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1. Detection of air and surface contamination by SARS-CoV-2 in hospital rooms of infected patients

Author

Po Ying Chia, Kristen Kelli Coleman, Yian Kim Tan, Sean Wei Xiang Ong, Marcus Gum, Sok Kiang Lau, Xiao Fang Lim, Ai Sim Lim, Stephanie Sutjipto, Pei Hua Lee, Than The Son, Barnaby Edward Young, Donald K. Milton, Gregory C. Gray, Stephan Schuster, Timothy Barkham, Partha Pratim De, Shawn Vasoo, Monica Chan, Brenda Sze Peng Ang, Boon Huan Tan, Yee-Sin Leo, Oon-Tek Ng, Michelle Su Yen Wong, Kalisvar Marimuthu, and for the Singapore 2019 Novel Coronavirus Outbreak Research Team

Subjects
Science
Abstract

Here, the authors sample air and surfaces in hospital rooms of COVID-19 patients, detect SARS-CoV-2 RNA in air samples of two of three tested airborne infection isolation rooms, and find surface contamination in 66.7% of tested rooms during the first week of illness and 20% beyond the first week of illness.

Published
2020
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2. Detection of Air and Surface Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospital Rooms of Infected Patients

Author

Yian Kim Tan, Gregory C. Gray, Donald K. Milton, Yee Sin Leo, Sean Wei Xiang Ong, Boon Huan Tan, Po Ying Chia, Timothy Barkham, Barnaby Edward Young, Oon Tek Ng, Partha Pratim De, Pei Hua Lee, Shawn Vasoo, Stephanie Sutjipto, Brenda Ang, Stephan C. Schuster, Sok Kiang Lau, Michelle Su Yen Wong, Marcus Gum, Monica Chan, Son Tt, Kalisvar Marimuthu, and Kristen K. Coleman

Subjects
Veterinary medicine, Air sampling, Isolation (health care), Coronavirus disease 2019 (COVID-19), business.industry, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Infection control, Medicine, Contamination, business, Airborne transmission, Air contamination
Abstract

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. We aimed to detect SARS-CoV-2 surface and air contamination and study associated patient-level factors. 245 surface samples were collected from 30 airborne infection isolation rooms of COVID-19 patients, and air sampling was conducted in 3 rooms.Air sampling detected SARS-CoV-2 PCR-positive particles of sizes >4 µm and 1-4 µm in two rooms, which warrants further study of the airborne transmission potential of SARS-CoV-2. 56.7% of rooms had at least one environmental surface contaminated. High touch surface contamination was shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.010).

Published
2020
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3. Absence of contamination of personal protective equipment (PPE) by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Author

Janice Leong, Timothy Barkham, Boon Huan Tan, Shawn Vasoo, Yian Kim Tan, Yee Sin Leo, Sean Wei Xiang Ong, Boon Kiat Toh, Barnaby Edward Young, Sok Kiang Lau, Oon Tek Ng, Stephanie Sutjipto, Po Ying Chia, Marcus Gum, Shehara M. Mendis, Brenda Ang, Kalisvar Marimuthu, Monica Chan, and Michelle Su Yen Wong

Subjects
Male, Microbiology (medical), 2019-20 coronavirus outbreak, Epidemiology, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Health Personnel, Pneumonia, Viral, medicine.disease_cause, Research Brief, Betacoronavirus, medicine, Humans, Personal protective equipment, Pandemics, Personal Protective Equipment, Coronavirus, biology, business.industry, SARS-CoV-2, COVID-19, Contamination, biology.organism_classification, medicine.disease, Virology, Pneumonia, Infectious Diseases, Equipment Contamination, Female, business, Coronavirus Infections
Published
2020
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4. Enzymatic Hydrolysis of Sodium Dodecyl Sulphate (SDS)—Pretreated Newspaper for Cellulosic Ethanol Production by Saccharomyces cerevisiae and Pichia stipitis

Author

Ming Jun Marcus Gum, Anli Geng, Fengxue Xin, and Ming Li Chen

Subjects
Paper, Bioengineering, Saccharomyces cerevisiae, Xylose, Applied Microbiology and Biotechnology, Biochemistry, Pichia, Hydrolysate, Fungal Proteins, chemistry.chemical_compound, Hydrolysis, Enzymatic hydrolysis, Sodium citrate, Ethanol fuel, Cellulose, Pichia stipitis, Molecular Biology, Chromatography, Ethanol, biology, Sodium Dodecyl Sulfate, General Medicine, biology.organism_classification, Refuse Disposal, chemistry, Fermentation, Biotechnology
Abstract

Fermentation of enzymatic hydrolysate of waste newspaper was investigated for cellulosic ethanol production in this study. Various nonionic and ionic surfactants were applied for waste newspaper pretreatment to increase the enzymatic digestibility. The surfactant-pretreated newspaper was enzymatically digested in 0.05 M sodium citrate buffer (pH 4.8) with varying solid content, filter paper unit loading (FPU/g newspaper), and ratio of filter paper unit/beta-glucosidase unit (FPU/CBU). Newspaper pretreated with the anionic surfactant sodium dodecyl sulphate (SDS) demonstrated the highest sugar yield. The addition of Tween-80 in the enzymatic hydrolysis process enhanced the enzymatic digestibility of newspaper pretreated with all of the surfactants. Enzymatic hydrolysis of SDS-pretreated newspaper with 15% solid content, 15 FPU/g newspaper, and FPU/CBU of 1:4 resulted in a newspaper hydrolysate conditioning 29.07 g/L glucose and 4.08 g/L xylose after 72 h of incubation at 50 degrees C. The fermentation of the enzymatic hydrolysate with Saccharomyces cerevisiae, Pichia stipitis, and their co-culture produced 14.29, 13.45, and 14.03 g/L of ethanol, respectively. Their corresponding ethanol yields were 0.43, 0.41, and 0.42 g/g.

Published
2009

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