Abstract

LINEZOLID RESISTANCE AMONG STAPHYLOCOCCUS HAEMOLYTICUS ISOLATED IN BAGHDAD CITY

Mustafa S. Al-Salmani*, , Tuqa S. Al-Salmani, Khairiyiah J. Al-Khataua

Abstract

Linezolid is an oxazolidinone antibiotic in clinical use for the treatmentof serious infections of resistant Gram-positive bacteria.Staphylococcus haemolyticus considered as the most antibioticresistantCoNS species. The aim of this study was to identify thelinezolid susceptibility among S. haemolyticus isolates which isolatedfrom Iraqi patients. Among 120 Staphylococcus isolates isolated fromblood cultures, 46 isolates were identified as S. haemolyticus during2014 -2015. Only two isolates were resistance to linezolid at allLinezolid used concentrations (i.e., 2μg/ml, 4μg/ml, 8μg/ml and20μg/ml), the rest (95.65%) were sensitive to it at 2μg/ml. Thesusceptibility of ten representative isolates (8 sensitive to linezolid and2 resist to it) showed the highest resistance recorded to Erythromycin as 10 isolates from 10(100%), which appeared to be due to methylation mechanisms in 9 isolates and one isolatedue to other mechanism. Resistance to Clindamycin and Chloramphenicol was recorded.

Keywords: Linezolid Resistance, Staphylococcus haemolyticus, Baghdad City, Iraq.