Fonterra botulism scare – some useful links

By Siouxsie Wiles 06/08/2013 7


As the Fonterra botulism story continues to rage in the media, here are a few links that people might find useful.

Fonterra Managing Director Gary Romano talking on Radio NZ Morning Report this morning – he confirms its the bacterium they have identified in the whey powder, not the toxin.

Microbiologists Prof John Brook and Associate Professor Steve Flint talk on Morning Report about the ‘dirty’ pipe.

I talked about the story with Jim Mora and his panel on Radio NZ this afternoon.

Here is a great summary of Clostridium botulinum and botulism produced by ESR in 2010. It has a nice table showing the differences between the different strain types, including heat susceptibility.

Here is a report from 2008 written by Graham Fletcher and colleagues at Plant and Food in which they describe their research looking for C. botulinum in water samples from around NZ. They found 1 of their 501 samples tested positive by molecular tests for the presence of toxin type A which can cause disease in humans. They suggested testing soils to see how prevalent C. botulinum is here.

Lindstrm and colleagues have written quite a nice review about botulism and dairy products, with a table describing outbreaks (1). It was published in 2010 in the journal Critical Reviews in Food Science and Nutrition which my university does have access to so I could read it. The outbreaks listed go back to 1912 and have been mainly due to cheeses. They list one case due to contaminated commercial infant formula which happened in the UK in 2001 (type I/toxin B) – the child survived. Here is the paper describing that case in more detail (2). The authors found C. botulinum type B in an opened and unopened container of infant formula. Here are the important paragraphs (my emphasis):

“The infant formula powder consumed by the patient was made in a batch of 122 388 cans in October 1998, which was recalled by the manufacturer in August 2001, and was towards the end of its shelf life in October/November 2001.”

“From the estimate of the numbers of organisms in the unopened can and assuming a random distributed of C. botulinum in the batch, a 900 g can would on average have 13 C. botulinum spores and the probability that a tin had no organisms is very small (< 1 in 100 000). If an infant’s average daily consumption of milk powder is 130 g, then the probability of exposure to one or more C. botulinum spores is approximately 0.85 per day (this is calculated using the Poisson distribution and assuming that the tins tested represent a random selection of the batch), and if only this single case resulted from this level of contamination then the attack rate is 1 per 728 209 exposures to the bacterium.”

If we knew what level of contamination was in Fonterra’s whey powder, we should be able to use this information to estimate how likely it is that the cans of recalled Karicare are contaminated and hence the likely level of risk to babies.

Reference:
1. (Miia Lindstrm, Jan Myllykoski , Seppo Sivel & Hannu Korkeala (2010) Clostridium botulinum in Cattle and Dairy Products, Critical Reviews in Food Science and Nutrition, 50:4, 281-304, DOI: 10.1080/10408390802544405)
2. Brett, M. M., McLauchlin, J., Harris, A., O’Brien, S., Black, N., Forsyth, R. J.,Roderts, D., and Bolton, F. J. (2005). A case of infant botulism with a possible link to infant formula milk powder:evidence for the presence of more than one strain of Clostridium botulinum in clinical specimens and food. J. Med. Microbiol. 54:769–776.


7 Responses to “Fonterra botulism scare – some useful links”

  • Excellent article.
    Puts it in perspective.
    Why cant the mainstream media communicate this?

    By way of comparison it seems the risk of Guillane Barre syndrome from campylobacter in chicken is orders of magnitude higher

  • The MPI Report here:

    http://www.mpi.govt.nz/Default.aspx?TabId=126&id=1956

    In section 6.1 Appendix 1 page 2 of the PPT, (Back end of the document) there is a table of the contamination levels of samples from the “Prework” and “Rework” of the whey product.

    Could someone enlighten us on the following:

    If these levels were detected at the time of production in a production facility (which it appears they were), what are the criteria for handling such results? Anyone want to take a punt on what should/could have happened to the product?

    The report appears to lack information about what happened between these tests and the ones in March 2013.

  • Along with the “handling” of the results, Is there anyone out there who might like to comment on the levels measured and the trigger levels for differing actions.

  • Ross,

    You wrote, “In section 6.1 Appendix 1 page 2 of the PPT, (Back end of the document) there is a table of the contamination levels of samples from the “Prework” and “Rework” of the whey product.”

    Do you mean the table under ‘Source of the SRC contamination’ on page 4 (not 2) of the Appendix? (I’m using the PDF copy.)

    re “trigger levels for differing actions”, I notice they mention a move to use as stockfeed based on a client’s standards in the second paragraph under ‘2.3 TESTING’:

    “The initial series of tests carried out in March 2013 were screening tests for sulphite-reducing clostridia (SRC), which detects particular species of Clostridium bacteria (not specific to C. botulinum). In March 2013, Fonterra Australia became aware that Clostridium results in some of this finished product exceeded Danone’s specifications and was downgraded to stockfeed. The colony forming units per gram (cfu/g) ranged between 29-98.”

    (The cfu/g levels in the test results shown in the Appendix range from ~100 to ~8000. I have no idea how these levels might relate to illness or different uses of the product and so on.)

    They note these colony counts won’t determine if the sample contains the toxin. (From quoted passage, “detects particular species of Clostridium bacteria (not specific to C. botulinum)”.)

    Likewise, I would guess that the mass spectroscopy used (MALDI TOF) will most likely be assessing the nature of abundant proteins in the bacteria (such as ribosomal proteins) to try determine what species are in the sample; if so this testing won’t say if the bacteria produce the toxin or not either.

    You wrote, “The report appears to lack information about what happened between these tests and the ones in March 2013.”

    The report indicates internal testing during April/May, then external animal testing for toxic effects in June – e.g. in section 2.3,

    “Fonterra advised that during its internal investigation of the SRC results it had conducted a MALDI TOF mass spectrometry test in the April-May 2013 period, which confirmed that the same type of Clostridium was present in both the nutritional powder produced at a Fonterra Australia plant and the WPC80 retention samples. The tests of the nutritional powders and the WPC80 retention samples, and the MALDI TOF results, established that the problem originated in the Fonterra Hautapu plant.

    “It was identified that the isolates were either C. sporogenes (non-toxic) or C. botulinum, and that further typing would be carried out to confirm the species and strain.

    “On 26 June, Fonterra formally engaged AgResearch to undertake a mouse bioassay test.

    “On 31 July, AgResearch reported to Fonterra the mouse bioassay results for all three isolates from the WPC80 as presumptively confirmed positive for C. botulinum.”

    (You’ll probably notice I’m avoiding offering any real insight, sorry. My microbiology training ended with my undergraduate training several decades ago; I work as a computational biologist, particularly on structural biology and genomics and furthermore usually on eukaryotes rather than microbes.)

  • My comment re “Re tested at the time of production” may not be right. Another read of the report suggest that the tests shown in the PowerPoint rable were done in 2013 from samples taken at the time of production. But it appears the product made immediately before (hydrolysate) the WPC was tested a tht time of production, and the product immediately after the WPC was made (again hydrolysate) was tested at the time of prodduction.

    Both these tests came back with low cfu/g counts.

    But I can’t seem to find any tests done on the WPC at the time of production…………ouch?