Nav: Home

Protective shield: How pathogens withstand acidic environments in the body

May 05, 2020

Certain bacteria, including the dangerous nosocomial pathogen MRSA, can protect themselves from acidic conditions in our body and thus ensure their survival. Researchers at the Biozentrum of the University of Basel have now elucidated an important mechanism in this process. A transport protein involved in cell wall biosynthesis plays a key role, they report in the journal "Nature Structural & Molecular Biology".

Each year, thousands of patients in Swiss hospitals become infected with dangerous pathogens that can hardly be controlled with antibiotics. The methicillin-resistant bacterium Staphylococcus aureus, MRSA for short, is particularly feared among the multi-resistant nosocomial germs. It can cause severe wound, respiratory and urinary tract infections and life-threatening sepsis. This is aggravated by the fact that MRSA causes chronic infections.

The cell wall as a therapeutic target

The bacterial cell wall is a key target in the search for new antimicrobials, as only an intact cell wall can protect the pathogens from the host's immune defence and from antibiotics. In a recent study, scientists led by Prof. Camilo Perez from the University of Basel's Biozentrum have elucidated the structure and function of a flippase transporter involved in the synthesis of lipoteichoic acids in the pathogen MRSA. Lipoteichoic acids are important biopolymers that provide stability to the cell wall of Gram-positive bacteria, facilitate colonization of the host and contribute to repelling antibiotics.

Transport of an "anchor" molecule to its destination

The cell wall is a highly dynamic layer that surrounds the cell membrane and protects bacteria. Lipoteichoic acids are long-chain biopolymers that are embedded in the cell wall. However, they only remain in place because they are bound to an "anchor" molecule at the cell membrane. Without this "anchor", lipoteichoic acids are not able to provide stability to the cell wall. "Based on our structural and functional analyses, we have been able to show for the first time how the "anchor" arrives at its destination and how bacteria energize this process," explains Perez. By moving hydrogen ions across the cell membrane, the flippase transporter is flipping the "anchor" molecule from the inside of the bacterial membrane, the site of its synthesis, to the outside, the site of lipoteichoic acid production.

Survival strategy of Gram-positive bacteria

"The fact that the transport of hydrogen ions is coupled with the synthesis of lipoteichoic acid represents a major survival advantage for these bacteria," says Perez. "The niches in the human body, which are preferentially colonized by Staphylococcus aureus, usually have an acidic microclimate. This means that the concentration of hydrogen ions is higher in these niches. The bacteria withstand these acidic conditions by simply building up a thicker protective layer of lipoteichoic acids."

The researchers have also been able to show that Staphylococcus aureus lacking the flippase transporter display severe growth defects upon acidic stress. According to the researchers, the flippase is essential for the survival of Staphylococcus aureus in our body and could be considered as a new pharmacological target for the treatment of dangerous MRSA infections.
-end-
Further information: Prof. Dr. Camilo Perez, University of Basel, Biozentrum, tel. +41 61 207 23 42, email: camilo.perez@unibas.ch

University of Basel

Related Bacteria Articles:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.
How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.
Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.