Enterococcal infections

Montecalvo MA Ramoplanin A novel antimicrobial agent with the potential to prevent vancomycin-resistant enterococcal infection in high-risk patients. J Antimicrob Chemother 2003 51(suppl 3) 31—35. 

Suggested Alternatives for Differential Diagnosis Enterobacter infections, enterococcal infections, klebsiella infections, proteus infections, providencia infections, Pseudomonas aeruginosa infections, serratia, shigellosis, and streptococcus group B infections. 

The role of Enterococcus as a pathogen is not clear. Enterococcal infection occurs more commonly in postoperative peritonitis, in the presence of specific risk factors indicating failure of the host defenses, or with the use of broad-spectrum antibiotics. 

Murray BE. Vancomycin-resistant enterococcal infections. N Engl J Med 2000 342 710-721. 

Penicillin plus streptomycin is effective for enterococcal endocarditis and 2-week therapy of viridans streptococcal endocarditis. Gentamicin has largely replaced streptomycin for these indications. Streptomycin remains a useful agent for treating enterococcal infections, however, because approximately 15% of enterococcal isolates that are resistant to gentamicin (and therefore to netilmicin, tobramycin, and amikacin) will be susceptible to streptomycin. 

Because of its potential toxicity, vancomycin is reserved for serious infections in which less toxic antibiotics are ineffective or not tolerated. Generally, vancomycin is administered intravenously because of poor intestinal absorption. It is the drug of choice for treating infections caused by methicillin-resistant staphylococci and penicillin-resistant Streptococcus pneumoniae. Vancomycin has been used to treat enterococcal infections because of their resistance to the P-lactam antibiotics, but most enterococci are now also resistant to vancomycin. Oral administration of rancomycin is important for treatment of some gastrointestinal infections such as pseudomembranous colitis caused by C. difficile. 

Levison ME, Mallela S. Increasing antimicrobial resistance therapeutic implications for enterococcal infections. Curr Infect Dis Rep 2000 2(5) 417-23. 

Raad I, Hachem R, Hanna H, Girgawy E, Rolston K, Whimbey E, Husni R, Bodey G. Treatment of vancomycin-resistant enterococcal infections in the immunocompromised host quinupristin-dalfopristin in combination with minocycline. Antimicrob Agents Chemother 2001 45(ll) 3202-4. 

Schwenger V, Mundlein E, Dagrosa EE, Fahr AM, Zeier M, Mikus G, Andrassy K. Treatment of life-threatening multi-resistant staphylococcal and enterococcal infections in patients with end-stage renal failure with quinupristin/dalfopristin preliminary report. Infection 2002 30(5) 257-61. 

Steady-state peak and trough concentrations are chosen for the patient based on the site and severity of the infection, as well as the known or suspected pathogen and avoidance of potential side effects. Cmax.ss values of between 20 and 40 mg/L and C in.ss values of between 5 and 10 mg/L typically are used for patients with moderate to severe methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, or penicillin-resistant enterococcal infections. After appropriate steady-state concentrations are chosen, the dosage interval required to attain those concentrations is computed, and r is rounded to a clinically acceptable value (12, 18, 24, 36, 48, or 72 hours) r = (In Cmax.ss - In Cmin.ss)/ - Finally, the maintenance dose is computed for the patient using a one-compartment-model intravenous bolus equation at steady state, and the dose is rounded off to the nearest 100 to 250 mg ... 

Sitges-Serra A, Lopez MJ, Girvent M, et al. Postoperative enterococcal infection after treatment of comphcated intraabdominal sepsis. Br J Surg 2002 89 361-367. 

Linezolid is approved for use in vancomycin-resistant enterococcal infections. There are very few alternatives available, and none of the other drugs listed are likely to be effective. The answer is (C). 

When used in combination with penicillin G, streptomycin continues to be a useful agent for treating enterococcal infections. About 15% of enterococcal isolates that are resistant to gen-... 

Bates J, Jordans JZ, Griffiths DT. Farm animals as a putative reservoir for vaiKomycin-cesis-tarn enterococcal infections in man. J Antimicrob (Smother 1994 34 507-516. 

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