| Summary: | Linezolid is currently used to treat infections caused by multidrug-resistant Gram-positive cocci. Both linezolid-resistant <i>S. aureus</i> (LRSA) and coagulase-negative staphylococci (CoNS) strains have been collected worldwide. Two isolates carrying linezolid resistance genes were recovered from laryngological patients and characterized by determining their antimicrobial resistance patterns and using molecular methods such as <i>spa</i> typing, MLST, SCC<i>mec</i> typing, detection of virulence genes and <i>ica</i> operon expression, and analysis of antimicrobial resistance determinants. Both isolates were multidrug resistant, including resistance to methicillin. The <i>S. aureus</i> strain was identified as ST-398/t4474/SCC<i>mec</i> IVe, harboring adhesin, hemolysin genes, and the <i>ica</i> operon. The <i>S. haemolyticus</i> strain was identified as ST-42/<i>mecA</i>-positive and harbored hemolysin genes. Linezolid resistance in <i>S. aureus</i> strain was associated with the mutations in the ribosomal proteins L3 and L4, and in <i>S. haemolyticus</i>, resistance was associated with the presence of <i>cfr</i> gene. Moreover, <i>S. aureus</i> strain harbored <i>optrA</i> and <i>poxtA</i> genes. We identified the first case of staphylococci carrying linezolid resistance genes from patients with chronic sinusitis in Poland. Since both <i>S. aureus</i> and CoNS are the most common etiological factors in laryngological infections, monitoring of such infections combined with surveillance and infection prevention programs is important to decrease the number of linezolid-resistant staphylococcal strains.
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