What antibiotic can be used to treat Urinary Tract Infection (UTI) caused by Serratia?

From the Guidelines

For treating a urinary tract infection (UTI) caused by Serratia, carbapenems like meropenem (1g IV every 8 hours) or imipenem-cilastatin (500mg IV every 6 hours) are typically the first-line choices, as recommended by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines 1.

Key Considerations

• Serratia species are naturally resistant to many antibiotics, including ampicillin, amoxicillin, first-generation cephalosporins, and nitrofurantoin, making antibiotic selection challenging.
• Treatment should be guided by susceptibility testing whenever possible, as resistance patterns vary.
• For complicated infections or in hospitalized patients, combination therapy might be necessary.
• The duration of treatment typically ranges from 7-14 days depending on infection severity.
• Patients should complete the full course of antibiotics even if symptoms improve before completion to prevent recurrence and development of resistance.

Alternative Options

• Fluoroquinolones such as ciprofloxacin (500mg orally twice daily for 7-10 days) may also be effective if the strain is susceptible.
• Plazomicin 15 mg/kg IV q12 h is recommended for cUTI due to CRE (Weak recommendation, very low quality of evidence) 1.
• Single-dose aminoglycoside is recommended for patients with simple cystitis due to CRE (Weak recommendation, very low quality of evidence) 1.

Important Notes

• The risk for nephrotoxicity increases after 7 days of aminoglycoside therapy, so shorter durations are recommended 1.
• Carbapenem-sparing treatments, such as piperacillin-tazobactam, amoxicillin/clavulanic acid, or quinolones, may be considered for low-risk, non-severe infections due to 3GCephRE, under the consideration of antibiotic stewardship 1.

From the FDA Drug Label

1.1 Lower Respiratory Tract Infections Imipenem and Cilastatin for Injection, USP (I.V.) for intravenous use is indicated for the treatment of lower respiratory tract infections caused by susceptible strains of ... Serratia marcescens. 1.5 Bacterial Septicemia Imipenem and Cilastatin for Injection, USP (I.V.) is indicated for the treatment of bacterial septicemia caused by susceptible strains of ... Serratia species. 1.7 Skin and Skin Structure Infections Imipenem and Cilastatin for Injection, USP (I.V.) is indicated for the treatment of skin and skin structure infections caused by susceptible strains of ... Serratia species.

The antibiotic that can be used to treat UTI caused by Serratia is Imipenem and Cilastatin for Injection, USP (I.V.) 2.

• Key points:
  • The drug label indicates that Imipenem and Cilastatin for Injection, USP (I.V.) is effective against Serratia marcescens and Serratia species.
  • It is essential to note that the dosage and administration of Imipenem and Cilastatin for Injection, USP (I.V.) should be based on suspected or confirmed pathogen susceptibility.
  • The recommended dosage for Imipenem and Cilastatin for Injection, USP (I.V.) in adult patients with creatinine clearance greater than or equal to 90 mL/min is shown in Table 1 of the drug label.

From the Research

Treatment Options for UTIs Caused by Serratia

• The studies 3, 4, 5, 6, 7 provide information on various treatment options for urinary tract infections (UTIs) caused by different bacteria, including Serratia.
• According to the study 6, carbapenems such as meropenem, imipenem/cilastatin, biapenem, and panipenem/betamipron have high activities against Enterobacteriaceae, including Serratia marcescens.
• The study 7 compares the efficacy of meropenem and imipenem/cilastatin in the treatment of complicated UTIs, including those caused by Serratia, and finds that both antibiotics produce satisfactory clinical and bacteriologic responses.
• Another study 4 mentions that meropenem is effective against extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae, which may include Serratia species.
• The study 5 evaluates the efficacy of cefiderocol, a new siderophore cephalosporin, against Gram-negative uropathogens, including those that may be resistant to carbapenems, but does not specifically mention Serratia.

Antibiotic Resistance and Treatment

• The study 3 highlights the importance of considering antibiotic resistance patterns when selecting empiric antibiotic therapy for UTIs.
• The study 6 notes that carbapenems are effective against ESBL-producing strains, but may not be effective against methicillin-resistant Staphylococcus aureus.
• The study 4 mentions that meropenem has a broad spectrum of activity against Gram-positive and Gram-negative pathogens, including those that may be resistant to other antibiotics.

Clinical Efficacy and Safety

• The studies 4, 6, 7 demonstrate the clinical efficacy and safety of meropenem and other carbapenems in the treatment of complicated UTIs.
• The study 5 finds that cefiderocol is well-tolerated and effective in the treatment of complicated UTIs caused by Gram-negative uropathogens.