Screening for resistant gram-negative microorganisms to guide empiric therapy of subsequent infection
- First Online:
- 298 Downloads
To define the potential of resistant gram-negative colonization surveillance to predict etiology of subsequent infection and improve adequacy of empiric antimicrobial treatment.
Retrospective cohort study.
A mixed medical–surgical six-bed intensive care unit (ICU), from November 2003 to December 2006.
All patients having at least one episode of ventilator-associated pneumonia (VAP) or bloodstream infection (BSI) caused by a resistant gram-negative pathogen during the study period.
Colonization surveillance of the respiratory tract and gastrointestinal tract was systematically performed in all ICU patients. Tracheal aspirates were obtained twice weekly and rectal swabs once weekly. Both tracheal and rectal samples were cultured in antibiotic-enriched media (containing ceftazidime, ciprofloxacin, imipenem or piperacillin/tazobactam), to focus on resistant gram-negative pathogen isolation.
Measurements and results
Colonization concordance between resistant, gram-negative pathogens of infectious episodes and previous, recent (≤7 days) colonization of the respiratory and gastrointestinal tract was determined, based on species identity and antimicrobial susceptibility. Concordance was 82% in VAP and 86% in BSI cases and was further confirmed by molecular testing of 15 randomly selected cases by REP-PCR. Previous colonization had high sensitivity and specificity in VAP, but was less specific in BSI cases. Knowledge of previous colonization improved the rate of adequate empiric antimicrobial treatment (91 vs. 40% in VAP and 86 vs. 50% in BSI cases, P < 0.05).
Colonization surveillance for resistant gram-negative microorganisms is predictive of subsequent infection etiology and can improve empiric antimicrobial treatment adequacy in a critical care setting.
KeywordsMultidrug-resistant bacteria Gram-negative bacteria Colonization Surveillance Ventilator-associated pneumonia Bacteremia
- 3.Dellinger RP, Carlet JM, Masur H, Gerlach H, Calandra T, Cohen J, Gea-Banacloche J, Keh D, Marshall JC, Parker MM, Ramsay G, Zimmerman JL, Vincent JL, Levy MM (2004) Surviving Sepsis Campaign guidelines for management of severe sepsis and septic shock. Intensive Care Med 30:536–555PubMedCrossRefGoogle Scholar
- 8.Blot S, Depuydt P, Vogelaers D, Decruyenaere J, De Waele J, Hoste E, Peleman R, Claeys G, Verschraegen G, Colardyn F, Vandewoude K (2005) Colonization status and appropriate antibiotic therapy for nosocomial bacteremia caused by antibiotic-resistant gram-negative bacteria in an intensive care unit. Infect Control Hosp Epidemiol 26:575–579PubMedCrossRefGoogle Scholar
- 12.Depuydt PO, Blot SI, Benoit DD, Claeys GW, Verschraegen GL, Vandewoude KH, Vogelaers DP, Decruyenaere JM, Colardyn FA (2006) Antimicrobial resistance in nosocomial bloodstream infection associated with pneumonia and the value of systematic surveillance cultures in an adult intensive care unit. Crit Care Med 34:653–659PubMedCrossRefGoogle Scholar
- 13.Malacarne P, Corini M, Maremmani P, Viaggi B, Verdigi S (2007) Diagnostic characteristics of routine surveillance cultures of endotracheal aspirate samples in cases of late-onset ventilator-associated pneumonia due to Acinetobacter baumannii. Infect Control Hosp Epidemiol 28:867–869PubMedCrossRefGoogle Scholar
- 16.Sanders K, Adhikari N, Friedrich J, Day A, Jiang X, Heyland D, for the Canadian Critical Care Trials Group (2008) Previous cultures are not clinically useful for guiding empiric antibiotics in suspected ventilator-associated pneumonia: secondary analysis from a randomized trial. J Crit Care 23:58–63PubMedCrossRefGoogle Scholar
- 18.Depuydt P, Benoit D, Vogelaers D, Decruyenaere J, Vandijck D, Claeys G, Verschraegen G, Blot S (2008) Systematic surveillance cultures as a tool to predict involvement of multidrug antibiotic resistant bacteria in ventilator-associated pneumonia. Intensive Care Med 34:675–682PubMedCrossRefGoogle Scholar
- 19.Papadomichelakis E, Kontopidou F, Kopterides P, Mavrou I, Paramythiotou E, Poulakou G, Antoniadou A, Giamarellou H, Armaganidis A (2007) A three-year retrospective study of systematic colonization surveillance in the ICU. Poster presented in the 20th ESICM Annual Congress, Berlin. Intensive Care Med 33(Suppl 2):S131Google Scholar
- 20.Poulakou G, Plachouras D, Kontopidou F, Antoniadou A, Papadomichelakis E, Armaganidis A, Giamarellou H (2008) Rapid surveillance of multidrug resistance in ICU patients, by use of antibiotic-containing agar plates. Poster presented in the 18th ECCMID, Barcelona. Clin Microbiol Infect 14(Suppl 4):S609–S610Google Scholar