# The Emergence of Linezolid-Resistant Staphylococcus Epidermidis in the COVID-19 Hospitalized Intubated Patients in North Khorasan, Iran

## TL;DR

The study found a high rate of linezolid-resistant Staphylococcus epidermidis in hospitalized, intubated COVID-19 patients in Iran, highlighting a growing antibiotic resistance threat.

## Contribution

The study reports a high prevalence of linezolid-resistant S. epidermidis in intubated COVID-19 patients, emphasizing the need for surveillance and infection control.

## Key findings

- 11 out of 185 hospitalized, intubated SARS-CoV-2 patients had bacterial co-infections, including S. epidermidis.
- 7 out of 9 S. epidermidis isolates were linezolid-resistant, with all isolates resistant to methicillin.
- Most isolates belonged to SCCmec I, indicating a specific resistance pattern in the region.

## Abstract

The present study aimed to investigate secondary bacterial infections among patients infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).
Coagulase-negative Staphylococci can infect immunocompromised patients. Linezolid resistance among Staphylococcus epidermidis is one of the most critical issues.

In 2019, 185 SARS-CoV-2-positive patients who were admitted to North Khorasan Province Hospital (Bojnurd, Iran), were investigated. Patients having positive SARS-CoV-2 reverse
transcriptase real-time polymerase chain reaction (RT-PCR) test results, who had a history of intubation, mechanical ventilation, and were hospitalized for more than 48 hours were included.

After microbiological evaluation of pulmonary samples, taken from intubated patients with clinical manifestation of pneumonia, co-infections were
found in 11/185 patients (5.94%) with S. epidermidis, Staphylococcus aureus, and Acinetobacter baumani, respectively.
Remarkably, seven out of nine S. epidermidis isolates were
linezolid resistant. Selected isolates were characterized using antimicrobial resistance patterns and molecular methods, such as Staphylococcal cassette chromosome mec (SCCmec) typing,
and gene detection for ica, methicillin resistance (mecA), vancomycin resistance (vanA), and chloramphenicol–florfenicol resistance (cfr) genes.

All of the isolates were resistant to methicillin, and seven isolates were resistant to linezolid. Nine out of 11 isolated belonged to the SCCmec I, while two belonged to the SCCmec IV.
It should be noted that all patients had the underlying disease, and six patients had already passed away.

The increasing linezolid resistance in bacterial strains becomes a real threat to patients, and monitoring such infections, in conjunction with surveillance
and infection prevention programs, is very critical for reducing the number of linezolid-resistant Staphylococcal strains.

A preprint of this study was published at https://europepmc.org/article/ppr/ppr417742.