Defining a pathogen

CHRIS HATZIS
Eavesdrop on Experts, a podcast about stories of inspiration and insights. It’s where expert types obsess, confess and profess. I’m Chris Hatzis, let’s eavesdrop on experts changing the world - one lecture, one experiment, one interview at a time.

Back in the early 1970s, the discipline of vaccinology - that’s the separate branch of medicine that develops vaccines - didn’t exist. There were too few vaccines to warrant it. Myron Levine (known as Mike) was determined to change that.

Shortly after founding that discipline, a fortuitous change in plans brought Mike to another scientist, Roy Robins-Browne, that shared his then “fringe-dwelling” passions. Mike Levine, now a vaccinologist and professor at the University of Maryland, and Roy Robins-Browne, professor, clinical microbiologist and research scientist at the University of Melbourne, discovered they held the same controversial belief about a particular pathogen that would go on to change how disease was treated forever.

Two world-leaders in microbiology and immunology together in the same room. Dr Andi Horvath unravelled their history together and the evolution of their fight against infectious diseases since 1978…

ANDI HORVATH
Roy, what do other people say you're famous for?

ROY ROBINS-BROWNE
Teaching.
[Laughter]

ANDI HORVATH
Why is that?

ROY ROBINS-BROWNE
Well, I've been in charge of teaching of medical microbiology at the University of Melbourne since 1982. I believe I've taught over 10,000 medical students, which would be approximately half the doctors practicing in Melbourne today. I'm well known amongst the medical profession.

ANDI HORVATH
You're the guy in microbiology. But you're also a clinical researcher? Is that right?

ROY ROBINS-BROWNE
That's correct, yes. I have a number of research interests. My main interest is a curiosity-driven interest which is how bacteria cause disease. It's something that's interested humanity since bacteria were first discovered, or first shown to cause disease by Louis Pasteur and others, about 140 years ago or so. It stalls, something that befuddles most people is how something so small can make us so ill. It's something that I find particularly interesting and it's been the focus of my work. But I'm also interested in the impact of infectious diseases on the community, so we do quite a lot of - I have done quite a lot of work in the past on looking at causes of diarrhoea. That was my main research interest. But I also am interested in how bacteria cause pneumonia and the importance of pneumonia, meningitis and other major infections.

ANDI HORVATH
Roy, I know you've been interested in antibiotic resistance as well. The drugs that are used to combat infectious diseases.

ROY ROBINS-BROWNE
You may be aware that resistance to antibiotics is one of the major health problems in the world today. We are in the early stages of the post-antibiotic era where antibiotics won't be effective to treat infections any more. There's various approaches how to deal with that and the most important approach is to educate people including the health professionals not to prescribe antibiotics inappropriately. But we also need alternatives to antibiotics and that's been my interest.

There's various ways that people have approached this. One is to use the traditional way. To find drugs, similar to the ones we currently use or new drugs. But, as a microbiologist I see that as not a long-term solution, because bacteria are very good at evolving and adapting to new drugs and they become resistant to them. Those drugs, when they're used, select for, it's a kind of Darwinian process - survival of the fittest - the resistant bacteria are the ones that persist and the susceptible ones, the ones that are damaged by the antibiotics, they are killed.

Our approach is entirely different. We work with bacteria that cause gut infections, because my interest is diarrhoea. We work with animal models and one of the bacteria we work with, and many other bacteria behave the same way, is they recognise when they're in the intestine; so they have molecules that are able to sense chemicals within the intestine that are found predominantly in the intestine, and in this particular case it's bicarbonate ions. So, bicarbonates are secreted into the intestine to neutralise stomach acid, and to stop it burning the mucosa, the lining of the intestine.

Bacteria, when they sense bicarbonate, know that they are in the small intestine, and this tells them that they're inside the host and it's time to switch on the factors they need to survive in the host. Factors that they don't need when they're outside the host. They're very economical.

ANDI HORVATH
Cheeky things.

ROY ROBINS-BROWNE
What we do, is we find a way to trick them. Prevent them from realising that they're in the intestine. They don't turn on these virulence factors; the factors that allow them to survive inside the host; and therefore, they can't cause disease. We've done this in an animal model and it's been very, very effective, and now we're working on human pathogens and we've got some leads that are looking very promising.

ANDI HORVATH
You can never retire.

ROY ROBINS-BROWNE
People have told me that before. They've told me that about teaching, too.

