Hospital-acquired infections – better diagnostics for rapid treatment

00:00:00: A hospital. A place where you generally don't like to go but are glad that it's there when

00:00:07: you need it. A place that smells of disinfectant. It's called clinically clean. And then, multi-resistant

00:00:17: bacteria. Hospital germ. A place where you are supposed to get well becomes a threat

00:00:21: to your health from pathogens that are often so persistent that there are hardly any effective

00:00:27: drugs against them. How can that be? And above all, how can we deal with it? Professor Susanna

00:00:39: Heusler and her molecular bacteriology research group at the HZI and the Twincore in Hanover

00:00:46: are investigating this. In this episode, we talk about the clever strategies bacteria use to

00:00:52: become multi-resistant hospital germs, how ways of dealing with them are being researched and what

00:00:58: we can all do to protect ourselves and vulnerable patients from them. Hi Susanna. How does the life

00:01:05: of a hospital-acquired multi-drug resistant bacterium look like? Maybe it's a good idea to

00:01:11: start to think about not so much the bacterium and whether it's a hospital bacterium but about

00:01:19: hospital-acquired infections. Because the hospital-acquired infections can occur or can be acquired

00:01:27: in different ways. So you can acquire an infection due to a pathogen that has been surviving in the

00:01:38: hospital as an example in the sink, in the drains. And then the bacterium is really a

00:01:46: bacterium that has been living in the hospital and has been also exposed to many antibiotics. But

00:01:52: you can also acquire a hospital-acquired infection by having contact with a patient either directly

00:02:01: or indirectly that is infected. So you acquire a pathogen from another patient. But you can also

00:02:09: get infected with your own bacteria that you might bring into the hospital. And the thing here

00:02:16: is that once you're in a hospital and a classical example would be a surgical procedure and you

00:02:24: have a wound and this wound gets infected after the procedure. And this infection might occur

00:02:30: with your own skin flora. This is also a hospital-acquired infection we have to deal with.

00:02:36: How do you know that a patient is infected with such a resistant hospital pathogen?

00:02:41: When we stick with the example of a wound infection, this is normally you see the clinical

00:02:49: signs very typical. So redness, swelling and pain. And it might even get a poor, you can get a

00:03:00: poor lens secretion, which is a sign of a bacterial infection and the wound will not heal. So the

00:03:07: physician might then take a swab, a sample and send it to the microbiological diagnostics lab,

00:03:15: where they then will do a culture from the patient's specimen. And they will isolate the

00:03:22: infecting agent. And then they will also do antimicrobial resistance profiling on this

00:03:26: pathogen. And then they will tell you, tell the physician whether the physician can give the

00:03:36: patient, if necessary, a certain antibiotic on what drug is still susceptible and what antibiotic

00:03:42: is resistant. And how is the situation in Germany and maybe compared to other countries?

00:03:52: The situation in the clinic when you deal with hospital-acquired infection is very much dependent

00:03:59: on what are the hygiene control measurements and the preventive activities that are implemented

00:04:08: in the hospital? What is the standard? And the standards vary a lot between different hospitals

00:04:13: and different regions and different countries. So in general, you can say that in the north,

00:04:19: you have lower hospital-acquired infection or the rate of hospital-acquired infection is much

00:04:25: lower, whereas in the south, they are higher. So in Germany, roughly, we have 500,000 nosocomial

00:04:33: infections that are reported each year. Okay. And you're specialized on the bacterium Pseudomonas

00:04:39: alginosa. Why this particular pathogen? For us Pseudomonas alginosa is a perfect model

00:04:46: organism. And we are interested in a model organism that causes problematic infections.

00:04:53: Pseudomonas is problematic because it's naturally resistant against a lot of different antimicrobial

00:05:00: reactions. And it also has a large variety of different violence factors and they help

00:05:08: in causing disease. So Pseudomonas can cause very severe acute infections. Pseudomonas is

00:05:15: also a pathogen that can cause chronic infections. They are very different. The problem is not

00:05:23: so much acute and severe, but a problem with therapy. They are very, very difficult to

00:05:31: treat. Where does it occur? And which conditions does it become dangerous for us? Pseudomonas

00:05:39: is a pathogen that can be found ubiquitous across the world, everywhere in the environment.

