What is the next step in treating a patient with a urinary tract infection caused by ESBL-producing Escherichia coli (E. coli) with a colony count of greater than 100,000 CFU/mL?

From the Guidelines

The next step in treating a patient with a urinary tract infection caused by ESBL-producing Escherichia coli with a colony count greater than 100,000 CFU/mL is to initiate treatment with a carbapenem antibiotic, such as Meropenem 1 g 8-hourly, as recommended by the 2017 WSES guidelines for management of intra-abdominal infections 1. Given the patient's urine culture result showing greater than 100,000 CFU/mL of ESBL-producing E. coli, with resistance to multiple antibiotics including amoxicillin-clavulanate, ampicillin, and ceftriaxone, treatment with a carbapenem is crucial due to its effectiveness against ESBL-producing organisms. Key considerations in managing this patient include:

• Ensuring adequate hydration to help flush out the bacteria
• Monitoring renal function during treatment, as carbapenems can affect kidney function
• Obtaining susceptibility testing to guide definitive therapy, although given the ESBL-producing status, carbapenems are a reasonable initial choice
• Considering infectious disease consultation for complex cases or if the patient's condition does not improve with treatment The choice of meropenem is based on its efficacy against ESBL-producing E. coli, as well as its recommendation in the guidelines for patients at risk for infection with community-acquired ESBL-producing Enterobacteriaceae 1. Other carbapenems like imipenem-cilastatin or doripenem could also be considered, but meropenem is specifically mentioned in the guidelines as an option for such infections.

From the FDA Drug Label

To reduce the development of drug-resistant bacteria and maintain the effectiveness of PIPRACIL and other antibacterial drugs, PIPRACILshould only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy PIPRACIL has been successfully used with aminoglycosides, especially in patients with impaired host defenses. Appropriate cultures should be made for susceptibility testing before initiating therapy and therapy adjusted, if appropriate, once the results are known.

The patient has a urinary tract infection caused by ESBL-producing Escherichia coli with a colony count of greater than 100,000 CFU/mL. The susceptibility test results show that the bacteria are susceptible to piperacillin/tazobactam and gentamicin. Based on the drug label information 2 and 3, the next step in treating this patient would be to use piperacillin/tazobactam or gentamicin as the primary antibiotic therapy. Piperacillin/tazobactam is a broad-spectrum antibiotic that is effective against a wide range of gram-positive and gram-negative bacteria, including ESBL-producing E. coli. Gentamicin is an aminoglycoside antibiotic that is also effective against ESBL-producing E. coli. The choice of antibiotic should be based on the severity of the infection, the patient's medical history, and the results of the susceptibility testing. It is essential to monitor the patient's response to therapy and adjust the treatment as needed to ensure effective treatment of the infection. Some key points to consider when treating this patient include:

• Using a broad-spectrum antibiotic such as piperacillin/tazobactam or gentamicin
• Monitoring the patient's response to therapy
• Adjusting the treatment as needed based on the results of the susceptibility testing and the patient's clinical response
• Considering the use of combination therapy with other antibiotics if necessary
• Ensuring that the patient receives adequate hydration and supportive care to help manage the infection.

From the Research

Treatment Options for Urinary Tract Infections Caused by ESBL-Producing E. coli

The patient has a urinary tract infection caused by ESBL-producing Escherichia coli with a colony count of greater than 100,000 CFU/mL. Based on the provided evidence, the following treatment options are available:

• Oral treatment options:
  • Nitrofurantoin 4, 5, 6
  • Fosfomycin 4, 5, 6
  • Pivmecillinam 4, 5, 6
  • Amoxicillin-clavulanate 4, 5
• Parenteral treatment options:
  • Piperacillin-tazobactam (for ESBL-E coli only) 4, 5
  • Carbapenems (including meropenem/vaborbactam, imipenem/cilastatin-relebactam, and sulopenem) 4, 5
  • Ceftazidime-avibactam 4, 5
  • Ceftolozane-tazobactam 4, 5
  • Aminoglycosides (including plazomicin) 4, 5

Considerations for Treatment

When selecting a treatment option, consider the following factors:

• Local susceptibility patterns 4, 5
• Patient characteristics, such as underlying medical conditions and recent antibiotic use 7, 8
• Disease severity and presentation 8
• Potential for resistance development 4, 5

Specific Treatment Recommendations

Based on the provided evidence, pivmecillinam and fosfomycin may be effective treatment options for uncomplicated UTIs caused by ESBL-producing E. coli 6. For febrile UTIs, piperacillin/tazobactam and carbapenems may be used, with no significant difference in clinical outcomes 8. However, the choice of treatment should be individualized based on patient and pathogen characteristics.