ANDI HORVATH
Mike, what do people say you're famous for?

MIKE LEVINE
I'm one of the pioneers in the discipline of vaccinology. When I started in the early 70s, if you looked for that term, you'd only find a few, just a couple of examples of that term even being used.

ANDI HORVATH
Oh, is that right? We were only really using drugs at that time, to combat infectious disease, were we?

MIKE LEVINE
No, the concept of vaccinology as a discipline didn't exist. There were a few vaccines. Very few vaccines. We didn't have the technology, we didn't know the process, the paradigm of developing a vaccine. All of that was to come. If you looked in what we call PubMed, a way on the internet of looking through the national library of medicine for publications that involved the word vaccinology, today you'll find thousands for the past year, 2018, and you'll see even subgroups of structural vaccinology and neonatal vaccinology etcetera.

I, early on, had an interest in trying to formalise this and established an academic unit called The Centre for Vaccine Development in 1974 with the goal of having all the components it would take to try to make, and eventually implement, vaccines for populations where big pharma, major vaccine manufacturers at the time, had no interest. Because the diseases we were targeting were ones that were only afflicting the poorest and most impoverished and there was no market. Without a market, there's no way for a big pharma to return their investment. All of these things were going on.

One then would be, as one of the fathers of vaccinology. The other, more through the United State's academic system, is I'm a bit of a dinosaur in that I arrived at the University of Maryland in 1970, actually on a short term assignment from the US Public Health Service, and come early next year will be my 49th year for a US academic to stay in one institution for almost half a century is exceedingly, exceedingly unusual.

ANDI HORVATH
I'm going to take a little side tangent. For those who are not familiar with bacteria and viruses. Both of them can cause diarrhoea and disease, and both of you deal with both types of pathogens?

ROY ROBINS-BROWNE
Yeah, to some extent. I'm predominantly a bacteriologist, but I'm interested in viruses, because as you say they both cause the sort of disease.

ANDI HORVATH
They both can cause diarrhoea.

ROY ROBINS-BROWNE
Yeah, correct.

ANDI HORVATH
Okay. Is there anything else that you want us to know about the differences between the pathogens? Because some you can treat with vaccines but some you can only treat with drugs, is that right?

MIKE LEVINE
Anything can be prevented with a vaccine. The first concept is prevention versus treatment. Drugs are to treat someone who already has the disease to minimise the consequences, prevent death, prevent hospitalisation etcetera, but they're already having discomfort and complications. Vaccines aim to prevent the clinical illness and that's a very fundamental difference. But vaccines can prevent bacterial infections, they can prevent viral infections that cause diarrhoeal illness and there's work going on to develop vaccines against one protozoan, one parasite, that's very important in causing a diarrhoeal illness.

ANDI HORVATH
What's the global burden of disease when it comes to gut diseases like diarrhoea?

MIKE LEVINE
It's enormous. There's something called the Global Burden of Disease that's published every year in the Lancet and what we have seen is just in the past decade, there's actually a diminution in deaths due to diarrhoeal illness. Deaths are overwhelmingly occurring in the least developed areas of the world. One of the reasons for that is the introduction of a rotavirus vaccine. Turns out that although there are many, many different pathogens, germs, agents that can cause diarrhoea in children in developing countries, a handful, in fact just four, account for about half of all deaths. This was a revelation.

It was from a study that Roy and I were very involved with called the Global Enteric Multicentre Study and it raised the concept that if you could develop vaccines against just four very, very tough pathogens, but if you could do that, one would be able to accelerate the improvement, the fall in mortality. One of those vaccines is already out there. It's not one that we, per se, developed but each of us played a role, is part of the big development. That's the rotavirus vaccine. Australia's famous for pioneering efforts in that vaccine.

ANDI HORVATH
Let's talk about how you two met. Let's recap that moment when Roy met Mike.

ROY ROBINS-BROWNE
Well, maybe I could start a little bit before that. I was working in South Africa at the time, where I was born and raised and did my medical degree and my PhD and my training in pathology. I was awarded an overseas traveling fellowship and I had a couple of places that I thought I might try. One of them was a very well-known research in the area of dysentery and that was Richard Hornick and he was working at the University of Maryland. I wrote him a letter and he wrote a very favourable reply. But by the time I actually went, by the time everything was organised to go to the University of Maryland, turns out that Dick had moved, and Mike was in charge and he came to fetch us from the airport, feeling very bedraggled, my wife and three children aged under five. I might let Mike take over from there, because it was pretty interesting.

