ECDC says risk from contaminated CRISPR kits low

The European Centre for Disease Prevention and Control (ECDC) released more information today about the do-it-yourself CRISPR (Cas 9) kits found to be contaminated with harmful bacteria, saying the risk of infection is low but does exist.

The kits were identified by the Bavarian Health and Food Safety Authority on Mar 24. As a result, the ECDC said Germany has halted all importation of the DIY Bacterial Gene Engineering CRISPR Kit, manufactured in the United States and sold on the Internet for $150.

The gene-editing kit is labeled as containing a harmless laboratory strain of Escherichia coli HME63, but tests on two kits ordered from the United States in November of 2016 and in March showed contamination with several pathogenic bacteria, including antibiotic-resistant bacteria.

The ECDC identified the pathogens as Klebsiella pneumoniae, Enterobacter, and Enterococcus faecalis, which belong to biological risk group 2. Biological risk group 2 pathogens require safety handling, including wearing personal protective equipment.

Despite the presence of risk group 2 pathogens, the ECDC identified the risk of infection for users of the kits as low "because the manipulation of the kit does not involve percutaneous injury-prone manipulations. However, infection resulting from the contamination of broken skin or mucous membranes may occur, even though the kit recommends and provides disposable gloves."

Caution for citizen scientists

At-home CRISPR kits are targeted at hobbyists and "citizen" scientists who want to participate in at-home experiments with genetic engineering by making precision genome edits in bacteria. The kits have become popular in recent years, and The Odin, the company selling the kit identified by German health officials, currently has a waiting list of about a week.

Though the risk of infection is low, the ECDC said that the bacteria from the kits could invade a human gastrointestinal track. "Bacteria with resistance can persist for several months in the intestinal tract of asymptomatic carriers. If a carrier develops severe illness and requires antimicrobial treatment, there is a potential risk that the antibiotic-resistant bacteria proliferate and subsequently cause multidrug-resistant infection."

Finally, the ECDC said that users of the CRISPR kit should dispose of their material in a safe way, so as not to introduce the multidrug resistant-bacteria into the environment. The agency didn't specify steps for safe disposal.

See also:

May 3 ECDC risk assessment

May 3 ECDC news release

CRISPR kit Web site

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