Increasing Antimicrobial Resistance of Gram-Positive Cocci in the Nostrils of Health Care Workers in the Post–COVID-19 Era Compared to Pre–COVID-19 Era in North Khorasan, Iran

Background: In the COVID-19 era, co-infections can lead to an increase in morbidity and mortality. Normal flora bacteria can transfer to the pulmonary tract and create bacterial co-infections. The nasal cavity is one of the main areas housing normal flora in the human body. Objectives: In this study, we evaluated the prevalence and antibiotic resistance of gram-positive cocci in the pre– and post–COVID-19 eras among health care workers. Methods: We assessed 376 nasal swabs from the pre–COVID-19 era and 376 from the post–COVID-19 era. Conventional and molecular methods were used to identify bacterial types and evaluate antimicrobial resistance. Results: The most common gram-positive cocci in the pre–COVID-19 samples were Staphylococcus aureus, S. epidermidis, S. capitis, S. hominis, S. haemolyticus, Streptococcus pneumoniae, and Enterococcus faecalis. In the post–COVID-19 samples, the most common gram-positive cocci were S. aureus, S. epidermidis, S. warneri, S. hominis, and E. faecalis. We observed higher resistance rates in post–COVID-19 samples, as well as resistance to linezolid and vancomycin in S. aureus, S. epidermidis, and S. hominis. Additionally, our isolates showed a high resistance rate to antiseptics. Conclusions: It seems that after the beginning of the COVID-19 pandemic, due to the change in the protective procedures in hospitals, the prevalence and variety of bacteria have decreased, but instead, they have been replaced by more pathogenic bacteria with higher antibiotic resistance.