Detection of Novel spa Types in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus in Iraq

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a gram-positive bacterium that is an opportunistic pathogen, causing infections in hospital settings and communities. MRSA has become a significant and increasing problem in Iraq. The aim of this study was to evaluate the genetic mutations of MRSA strains, especially in the spa gene, isolated from patients in Wassit, Iraq.Methods and Results: Biochemical tests were conducted to identify S. aureus isolates and then on MRSA. The MRSA was identified by the Chrome Agar method and confirmed by PCR with genotyping of the mecA gene. The disk diffusion method was used to detect antibiotic resistance to three different common antibiotics used at Wassit hospitals. The Vitek-2 compact system was utilized for the detection of the minimum inhibitory concentration (MIC) of vancomycin. All MRSA strains in this study were tested to screen the mecA gene, with 21 strains subjected to the molecular typing method for the spa gene. Out of 166 samples, 132(79.5%) contained S. aureus and 34(20.4%) were identified as MRSA. Genotyping showed that out of 34 MRSA, 31(91.2%) isolates were mecA-positive. The spa gene was detected in 21(61.8%) isolates out of 34 MRSA samples. The spa typing of 21 MRSA samples revealed four different spa types, as follows: t386 (3/14.3%), t3576 (1/4.8%), t10002 (1/4.8%), and t10234 (1/4.8%). High polymorphism rates were shown in isolates of spa type t386. Conclusion: Our data represent the first report to detect novel mutations in the spa gene in the MRSA clinical isolates from Wassit hospitals, Iraq.