ANDI HORVATH
What happened then?

MIKE LEVINE
Well, my wife and I drove down to pick up Roy and his family. Roy, with his wife Gail and three little girls, just travelled all the way from Johannesburg and when we saw them, they were totally bedraggled and exhausted with giant suitcases. They looked like refugees. We got into the car, we started driving to take them to a lodging. They lodged the first night in a hotel, then we invited them to stay with us until they could find housing.

During that trip, in one hour it was like I had discovered a scientific soulmate. At the time, we both had two great interests. One was something called typical or classical enteropathogenic E. coli and the other was diarrhoeal disease among children in developing countries. Enteropathogenic E. coli at the time, the dogma was that these organisms were not pathogens and there were only a handful of people in the entire world who believed, looking at the same data that existed, that indeed they were pathogens.

The reason they were not considered pathogens is that two new mechanisms of causing diarrhoea had been discovered and publicised greatly through a New England Journal of Medicine from Burke, DuPont and [Decornic] at the University of Maryland and Sam Formal at Walter Reed. One was the ability of E. coli to cause diarrhoea by making a heat stable enterotoxin. That's a pathotype or category of the E. coli called enterotoxigenic E. coli. The other was the ability of another category of E. coli to invade intestinal cells and cause a dysentery-like illness. These enteropathogenic E. coli that Roy and I thought had strong epidemiologic evidence of causing disease, did not do those two things.

All of microbiology and infectious diseases concluded that EPEC, enteropathogenic E. coli, were not pathogens. We believed they had to be causing disease by a totally different mechanism. There were really only three or four people in the world, and suddenly, who believed that, and if you did believe that you were considered to be a bit demented or lost.

ANDI HORVATH
On the fringe.

MIKE LEVINE
On the fringe, exactly. On the fringe. Here in this same little Volkswagen bus, were these two people.

ROY ROBINS-BROWNE
If you had said to the people in the world who believed that these were pathogens.
[Laughter]

MIKE LEVINE
That was the beginning of almost four decades of...

ROY ROBINS-BROWNE
So, we're instant soulmates.

ANDI HORVATH
You established that these were indeed pathogens that used a different mechanism in order to cause dysentery and diarrhoea in the body.

MIKE LEVINE
In collaboration with other folks. Roy's coming to the Centre for Vaccine Development was absolutely critical. We thought maybe there were different enterotoxins that we hadn't looked at, but over the next few years we built up a cadre of people, some in the UK, some in Melbourne and some in Baltimore, that turned this orphan non-pathogen into, for many years, the best studied at the molecular pathogenesis level of any diarrhoeal pathogen.

ANDI HORVATH
Wow. You turned around dominant dogma at the time. You said, no, no it's got to be this. We think it's this. Tell me about certain pivotal points where it started to take traction in the industry, that this indeed was serious and we could treat it. We now understand it.

MIKE LEVINE
Well, one was a collaboration with one of the few other people in the world, who was Bernard Rowe, he was head of Bacterial Enteric at Colindale in the UK. He had in his collection the strains that caused the epidemics that we had read about and concluded this is a real clinical epidemiologic bacteriologic syndrome. At a dinner in Washington in the mid-70s I happened to sit next to Bernard Rowe and we started talking and he was another rare individual who believed these were pathogens, and he agreed to provide those strains to me. With those strains I set up amongst college students in Baltimore, at the University of Maryland in Towson State and some other - set up for a bunch of college students to come in and to, with informed consent and explanation, to help us find out whether these bugs could cause diarrhoea.

ANDI HORVATH
They had to take the bugs?

MIKE LEVINE
They took the bugs. They came in, they had a nice little time, they had to be resident on our research ward. They bonded, they had a great time. But they either ingested one of three of Bernard Rowe's famous outbreak EPECs which typically caused diarrhoea in infants, or they took a normal E. coli. Because other forms of E. coli in our intestine, all of us, are very important for digestion and physiological and liver function etcetera. Anyway, two of these EPEC, classical EPEC, negative for the heat label and a heat stable enterotoxin negative for entero-invasiveness, caused unequivocal diarrhoea in volunteers.

ANDI HORVATH
Oh no.

