Telecom turtle might bring more than increased sales

A recent series of adverts for Telecom in New Zealand features a young boy and his pet turtle.  The adverts are quite funny and obviously are appealing to adults and children alike.  They may even result in more sales of cellphones.  Apparently, a side effect of this advertising is greatly increased sales of turtles, which are now practically unobtainable, according to the 3-News this evening.

If you have bought a baby turtle, or are given one for Christmas, make sure that you wash your hands carefully after handling it and that children are instructed on hygiene - touching or kissing turtles (why would you?) might result in a Salmonella infection.  Don't forget that the infecting dose for Salmonella may be quite small and the bacteria are easily transferred from hands to mouth.  I'm not sure of the incidence of Salmonella in turtles in New Zealand, but in America, there is a high frequency of carriage in baby turtles, with a concomitant infection rate in children.

Be careful out there, folks.

Toxic kai moana. Summer warnings

In what has been termed the worst toxic shellfish poisoning in the region's history, twenty people have become ill after eating shellfish collected in New Zealand's Bay of Plenty.  Ten of these victims have been hospitalised and two are in intensive care.

The symptoms of this type of paralytic shellfish poisoning (PSP) range from numbness of the lips, through to vascular collapse and respiratory failure.  The toxins are actually a group of chemicals called saxitoxins and gonyautoxins and are produced by certain species of algae and released into the shellfish after ingestion.

Kai Moana means seafood in the Maori language and at this time of year, when families gather at beaches for barbecues and picnics, many people will collect shellfish to eat.  Unfortunately, cooking will not destroy the toxin, which is produced by dinoflagellates ingested by the shellfish.  Though it is difficult to measure precisely, it appears that mussels filter between 8 and 10 litres of water per day, so they are able to concentrate the dinoflagellates to high levels in their gills and gut.  The dinoflagellates themselves grow more rapidly in warm water containing high levels of nutrients.  They may be responsible for 'red tides'.

The only way to be safe is to heed warnings not to collect shellfish from the affected waters.  Signs are usually erected by the Ministry of Primary Industries warning of the risk and indicating the extent of affected waters.

And while you are planning your summer picnics and barbecues, think about how you will keep your family safe from other forms of food poisoning.  Make sure that meats and fish are kept cool, and handle only with washed hands.  If you are barbecuing, make sure that food is cooked thoroughly and remember to use clean plates and utensils for serving cooked food, as raw meat may contain pathogens.

Above all, have a safe and happy Christmas holiday.  Thanks for reading Safe Food in 2012.

John

Antibiotic Resistance in the Environment

Recently I wrote a post about excessive use of antibiotics in animal rearing and the potential for spread of antibiotic resistant bacteria.

One of my research students is studying the presence of antibiotic resistance genes in bacteria in stream and river muds, comparing pristine waters with polluted along a stretch of a river in the Waikato region of New Zealand.

She sampled mud from the river and isolated bacteria.  Her next step was to test the bacteria for resistance to a set of antibiotics drawn from two classes of antibiotics used in animal rearing and human therapy.

The results are surprising:  of 40 isolates, only one was sensitive to any of the antibiotics tested.  At this stage, there is no smoking gun, but it is certainly of concern to see such antibiotic resistance in so many different bacteria in the environment.

***. This article was published on 05/12/2012.  I recently read another article by Jack Heinemann and Sophie Joy van Hamelsveld in Stuff:  https://www.stuff.co.nz/pou-tiaki/300930926/antibioticresistant-bacteria-in-wild-cockles-and-watercress-putting-people-at-risk-of-serious-illness.  

This raises yet another concern about antibiotic resistance.  The testing of water for recreational use does not guarantee that mahinga kai, wild-harvested foods, such as shellfish, are safe to eat.  Shellfish can concentrate bacteria from the water to high levels, even when the tested water appears to be safe. ***

Unwanted passenger on cruise liner

Recently, the cruise liner Voyager of the Seas was struck with what appears to have been a Norovirus outbreak.   'Norovirus' is not a unique organism; there are many different strains, so you can become infected several times during your life.   Norovirus causes diarrhoea and vomiting, which in turn result in contamination of surfaces and generation of aerosols.  If you get virus particles in your mouth, you are highly likely to contract the disease, which appears to have a very high hit rate in exposed people.  (Now do you understand why I never get invitations to be an after-dinner speaker?)

 The virus may be present in the intestines before the onset of symptoms, and may remain in faeces for more than two weeks after recovery.  During all of this time, the virus can be spread. The problem is compounded when a population is effectively captive, such as in hostels or on a cruise liner.  The virus lives for quite a long time on surfaces, so door knobs, bathroom surfaces, lift buttons, soiled bed linen and clothes can be sources of virus particles.  If someone throws up in the dining room, other diners are immediately at risk from the aerosol.  Obviously, if the ill person is working in the kitchens, this is even more serious, as all exposed food and utensils may become contaminated.

