From the FDA Drug Label
Aerobic gram-negative microorganisms Campylobacter jejuni Proteus mirabilis Citrobacter diversus Proteus vulgaris Citrobacter freundii Providencia rettgeri Enterobacter cloacae Providencia stuartii Escherichia coli Pseudomonas aeruginosa Haemophilus influenzae Salmonella typhi Haemophilus parainfluenzae Serratia marcescens Klebsiella pneumoniae Shigella boydii Moraxella catarrhalis Shigella dysenteriae Morganella morganii Shigella flexneri Neisseria gonorrhoeae Shigella sonnei
Ciprofloxacin is active against Proteus mirabilis and Proteus vulgaris.
- The MIC values for these microorganisms are not explicitly stated in the label, but the label does indicate that ciprofloxacin has been shown to be active against most strains of Proteus mirabilis and Proteus vulgaris, both in vitro and in clinical infections. 1
Gram-negative bacteria • Citrobacter species • Enterobacter species • Escherichia coli • Klebsiella species • Haemophilus influenzae • Neisseria meningitidis • Proteus mirabilis • Proteus vulgaris • Pseudomonas aeruginosa • Serratia species
Ceftazidime is active against Proteus mirabilis and Proteus vulgaris.
- The MIC values for these microorganisms are not explicitly stated in the label, but the label does indicate that ceftazidime has been shown to be active against most isolates of Proteus mirabilis and Proteus vulgaris, both in vitro and in clinical infections. 2
MICROORGANISMS 1 Meropenem for Injection n 2/N 3 (%) 4 Gram-positive aerobes Staphylococcus aureus, methicillin susceptible Streptococcus pyogenes (Group A) Streptococcus agalactiae (Group B) Enterococcus faecalis Viridans group streptococci Gram-negative aerobes Escherichia coli Pseudomonas aeruginosa Proteus mirabilis Anaerobes Bacteroides fragilis Peptostreptococcus Species
Meropenem is active against Proteus mirabilis.
- The clinical efficacy rate for Proteus mirabilis is 85% (11/13). 3
From the Research
Proteus infections should be treated with antibiotics that are effective against gram-negative bacteria, with fluoroquinolones, third-generation cephalosporins, or trimethoprim-sulfamethoxazole as first-line options, and carbapenems or aminoglycosides for more severe infections, as guided by culture and sensitivity testing 4, 5, 6, 7, 8.
Treatment Options
- Fluoroquinolones (ciprofloxacin 500mg twice daily or levofloxacin 750mg once daily for 7-14 days)
- Third-generation cephalosporins (ceftriaxone 1-2g daily IV)
- Trimethoprim-sulfamethoxazole (160/800mg twice daily for 7-14 days)
Severe Infections
- Carbapenems like meropenem (1g IV every 8 hours) or imipenem (500mg IV every 6 hours)
- Aminoglycosides such as gentamicin (5-7mg/kg IV once daily) for synergistic effects
Considerations
- Antibiotic selection should be guided by culture and sensitivity testing as Proteus species can develop resistance 6
- Proteus bacteria produce urease which alkalinizes urine, potentially leading to stone formation, so maintaining adequate hydration during treatment is important
- For recurrent urinary tract infections caused by Proteus, addressing any underlying structural abnormalities or removing infected stones may be necessary for complete resolution
Recent Findings
- A study found that oral β-lactam antibiotics may be a reasonable step-down treatment option for Enterobacterales bacteremia from a suspected urine source, including Proteus spp, with no significant difference in mortality compared to fluoroquinolones or trimethoprim-sulfamethoxazole 4
- Another study suggested that cephalexin and cefadroxil, first-generation oral cephalosporins, may be effective for treating uncomplicated lower urinary tract infections caused by Proteus mirabilis 5