MIKE LEVINE
At the same inoculum level the normal flora did nothing. The type of diarrhoea, the extent that - it was unequivocal. That was one piece. But then there were many, many other steps and our colleagues and friends contributed. I'll let Roy take it from there, of how we built the evidence.

ROY ROBINS-BROWNE
I think the next important step was also in Bernard Rowe's laboratory where a Mexican Scientist, Alejandro Cravioto, was doing some work with cell culture, and he showed that these E. coli can stick to those cells in quite an unusual pattern. They form tiny little groups on the cells and we hadn't - nobody hadn't seen that people were using tissue culture for various tools in studying how gastrointestinal pathogens cause disease. For example, Mike spoke about how bacteria can invade the intestinal epithelium and you can show that in a test tube.

Alejandro was looking at that type of thing and then he saw that these actually don't invade the cells, but they stick to the cells in this unusual pattern. Subsequently, someone showed that - people in the UK showed that that ability to stick to cells was encoded on a piece of DNA separate from the chromosomes. Bacteria have a single chromosome and then quite often they have small bits of DNA independent of that chromosome. It's sort of almost parasitic for the bacteria but sometimes they help the bacteria to become resistant to antibiotics, for example, or to make them better pathogens.

ANDI HORVATH
They've got these accessory DNAs floating around with them?

ROY ROBINS-BROWNE
Yes. And they're retained in the bacteria, especially when they can give the bacterium an advantage in being able to stick to the intestine, gives them an advantage in the intestine. Particularly if they stick to the lining of the small intestine, because the small intestine doesn't have a lot of resident bacteria. The large intestine is jammed full of bacteria. In fact, people would be aware that, you know, how many bacteria we carry with us, and about 70 per cent of all of the bacteria we carry with us, are in the large intestine. It's a total zoo there of bacteria, maelstrom of bacteria, it would be a very uncomfortable place live.

But a nice quiet place to live actually, is the small intestine. But the small intestine is like a very fast flowing stream because the gut contents move very quickly through this very long small intestine. Bacteria, if want to stay there, they need to be able to hang on to those epithelial cells. This plasmid, this extra bit of DNA, encodes factors that allows the bacteria to stick to the intestinal cells. That was shown and then it was shown that they were a unique kind of adherence factor, that was found at that time only in E. coli but then subsequently found in other bacteria. I let might let Mike talk about, because he did some similar work in this area to show how important that plasmid was.

MIKE LEVINE
We had assembled over the next few years, a few new folks in Baltimore to work on this. I had recruited James Caper, Jim Caper from Stan Falco's laboratory. Stanley Falco who passed away last year was certainly one of the greatest, if not the greatest bacterial enteric patho-geneticist and we were able to bring someone from that background. Jim was able to isolate this 60-Megadalton plasmid.

ANDI HORVATH
That's the accessory DNA?

MIKE LEVINE
That's right, and was able to with one of his graduate students, to create a strain that was plasmid-minus. That allowed us to do some very interesting studies where we had sera from the challenge strain and we did a relatively simple analysis by modern standards, of taking the pre-challenge and the post-challenge a few weeks later sera from these volunteers who did develop diarrhoea and we made protein spreads on a gel from the bacteria and we did what was called the western blot. Looking to see if there were any proteins that lit up in sera from people who ingested the plasmid-plus strain. We'd also given to some student volunteers the plasmid-minus strain, at that point and we found this protein...

ANDI HORVATH
So you created a map of protein essentially?

MIKE LEVINE
That's right. And here's this one very dominant protein at a size called 94-Kilodaltons that was present after infection with the proteins from the plasmid-plus strain. That 94-Kilodalton protein later came to be intimin, a very, very important protein. Out of this came some diagnostic tools, also a collaboration with an investigator named Harley Moon, who was a veterinarian who worked with piglets. With intestinal loops in animals, it was possible to give - put into the loops these EPEC strains. Then using histopathology - Roy's a trained histopathologist that could really appreciate what was done - a very unusual type of attachment was seen. That was for a while, pathognomonic of these E. coli. Then later in Jim Kaper's lab, they identified a chromosomal locus called the LEE and that locus produced a lot of different proteins that lead to this type of unusual intestinal attachment.

ANDI HORVATH
So together, and with your extended teams and collaborators, you identified what's happening at the molecular level, the genetic level, the protein level, and this of course then rippled into new ways of diagnosis, possible treatments. You witnessed enormous change, or rather, instigated enormous change in the industry. Roy, your lectures must have changed from year to year.
[Laughter]

ROY ROBINS-BROWNE
Very much so.