The cruise line might be criticised for not promptly informing passengers waiting to board in Sydney about the problem, but the necessary disinfection of a whole ship is a major undertaking, and it appears that the line has made strenuous efforts to protect new passengers from infection.

What can you do to protect yourself?  Rigorous hand washing with soap and hot water (sing Happy Birthday to yourself twice while washing, to ensure that you spend enough time working the soap into hands and under nails) particularly after visiting the toilet or changing baby's nappy and before eating or preparing food.  Do not prepare food for others if you have diarrhoea.  Use of alcohol hand sanitisers may be beneficial, but these are not a substitute for washing.

Wash raw fruits and vegetables before eating them and be sure to cook seafoods thoroughly - Norovirus can survive temperatures of around 60 C.

If you are caring for someone who has symptoms of vomiting and diarrhoea,  handle soiled clothing carefully to avoid generating aerosols; wear rubber or disposable plastic gloves.  Use strong bleach solution to disinfect surfaces in bathrooms etc.  

Odd spot:

In the case of chlorine solutions, more is not necessarily better.  If the solution is made from bleaching powder (sodium or potassium hypochlorite), the more powder we add, the more alkaline the solution becomes.  The active component in a solution of bleach is actually hypochlorous acid.  This acid is unstable and breaks down in alkaline solution.  At pH 10, almost no hypochlorous acid is present in the solution.  Thus, a solution of hypochlorite containing 1000 ppm has a pH of 11.0 - 12.00 and has no active hypochlorous acid, while a solution with only 25 ppm has a pH of 8.0 - 9.0 and so is actually more germicidal than the higher concentration.

Mould, the consumer and the retailer

Many searchers of this blog have asked "Will spoiled food make you sick?"  I have commented on this before.

Over the last few weeks, I have purchased two blocks of cheddar cheese from a large supermarket chain in New Zealand.  When they were opened, both blocks were found to have a few mould colonies growing along the edges and at the corners.  This became apparent when the plastic film was peeled back.

Do these mould colonies represent a health hazard?  According to Dr. John Pitt, Aspergillus flavus is unable to produce aflatoxin at refrigerator conditions, so it is unlikely that there is a health hazard if the cheese is eaten.  I just cut the mould off, together with a bit extra to avoid eating cheese with changed flavour resulting from the mould growth. 

My wife, who is obsessed with "food going out of it's date stamp" suggested that the cheese might be old,  ("Well, that's why you buy mature cheese, dear"), but the best-before date stamp was mid-2013.

I wrote, complaining to the supermarket chain and pointing out that there were probably only two reasons  that these blocks of cheese could have had mould growth inside the pack - the cheese was packed under poor hygiene conditions in which mould spores were able to contaminate the block, and maybe the film had been pulled too tightly at the edges and corners, increasing the gas permeability and allowing air to penetrate the pack to allow the strictly aerobic moulds to grow.

No harm, no foul you might say.  But the consumer is entitled to buy safe, wholesome food and to have mouldy cheese only when mould is part of the normally accepted description of the cheese, such as Brie, Camembert and Roquefort.  Cheddar is not mould-ripened.

What I found interesting about this, besides the technical issue, was that the supermarket chain completely ignored my complaint, not even sending some sort of "We are looking into it" brush-off.  Do they not care about consumer perceptions of their stores, or does this happen so often that they feel it is 'normal'?

Eat at your own risk?

I just spent a week in Miami attending the 6th American Society for Microbiology Biofilms Conference.  Over 400 biofilm microbiologists met to discuss all aspects of biofilm research.

Of course, nobody can sit in a darkened room and listen to heavy duty research papers all day for a week, and food microbiologists always have to investigate the local food and beverage outlets!

A couple of menus caught my eye.  One was on the waterfront in Downtown, where raw food seemed to be the major offering.  Another was in one of the glorious sidewalk restaurants on Ocean Drive.  Both had almost identical wording:
"Consuming raw or undercooked hamburgers, meats, poultry, seafood, shellfish or eggs may increase your risk of foodborne illness, especially if you have certain medical conditions".

All good, and if you want to eat such delicacies, you need to be informed of the risks.  Consumption of any of these foods can potentially lead to illness.  Consumers are totally dependent on the purity of the raw materials and the water from which they are sourced, as well as the hygiene of preparation; a range of bacteria and viruses can be found in raw foods.

I wonder what Bill Marler would have to say about such a disclaimer - is the restaurant owner absolved of responsibility, assuming they take reasonable care in preparation, if a customer can show that they became ill as a result of eating the raw or rare-cooked food?

Odd Spot - cause of my heartburn?

Sometimes the life of a food safety researcher can be fun.  (Well, actually it's nearly always fun).

Today I saw this interesting ingredient listed on a meat pie:

Look at the fourth line down.  Perhaps this is why I get heartburn when I eat meat pies.