiric treatment with anti-pseudomonal penicillins or carbapenems with line removal is typically required.

Atypical presentation of Abiotrophia defectiva infective endocarditis in an octogenarian.

Blood cultures should be performed in non-specifically unwell older adults following nonspecific presentations. Prompt diagnosis and commencement of targeted antimicrobial therapy are essential in older patients with A. defectiva IE.

Impacts of small vestibular schwannoma on community ambulation, postural, and ocular control.

OBJECTIVES/HYPOTHESIS: To investigate balance, community mobility, gaze instability, and dizziness handicap and assess falls risk in people who are conservatively managed with small vestibular schwannoma (VS). STUDY DESIGN: Cross-sectional study with controls. METHODS: The study involved 18 people (mean age 58.7 ± 12.2 years) diagnosed with VS (<12 mm) and 22 age-matched controls (mean age 56.9 ± 8.0 years). Measures included standing on firm and foam surfaces with feet apart, then together with eyes open and closed, Timed Up and Go (TUG) test and dual TUG test, Dynamic Gait Index, 6-Minute Walk Test, Halmagyi Impulse Test, Dynamic Visual Acuity Test, and the Dizziness Handicap Inventory. RESULTS: The clinical group failed more trials standing feet together on foam with eyes closed (P < .05); had inferior mobility and walked more slowly with divided attention (P < .05); had more difficulty walking with head movement, negotiating obstacles, and using stairs (P < .01); and walked shorter distances (P < .001) than controls. Reduced gaze stability (P < .01) and higher total (P = .007) and subcategory dizziness handicap scores (P < .05) were revealed compared to age-matched controls. CONCLUSIONS: Although outcomes for the clinical group are inferior to the control group across all measures and the dizziness impact is higher, the results fall in the low-risk category for falls. Preliminary data (level 4 evidence) support using a suite of clinical measures to monitor people with VS during conservative management. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:1147-1152, 2017.