ANDI HORVATH
How did that work?

ROY ROBINS-BROWNE
I might, just before we talk about that, I might just...

ANDI HORVATH
Add a bit in? Sure.

ROY ROBINS-BROWNE
Yeah, because there was a really interesting thing regarding this 94-Kilodalton protein that Mike referred to. As Mike mentioned, when the plasmid was there, volunteers made antibodies to it. When the plasmid wasn't there, they didn’t. Then later we showed that when the bacteria carried the plasmid, they made this protein and when they didn't carry the plasmid, they didn't make the protein. The obvious inference was, that the protein, the genes for the protein, are on the plasmid. I mean that's what you would think. We looked really hard. In fact, I went into sabbatical with Mike in 1986 and one of my things that I was doing there was trying to find the genes that encoded this really interesting and obviously important protein, and no matter how hard I looked, I couldn't find it.

The answer subsequently was uncovered in Jam Kaper's lab, who worked with Mike, is that in fact the genes for intimin, that protein, are actually on the chromosome within that LEE, that Mike mentioned. But the reason the plasmid was important, is the plasmid regulated the production - and I was talking earlier about regulation and switching on things that are needed inside the host - the control was in the plasmid. And so, when the plasmid wasn't there, it didn't get turned on.

ANDI HORVATH
So the regulation of the genes was outsourced to this plasmid.

ROY ROBINS-BROWNE
Isn't that remarkable?

ANDI HORVATH
That is remarkable. This is like a detective novel. Finding out who's the accomplice, which was the plasmid regulator; who's the culprit, which is that LEE chromosome protein; and this is an extraordinary detective mission. I think I need to turn this into a crime podcast actually. I'm going to re-edit this to be like a crime scene of dysentery and diarrhoea and then get to the culprits which are molecular.

MIKE LEVINE
One other thing on this. When we work in the laboratory trying to get an EPEC strain to shed this EAF plasmid it was almost impossible.

ANDI HORVATH
Oh, it wouldn't separate with it?

MIKE LEVINE
No. A hammer and chisel. Yet, when we did another volunteer study and now had the tools to look at the putative EPEC strains coming out, one half of the E. coli colonies that come out of a human being have lost the plasmid. This also was kind of a harbinger of the importance of the microbiome etcetera. This was amazing to us, and we had no idea how that could be happening. Because we had a graduate student [Mary Baldini] who had tried for one year. Tried everything known at the time, to get that plasmid out. Finally, she did but volunteers did it in one passage.
[Laughter]

ANDI HORVATH
How extraordinary and it's why clinical and lab-based research works well together.

ROY ROBINS-BROWNE
Exactly.

ANDI HORVATH
That's a perfect example of trying to do it in the lab, but in actual fact the clinical studies were doing it for you. That's extraordinary. Okay, back to the question, Roy. Roy, how did your lectures change over the decades?

ROY ROBINS-BROWNE
Well, you know, when you've been in an area like medical microbiology as long as I have, you go through periods which you realise, oh, revolutionary periods. I started doing research around the time of the recombinant DNA revolution when you can start manipulating genes and we used to use this kind of modern genetics. Before that, when bacterial genetics was very laborious, it was very hard to work out what was going on, recombinant DNA made that much easier. Subsequently, we're now in yet another revolutionary phase of microbiology, which is whole genome sequencing where we can learn the genome of all the genes in a bacterium within a few hours. Something would have, you know when they first did it, would have took many, many, many months and now it's becoming a clinical diagnostic tool and certainly a very important public health tool. For we were tracing epidemics within hospitals, outside hospitals and so on.

Obviously, our teaching has to reflect that and so we teach diagnostic microbiology now, totally differently to the way we did. I can tell you a funny little story about that because in the 1990s I set an exam question for science students, but doing a subject on medical microbiology, which was, how you might identify a new variety of E. coli that showed it was different from the current ones. But you know, in the same we had looked at enteropathogenic E. coli and showed it was different from enterotoxigenic E. coli and enteroinvasive E. coli. I had a question phrased around that, and the student said, sequence the genome. And the first genome had just been sequenced around their time, was Haemophilus influenzae. I said, you know, big red, cross that out, don't be ridiculous and that. Of course, now that's the right answer.
[Laughter]

ANDI HORVATH
Oops.

