Antimicrobial-resistant faecal organisms in algae products marketed as health supplements

Dietary supplements are increasingly popular in Irish society. One of these is blue-green algae which is used with a variety health benefits in mind. A batch of Chlorella powder was found to be contaminated with Salmonella species in Ireland in 2015. This prompted additional testing of a total of 8 samples of three different products (Chlorella, Spirulina and Super Greens), for other faecal flora and antimicrobial resistance in any bacteria isolated. All 8 samples cultured enteric flora such as Enterococci, Enterobacteriaceae and Clostridium species. Antimicrobial susceptibility testing revealed one isolate with extended-spectrum ?-lactamase (ESBL) activity and one with carbapenemase activity. Clinicians caring for vulnerable patients should be aware of the potential risk of exposure to antimicrobial resistant bacteria associated with these products.