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| Image created by Dr. Michael J. Miller |
The European Pharmacopoeia has released a supplement containing a new general chapter that describes an alternative bacterial endotoxins (BET) test to the classic limulus amoebocyte lysate (LAL)-based method.
The new chapter 2.6.32. Test for bacterial endotoxins using recombinant factor C describes how recombinant factor C (rFC) based on the gene sequence of the horseshoe crab and fluorimetric detection can be used to quantify endotoxins from gram-negative bacteria.
Supplement 10.3 also contains the revised chapter 5.1.10. Guidelines for using the test for bacterial endotoxins, which has been updated to reflect the new status of rFC-based methods and give prerequisites for their deployment by users of the pharmacopoeia.
According to the Council of Europe (EDQM), chapter 2.6.32 has the potential to become a standardised method, which will become official in the 39 signatory countries to the European Pharmacopoeia convention.
BET tests using rFC can be used in the same way as LAL-based methods once they have been demonstrated as fit for purpose with the specific substance or product. The use of rFC for BET testing does not need to be validated, making its implementation easier; however, the replacement of an LAL-based method by an rFC-based method is considered as the use of an alternative method by the EDQM.
BET testing currently relies on two species of horseshoe crab as the sole source of lysate. Both Limulus polyphemus and Tachypleus tridentatus are endangered species and so a more sustainable option has been the topic of controversy. It was said the new chapter marks a significant step towards alleviating the need for these animal resources.
The EDQM’s Director, Susanne Keitel, explained: “When used under appropriate conditions, rFC-based methods provide the same guarantee of a product’s compliance with the test for bacterial endotoxins – and therefore, of its safety for use in patients – as LAL-based methods”.
The new general chapter 2.6.32 and the revised general chapter 5.1.10 will become effective on 1 January 2021.
Sources: EDQM and European Pharmaceutical Review
This was a very good article in your newsletter. However, there is one issue that was incorrect. Limulus polyphemus is not an endangered species. It is a highly managed and regulated fishery by the Atlantic States Marine Fisheries (ASMFC). It’s listing as “threatened” has more to do with the Red Knot, a bird species that travels from Tiera del Fuego to the Arctic every year to breed. The Red Knot is endangered, and consumes Limulus eggs on the Delaware Bay shores in late May, on its journey. The effect of LAL production on the population is minimal, according to the peer-reviewed 2019 Stock Assessment Report (1). The harvest for bait is also highly managed according to the Adaptive Resource Model (ARM), designed by experts at USGS, NOAA, State Departments of Natural Resources, and the ASMFC. The package quota for bait use is determined annually for the next year, and published on the ASMFC website Horseshoe Crab page. (http://www.asmfc.org/species/horseshoe-crab) What isn’t currently regulated is by-catch, and is estimated to be 50% of all crabs accidentally caught when fishing for other species. That loss is significantly higher than the bait harvest. Another loss not mentioned is the 10% mortality due to stranding upside down after spawning. That loss is estimated to be 10% of the population. The Limulus population of the Delaware Bay area is estimated to be between 25 and 30 million. Therefore between 2.5 and 3 million Limulus die annually due to stranding in Delaware Bay alone. The Ecological Research and Development Group (ERDG, www.horseshoecrab.org) developed the “Just flip ‘em” (2) program to try to get people to turn stranded crabs over when they are seen on the beach, which allows the crabs to return to the water and survive. Please also see the excellent article by Dr. Jim Cooper “The LAL Industry's Remarkable Stewardship of Horseshoe Crabs” (3) in this blog
ReplyDeleteHope this helps!
Allen L. Burgenson
Chair, Horseshoe Crab Advisory Panel
Atlantic States Marine Fisheries
References:
1. Atlantic States Marine Fisheries Commission. 2019 Horseshoe Crab Benchmark Stock Assessment and Peer Review Report. Arlington VA : s.n., 2019. p. 3.
2. Ecological Research and Development Group (ERDG). Just flip 'em!™ Program. Horseshoe Crab.org. [Online] [Cited: June 29, 2020.] https://www.horseshoecrab.org/act/flipem.html.
3. Cooper, James F. rapidmicrobiology eNewsletter - July 21, 2020. The LAL Industry's Remarkable Stewardship of Horseshoe Crabs. [Online] July 21, 2020. [Cited: July 21, 2020.] https://www.rapidmicrobiology.com/news/the-lal-industry39s-remarkable-stewardship-of-horseshoe-crabs.