Tabitha Bice, PGY2

Le Bonheur Children's Hospital, Memphis, Tennessee

Objectives: 

1. Discuss potential patient specific risk factors associated with isolation of Citrobacter, Enterobacter, Morganella, and Serratia species from respiratory tract cultures with detectable resistance to third generation cephalosporins

2. Evaluate potential treatment options for pediatric patients growing Citrobacter, Enterobacter, Morganella, and Serratia in their respiratory secretions

Abstract:

Introduction: Citrobacter, Enterobacter, Serratia, and Morganella species are Gram negative organisms that can exhibit inducible resistance after exposure to third generation cephalosporin and other beta-lactam antimicrobials. Respiratory colonization is frequent in intubated children or children with tracheostomies. Positive respiratory tract cultures often result in unwarranted patient exposure to antimicrobials, typically third generation cephalosporins, which can lead to expression of the inducible beta-lactamase. The primary objective of this study is to evaluate and quantify patient specific risk factors associated with isolation of Citrobacter, Enterobacter, Morganella, and Serratia species with detectable resistance to third generation cephalosporins. The secondary objective is to evaluate treatment outcomes in patients growing these isolates in their respiratory secretions when treated with third generation cephalosporins.

Methods: This study is approved by our Institutional Review Board. It is a single-center, retrospective cohort review of pediatric patients age 0 to 18 years admitted to Le Bonheur Children’s Hospital from January 1, 2013 to July 31, 2018. Patients were included if Citrobacter, Enterobacter, Morganella, or Serratia was isolated from a respiratory tract culture. All patients with a diagnosis of cystic fibrosis were excluded. Data currently being collected for each patient includes age, gender, admission diagnosis, preexisting conditions, prior hospitalizations, prior positive cultures with the same organism, antimicrobial exposure in the past thirty days, requirement for intubation and duration of intubation prior to culture, presence of a tracheostomy, and whether the patient had a documented change in respiratory status prior to obtaining the culture. Laboratory data being collected includes source of the respiratory tract culture specimen, antimicrobial susceptibilities, white blood cell count and semi-quantitative bacterial load, from 1+ to 4+, in the respiratory specimen when available. Each patient’s empiric antimicrobial therapy regimen and modifications made to the regimen after susceptibility data became available will be evaluated. Univariate and multivariate logistic regression analyses will be utilized to identify independent risk factors for organism resistance to third generation cephalosporins. Mann-Whitney U test, Chi-squared, or Fisher’s exact tests will be utilized to make between group comparisons when applicable.

Results: Results will be submitted within final slides

Conclusion: Conclusion will be submitted within final slides

Handout Slides:

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