Journal Article

The ecological effects of selective decontamination of the digestive tract (SDD) on antimicrobial resistance: a 21-year longitudinal single-centre study

van der Meer, Nardo J. M., van der Voort, Peter H. J., Wester, Jos P. J., Buitinck, Sophie, Rijkenberg, Saskia, Jansen, Rogier, Bosman, Rob J.

2019

Overview

Background The long-term ecological effects on the emergence of antimicrobial resistance at the ICU level during selective decontamination of the digestive tract (SDD) are unknown. We determined the incidence of newly acquired antimicrobial resistance of aerobic gram-negative potentially pathogenic bacteria (AGNB) during SDD. Methods In a single-centre observational cohort study over a 21-year period, all consecutive patients, treated with or without SDD, admitted to the ICU were included. The antibiotic regime was unchanged over the study period. Incidence rates for ICU-acquired AGNB’s resistance for third-generation cephalosporins, colistin/polymyxin B, tobramycin/gentamicin or ciprofloxacin were calculated per year. Changes over time were tested by negative binomial regression in a generalized linear model. Results Eighty-six percent of 14,015 patients were treated with SDD. Most cultures were taken from the digestive tract (41.9%) and sputum (21.1%). A total of 20,593 isolates of AGNB were identified. The two most often found bacteria were Escherichia coli ( N  = 6409) and Pseudomonas ( N  = 5269). The incidence rate per 1000 patient-day for ICU-acquired resistance to cephalosporins was 2.03, for polymyxin B/colistin 0.51, for tobramycin 2.59 and for ciprofloxacin 2.2. The incidence rates for ICU-acquired resistant microbes per year ranged from 0 to 4.94 per 1000 patient-days, and no significant time-trend in incidence rates were found for any of the antimicrobials. The background prevalence rates of resistant strains measured on admission for cephalosporins, polymyxin B/colistin and ciprofloxacin rose over time with 7.9%, 3.5% and 8.0% respectively. Conclusions During more than 21-year SDD, the incidence rates of resistant microbes at the ICU level did not significantly increase over time but the background resistance rates increased. An overall ecological effect of prolonged application of SDD by counting resistant microorganisms in the ICU was not shown in a country with relatively low rates of resistant microorganisms.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adult / Aged / Aged, 80 and over / Anti-Bacterial Agents - pharmacology / Anti-Bacterial Agents - therapeutic use / Antibacterial agents / Antibiotics / Antimicrobial agents / APACHE / Bacteria / Cephalosporins / Ciprofloxacin / Clinical trials / Critical care / Critical Care Medicine / Critically ill / Decontamination - methods / Decontamination - standards / Decontamination - statistics & numerical data / Development and progression / Drug resistance / Drug Resistance, Microbial - physiology / Ecological effect / Emergency Medicine / Escherichia coli / Female / Gastrointestinal system / Gastrointestinal Tract - drug effects / Gastrointestinal Tract - physiopathology / Gram-negative bacteria / Gram-positive bacteria / Health aspects / Health surveillance / Humans / Infections / Intensive / Intensive care / Intensive Care Units - organization & administration / Intensive Care Units - statistics & numerical data / Length of Stay - statistics & numerical data / Longitudinal Studies / Male / Medicine / Medicine & Public Health / Microbial drug resistance / Microbial ecology / Microorganisms / Middle Aged / Netherlands / Patients / Resistance / Retrospective Studies / SDD / Selective digestive tract decontamination / Tobramycin