Saturday, December 22, 2012

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.

Tuesday, December 18, 2012

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




Tuesday, December 4, 2012

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.