What is the management and treatment of Catheter-Associated Urinary Tract Infections (CAUTI) caused by various microorganisms?

Management of Catheter-Associated Urinary Tract Infections by Microorganism

The management of CAUTI varies significantly by causative organism, with catheter removal being the cornerstone of treatment for most pathogens, combined with organism-specific antimicrobial therapy tailored to duration based on clinical response and catheter type.

General Principles Across All Microorganisms

Replace the catheter before starting antimicrobials if it has been in place ≥2 weeks, as biofilms on both internal and external surfaces protect uropathogens from antimicrobials and host immune response, making bacteria inherently resistant to treatment 1. This approach decreases polymicrobial bacteriuria, shortens time to clinical improvement, and lowers recurrence rates within 28 days 1.

• Obtain urine culture from the new catheter before initiating antibiotics to guide appropriate therapy 1
• Remove the catheter entirely after completing antibiotic treatment if no longer medically indicated 2
• Duration of treatment is typically 7 days for prompt symptom resolution or 10-14 days for delayed response 2

Gram-Negative Bacilli

Standard Gram-Negative Organisms

Remove nontunneled catheters and treat with appropriate antimicrobials for 10-14 days when there is no evidence of septic thrombosis or endocarditis 3.

• For tunneled catheters that cannot be removed in hemodynamically stable patients, treat for 14 days with systemic and antibiotic lock therapy 3
• Quinolones such as ciprofloxacin with or without rifampin are preferred for retained catheters because they can be given orally and eradicate gram-negative bacilli from foreign bodies 3

High-Risk Gram-Negative Pathogens

Strongly consider catheter removal for Pseudomonas species (other than P. aeruginosa), Burkholderia cepacia, Stenotrophomonas, Agrobacterium, and Acinetobacter baumannii, especially if bacteremia persists despite appropriate antimicrobials or the patient becomes unstable 3.

• Empirical therapy for suspected gram-negative CAUTI should include drugs active against P. aeruginosa, particularly in neutropenic patients 3
• For prolonged bacteremia after catheter removal and appropriate therapy, especially with underlying valvular heart disease, extend treatment to 4-6 weeks 3
• In cases of serious CAUTI with previous antibiotic exposure or healthcare-associated bacteremia, initiate empirical treatment with activity against multiresistant uropathogens 4

Gram-Positive Organisms

Staphylococcus aureus

Remove nontunneled catheters suspected as the source of S. aureus bacteremia and reinsert at a different site 3.

• Perform transesophageal echocardiography (TEE) for patients without contraindications to identify complicating endocarditis requiring 4-6 weeks of therapy 3
• Transthoracic echocardiography has low sensitivity and is not recommended for excluding catheter-related endocarditis 3
• Patients with negative TEE and catheter removal should receive 14 days of systemic antibiotic therapy 3
• For tunneled catheters with uncomplicated intraluminal S. aureus infection, remove the catheter or, in selected cases, retain and treat with systemic and antibiotic lock therapy for 14 days 3
• Remove tunneled catheters if there is evidence of tunnel, pocket, or exit-site infection 3

Bacillus and Corynebacterium Species

Remove catheters in all cases of Bacillus and Corynebacterium bacteremia, as the vast majority of catheter-related bloodstream infections from these organisms require catheter removal 3.

Mycobacteria

Remove catheters for all infections due to Mycobacterium fortuitum and Mycobacterium chelonae 3.

Fungal Pathogens

Candida Species

Treat all patients with candidemia; use amphotericin B for hemodynamically unstable patients or those with prolonged prior fluconazole therapy 3.

• Hemodynamically stable patients without recent fluconazole therapy or with fluconazole-susceptible organisms can receive fluconazole instead of amphotericin B 3
• Continue antifungal treatment for 14 days after the last positive blood culture and resolution of signs and symptoms 3
• Remove tunneled catheters in all cases of documented catheter-related fungemia 3
• Salvage therapy for infected tunneled catheters is not recommended for routine use, as success rates with systemic and antibiotic lock therapy are only approximately 30% 3

Candida krusei

Treat with amphotericin B specifically for C. krusei infections 3.

Malassezia furfur

Discontinue intralipids and remove the catheter, especially for nontunneled catheter infections 3.

• Treat with amphotericin B 3

Critical Prevention Measures

Do not administer prophylactic antimicrobials routinely at catheter placement, removal, or replacement, as this promotes antimicrobial resistance without reducing CAUTI 1.

• Do not routinely screen for or treat catheter-associated asymptomatic bacteriuria in patients with short-term or long-term indwelling catheters 1
• Consider antimicrobial treatment of asymptomatic bacteriuria that persists 48 hours after short-term catheter removal in women to reduce subsequent CAUTI risk 1
• Duration of catheterization is the most important modifiable risk factor for CAUTI development 5, 6

Common Pitfalls

• Failing to replace catheters in place ≥2 weeks before starting antibiotics reduces treatment efficacy due to established biofilms 1, 2
• Treating asymptomatic bacteriuria in catheterized patients (except specific circumstances) does not reduce subsequent CAUTI and increases antimicrobial resistance 1
• Removing catheters before completing appropriate antibiotic treatment may lead to persistent infection 2
• Not obtaining cultures before initiating antibiotics leads to inappropriate antibiotic selection given the high likelihood of resistant organisms 2