What are the antibiotic options for a urinary tract infection caused by Carbapenem-Resistant Enterobacteriaceae (CRE), specifically Klebsiella pneumoniae?

From the Guidelines

For urinary tract infections caused by Carbapenem-Resistant Enterobacteriaceae (CRE) like Klebsiella pneumoniae, the primary antibiotic option is ceftazidime/avibactam 2.5 g IV q8h or meropenem/vaborbactam 4 g IV q8h, as recommended by recent guidelines 1. Given the susceptibility pattern of the organism, with resistance to most antibiotics but susceptibility to amikacin and gentamicin, and considering the severity of the infection, the choice of antibiotic should be guided by the most recent and highest quality evidence available. The patient's infection is caused by Klebsiella pneumoniae, which is a type of CRE, and the antibiotic sensitivity testing shows that the organism is susceptible to amikacin and gentamicin, but resistant to most other antibiotics, including carbapenems. Considering the severity of the infection and the limited treatment options, ceftazidime/avibactam or meropenem/vaborbactam are the most appropriate choices, as they have been shown to be effective against CRE infections in recent studies 1. Some key points to consider when treating CRE infections include:

• The importance of antimicrobial susceptibility testing to guide treatment choices
• The need for close monitoring of the patient's response to treatment and adjustment of the treatment plan as needed
• The potential for combination therapy, such as the use of multiple antibiotics, to improve treatment outcomes
• The importance of supportive measures, such as adequate hydration and urinary catheter removal, to help manage the infection. It is also important to note that the treatment of CRE infections is challenging and requires careful consideration of the patient's individual needs and the specific characteristics of the infecting organism. In this case, the use of ceftazidime/avibactam or meropenem/vaborbactam, as recommended by recent guidelines 1, is the most appropriate choice for treating the patient's CRE infection.

From the FDA Drug Label

Gentamicin Injection, USP is indicated in the treatment of serious infections caused by susceptible strains of the following microorganisms: Pseudomonas aeruginosa, Proteus species (indole-positive and indole-negative), Escherichia coli, Klebsiella-Enterobacter-Serratia species, Citrobacter species and Staphylococcus species (coagulase-positive and coagulase-negative) Clinical studies have shown gentamicin injection to be effective in bacterial neonatal sepsis; bacterial septicemia and serious bacterial infections of the central nervous system (meningitis), urinary tract, respiratory tract, gastrointestinal tract (including peritonitis), skin, bone and soft tissue (including burns) Aminoglycosides, including gentamicin, are not indicated in uncomplicated initial episodes of urinary tract infections unless the causative organisms are susceptible to these antibiotics and are not susceptible to antibiotics having less potential for toxicity Urinary Tract Infections: For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris

The antibiotic options for a urinary tract infection caused by Carbapenem-Resistant Enterobacteriaceae (CRE), specifically Klebsiella pneumoniae, are:

• Gentamicin: Susceptible, as indicated by the antibiotic sensitivity test results.
• Trimethoprim/Sulfamethoxazole (Co-trimoxazole): Susceptible, as indicated by the antibiotic sensitivity test results.
• Amikacin: Susceptible, as indicated by the antibiotic sensitivity test results.

These options should be considered based on the severity of the infection, the susceptibility of the organism, and the potential for toxicity 2, 3.

From the Research

Antibiotic Options for CRE-Positive Urine Culture

The patient has a urine culture positive for Carbapenem-Resistant Enterobacteriaceae (CRE), specifically Klebsiella pneumoniae, with significant growth of the organism (>100,000 CFU/mL) and a colony count indicating a severe infection.

Antibiotic Sensitivity

The antibiotic sensitivity test shows that the organism is susceptible to:

• Amikacin
• Gentamicin
• Trimethoprim/Sulfamethoxazole (Co-trimoxazole)

Treatment Options

Based on the evidence, the following treatment options can be considered:

• Amikacin: Studies have shown that amikacin is an effective treatment option for CRE-positive Klebsiella pneumoniae infections, with high clinical and microbiological success rates 4, 5.
• Gentamicin: Although there is limited evidence specifically for gentamicin in the treatment of CRE-positive Klebsiella pneumoniae infections, its susceptibility profile makes it a potential option.
• Trimethoprim/Sulfamethoxazole (Co-trimoxazole): This antibiotic combination may be considered as an alternative treatment option, especially in cases where other antibiotics are not suitable.
• Other options: Doxycycline 6, 7 and nitroxoline 8 have been reported as potential treatment options for multi-resistant uropathogenic bacteria, including Klebsiella pneumoniae, although more evidence is needed to support their use in CRE-positive infections.

Considerations

When selecting a treatment option, it is essential to consider the patient's clinical condition, potential side effects, and the risk of nephrotoxicity, particularly with the use of amikacin and gentamicin. Combination therapy with colistin should be used with caution due to the increased risk of nephrotoxicity 5.