microbial contamination

On-site, In-house Environmental Monitoring to Obtain Species-Level Microbial Identification

Posted on by Michele Arduengo

Loss of life and serious illness from contamination of manufactured products that are consumed as food or used in medical procedures illustrate the need to prevent contamination events rather than merely detect them after the fact.  High-profile news stories have described contamination events in compounding pharmacies (1), food processing and packaging plants (2) and medical device manufacturers (3). Although contamination in manufacturing settings can be physical, chemical, or biological, this article will focus environmental monitoring to determine the quality of a manufacturing facility with respect to microbial contamination.

Scientist in pharmaceutical manufacturing facility performing environmental monitoring.

To ensure that the products they produce and package are manufactured in a high-quality, contaminant-free environment, many industries are required to establish routine environmental monitoring programs. Samples are collected from all potential sources of contamination in the production environment including air, surfaces, water supplies and people. Routine monitoring is essential to detect trends such as increases in potential pathogens over time or the appearance of new species that have not been seen before so that contamination events can be prevented.

Because environmental monitoring requires identification to the level of the species, most environmental monitoring programs will collect samples and then send them off to a facility to be sequenced for genomic identification of any microbial species. Such genotypic analysis involves DNA sequencing of ribosomal RNA (rRNA) genes to determine the taxonomic classification of bacteria and fungi. In this method, informative sections of the rRNA genes are amplified by PCR; the PCR products sequenced; the sequence is compared to reference libraries; and the results interpreted to make a species-level identification for a given microbial isolate.

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Finding Life on Mars May Be Complicated by Microbes Hitching a Ride from Earth

Posted on by Sara Klink

“The Andromeda Strain”, a novel written by Michael Crichton, remains one of my favorite science fiction novels for two reasons (spoiler alert for the plot): The US government deliberately sent objects into space to scoop up extraterrestrial microorganisms and examine their potential to be used as a weapon (with the expected consequences of contaminated space probes falling near human habitats and causing trouble), and the deadly organism infecting humans is stopped in its tracks by the inescapable bounds of its pH requirements exemplified by two survivors in an afflicted town: a crying baby and a Sterno-drinking man. Reality may be a bit different from the novel but the principle is the same: We are launching probes from our planet and sending them to other planetary bodies, sometimes to stay on another planet, sometimes to return to Earth. In both cases, worries about terrestrial organisms contaminating other planets and extraterrestrial organisms contaminating Earth are valid. Because we are sending more and more probes to examine the possibility of life on other planetary bodies, Curiosity being the most recent example, the question remains: How do you adequately test for organisms that may be hitching a ride from Earth into space? Continue reading “Finding Life on Mars May Be Complicated by Microbes Hitching a Ride from Earth”