Relationship Between COVID-19 and Linezolid-Resistant Enterococci: A Retrospective Single-Center Study

To evaluate the correlation between whether the COVID-19 pandemic turned out to be a great premise for increasing the incidence of linezolid resistance infections.

The current retrospective study included data from March 2018 to March 2023 from a single center. The clinical records of the patients were reviewed to extract clinical data. Data gathered from medical records included demographic information, the type of specimen taken, the organism identified, and its sensitivity. Antibiotic susceptibility testing and bacterial identification are both done using the fully automated VITEK system.

The total number of samples collected in all the groups, i.e., Group 1 (PRE-COVID), Group 2 (COVID), and Group 3 (POST-COVID), were 201, 127, and 1315, respectively. Out of a total of 201 samples in Group 1, i.e., from March 2018 to February 2020, 47 (23.38%) samples were collected from blood, 104 (51.74%) samples were collected from urine, and the rest of the samples were collected from other sources (pus, sputum, wound, stool, pleural fluid, etc.). In Group 2, i.e., from March 2020 to February 2021, the total number of samples collected was 127, of which 21 were collected from blood, 86 were from urine, and the remaining 20 samples were from other sources. A total of 1315 samples were collected between March 2021 and February 2023, i.e., in Group 3, 598 samples were collected from blood and 548 samples from urine. The most common isolates in the study were Enterococcus faecalis (35.7%) and Enterococcus faecium (61.0%).

A new threat seems to be emerging in the era of COVID-19, the Enterococcus genus. Though the mechanism remains unidentified, the viral infection seems to cause changes in the bacterial flora, favoring Enterococcus and increasing gut permeability, which provides the perfect environment for Enterococcus bacteria to develop invasive infections. In our study, the prevalence of linezolid resistance was 18.2% for five years.