Staphylococcus aureus Meningitis

Abstract

Staphylococcus aureus meningitis is a challenging disease and little is known about its epidemiology. There are no established management guidelines. We retrospectively reviewed the clinical information, bacteriologic data, and outcomes of all 33 patients with cerebrospinal fluid (CSF) cultures positive for S aureus seen at a single urban teaching hospital from 1999 to 2008. Pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction for staphylococcal cassette chromosome mec (SCCmec), accessory gene regulator (agr) typing, and Panton-Valentine leukocidin (PVL) loci were done on methicillin-resistant S aureus (MRSA) CSF isolates starting in 2005. S aureus caused 12 (36%) cases of postoperative and 21 (64%) cases of hematogenous meningitis. MRSA isolates were found in 6 (50%) cases of postoperative and 10 (48%) cases of hematogenous meningitis. Twelve (75%) of the 16 MRSA infections occurred in the last 5 years of the study. Hematogenous meningitis was associated with older age (p = 0.04), injection drug use (p < 0.01), community-acquired infection (p < 0.01), underlying disease (p = 0.01), staphylococcal infection outside the central nervous system (p = 0.01), altered mental status (p = 0.02), fever (p = 0.01), septic shock (p = 0.03), and bacteremia (p < 0.01). The analysis of the 9 MRSA isolates showed 3 PFGE types: 3 USA100 (33%), 5 USA300 (56%), and 1 USAnot100-1100 (11%). For SCCmec typing, there were 2 (22%) type II and 7 (78%) type IV. All USA300 strains were SCCmec IVa. For agr typing, there were 5 (56%) type I and 4 (44%) type II. Three isolates (33%) were positive for the PVL gene and were USA300 strains. Most patients received nafcillin or vancomycin with or without rifampin or trimethoprim/sulfamethoxazole for a mean period of 17 days (range, 1-42 d). Overall mortality was 36%, and it was associated with community-acquired infection (p = 0.02). Postoperative and hematogenous S aureus meningitis are distinct clinical syndromes. S aureus hematogenous meningitis has devastating clinical consequences and elevated mortality rates, especially if it is acquired in the community. The incidence of MRSA meningitis increased over the last 5 years of the study. Treatment of choice is nafcillin for methicillin-sensitive strains and vancomycin for MRSA strains. The addition of trimethoprim/sulfamethoxazole or rifampin to vancomycin is recommended in severe cases and community-acquired MRSA infections. Linezolid is also a good option due to its good CSF penetration and favorable case reports. The mortality rate is higher in infections acquired in the community.

Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management

“…The initial source of hematogenous S. aureus meningitis is generally IE, pneumonia, or SSTI (788). The mortality rate for hematogenous S. aureus meningitis is higher (43 to 50%) than that occurring postsurgically (14 to 25%) (780,787). Among S. aureus meningitis cases, methicillin resistance has been increasing in recent years (786,(789)(790)(791).…”

“…S. aureus meningitis may either arise by hematogenous spread from a non-CNS focus of infection or be secondary to neurosurgical intervention (785,786). Hematogenous S. aureus meningitis is usually community acquired (780,785) and, compared with postsurgical S. aureus meningitis, typically affects older individuals (mean age of 59 years versus 40 years; P ϭ 0.04) (787) with severe medical comorbidities such as diabetes or chronic kidney disease (780,787). The initial source of hematogenous S. aureus meningitis is generally IE, pneumonia, or SSTI (788).…”

“…The major predisposing factors for postsurgical meningitis are (i) the presence of an intrathecal device or ventriculoperitoneal shunt (780,787,792), (ii) recent neurosurgery, and (iii) a CSF leak (780 (794). Risk factors for mortality among patients with S. aureus meningitis include a hematogenous compared with a postsurgical source (e.g., 56% mortality for a hematogenous source versus 18% for a postsurgical source within a national Danish study [795]), increasing age and number of comorbidities (794), the presence of septic shock (787), and concurrent IE (782,784).…”

“…S. aureus is an uncommon cause of bacterial meningitis, accounting for 4.9 to 6.4% of cases (779)(780)(781)(782)(783)(784). S. aureus meningitis may either arise by hematogenous spread from a non-CNS focus of infection or be secondary to neurosurgical intervention (785,786).…”

Review: apoptotic mechanisms in bacterial infections of the central nervous system

“…Meningitis, caused by hematogenous spread, or acquired post-neurosurgery is of rising incidence and importance especially due to an increase in methicillin-resistant S. aureus (MRSA) strains in recent years. Although MRSA-mediated meningitis is rare, it has a high mortality rate, and is therefore a very serious disease (Aguilar et al, 2010; Pintado et al, 2012). Studies on the effect of S. aureus LTA on rat brain cells have shown that it can induce cerebellar neuronal cell death but only in the presence of glial cells.…”