00:05:48: It needs a little bit of water, but then you can find it almost everywhere. But you can

00:05:52: also find it in the hospital. And in the hospital it's mainly in the drain, so it needs a little

00:05:57: bit of water. You find it in the bathrooms in the drains. Pseudomonas alginosa is not

00:06:02: really a dangerous pathogen. It's a very typical opportunistic pathogen. This means that it's

00:06:11: not dangerous for healthy individuals, but it can cause very severe infections in compromised

00:06:19: patients. Compromised patients for Pseudomonas infection are mainly patients where you have

00:06:27: broken the first physical barrier. Pseudomonas has problems in overcoming the first physical

00:06:33: barrier. If you help them, for example, in intubated patients, then Pseudomonas can cause

00:06:39: a lung infection. Or patients that have a catheter in their urinary tract, they can then

00:06:47: suffer from urinary tract infections. And the same also in wounds. The skin is a very

00:06:53: good physical barrier. It helps to protect against Pseudomonas infections. When you have

00:06:59: a wound, this physical barrier is broken. Pseudomonas can cause very severe wound infections that

00:07:08: often become chronic. And this is mainly associated with the bacteria forming biofilms in these

00:07:13: wounds. I think biofilms primarily, we know it as a layer of slime, for example, on boats

00:07:22: that lie in the water. But what makes the biofilms of hospital pathogens so dangerous?

00:07:31: The bacteria produce the slime themselves. It's a polysaharide, and it's a physical barrier

00:07:38: that protects them very well from the immune system. But also from very different environmental

00:07:42: insults. And that's also when you see biofilms in nature. This is mainly physical inside.

00:07:50: so heat and sun and so this is a very good protection.

00:07:55: It also helps to protect against the immune cells.

00:07:58: But it's also important,

00:07:59: the slime is sticking the bacteria one to the other

00:08:02: and then usually also the whole bacteria population

00:08:05: onto a surface and that is localizing them

00:08:09: in a certain place in the body,

00:08:12: mainly on abiotic surfaces.

00:08:16: And at the same time, this shielding leads to

00:08:21: a difference in the growth behavior of the bacteria.

00:08:27: So they grow much, much slower

00:08:30: in these shielded exopole,

00:08:32: zaharite and cased biofilm communities.

00:08:35: And that's very important

00:08:36: because they change their metabolism.

00:08:38: The metabolism becomes slower.

00:08:41: And then the antibiotics that usually need

00:08:44: a fast growing bacteria to act perfectly,

00:08:47: they are less efficient.

00:08:48: And that's our problem, biofilm bacteria.

00:08:51: Once biofilms are formed, it's really difficult to treat.

00:08:54: - Okay, I think that is the biggest challenge,

00:08:57: also in the clinic, when fighting bacterial infections.

00:09:02: - Yeah, that's a very big challenge.

00:09:03: So they're not really very good solutions in the clinic.

00:09:08: So we currently and others research to think about

00:09:13: whether there's a way of somehow awakening the bacteria

00:09:17: so that they grow faster again.

00:09:19: And then you can target them again

00:09:21: with our classical antibiotics

00:09:22: because our antibiotics in fact are very, very good.

00:09:25: But in certain situations, either you are too late,

00:09:29: you treat too late is a big challenge,

00:09:31: or the bacteria are in these biofilms,

00:09:34: they are not really exposing themselves

00:09:36: to the antibiotic and that's a problem.

00:09:39: - Okay, you also lead a research group at Twin Core,

00:09:42: the Center for Experimental and Clinical Infection Research.

00:09:46: This is the site of the HZi,

00:09:48: where we're set up together with Hanover Medical School.

00:09:52: What are the benefits of that cooperation

00:09:55: with the medical school here in Hanover?

00:09:58: - Yeah, we are very happy to have also a part

00:10:01: of the research group at the medical school,

00:10:03: not only at the HZi,

00:10:04: where we have access to really good infrastructure

00:10:07: and we do a lot of sequencing of bacterial genomes.

00:10:10: And that's really something that we do at the HZi.

00:10:13: But the group at the MRH has a closer contact,

00:10:17: especially to the medical microbiologist

00:10:19: at the medical school.

00:10:21: And that's important.

00:10:22: We also get a lot of clinical samples

00:10:24: and so bacteria strains from the medical microbiologist.

00:10:28: And this is very important for our research.

00:10:31: And we also talk to clinicians at the site.

00:10:35: - Yeah, okay.

00:10:37: How can you better diagnose bacterial infections

00:10:40: and these bacterial infections?

00:10:42: What do you need for this?

00:10:44: And maybe what's missing yet?

