Microbiology: Pathogen Interactions and Infections

Questions and Answers

What role does the adherence of pathogenic bacteria play in microbial infections?

It reduces the effectiveness of the immune response.

It helps bacteria to be flushed out of the body.

It leads to the development of antibodies.

It allows bacteria to colonize and cause disease. (correct)

Why are biofilms formed by pathogenic bacteria difficult to treat?

They are resistant to antibiotic treatments. (correct)

They form on natural surfaces only.

They prevent bacteria from adhering to surfaces.

They increase the body's immune response.

What surgical procedure is often required to successfully treat prosthetic joint infections (PJIs)?

Antibiotic therapy alone.

Replacement of the entire prosthesis.

Amputation of the affected limb.

Debridement of colonized biofilm. (correct)

Which natural surfaces exhibit antibacterial properties that researchers are studying for biomimetic applications?

Shark skin, insect wings, and lotus leaves. Signup and view all the answers

What is the primary reason for researchers to explore using titanium dioxide (TiO2) in antibacterial nanofabrication?

It mimics natural contact killing surfaces. Signup and view all the answers

What is the key challenge with treating infections associated with implanted medical devices?

The formation of biofilms on these devices. Signup and view all the answers

What characteristic of shark skin, insect wings, and lotus leaves allows them to kill bacteria on contact?

Their structural nanostructures. Signup and view all the answers

What is a significant threat in orthopedic medicine related to pathogenic bacteria?

Prosthetic joint infections (PJIs). Signup and view all the answers

What is a primary reason TiO2 is promising for medical applications against bacteria?

It can cause physical damage to gram-negative bacterial cells. Signup and view all the answers

Why is the portal of entry important for the establishment of an infection?

It ensures the pathogen encounters compatible tissues. Signup and view all the answers

What role do receptor molecules play in the infection process?

They facilitate the adhesion of pathogens to host tissues. Signup and view all the answers

Which type of bacteria has shown limited potential for destruction by TiO2?

Staphylococcus aureus. Signup and view all the answers

What specific characteristic of the bacterium Streptococcus pneumoniae affects its potential to cause infection?

The acidity of the stomach. Signup and view all the answers

What adaptive feature do receptors on pathogens possess?

They specifically bind to complementary host molecules. Signup and view all the answers

Why would the application of antibacterial nanostructures on medical implants be beneficial?

They can prevent and control infections without antibiotics. Signup and view all the answers

What composition primarily makes up adhesins on pathogen surfaces?

Glycoproteins or lipoproteins. Signup and view all the answers

Study Notes

Microbial Infection and Pathogenesis

Pathogenic bacteria adhere to surfaces, including natural tissue surfaces (tooth enamel, mucous membranes) and artificial surfaces (implanted medical devices, catheters, prosthetic heart valves, artificial joints), which leads to the formation of biofilms and disease.
Biofilms are difficult to treat with antibiotics, and successful treatment often requires physical removal of the colonized biofilm through debridement.

Killing Pathogens on Contact

Certain animal and plant tissue surfaces (shark skin, insect wings, lotus leaves) exhibit antibacterial properties, killing bacteria on contact by disrupting their cytoplasmic membranes.
Antibacterial nanofabrication methods have been developed using titanium dioxide (TiO2) to mimic natural contact killing, showing promise in destroying gram-negative bacteria on contact.

Human–Pathogen Interactions

The portal of entry is critical for the establishment of an infection, as a pathogen that gains access to incompatible tissues is typically ineffective.
Receptor molecules on the surfaces of both the pathogen and host cells are important for adhering the pathogen to host tissues.
Specific receptors can be important for the binding of various types of pathogenic microbes (bacteria, viruses, parasites) to host cells.
Adhesins, composed of glycoprotein or lipoprotein, are receptors on the pathogen surface that bind specifically to complementary molecules in the host, alerting the pathogen that it has arrived on a suitable infection site.

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Description

Learn about pathogenic bacteria, their adherence to surfaces, and how they cause disease. Understand the role of natural and artificial surfaces in microbial infections.