ROY ROBINS-BROWNE
The student was very impressive. I need to get that paper back and apologise.

ANDI HORVATH
Consider this podcast the global apology to those students. Gosh. What inspired you both to get into this area? What were triggers as undergraduates or even as school students, that said, wow, this invisible world of microbiology and immunology is fascinating, I've got to go down that path?

MIKE LEVINE
I got into it somewhat by accident. I was always interested in tropical paediatrics, you could call it. Now the term global health and global paediatrics is very common, but in the 1960s when I was a medical student, that was pretty unheard of. Very difficult to have experiences but I was able, in one way or another, to secure working in places for several months at a time as a medical student. The last one I did was at the Jinnah Children's Hospital in Karachi Pakistan. The last three months of medical school before I started a paediatric residency and I worked on a diarrhoeal research project, the clinical one.

What impressed me was that despite having the best clinical microbiology laboratory in Pakistan at the time, supported by a collaboration with a US medical school in Indiana, the Jinnah Children's' Hospital could only look for a handful of bacterial pathogens. It was all a black box. Here are these sick kids, many of whom died, many of whom became malnourished, we had no idea what the ideologies were. It did stimulate me to become interested. On my way back home, I spent a week in what at the time, this is 1967, what was called East Pakistan, now Bangladesh. I visited the [Colla] research laboratory and there I saw research going on at every level. Clinical, physiologic, immunologic, bacteriologic in a developing country situation, attempting to use as much as they could state of the art methodologies that they could get to that place.

That had a very strong influence on me. That would come later to lead to our Centre for Vaccine Development establishing a few sister units. One in west Africa for example, that is now a very well recognised highlighted centre of excellence in a country that's, by UN standards, the sixth or seventh least developed in the world. An unusual anomaly. But I would trace my interest all the way back to 1967 for that.

ANDI HORVATH
Roy?

ROY ROBINS-BROWNE
Mine was even more by accident. At school I was interested in science, but I went to a boy's school and we didn't do biology at all. I learnt about physics and chemistry because girls did biology.

ANDI HORVATH
Okay. That's changed.

ROY ROBINS-BROWNE
1960s. Then I finished high school, aged 17. I didn't really know what I wanted to do but my Dad had died when I was 12, he was a doctor and I was an only child and people assumed I should do medicine. I didn't know what I wanted to do and I thought 'well I'll do medicine because it gives me another six or seven years to think about it'.
[Laughter]

I did that and I really enjoyed the part of medicine where you worked in the laboratory and you tried to work things out, and looking down a microscope and all that other stuff that almost all the other students hated. I was pretty unusual. I finished my medical training and at the first opportunity I applied for a job in laboratory medicine with the idea of becoming a pathologist. They had an opening for a trainee in microbiology. It wasn't something that had particularly interested me as a medical student. Although I did quite well in the exams but I, as I say, I far preferred anatomical pathology.

But I was quite happy because in those days people became what were called general pathologists. You'd rotate through the various sub-disciplines of pathology. You know, it's a circle, you may - can start anywhere and you end up in the same, come back and then it's all over. That was the intent. I found that I really enjoyed microbiology. I found it challenging and interesting. While I was in this training period, the college of pathologists actually changed the rules and they decided general pathologists weren't a good idea anymore because the knowledge in pathology was growing so much, that no one person can do all of pathology properly. They said, what we're going to do is limit you to do two. I said okay, that's fine, I'll go and do haematology. I really enjoyed haematology, I found it really interesting and I got involved...

ANDI HORVATH
That’s the study of blood.

ROY ROBINS-BROWNE
Yes. It's much easier conceptually than microbiology which is huge. Haematology, as I used to joke, you know it's sort of red cells, white cells, platelets where there's bits of cells that help your blood clot, and basically that's it. If you know that you know everything, so it's not too much. It's easy to get your head around. I did that for 18 months and I decided I was going to become a haematologist.

I'd already had a PhD program laid out, because then often after you do the first part of your pathology exams, the idea is you do some research and a higher level training. But part of that is, research could actually lead to a PhD, so you could do formal research. You do PhD part time and studying pathology part time. That's what I'd had that all planned. I was going to do that. My boss, who was going to be my PhD supervisor got a promotion and he said, I'm not able to supervise you anymore. I was somewhat impetuous, I said I was an only child I like to get my own way. In 30 seconds, I'd decided I'm not going to stay here, they don't want me, I'm going somewhere else. Microbiology was quite fun, I'll go back there and see if my boss there would have me. I said, okay I've decided I want to specialise in microbiology and would you supervise my PhD. He said, that's fine you've got to come up with a new PhD program because this one - so I was going to be an immunohematologist, which I think's quite a sexy area.
[Laughter]

ANDI HORVATH
It works for me.

