|CONTAMINANTS IN BABY FOODS|
Fatal case of bacterial infection in formula-fed baby in the USA increases urgency of circulating correct information about harmful bacteria
In June 2016, a baby less than one month old died from meningitis and sepsis in Michigan, USA. These invasive infections were caused by the rare but dangerous bacteria called Enterobacter sakazakii. As the baby’s parents said when describing the effects of the Enterobacter infection: « We have never heard of this infection, ever … Nobody has. » .
Confusion reigns : What is Enterobacter sakazakii and why is it such a serious problem in powdered formula?
Enterobacter sakazakii has had a confusing name change to Cronobacter sakazakii , but there is no confusion about the severity of infections it can cause in babies fed powdered formulas. The World Health Organization and the Food and Agriculture Organization of the United Nations have both recognized the problem and in 2007 issued Guidelines on preparation, storage and handling of powdered infant formula. Insert hyperlink here:
The need for safer methods of powdered formula preparation is due to the immense capacity for survival and resistance of these bacteria, and to their potential for causing life-threatening infections. These are summarised here
Enterobacter sakazakii is a true survivor – with potentially disastrous consequences for infant health
In 2015 researchers in the USA published the results of work on the intrinsic properties of these bacteria that include « resistance to heat, ultraviolet radiation, oxygen radicals, stomach acids and pasteurization ». This means that they are very difficult to inactivate – to kill. In addition, the stomachs of newborn babies are less acidic than those of adults, making it easier for the bacteria to multiply rapidly if they are ingested in contaminated formula. Enterobacter sakazakii is also resistant to desiccation and can thus survive in dried powdered formula even over long periods . The bacterial cells attach to Teflon and plastics and « can form biofilms, which render them resistant to high-level disinfection. » This means that feeding utensils such as plastic bottles and enteral feeding tubes can be a breeding ground for the bacteria to enter the baby’s stomach.
Worse still, the bacteria utilizes sialic acid in formulas that are fortified with this additive. The researchers hypothesise that « Sialic acid is an additive to powdered infant formula because of its reported ability to foster healthy brain development in the neonate.» Enterobacter sakazakii is « unique in the Cronobacter genus in that it can utilize sialic aciid for growth. » Ironically, it is Enterobacter sakazakii which can cause neonatal brain infections such as meningitis, leading to brain damage.
Vital importance of testing for harmful bacteria in powdered formulas and developing methods to inactivate them
Like all industrially processed foods, powdered formulas are not sterile products because there is no final sterilization procedure. Powdered formulas may become contaminated at factory level by bacteria such as Cronobacter species, particularly Cronobacter (formerly Enterobacter) sakazakii, and species of Salmonella introduced during manufacturing processes. Once the formula powder is mixed with water to make up the feed, even tiny amounts of these bacteria can multiply and rapidly form colonies in the warm milk and can cause severe invasive infections.
It is imperative that packages of powdered formulas should be tested regularly and reliably for the presence of Enterobacter sakazakii. But there is also confusion about testing : the Michigan baby was fed Enfamil Gentlease powdered formula but the manufacturers, Mead Johnson, assert that there were no bacteria in the can of formula that was tested.
The article cited above at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4489094/ explains that Enterobacter sakazakii is difficult to detect in powdered formula because it forms clumps and is not uniformly distributed throughout the batches « Cronobacter species tend to be non-homogeneously distributed …This property limits the utility of random sampling of powdered infant formula batches for quality assurance and public health surveillance. » See this article for discussion of the different measures for testing : “ How to tackle the problems of safety and quality of formula: examining effective measures ”
Research alerts on new methods for rapid detection or inactivation of harmful bacteria
To tackle the difficulties of detection, researchers in many countries are working to identify improved methods, for example in South Korea.
In July 2016 researchers in South Korea developed a more sensitive testing method, explaining that « Cronobacter species (Cronobacter spp.) are hazardous foodborne pathogens associated with baby food, powdered infant formula (PIF). » They report that their new INC-ELISA method is based on a novel immunoglobulin G (IgG), anti-Cronobacter IgG, which is able to detect seven Cronobacter spp. This « novel anti-Cronobacter IgG facilitated highly sensitive, efficient, and rapid detection of Cronobacter spp. in baby food. » However, does rapid testing mean reliable testing ? The market for new tests to detect harmful bacteria is expanding – and lucrative.
Other researchers are developing combined treatments to kill these harmful bacteria. But because the bacteria are so resistant, a combination of three treatments is needed to prevent the bacteria from multiplying and causing infection. However, it can be asked how the average parent or care-giver could possibly combine these complex treatments, and thus whether they are intended for use by manufacturers, if indeed they are proven to be effective.
In 2016 Chinese researchers studied various treatments to inactivate Cronobacter/Enterobacter sakazakii. The results were published in the Journal of the Michigan based American Society of Agricultural and Biological Engineers, with the explanation « Powdered infant formula milk is prone to Cronobacter sakazakii (C. sakazakii) contamination, which is fatal to infants. » These bacteria are heat-resistant and so various combinations were explored to reconstitute the powdered infant formula, using very hot water ranging from 60°C-75°C combined with radio frequency and hot air treatment. Water temperature of 70°C combined with radio frequency and hot air treatment achieved a reduction in Cronobacter sakazakii while retaining the quality of powdered milk formula and avoiding the protein becoming denatured. «
See Comparison of Cronobacter sakazakii death kinetics in powdered infant formula using hot water and combined radio frequency and hot air treatment Urgency of informing about methods for safer preparation
Urgency of informing about methods for safer preparation
All the above cited articles provide robust evidence that it is more important than ever to address the problem of contamination of powdered formulas by Enterobacter sakazakii. It is not only formula-fed premature or immuno-compromised infants and newborns who can be at risk but also infants up to one year and older babies. See WHO/FAO Enterobacter sakazakii in powdered follow-up formulae: Meeting Report:
In 2016 the US CDC therefore issued a renewed alert : See 2016 alert by the US Centers for Disease Control and Prevention on the risks of harmful bacteria in formulas:
It is significant that, also in 2016, researchers in Italy published research on precautions to be taken to protect infants fed powdered formulas, with the rationale « Powdered infant formulas are usually not sterile and may frequently be contaminated by several bacteria strains. « They note « Contamination of powdered milk cans has been reported to range from 6.6% in Brazil to 29 % in China. » They therefore discuss the advice to parents, care-givers and health professionals to prevent foodborne infectious diseases when preparing and storing formula.
Different recommendations for preparation, handling and storage cause further confusion because manufacturers argue that the ‘killer step’ of using very hot water to prepare powdered formula may indeed inactivate the bacteria – but will also kill off the probiotic bacteria which enable manufacturers to make unsubstantiated claims for the superiority of their particular brand. See What do we really know about probiotic bacteria and prebiotics added to formulas? Are the promotional claims made by manufacturers justified? Why are these claims banned in many countries?
The Italian research reviews national guidance in the United Kingdom, the European Union and the US Centers for Disease Control. All of these, as well as many other countries, follow the World Health Organization’s Guidelines: Use water that has first been boiled and then cooled to no less than 70°C (158°F) to mix the powdered formula. Use formula within 2 hours of preparation. If the baby does not finish the entire bottle of formula, discard the unused formula.
 Enterobacter sakazakii was redefined in 2008 as a species in a new genus named Cronobacter. This means that it is also referred to as Cronobacter sakazakii, or as Cronobacter species (spp.) Cronos or Cronus was the name of the Greek Titan who devoured his own children: https://en.wikipedia.org/wiki/Cronus