The SARS-CoV-2 infection has increased the number of patients entering Intensive Care Unit (ICU) facilities and antibiotic treatments. Concurrently, the multi-drug resistant bacteria (MDRB) colonization index has risen. Considering that most of these bacteria are derived from gut microbiota, the study of its composition is essential. Additionally, SARS-CoV-2 infection may promote gut dysbiosis, suggesting an effect on microbiota composition. This pilot study aims to determine bacteria biomarkers to predict MDRB colonization risk in SARS-CoV-2 patients in ICUs. Seventeen adult patients with an ICU stay >48 h and who tested positive for SARS-CoV-2 infection were enrolled in this study. Patients were assigned to two groups according to routine MDRB colonization surveillance: non-colonized and colonized. Stool samples were collected when entering ICUs, and microbiota composition was determined through Next Generation Sequencing techniques. Gut microbiota from colonized patients presented significantly lower bacterial diversity compared with non-colonized patients (p < 0.05). Microbiota in colonized subjects showed higher abundance of Anaerococcus, Dialister and Peptoniphilus, while higher levels of Enterococcus, Ochrobactrum and Staphylococcus were found in non-colonized ones. Moreover, LEfSe analysis suggests an initial detection of Dialister propionicifaciens as a biomarker of MDRB colonization risk. This pilot study shows that gut microbiota profile can become a predictor biomarker for MDRB colonization in SARS-CoV-2 patients.

The growing global threat of multidrug-resistant (MDR) bacteria has been exacerbated by inadequate antibiotic consumption and the difficulty in developing new therapeutic strategies. Selective Digestive Decontamination (SDD) is presented as an encouraging measure to prevent the appearance and colonization of MDR bacteria. We compared the pattern of antibiotic consumption in the Intensive Care Unit (ICU) of our hospital before and after the implementation of the SDD protocol. This quasi-experimental study was conducted in an ICU from June-2021 to June-2023. The incidence of nosocomial infections, colonizations, and the number of isolated MDR bacteria, as well as the defined-daily-dose (DDD), were monitored. A total of 3266 patients were included, with 1532 in the pre-intervention group and 1734 in the post-intervention group. The median age was 62 years, 66% were male, and the average APACHE II and SOFA scores were 15 and 6.5, respectively. There was a significant reduction in overall antibiotic consumption in the post-SDD group (p= 0.028), highlighting a decrease in Carbapenemase-Producing Enterobacteriaceae (CPE) (p= 0.0099). There was also a reduction in colonization incidence density and nosocomial infections. Implementing the SDD protocol significantly reduced antibiotic consumption in the ICU, suggesting important implications for infection control and antimicrobial resistance management.