ROY ROBINS-BROWNE
But it turned out I became a medical microbiologist and then one thing led to another. That particular boss was interested in researching causes of diarrhoea in black African children, which was a major cause of death in South Africa at the time. It was the time when rotavirus had just been discovered in Melbourne, when enterotoxigenic E. coli had just been discovered in the UK and been, much work done on it in the United States including at the University of Maryland in Baltimore. I thought well, these are the really important areas to look at and important pathogens to find. We went and looked for them but instead we found enteropathogenic E. coli. That's when I became a convert.

ANDI HORVATH
Thank goodness for us. I've got a question for you both and that is, humans versus microbes. Are we winning the battle thanks to this work that's gone on since the 70s? Well, since Pasteur.

MIKE LEVINE
I would say from the narrow perspective of vaccines, yes in many ways in terms of our ability to apply the advent of biotechnology, all these new methodologies. We can create almost - a vaccine against almost any pathogen that comes, with a few exceptions, given the right resources and interest, resources including finances. We've had some marvellous successes including some of the earlier vaccines.

What we are facing now is the flip side of the success of vaccines. Take measles as an example. People forget what a ravishing disease measles was for children. Even in the industrialised countries with one out of every 700 dying and one - and 10 per cent going into hospital and all kinds of adverse reactions. Some children developing encephalitis, about one out of a thousand. Measles vaccine gets introduced and we see within a couple of years a 90 per cent drop in the burden, the number of cases per year. Over a generation then, parents who - every one of whom recognised, had measles themselves - next generation, measles is as exotic as small pox or Ebola.

We have this problem of anti-vaccine and vaccine hesitancy with parents going on the internet, doing their research and coming upon some websites that look very official and knowledgeable, that take facts and weave them into a fabric that gives a very wrong conclusion. So we see young parents deciding this is not a problem any more, why should I have my child receive vaccine when there's a one in a million - any way. I see that as a huge problem and we must battle this problem because vaccines that apply the best technology that sit on a shelf, don’t do any good for any one.

ROY ROBINS-BROWNE
I don't see it quite in the same way you see it. I don't think it's humans versus bacteria. Bacteria were on the earth a few billion years before us...

ANDI HORVATH
True.

ROY ROBINS-BROWNE
...and they'll be here billions of years after us.

ANDI HORVATH
And they evolve faster than us.

ROY ROBINS-BROWNE
And they evolve very much faster than us. The generation of an E. coli in the laboratory at any rate, is about 20 to 30 minutes.

ANDI HORVATH
Which is why the antibiotic resistance crash that we're facing is terrifying.

ROY ROBINS-BROWNE
Exactly. That's part of them winning the battle and that's why we need a new type of approach. There's all different types of approaches, as I indicated and there's no one clear way, but a good start is education and using antibiotics more appropriately. In fact, the improvements in diagnosis allow us to use antibiotics more appropriately because doctors were often treating blind because one of the problems is getting bacteria to grow. Even if they grow really fast, they do have short generations, but it still takes a day or two to get a result of the laboratory to say it's susceptible to this antibiotic, it's resistant to that antibiotic.
What doctors would do, and perfectly reasonably, assess for serious illness, is they treat patients with one or more antibiotics that have a very broad spectrum. What we call shotgun treatment. Hoping to hit something. Whereas instead of shotguns we'd like to use rifle bullets to target something very specific. But you can't do that until now. Because through the latest molecular revolution in microbiology, whole genome sequencing, amplifying genes by PCR, you can detect resistance very, very much faster and then target the treatment much more quickly. It's actually already showing signs of improvement that doctors are prescribing more appropriately using rifle bullets rather than shotgun. That will help us deal with resistance.

ANDI HORVATH
So we can get on top of antibiotic resistance?

