Tag Archives: Canadian Encyclopedia

Haiti, cholera, University of Alberta, and nano-syringes

As I’ve noted before the word nano pops up in unexpected places, in this case, in a news release about a University of Alberta medical researcher’s work on cholera bacteria. We tend not to think about cholera in Canada these days but it was a serious problem here as it still is elsewhere. From the Canadian Encyclopedia essay on cholera in Canada,

Cholera first reached Canada in 1832, brought by immigrants from Britain. Epidemics occurred in 1832, 1834, 1849, 1851, 1852 and 1854. There were cases in Halifax in 1881. The epidemics killed at least 20 000 people in Canada. Cholera was feared because it was deadly and no one understood how it spread or how to treat it. The death rate for untreated cases is extremely high. Grosse Île, near Québec, was opened in 1832 as a quarantine station and all ships stopped there for inspection.

The essay goes on to note that between 1995 and 2004 Canada’s reported annual number of cases ranged from one to eight. Meanwhile, Haiti is experiencing a serious outbreak of cholera as it recovers from last year’s earthquake. From the University of Alberta’s Feb. 3, 2010 news release,

Just over a year after the earthquake in Haiti killed 222,000 people there’s a new problem that is killing Haitians. A cholera outbreak has doctors in the area scrambling and the water-borne illness has already claimed 3600 lives according to officials with Médicin Sans Frontières (Doctors without Borders) [sic].

Bacteriologist Stefan Pukatzki recently achieved a breakthrough understanding of cholera’s disease process which will hopefully help stem outbreaks in the future.

Pukatzki discovered that Vibrio cholerae uses molecular nano-syringes to puncture host cells and secrete toxins straight in to the other organism; this is called the type six secretion system. [emphasis mine]

“Vibrio cholerae uses these syringes so when it comes in contact with another bacteria, like E. coli, which is a gut bacterium, it kills it,” said Pukatzki. “That’s a novel phenomenon. We knew it [Vibrio cholerae] competed with cells of the immune system but we didn’t know it was able to kill other bacteria.

“Keep in mind these syringes are sitting on the outside of the bacterium so they make good vaccine targets,” said Pukatzki. “That’s actually better because you could either inhibit the type six function or you could induce an immune response with these components that are sitting on the outside.”

I’m very interested to see that he (or the writer of the news release) used ‘nano’ as a prefix given that it was already described as molecular. I don’t make much of it other than the fact that it served to grab my attention.