Staphylococcus aureus meningitis in adults:: A clinical comparison of infections caused by methicillin-resistant and methicillin-sensitive strains

Background: This study was undertaken to compare the clinical characteristics of adult methicillin-sensitive Staphylococcus aureus (MSSA) meningitis and adult methicillin-resistant S. aureus (MRSA) meningitis. Patients and Methods: The clinical characteristics and therapeutic outcomes of 19 adult patients with S. aureus meningitis, including eight with MSSA infections and 11 with MRSA infections' were analyzed. A comparison was made between the clinical data of the patients with MSSA infections and those with MRSA infections. Results: Before the end of 1995, MSSA infection was involved in all the adult patients with S. aureus meningitis but thereafter, MRSA infection was involved in 79% of the cases. The clinical characteristics found in patients with MSSA infection included underlying medical disorders (75%), community-acquired infection (75%) and mortality rate (13%). The clinical characteristics found in patients with MRSA infection included post-neurosurgical states (91%), nosocomial infections (100%), men outnumbering women (8 : 3), hydrocephalus (36%) and mortality rate (56%). Comparative study between the patient groups (hematogenous and post-neurosurgical) showed that only the mode of acquisition of infection had statistical significance. Conclusions: This study showed an increase in MRSA infections in adult S. aureus meningitis in recent years. The clinical characteristics of patients with MSSA and MRSA meningitis were different. Community-acquired infection was common in hematogenous S. aureus meningitis, while nosocomial infection was common in post-neurosurgical S. aureus meningitis. Vancomycin should be considered as one of the drugs of choice for initial therapy of adult bacterial meningitis, especially in post-neurosurgical patients.