Dysbiosis: An Indicator of COVID-19 Severity in Critically Ill Patients.

Here, we examined the dynamics of the gut and respiratory microbiomes in severe COVID-19 patients in need of mechanical ventilation in the intensive care unit (ICU). We recruited 85 critically ill patients (53 with COVID-19 and 32 without COVID-19) and 17 healthy controls (HCs) and monitored them for up to 4 weeks. We analyzed the bacterial and fungal taxonomic profiles and loads of 232 gut and respiratory samples and we measured the blood levels of Interleukin 6, IgG, and IgM in COVID-19 patients. Upon ICU admission, the bacterial composition and load in the gut and respiratory samples were altered in critically ill patients compared with HCs. During their ICU stay, the patients experienced increased bacterial and fungal loads, drastic decreased bacterial richness, and progressive changes in bacterial and fungal taxonomic profiles. In the gut samples, six bacterial taxa could discriminate ICU-COV(+) from ICU-COV(-) cases upon ICU admission and the bacterial taxa were associated according to age, PaO2/FiO2, and CRP levels. In the respiratory samples of the ICU-COV(+) patients, bacterial signatures including Pseudomonas and Streptococcus were found to be correlated with the length of ICU stay. Our findings demonstrated that the gut and respiratory microbiome dysbiosis and bacterial signatures associated with critical illness emerged as biomarkers of COVID-19 severity and could be a potential predictor of ICU length of stay. We propose using a high-throughput sequencing approach as an alternative to traditional isolation techniques to monitor ICU patient infection.

Health-care-associated bloodstream infections at admission to the ICU.

BACKGROUND: Infections occurring among outpatients having recent contact with the health-care system have been recently classified as health-care-associated infections to distinguish them from hospital- and community-acquired infections. Patients with bloodstream infections (BSIs) were studied to assess health-care-associated infections at admission in the ICU. METHODS: This work was a multicenter, prospective, observational study of all adult patients with BSI at ICU admission at 27 Spanish hospitals and one Argentine hospital. Cases of BSI were classified as community-acquired BSI (CAB), health-care-associated BSI (HCAB), or hospital-acquired BSI (HAB), and their characteristics were compared. RESULTS: Of 726 BSIs, 343 (47.2%) were CABs, 252 (34.7%) were HABs, and 131 (18.0%) were HCABs. Potentially antibiotic-resistant pathogens were more frequently isolated in HABs (34.8%) and HCABs (27.6%) than in CABs (10.3%) (P < .001). Logistic regression analysis revealed that HABs (OR, 4.6; 95% CI, 2.9-7.3), HCABs (OR, 3.1; 95% CI, 1.8-5.4), and BSIs of unknown origin (OR, 1.7; 95% CI, 1.0-2.8) were independently associated with the isolation of potentially antibiotic-resistant pathogens. The incidence of inappropriate treatment was significantly higher in HABs (OR, 3.4; 95% CI, 2.1-5.3) and in HCABs (OR, 1.8; 95% CI, 1.0-3.2) than in CABs. CONCLUSIONS: One in five BSIs diagnosed at ICU admission is health-care-associated. The incidence of potentially drug-resistant pathogens in HCABs is more similar to that of HABs, and they should be treated as such until culture data are available.