Clinical Research: Microbial Contamination of Low-Profile Balloon Gastrostomy Extension Tubes and Three Cleaning Methods

Much effort has been focused on sanitation of fresh produce at the commercial level; however, few options are available to the consumer. The purpose of this study was to determine the efficacy of different cleaning methods in reducing bacterial contamination on fresh produce in a home setting. Lettuce, broccoli, apples, and tomatoes were inoculated with Listeria innocua and then subjected to combinations of the following cleaning procedures: (i) soak for 2 min in tap water, Veggie Wash solution, 5% vinegar solution, or 13% lemon solution and (ii) rinse under running tap water, rinse and rub under running tap water, brush under running tap water, or wipe with wet/dry paper towel. Presoaking in water before rinsing significantly reduced bacteria in apples, tomatoes, and lettuce, but not in broccoli. Wiping apples and tomatoes with wet or dry paper towel showed lower bacterial reductions compared with soaking and rinsing procedures. Blossom ends of apples were more contaminated than the surface after soaking and rinsing; similar results were observed between flower section and stem of broccoli. Reductions of L. innocua in both tomatoes and apples (2.01 to 2.89 log CFU/g) were more than in lettuce and broccoli (1.41 to 1.88 log CFU/g) when subjected to same washing procedures. Reductions of surface contamination of lettuce after soaking in lemon or vinegar solutions were not significantly different (P > 0.05) from lettuce soaking in cold tap water. Therefore, educators and extension workers might consider it appropriate to instruct consumers to rub or brush fresh produce under cold running tap water before consumption.

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A comprehensive metagenomics framework to characterize organisms relevant for planetary protection

Microbiome ◽

10.1186/s40168-021-01020-1 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

David C. Danko ◽

Maria A. Sierra ◽

James N. Benardini ◽

Lisa Guan ◽

Jason M. Wood ◽

...

Keyword(s):

Microbial Contamination ◽

Mission Planning ◽

Air Filtration ◽

Human Pathogens ◽

Analysis Pipeline ◽

Planetary Protection ◽

Room Condition ◽

Protection Goals ◽

Cleaning Methods ◽

Selective Environment

Abstract Background Clean rooms of the Space Assembly Facility (SAF) at the Jet Propulsion Laboratory (JPL) at NASA are the final step of spacecraft cleaning and assembly before launching into space. Clean rooms have stringent methods of air-filtration and cleaning to minimize microbial contamination for exoplanetary research and minimize the risk of human pathogens, but they are not sterile. Clean rooms make a selective environment for microorganisms that tolerate such cleaning methods. Previous studies have attempted to characterize the microbial cargo through sequencing and culture-dependent protocols. However, there is not a standardized metagenomic workflow nor analysis pipeline for spaceflight hardware cleanroom samples to identify microbial contamination. Additionally, current identification methods fail to characterize and profile the risk of low-abundance microorganisms. Results A comprehensive metagenomic framework to characterize microorganisms relevant for planetary protection in multiple cleanroom classifications (from ISO-5 to ISO-8.5) and sample types (surface, filters, and debris collected via vacuum devices) was developed. Fifty-one metagenomic samples from SAF clean rooms were sequenced and analyzed to identify microbes that could potentially survive spaceflight based on their microbial features and whether the microbes expressed any metabolic activity or growth. Additionally, an auxiliary testing was performed to determine the repeatability of our techniques and validate our analyses. We find evidence that JPL clean rooms carry microbes with attributes that may be problematic in space missions for their documented ability to withstand extreme conditions, such as psychrophilia and ability to form biofilms, spore-forming capacity, radiation resistance, and desiccation resistance. Samples from ISO-5 standard had lower microbial diversity than those conforming to ISO-6 or higher filters but still carried a measurable microbial load. Conclusions Although the extensive cleaning processes limit the number of microbes capable of withstanding clean room condition, it is important to quantify thresholds and detect organisms that can inform ongoing Planetary Protection goals, provide a biological baseline for assembly facilities, and guide future mission planning.

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3PC-052 Chemical disinfectants vs sterile water and composite fibre: the effect of cleaning methods on microbial contamination in a class a pharmaceutical compounding environment

10.1136/ejhpharm-2019-eahpconf.133 ◽

2019 ◽

Author(s):

E Gleditsch

Keyword(s):

Microbial Contamination ◽

Sterile Water ◽

Composite Fibre ◽

Class A ◽

Cleaning Methods

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TEM characterization of silicon epitaxial layer grown on Si-TaS2, eutectic composites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088324 ◽

1991 ◽

Vol 49 ◽

pp. 802-803

Author(s):

C.M. Sung ◽

M. Levinson ◽

M. Tabasky ◽

K. Ostreicher ◽

B.M. Ditchek

Keyword(s):

Substrate Surface ◽

Bulk Sample ◽

Surface Cleaning ◽

Native Oxide ◽

Czochralski Growth ◽

Ion Milling ◽

Cross Sectional ◽

Cleaning Methods ◽

Field Emission Cathodes

Directionally solidified Si/TaSi2 eutectic composites for the development of electronic devices (e.g. photodiodes and field-emission cathodes) were made using a Czochralski growth technique. High quality epitaxial growth of silicon on the eutectic composite substrates requires a clean silicon substrate surface prior to the growth process. Hence a preepitaxial surface cleaning step is highly desirable. The purpose of this paper is to investigate the effect of surface cleaning methods on the epilayer/substrate interface and the characterization of silicon epilayers grown on Si/TaSi2 substrates by TEM.Wafers were cut normal to the <111> growth axis of the silicon matrix from an approximately 1 cm diameter Si/TaSi2 composite boule. Four pre-treatments were employed to remove native oxide and other contaminants: 1) No treatment, 2) HF only; 3) HC1 only; and 4) both HF and HCl. The cross-sectional specimens for TEM study were prepared by cutting the bulk sample into sheets perpendicular to the TaSi2 fiber axes. The material was then prepared in the usual manner to produce samples having a thickness of 10μm. The final step was ion milling in Ar+ until breakthrough occurred. The TEM samples were then analyzed at 120 keV using the Philips EM400T.

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