What is the recommended management for Serratia infections?

From the Guidelines

The recommended management for Serratia infections is meropenem, a carbapenem agent, due to its broad range of in vitro activity and less seizure proclivity compared to other options, as suggested by studies such as 1. When managing Serratia infections, it's crucial to consider the organism's intrinsic resistance patterns.

• Third-generation cephalosporins and fluoroquinolones may also be considered, but carbapenems like meropenem are often preferred due to their efficacy against gram-negative bacilli, including Serratia marcescens, as noted in 1.
• For severe infections, combination therapy with an aminoglycoside like amikacin may be necessary, but this should be guided by susceptibility testing and the severity of the infection.
• Treatment duration typically ranges from 7-14 days, depending on the site and severity of the infection, with longer courses needed for complicated infections.
• Source control through drainage of abscesses or removal of infected devices is essential when applicable, as it directly impacts morbidity, mortality, and quality of life.
• In cases where Serratia infections are suspected, particularly in immunocompromised patients or those with healthcare-associated infections, broader initial coverage may be warranted until susceptibilities are known, emphasizing the importance of timely and effective management to improve patient outcomes, as implied by the context of 1.

From the FDA Drug Label

PIPRACIL is indicated for the treatment of serious infections caused by susceptible strains of the designated microorganisms in the conditions listed below: ... Septicemia including bacteremia caused by E. coli, Klebsiella spp., Enterobacter spp., Serratia spp., P. mirabilis, S. pneumoniae, enterococci, P. aeruginosa, Bacteroides spp., or anaerobic cocci.

Lower RespiratoryTract Infections caused by E. coli, Klebsiella spp., Enterobacter spp., P. aeruginosa, Serratia spp., H. influenzae, Bacteroides spp., or anaerobic cocci.

Skin and Skin Structure Infections caused by E. coli, Klebsiella spp., Serratia spp., Acinetobacter spp., Enterobacter spp., P. aeruginosa, Morganella morganii, Providencia rettgeri, Proteus vulgaris, P. mirabilis, Bacteroides spp., including B. fragilis, anaerobic cocci, or enterococci.

The recommended management for Serratia infections is treatment with piperacillin-tazobactam (IV) as it is indicated for the treatment of serious infections caused by susceptible strains of Serratia spp. 2.

• The usual dosage of piperacillin-tazobactam for serious infections is 3 to 4 g given every four to six hours as a 20- to 30-minute infusion.
• The maximum daily dose for adults is usually 24 g/day.
• The average duration of piperacillin-tazobactam treatment is from seven to ten days, except in the treatment of gynecologic infections, which is from three to ten days; the duration should be guided by the patient's clinical and bacteriological progress 2.

From the Research

Management of Serratia Infections

• The recommended management for Serratia infections includes the use of carbapenems or aminoglycosides in combination with third-generation (and eventually fourth-generation) cephalosporin 3.
• For uncomplicated urinary infections, cotrimoxazole should be considered 3.
• Prolonged infusion of meropenem has been shown to be effective in treating Serratia marcescens meningitis, with adequate exposure at the site of infection and a successful clinical response 4.
• Serratia marcescens isolates have been found to be resistant to a wide range of antibiotics, including ampicillin, carbenicillin, gentamicin, and tobramycin 5.
• The choice of antimicrobial agent is crucial in the treatment of Serratia marcescens infections, with moxalactam, imipenem, and ciprofloxacin being recommended due to their good activity against the bacteria 6.
• Extended spectrum beta-lactamases (ESBLs) and derepressed AmpC production are common mechanisms of beta-lactam antibiotic resistance in Serratia marcescens strains, making carbapenems a suitable treatment option 7.

Antibiotic Susceptibility

• Serratia marcescens isolates have been found to be susceptible to imipenem, moxalactam, and ciprofloxacin 6.
• The bacteria have also been found to be resistant to ampicillin, cephalothin, and nitrofurantoin 6, 7.
• The use of combination therapy, such as carbapenems and aminoglycosides, may be effective in treating Serratia marcescens infections 3.

Clinical Features

• Serratia marcescens bacteremia is often associated with severe underlying disease, such as diabetes mellitus, and nosocomial infection 6.
• Clinical syndromes include primary bacteremia, pneumonia, urinary tract infection, suppurative thrombophlebitis, and surgical wound infection 6.
• The overall mortality rate for Serratia marcescens bacteremia is high, with 50% of patients dying from the infection 6.