Question

If a mutation occurred in Escherichia coli that deleted the gene for an adhesin, what effect might it have on the ability of \(E\). coli to cause urinary tract infections?

Short answer

The deletion of the gene for an adhesin could potentially reduce the ability of \(E\). coli to cause urinary tract infections, due to a reduced capacity to attach to cells within the urinary tract and establish an infection.

Step-by-step solution

Understanding what adhesins do in bacteria

Adhesins are proteins that are found on the surface of bacteria. They play an important role in allowing bacteria to attach to host cells. This attachment is often a critical first step in the establishment of many bacterial infections.

Analyzing the potential effect of a mutation that deletes the gene for an adhesin

If the gene for an adhesin in \(E\). coli was deleted, the bacterium would not be able to produce this adhesin protein on its surface.

Predicting the effect on the ability of \(E\). coli to cause urinary tract infections

Without this adhesin, the ability of \(E\). coli to attach to cells within the urinary tract may be impaired. This could potentially result in a reduced capacity to initiate an infection because they might be more likely to be flushed out of the urinary tract before they can establish an infection.

Key concepts

Escherichia coli

Escherichia coli, commonly known as E. coli, is a type of bacteria that is often found in the environment, foods, and intestines of people and animals. While many strains of E. coli are harmless and a normal part of the gut flora, some can be pathogenic and cause illnesses.

Pathogenic strains of E. coli can lead to various types of infections, such as gastrointestinal infections, respiratory illnesses, and urinary tract infections. These harmful strains possess distinctive virulence factors which allow them to establish and cause infections in hosts. Adhesins are one of these vital virulence factors that assist in bacterial adhesion and colonization.

Urinary Tract Infections

Urinary tract infections (UTIs) are common bacterial infections that affect the urinary system, comprising the kidneys, ureters, bladder, and urethra. E. coli is the predominant cause of UTIs, responsible for about 80% of cases.

UTIs can range from infections of the bladder, known as cystitis, to more serious infections if they spread to the kidneys. Symptoms often include frequent urination, a strong urge to urinate, cloudy urine, and pelvic pain. The ability of bacterial cells such as E. coli to adhere to the epithelial cells of the urinary tract is a critical factor in the pathogenesis of such infections. This adhesion prevents the bacteria from being flushed out during urination.

Mutation Effects

Mutations refer to changes in the DNA sequence of an organism which can impact its normal functions. In bacteria like E. coli, a mutation can alter or deactivate important genes, such as those coding for adhesins.

A deletion mutation of the gene responsible for adhesin production affects the ability of E. coli to stick to cells in the urinary tract. This is significant because it may hinder the establishment of infection.

• The bacteria might lose the ability to firmly attach to host cells, reducing infection spread.
• This inability to adhere effectively could result in the bacteria being expelled from the urinary tract more easily during urination.

Therefore, such mutations can limit the pathogenic capabilities of E. coli.

Microbial Pathogenesis

Microbial pathogenesis is the process by which microbes, like bacteria, cause diseases in a host. The initial step in many bacterial infections is adherence to host tissues, facilitated by molecules known as adhesins.

For E. coli, adhesins allow the bacteria to attach tightly to the urinary tract cells—a vital step in evading the body's natural flushing mechanism. Once adhered, the bacteria can multiply, and other virulence factors can take effect, leading to inflammation and infection.

• Without adhesins, the effectiveness of E. coli as a pathogen reduces as it can't establish a strong foothold.
• The understanding of microbial pathogenesis aids in developing strategies to prevent and treat infections.

Targeting adhesins could be a potential therapeutic strategy to prevent bacteria from causing infections in the first place.