An observational study protocol on wastewater measurements and diaper culture to estimate antimicrobial resistance in long-term care facilities for people with intellectual disabilities: The GIRAF-MIC study protocol.

Introduction: Antimicrobial resistance (AMR) has become one of the leading global health threats. It is critical to understand the burden of AMR, particularly among vulnerable populations such as people with intellectual disabilities residing in long-term care facilities (ID-LTCFs). Traditional study methods to estimate the burden of AMR in these settings, such as rectal swabs to measure the prevalence of MDRO carriage, are considered burdensome for this population. This underscores the importance of a non-invasive method to assess the burden of AMR among people living in ID-LTCFs. This publication describes a study protocol for an alternative approach to estimate AMR, specifically Extended Spectrum Beta-Lactamase (ESBL) and carbapenemase-producing Enterobacterales (CPE), in ID-LTCFs in the Netherlands, through wastewater measurements combined with analysis of stool collected from diaper material. The protocol provides detailed information about the study design and methodologies proposed for a pilot study.

Methods and analysis: Wastewater samples will be obtained from the sewers of ID-LCTFs using passive samplers. Additionally, as a considerable part of ID-LTCF residents are incontinent, stool samples will be collected from diaper material which will be obtained from incontinent residents living in participating ID-LTCFs. The wastewater and stool samples will be cultured on selective media to detect ESBL-producing Enterobacterales and carbapenem producing Enterobacterales (CPE) strains. Determination of strains will be carried out using MALDI-TOF and phenotypical tests will be carried out to confirm ESBL and CPE producing strains. In wastewater samples, bacterial concentrations will be determined, expressed in colony forming unit (CFU) per passive sampler, while in stool from diaper material the presence or absence of ESBL and CPE will be reported in proportions.

Ethics and dissemination: The procedures described in this study protocol will be conducted in line with principles outlined in the Declaration of Helsinki, Code of Conduct for Health research, as well as the General Data Protection Regulation. Approval in advance by an ethical research committee or institutional review board is deemed unnecessary by current national and European legislation.