Scope: The aim of these guidelines is to provide recommendations for  decolonizing regimens targeting multidrug-resistant Gram-negative  bacteria (MDR-GNB) carriers in all settings.

Methods:  These evidence-based guidelines were produced after a systematic  review of published studies on decolonization interventions targeting  the following MDR-GNB: third-generation cephalosporin-resistant  Enterobacteriaceae (3GCephRE), carbapenem-resistant Enterobacteriaceae  (CRE), aminoglycoside-resistant Enterobacteriaceae (AGRE),  fluoroquinolone-resistant Enterobacteriaceae (FQRE), extremely  drug-resistant Pseudomonas aeruginosa (XDRPA), carbapenem-resistant  Acinetobacter baumannii (CRAB), cotrimoxazole-resistant Stenotrophomonas  maltophilia (CRSM), colistin-resistant Gram-negative organisms  (CoRGNB), and pan-drug-resistant Gram-negative organisms (PDRGNB). The  recommendations are grouped by MDR-GNB species. Faecal microbiota  transplantation has been discussed separately. Four types of outcomes  were evaluated for each target MDR-GNB:(a) microbiological outcomes  (carriage and eradication rates) at treatment end and at specific  post-treatment time-points; (b) clinical outcomes (attributable and  all-cause mortality and infection incidence) at the same time-points and  length of hospital stay; (c) epidemiological outcomes (acquisition  incidence, transmission and outbreaks); and (d) adverse events of  decolonization (including resistance development). The level of evidence  for and strength of each recommendation were defined according to the  GRADE approach. Consensus of a multidisciplinary expert panel was  reached through a nominal-group technique for the final list of  recommendations.

Recommendations:  The panel does not recommend routine decolonization of 3GCephRE  and CRE carriers. Evidence is currently insufficient to provide  recommendations for or against any intervention in patients colonized  with AGRE, CoRGNB, CRAB, CRSM, FQRE, PDRGNB and XDRPA. On the basis of  the limited evidence of increased risk of CRE infections in  immunocompromised carriers, the panel suggests designing high-quality  prospective clinical studies to assess the risk of CRE infections in  immunocompromised patients. These trials should include monitoring of  development of resistance to decolonizing agents during treatment using  stool cultures and antimicrobial susceptibility results according to the  EUCAST clinical breakpoints.

Keywords: Acinetobacter; Carbapenemase; Decolonization; Enterobacteriaceae;  Extended-spectrum β-lactamase; Guideline; Multidrug-resistant  Gram-negative; Pseudomonas; Stenotrophomonas.