Coming back to the interest in infection and medicine partly was this business of an intense interest versus the generality of medicine, and partly the actual interest in how infections work, both epidemiologically and in the patient. And the other reason I found that quite intensely interesting is that it's a wonderful teaching tool that... you know, host and parasite, the host is that patient there and the parasite – what's it doing, how do they relate, what happens, both at the individual level, how do you treat meningitis, and what is this bug doing? And that, again, is communication with patients. The patient says, which is an only too reasonable question, 'Why did my child get meningitis?' That's an extraordinarily difficult question, and we do have answers, but rather kind of high-tech, fancy answers. It's very hard to bring those to come to terms with the patient's or the relatives' biological understanding. Do you see what I mean? It's trying to...

[Q] Yes, yes, yes, yes.

And when we talk about communication that's exactly the kind of point which crops up. But, I mean, it's also a wonderful tool because I think medical students, they're very nice but they can be pretty boring, aren't they, with textbooks and stuff and you... when you see, sometimes it directly impacts on what you see. Now, take gastroenteritis. We saw Shigella – that's dysentery – and Salmonella and all these bugs, and unknown ones, epidemics, individual cases, lots of them, and then we started seeing ones with multiple resistance to antibiotics and I found this intensely difficult to understand that the actual mechanism, the biochemical mechanism by which... the gene coding for the protein which makes you resistant to streptomycin, is a completely different product from the one giving you resistance to tetracycline or to penicillin. How is it they could all be jumbled together? I mean, that's really peculiar thing, isn't it, really? And, some Japanese workers found a fascinating thing, which, of course, none of us read Japanese so we didn't know, but the year after one called Naomi Datta at the Hammersmith published this book on transferable drug resistance and in those days I used to read The Journal of Hygiene, as it was then called, and it's one of those eureka moments – not that I found it, but I thought, read the paper and think, Ha! That's it! Which is a terrific thrill, isn't it, when you see a science thing linking up with what you're looking at.

[Q] Yes.

And the basis of it is, as you well know, it's horizontal gene transfer in this case, by plasmins bits of DNA floating round free of the chromosome, which, as we now know, have incredibly ingenious mechanisms to gather different genes together, and it's a major – it's not the only mechanism – it's the major mechanism of drug resistance and this absolutely precise and exactly was what you were seeing, and it also explained why antibiotic resistance... well, one of the reasons why antibiotic resistance was a huge problem. So, it was one of the, I mean, mostly you don't know that, you just don't know what's going on, but this was a case where the science and the medicine and the epidemiology, bingo, they came linking up completely really.