ROY ROBINS-BROWNE
That's one strategy that we see and there's lots of other complementary strategies. Finding new antibiotics and educating the public. But I think the public, certainly within Australia, are getting much more - better educated. One difference I've noticed. When I came to Australia, I gave lectures on antibiotics and that was quite interested in antibiotic usage. In 1982, I went and looked at the PBS, the Pharmaceutical Benefits Scheme data on drug usage and I think in the top 10 drugs prescribed in Australia, three were antibiotics. Now in the top 20, only one's an antibiotic. It's really - so people are using antibiotics far less. Or I think that [may also reflect] using other drugs much more. Anti-inflammatories and so on.

ANDI HORVATH
Yeah. What's your advice to young researchers? If they feel they're up against dominant dogma but they've got a real hunch and some evidence that's looking like there's an alternate way of exploring nature?

MIKE LEVINE
I would draw upon this extraordinary experience and friendship that Roy and I have had, and our families over almost 40 years. When we started being loners believing that enteropathogenic E.coli really were pathogens and all our mentors and the most powerful and respected individuals in the area of bacterial infections thought that we were a bit loony, we believed, we got a degree of affirmation from each other, we stuck with it and within a decade we were able to see many groups across the world working on the same thing. Unequivocally recognising this is a pathogen and within some years thereafter, there were international conferences and with some degree of pride and satisfaction we could know that this bug, that people thought was a non-pathogen, by the doggedness of staying with our beliefs, we could see this become - with many people saying it was the best studied at the level of molecular pathogenesis, bacterial enteropathogen that existed.

ANDI HORVATH
So really effort into your ideas, almost trying to prove yourself wrong, or right is a good way to go?

MIKE LEVINE
Yes. Stick with it.

ROY ROBINS-BROWNE
I totally agree with that. That's the way I started. As I said, I set out to show that enterotoxigenic E. coli and rotavirus were important causes of diarrhoea and no matter how hard I tried that, I had to accept the alternative which was that enteropathogenic E.coli was important. I think what you learn from that is, you have to believe the evidence and then don't try and find explanations why that's wrong. That’s what the other people were doing, they said, these are just enterotoxigenic E. coli and enteroinvasive E. coli that have lost the plasmids and I said, they're not, clearly they're not because they're not the same kind of E. coli. There were a lot of ways of looking at sub-groups of E. coli in those days that you could say 'well, they're not the same'. Believe the evidence.

ANDI HORVATH
Believe the evidence. It's there in front of you. This story kind of mimics a little bit the helicobacter pylori story as well. In the sense that I remember studying physiology and there were three theories to why we had stomach ulcers. One was overactivity of acid, I think one was overactivity or sensitivity to it...

ROY ROBINS-BROWNE
Stress.

ANDI HORVATH
Stress. Then there was this fringe theory that it was a bacterial infection. Of course, by the time I graduated it was no longer the fringe theory.

ROY ROBINS-BROWNE
That was another. That's a revolution in medicine that we witnessed which was ulcers, peptic ulcers, gastric and duodenal ulcers were caused by stress. It was a psychosomatic disease that you treated with surgery. Then it became an infectious disease that you treated with antibiotics.

ANDI HORVATH
There's still a lot of work to be done. Would that be true?

MIKE LEVINE
Yes.

ROY ROBINS-BROWNE
No doubt.

ANDI HORVATH
Okay, young scientists, on to it. I feel like that on behalf of planet earth, I need to thank you two for being disease heroes and for propelling an amazing spectrum of research that has led to diagnosis and treatment with you and your colleagues and extended family of microbiologists and immunologists. We're getting there. Thank you, Mike.

MIKE LEVINE
Thank you.

ANDI HORVATH
Thank you, Roy.

ROY ROBINS-BROWNE
Thank you very much.

CHRIS HATZIS
Thank you so much to Professor Mike Levine, pioneer of vaccinology at the University of Maryland, and to Professor Roy Robins-Browne, clinical microbiologist and research scientist at the University of Melbourne. And thanks to our reporter Dr Andi Horvath.

Eavesdrop on Experts - stories of inspiration and insights - was made possible by the University of Melbourne. This episode was recorded on November 19, 2018. You’ll find a full transcript on the Pursuit website. Audio engineering by me, Chris Hatzis. Co-production - Dr Andi Horvath and Silvi Vann-Wall. Eavesdrop on Experts is licensed under Creative Commons, Copyright 2018, The University of Melbourne. Don’t forget to drop us a review on iTunes, and check out the rest of the Eavesdrop episodes in our archive. I’m Chris Hatzis, producer and editor. Join us again next time for another Eavesdrop on Experts.