Incidence and risk factors for acquired colonization and infection due to extended-spectrum beta-lactamase-producing Gram-negative bacilli a retrospective analysis in three ICUs with low multidrug resistance rate

Nicolas Massart (1) , Christophe Camus (1, 2, 3, 4) , François Benezit (1, 4, 2, 3) , Mikael Moriconi , Pierre Fillatre , Yves Le Tulzo (1, 4, 2, 3)

1 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]
2 CIC - Centre d'Investigation Clinique [Rennes]
3 SFR UMS CNRS 3480 - INSERM 018 - Biosit : biologie, santé, innovation technologique
4 UR Médecine - Université de Rennes - Faculté de Médecine

The purpose of this study is to assess risk factors for the acquisition of extended-spectrum β-lactamase-producing Gram-negative bacilli (ESBL-GNB) colonization and infection (AI) in ICUs with low ESBL-GNB prevalence rate. We conducted a retrospective observational study in three ICUs in Bretagne, France. All patients admitted from January 2016 to September 2017 with a length of stay of 2 days or more were included. Universal screening for ESBL-GNB colonization was performed in all participating ICUs. Of the 3250 included patients, 131 (4.0%) were colonized at admission, 59 acquired colonization while hospitalized (1.9%; 95% CI [1.5-2.5%]), and 15 (0.5%; 95% CI [0.3-0.8%]) acquired ESBL-GNB infections. In the case of infection, the specificity and the negative predictive values of preexistent colonization for the ESBL-GNB etiology were 93.2% [91.5-95.1%] and 95.2% [93.5-97.1%], respectively. Colonization was the main risk factor for ESBL-GNB AI (OR = 9.61; 95% CI [2.86-32.29]; p < 0.001). Antimicrobial susceptibility of non-ESBL-GNB isolates responsible for AI was similar for any non-carbapenem β-lactam (95%) and imipenem (94%). ESBL-GNB AIs were rare in ICUs with low ESBL-GNB prevalence rate. Prior colonization was the main risk factor for subsequent infection. Empirical carbapenem therapy could be avoided in non ESBL-GNB colonized patients with suspected AI.

Mots clés: Healthcare-associated pneumonia; Decontamination; Gram-negative bacteria; Bacteremia; Extended-spectrum beta-lactamase-producing Enterobacteriaceae

Domaines: Sciences du Vivant [q-bio]; Médecine humaine et pathologie; Maladies infectieuses

Nicolas Massart, Christophe Camus, François Benezit, Mikael Moriconi, Pierre Fillatre, et al.. Incidence and risk factors for acquired colonization and infection due to extended-spectrum beta-lactamase-producing Gram-negative bacilli a retrospective analysis in three ICUs with low multidrug resistance rate. European Journal of Clinical Microbiology and Infectious Diseases, 2020, 39 (5), pp.889-895. ⟨10.1007/s10096-019-03800-y⟩. ⟨hal-02440783⟩