Escherichia coli (E. coli) are bacteria that normally live in the intestines of people and animals. While most strains are harmless, some can cause illness, and treating these infections has grown more challenging with antibiotic resistance. A specific type involves bacteria that produce enzymes called extended-spectrum beta-lactamases (ESBLs). These enzymes break down many common antibiotics, making the resulting infections difficult to treat.
ESBL-producing E. coli is a strain that has this resistance mechanism, making it a concern in both healthcare facilities and the community. The bacteria can cause a range of infections, from urinary tract infections to more severe bloodstream infections. Understanding this resistant bacteria is important for treatment and prevention.
How Infections Occur and Who is at Risk
ESBL E. coli infections can be acquired in both healthcare and community settings. In facilities like hospitals and long-term care homes, the bacteria can spread through contact with contaminated hands or surfaces. Community-associated infections occur in healthy individuals, sometimes through contaminated food or water. International travel to areas with a high prevalence of these bacteria is also a risk factor.
A distinction must be made between colonization and active infection. A person can be colonized, meaning they carry the ESBL-producing bacteria in their body without showing any signs of illness. An active infection occurs when these bacteria move to another part of the body and cause symptoms, so not everyone who carries the bacteria will become sick.
Several factors increase the risk of developing an ESBL E. coli infection. Individuals recently hospitalized or in a long-term care facility are at higher risk. Prolonged or recent use of broad-spectrum antibiotics is a significant contributing factor. Other risks include a weakened immune system, the presence of an indwelling urinary catheter, and recurrent urinary tract infections.
Symptoms and Diagnosis
The symptoms of an ESBL E. coli infection depend on the affected body part and are the same as those caused by non-resistant bacteria. For instance, a urinary tract infection, a common site for E. coli, can cause a burning sensation during urination, frequent urination, or back pain. A skin infection may present as a localized area of redness, tenderness, or pus.
When the bacteria enter the bloodstream (bacteremia), it can lead to systemic symptoms such as fever, chills, and a general feeling of being unwell. Lung infections, or pneumonia, may cause a cough and difficulty breathing. Gastrointestinal symptoms like diarrhea, stomach cramps, and vomiting can also occur.
Diagnosing an ESBL E. coli infection starts with collecting a sample from the suspected site, such as urine, blood, or a wound swab. The sample is sent to a laboratory for a culture to grow and identify the bacteria.
Once E. coli is confirmed, susceptibility testing is performed. This test exposes the bacteria to different antibiotics to determine which are effective. The presence of the ESBL enzyme is confirmed by observing resistance to specific antibiotics like cephalosporins, which guides the physician in selecting a treatment.
Treatment Approaches for Resistant Infections
The ESBL enzyme renders many standard antibiotics ineffective. Beta-lactam antibiotics, like penicillins and most cephalosporins, are broken down by these enzymes. This resistance requires the use of alternative antibiotics to successfully treat the infection. The choice of antibiotic depends on the infection’s severity and location, as well as the results of susceptibility testing.
For serious infections, such as bloodstream infections or hospital-acquired pneumonia, carbapenems are a primary treatment. This class of antibiotics, including drugs like meropenem and ertapenem, is reliable against ESBL-producing organisms because they are stable against the enzyme. These medications are administered intravenously in a hospital setting.
For less severe infections, such as uncomplicated urinary tract infections (cystitis), other options are available. Nitrofurantoin and fosfomycin can be effective oral options for treating these UTIs. Some combination drugs, which pair a beta-lactam antibiotic with a beta-lactamase inhibitor like piperacillin-tazobactam, may also be used.
Patients must complete the full course of any prescribed antibiotic as directed by their healthcare provider. Finishing the treatment helps ensure the infection is fully eradicated and reduces the risk of further resistance developing. The management of these infections requires careful antibiotic selection based on lab results for the best outcome.
Preventing the Spread of ESBL E. coli
Preventing the spread of ESBL E. coli involves actions in community and healthcare settings. For the public, good hand hygiene is a primary defense. Washing hands thoroughly with soap and water, especially after using the bathroom, before preparing food, and after contact with animals, can reduce transmission risk. When soap and water are not available, an alcohol-based hand sanitizer is an effective alternative.
In healthcare environments, infection control prevents transmission. A key component is contact precautions for patients infected or colonized with ESBL E. coli. This means healthcare workers wear gloves and gowns when entering the patient’s room to prevent carrying the bacteria to others. Patients with these bacteria may also be placed in a single room or with other patients who have the same bacteria.
Thorough cleaning and disinfection of patient rooms and medical equipment are also standard procedures. Surfaces that are frequently touched, such as bed rails, doorknobs, and call buttons, are regularly cleaned to eliminate the bacteria. These combined efforts help contain the spread of ESBL E. coli within the hospital and protect patients.