Publications by authors named "Jeffrey Liang"

2 Publications

  • Page 1 of 1

Local adaptation of within a hospital hot water system increases tolerance to copper.

Appl Environ Microbiol 2021 Mar 5. Epub 2021 Mar 5.

Department of Civil Engineering, Polytechnique Montréal, Montréal, QC, Canada.

In large-building water systems, is exposed to common environmental stressors such as copper. The aim of this study was to evaluate the susceptibility to copper of isolates recovered from various sites: two clinical and seven environmental from hot water systems biofilm & water, and from cooling tower water. After one-week acclimation in simulated drinking water, strains were exposed to various copper concentrations (0.8 to 5 mg/L) for over 672 hours. Complete loss of culturability was observed for three isolates, following copper exposure to 5 mg/L for 672h. Two ST1427-like isolates were highly sensitive to copper, while the other two, isolated from biofilm samples, maintained higher culturability. The expression of the copper resistance gene evaluated by RT-qPCR was significantly higher for the biofilm isolates. All four ST1427-like isolates were recovered from the same water system during an outbreak. Whole genome sequencing results confirmed that the four isolates are very close phylogenetically, differing by only 29 single nucleotide polymorphisms, suggesting adaptation to microenvironmental conditions, possibly due to epigenetic regulation. These results indicate that the immediate environment within a building water distribution system influences the tolerance of to copper. Increased contact of biofilm strains with copper piping or copper alloys in the heat exchanger might lead to local adaptation. The phenotypic differences observed between water and biofilm isolates from the hot water system of a healthcare facility warrants further investigation to assess the relevance of evaluating disinfection performances based on water sampling alone. is a pathogen indigenous to natural and large building water systems in the bulk and the biofilm phases. The immediate environment within a system can impact the tolerance of to environmental stressors, including copper. In healthcare facilities, copper levels in water can vary, depending on water quality, plumbing materials and age. This study evaluated the impact of the isolation site (water vs biofilm, hot water system vs cooling tower) within building water systems. Closely related strains isolated from a healthcare facility hot water system exhibited variable tolerance to copper stress shown by differential expression of , with biofilm isolates displaying highest expression and tolerance. Relying on the detection of in water samples following exposure to environmental stressor such as copper may underestimate the prevalence of , leading to inappropriate risk management strategies and increasing the risk of exposure for vulnerable patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AEM.00242-21DOI Listing
March 2021

Social Interaction Skill Intervention for Autistic Adults with Intellectual Disability and Limited Language: A Pilot of the SKILL Program.

J Autism Dev Disord 2020 Aug 18. Epub 2020 Aug 18.

Koegel Autism Center, University of California Santa Barbara, Santa Barbara, CA, USA.

There is a dearth of research that focuses on social intervention efforts for adults on the autism spectrum with intellectual disability and limited conversational language. Using a multiple baseline experimental design, this pilot investigation of the Socialization Knowledge for Individuals with Limited Language (SKILL) program evaluated a novel peer-facilitated group program specifically designed to target social interaction skills for this population. Findings from five pilot participants yielded evidence of social improvements across specific verbal skills (on-topic conversational contributions and responses) and nonverbal behaviors (eye-contact, active listening), as evidenced by coded social conversation probes and parent-report measures. These findings demonstrate the promise of a socialization intervention for a population that has historically been neglected in the social intervention research literature.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10803-020-04659-1DOI Listing
August 2020