00:10:47: - At the moment,

00:10:48: the classical medical microbiological diagnostics

00:10:51: really relies on having a sample

00:10:54: and culturing the bacteria from the sample.

00:10:56: This takes a lot of time

00:10:58: and it's also very labor intensive.

00:11:00: So we think the future will be really going

00:11:03: into molecular diagnostics.

00:11:05: We will probably read out bacterial genomes.

00:11:11: And by doing that,

00:11:12: we will be able to predict whether they are antibiotic resistance

00:11:15: or whether we can treat them

00:11:17: still with certain classes of antibiotics.

00:11:19: So this will probably be the future

00:11:21: and we are really working on making this happen.

00:11:24: - You also set up a laboratory in Copenhagen.

00:11:30: What exactly do you examine there

00:11:32: and how often are you there?

00:11:34: - Yeah, we have a lab in Copenhagen since 2019.

00:11:38: And in the first three years,

00:11:40: I really have been there at the Riesh Hospital,

00:11:44: that's the university clinic in Copenhagen.

00:11:48: And the main aim here is to establish a pipeline

00:11:52: so that we get the clinic isolates

00:11:54: from the hospitalized patients.

00:11:56: And we get a lot,

00:11:57: we get probably 80% of these clinic isolates.

00:12:01: We get them into our lab

00:12:02: and we do whole genome sequencing

00:12:04: also in an automated process.

00:12:07: We do whole genome sequencing on them.

00:12:10: And we roughly sequence 1,000 isolates per month.

00:12:13: - Crazy.

00:12:14: And this is the researcher side,

00:12:16: but what can physicians and nurses do to prevent resistances?

00:12:21: - Yeah, the main thing in the hospital

00:12:24: or also outside the hospital is to be aware

00:12:27: that once you give an antibiotic,

00:12:29: you give the bacteria the chance

00:12:32: or when they are exposed to the antibiotic,

00:12:34: they need to develop strategies in order to still survive.

00:12:39: So the major thing is to really reduce antibiotic use.

00:12:45: That's the main thing.

00:12:48: But when you give an antibiotic,

00:12:50: when you decided this is an important treatment

00:12:54: for the patient,

00:12:55: then you really have to stick to the dosage

00:12:58: and also to the correct time interval

00:13:02: that you give the antibody.

00:13:03: That's really important.

00:13:05: And the other important thing is, of course,

00:13:06: we have in the hospitals,

00:13:08: we have to care and do a lot about stopping transmission.

00:13:13: And this is, of course, hygiene.

00:13:17: So hygiene is a very, very important thing.

00:13:20: And hygiene in the hospital means mainly hand death infection.

00:13:26: This is the thing.

00:13:29: - Has your work changed your own hygiene standards

00:13:34: in everyday life?

00:13:37: - Actually, not so much because I know

00:13:39: we are not exposed to very dangerous bacteria.

00:13:43: So most of what we have been talking about,

00:13:46: these are oponynistic infections,

00:13:50: meaning that you have to have a certain predisposition.

00:13:53: But of course, it also happens in daily life

00:13:55: that you cut yourself and you have a wound.

00:13:59: And then you have to care for that this wound

00:14:05: is properly dealt with and is not exposed to an infection.

00:14:10: Maybe I will, I know a little bit better

00:14:15: about how important this is,

00:14:17: but actually, I think people know.

00:14:21: So no, not really that we do something different

00:14:24: because we are not very much exposed

00:14:27: as healthy individuals to infections.

00:14:29: - You're researching very, very, or you, yeah.

00:14:34: You spend very much time for your research,

00:14:39: but I think you also need some kind of work-life balance.

00:14:43: What is important for you in your free time?

00:14:46: How can you relax?

00:14:47: - I love to stay with my family.

00:14:50: I really love to be around my husband and my two daughters.

00:14:54: And I have a large garden.

00:14:56: I love gardening and being in nature.

00:14:59: - Nice.

00:15:00: Thank you for your time.

00:15:01: - Thank you.

00:15:02: (upbeat music)

00:15:04: (upbeat music)

00:15:07: (upbeat music)

00:15:10: (upbeat music)

00:15:12: (upbeat music)

00:15:15: (upbeat music)

00:15:17: (upbeat music)

00:15:20: (upbeat music)

00:15:22: (upbeat music)

00:15:25: (upbeat music)

00:15:28: (upbeat music)

00:15:30: (upbeat music)

00:15:33: (upbeat music)

00:15:35: (upbeat music)

00:15:38: [MUSIC]