Colonization sites in carriers of ESBL-producing Gram-negative bacteria

Joffrey Van Prehn,Anna M Kaiser,Rosa Van Mansfeld,Christina M J E Vandenbroucke-Grauls,Suzanne D Van Der Werff

doi:10.1186/s13756-018-0344-y

Joffrey Van Prehn, Anna M Kaiser + Show 3 more

Open Access

https://doi.org/10.1186/s13756-018-0344-y

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Abstract

ObjectiveThe distribution of Extended-Spectrum Beta-Lactamase-producing Gram-negative bacteria (ESBL-GNB) colonization sites is relevant for infection control guidelines on detection and follow-up of colonization. We questioned whether it is possible to rely solely on rectal swab culture for follow-up of ESBL-GNB colonization.MethodsWe retrospectively assessed ESBL-GNB colonization sites in patients in a tertiary hospital in the Netherlands. The Laboratory Information Management System was queried for all bacterial cultures obtained between January 2012 and August 2016. All patients with one or more cultures positive for ESBL-GNB were identified and the distribution of ESBL-GNB positive sample sites was assessed. A subgroup analysis was performed on patients for whom at least one rectal swab specimen was available.ResultsWe identified 1011 ESBL-GNB carriers with 16,578 specimens for analysis. ESBL-GNB were most frequently isolated from the rectum (506/1011), followed by the urogenital (414/1011) and respiratory tract (142/1011), and pus (136/1011). For 588 patients at least one rectal swab specimen was available. In this subgroup, ESBL-GNB colonization was detected only in the rectum in 55.4% (326/588) of patients, in 30.6% (180/588) in the rectum and a different culture site, and in 13.9% (82/588) no rectal colonization was detected.ConclusionsRectal colonization with ESBL-GNB was detected in 86% of ESBL-GNB carriers. However, in 14% of ESBL-GNB carriers we did not detect rectal colonization. Therefore, samples taken for follow-up of colonization with multi-drug resistant Gram-negative bacteria (MDR-GNB) should ideally also include samples from the site where the MDR-GNB was initially found.

Highlights

Infection control guidelines give clear recommendations for the detection of colonization with multidrug-resistant Gram-negative bacteria (MDR-GNB) [1, 2]
We questioned whether it is possible to rely on the rectum as the single site to obtain cultures for follow-up of MDR-GNB colonization. To this end we retrospectively investigated the distribution of van Prehn et al Antimicrobial Resistance and Infection Control (2018) 7:52 colonization sites in patients colonized with ExtendedSpectrum Beta-Lactamase-producing Gram-negative bacteria (ESBL-GNB), and assessed the value of rectal swab culture in a subgroup that had at least one rectal swab culture available
Criteria for screening for ESBL production were applied according to the Dutch Society for Medical Microbiology guideline: positive ESBL screening was defined as a MIC > 1 mg/L for cefotaxime and/or ceftazidime [2]

Summary

Methods

Setting In our tertiary teaching hospital, we have an active screening policy for MDR-GNB, which includes ESBLproducing Gram-negative bacteria. Phenotypic ESBL confirmation was performed with combination disk diffusion testing. ESBL production in nonfermenters was confirmed by cefepime combination disk diffusion testing. Subgroup analysis To assess the value of rectal swab culture we performed a subgroup analysis on patients for whom at least one rectal swab specimen was available. This subgroup was further divided in patients that had been admitted to the ICU or haematology wards (where SDD is used) at least once, and patients that had never been admitted to one of these wards

Results

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