Survival Rivals

The X-Bacteria – Video Transcript

Voiceover: “The X-Bacteria. Explore how antibiotic resistance spreads across bacteria. Discover how selection works. Find out about aseptic technique. Watch this video for more info on your free experiment, including handy tips on how to ensure great results.”

Mrs Hutt (interview): “The X-Bacteria experiment is a great practical. Students love it, they find it highly motivating and it’s elegant and simple, and quite straightforward actually to run.

“Basically what they do is mate two different strains of E. coli and this procedure then involves the bacteria themselves transferring genes. So it’s an example of genetic modification and that wows them for sure.

“All the instructions that come with the kit are incredibly clear and I think our technicians found absolutely no problem following the protocols. They did say to me that you’ve got to be quite organised and plan ahead.”

Voiceover: “One thing that’s very important is to prepare the broth cultures at least two days before the first lesson. Although the kit involves some high-powered science, the first lesson is quite straightforward.”

First girl: “Today we did a practical about the conjugation of bacteria and the effect of mating two different types of bacteria which are resistant to different antibiotics.”

Mrs Hutt (interview): “They mix the two different strains and put them in a sterile manner into a third nutrient broth.”

Voiceover: “The free kit contains two strains of E. coli which don’t even need refrigeration but just need to be kept in a cool dark place until you require them. And although you’re handling bacteria in the classroom, the risk is very low so long as correct procedures are followed.

“Once you’ve added the antibiotics to the agar, keep it in a water bath and pour quickly, otherwise the antibiotic may go off. If you follow the protocol closely the antibiotics will pose no hazard.”

Mrs Hutt (interview): “The plating out part – lesson two of the protocol – this requires again students to be organised. Using aseptic technique does make them feel they’re doing real science, the seriousness of it appeals very much. The great thing about this practical is that you can get such emphatically clear results.”

Mrs Hutt (in classroom): “Draw on where you expect to see colonies…”

First boy: “On the rifampicin, the R should be coloured in…”

Voiceover: “Lesson three is where the students get their results.”

Mrs Hutt (interview): “The students loved it. They’re so motivated they’re willing to come back, and when students give up their own time you know they seriously like it.”

Voiceover: “And the results are… the chloramphenicol plate has colonies from donor and mated strains… the rifampicin plate has colonies from recipient and mated strains… the chloramphenicol plus rifampicin plate has colonies from mated strain only.”

First boy: “We predicted that when we mated both of the bacteria that they would be resistant to both antibiotics, and that came true.
Interviewer: “So, are you pleased with that?”
First boy: “Yeah, we’re pleased with our results.”

Second girl: “It was a really interesting experiment because it’s different from the other things that we’ve done before, because you go into the genetics and mating of bacteria and something that’s done in actual laboratories with other biologists, so it was really interesting.”

Mrs Hutt (in classroom): “You’ll be very glad to know that all of your plates will now be taken straight to the prep room to be autoclaved, and that means all growth, all bacteria, whatever their resistance, will be destroyed.”

Voiceover: “And if you don’t have an autoclave, a pressure cooker will do just as well.”

Mrs Hutt (interview): “It does fit so neatly into the specifications – bacterial evolution and the problem of antibiotic resistance – and students themselves have this in their heads from watching the news and therefore it seems incredibly relevant.”