Is Klebsiella sensitive to levofloxacin (fluoroquinolone antibiotic)?

Klebsiella Sensitivity to Levofloxacin

Yes, Klebsiella species are generally sensitive to levofloxacin, with susceptibility rates of approximately 85-97% for most Klebsiella isolates, though resistance rates vary by region and specific strain. 1, 2

Susceptibility Data

Klebsiella species demonstrate good overall susceptibility to fluoroquinolones, including levofloxacin:

• According to the American Academy of Pediatrics guidelines, only 3% of 271 bloodstream isolates of E. coli and Klebsiella species collected over 4 years (1999-2003) were resistant to fluoroquinolones 1
• The SMART data from Taiwan revealed that more than 85% of Enterobacteriaceae (including Klebsiella species) were susceptible to fluoroquinolones 1, 2
• For ESBL-producing Klebsiella pneumoniae specifically, approximately 50-60% remain susceptible to levofloxacin 2

Clinical Applications

Levofloxacin is FDA-approved for infections caused by susceptible Klebsiella pneumoniae in several clinical scenarios:

• Nosocomial pneumonia 3
• Community-acquired pneumonia 3
• Complicated urinary tract infections (both 5-day and 10-day regimens) 3

Resistance Considerations

Several important factors affect Klebsiella sensitivity to levofloxacin:

• Resistance mechanisms in Klebsiella include:

  • Mutations in DNA gyrase and topoisomerase IV genes 4
  • Plasmid-mediated resistance via qnr genes 5
  • Efflux pumps and porin alterations 5

• Levofloxacin appears to have a lower propensity to select for resistance compared to some other fluoroquinolones. In comparative studies, levofloxacin was most capable of limiting the occurrence of resistance among tested fluoroquinolones 4

• Case reports demonstrate successful treatment of Klebsiella infections with levofloxacin, including bacteremia caused by Klebsiella rhinoscleromatis 6

Regional Variation

Resistance patterns vary significantly by:

• Geographic region
• Healthcare setting (community vs. hospital-acquired)
• Prior antibiotic exposure
• Patient population

Clinical Recommendations

1. Obtain culture and susceptibility testing before initiating therapy whenever possible 3

2. Consider local resistance patterns when selecting empiric therapy, as fluoroquinolone resistance rates vary by region 2

3. For serious infections, combination therapy may be appropriate initially until susceptibility results are available

4. Monitor for treatment response and consider alternative agents if clinical improvement is not observed

5. For ESBL-producing Klebsiella, be aware that susceptibility to levofloxacin is reduced (approximately 50-60%) 2

Dosing for Klebsiella Infections

• Standard dosing: 500-750 mg once daily
• Duration depends on infection site:
  • Complicated UTI: 750 mg once daily for 5 days or 250-500 mg once daily for 10 days
  • Pneumonia: 750 mg once daily for 5 days or 500 mg once daily for 7-14 days 2
• Dose adjustment required in renal impairment 2

In summary, levofloxacin remains an effective option for treating Klebsiella infections when susceptibility is confirmed, though resistance monitoring and appropriate antibiotic stewardship are essential to preserve its efficacy.