Evaluation of two culture-based methods for the early detection of methicillin-resistant Staphylococcus aureus nasal carriage in pre-operative neurosurgical patients

Abstract

Background: Pre-operative screening for nasal carriage of methicillin-resistant Staphylococcus aureus(MRSA) is practiced to reduce the risk of post-operative MRSA infections. Although controversies prevail on the necessity for screening, we perform MRSA screening in all pre-operative neurosurgical patients due to the benefits incurred. Aim: The aim of this study was to evaluate two different culture-based methods for rapid screening of MRSA nasal carriage among pre-operative neurosurgical patients. Methods: This cross-sectional, single-centre study was conducted in a tertiary healthcare facility in South India. All pre-operative neurosurgery patients were screened for nasal carriage of MRSA using two culture-based methods. Advantage of the newer screening method using chromogenic media over the conventional method was evaluated. A positive screening test was considered an indication for decolonisation using mupirocin and chlorhexidine prior to surgery. A repeat negative screening was ensured before the surgical procedure. Results: MRSA colonisation rate among pre-operative neurosurgical patients in our study was 2.7%. Good correlation was observed between the two screening methods evaluated. Newer method using chromogenic media on comparison with conventional culture showed better turnaround time and shorter pre-operative stay of patients. Because the turnaround time is reduced, earlier contact isolation practice and treatment initiation was achieved for better care of MRSA carriers. Conclusion: Chromogenic media usage for screening the nasal carriage of MRSA is beneficial to patients, surgeons and laboratory personnel. Decrease in turnaround time and processing time and early initiation of isolation along with major reduction in reagent usage are the benefits achieved.