Missed epidural brain abscess after furunculosis

Homeless Patient With Community-Acquired Methicillin-Resistant Staphylococcus aureus Brain Abscesses

Brain abscess secondary to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection is a rare, yet highly fatal disease. This article presents the case of a 45-year-old homeless female with a medical history of bipolar disorder, seizure disorder, and substance use disorder who was admitted with altered mental status. Laboratory tests on admission revealed neutrophil-predominant leukocytosis, elevated inflammatory markers (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), and lactic acid. MRI brain demonstrated multiple cerebral abscesses with surrounding edema and sagittal vein thrombosis. The patient was initiated on broad-spectrum antibiotics and underwent a right-sided minimally invasive needle biopsy of the abscess and left frontal craniotomy for abscess evacuation, the culture of which confirmed the diagnosis of MRSA infection. As the patient did not have any hospitalization or procedure in the recent past, a diagnosis of CA-MRSA was made. The patient's clinical status improved following the procedure and antibiotic administration, but she left against medical advice before completing treatment. This case highlights the importance of early recognition and aggressive management of CA-MRSA infections, especially in vulnerable populations such as the homeless.

Infratentorial Epidural Abscess Secondary to Furunculosis: Case Report and a Review of the Literature

The authors describe a case of infratentorial epidural abscess caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in a patient with a recent history of cutaneous furunculosis. This 29-year-old male presented with an occipital headache associated with fever, vomiting, and neck stiffness. Admission magnetic resonance imaging showed a retrocerebellar epidural abscess. Antimicrobial therapy was started, and the patient underwent craniectomy for evacuation of the abscess. Cultures of the surgical specimen were consistent with CA-MRSA. Postoperatively, the patient's condition improved with the resolution of symptoms, and he was discharged home with indication of 6 weeks of antibiotic therapy. Furunculosis is a very rare cause of intracranial epidural abscess but should be considered as a source of infection in an immunocompetent patient.

Treatment of Staphylococcus aureus Infections

Staphylococcus aureus, although generally identified as a commensal, is also a common cause of human bacterial infections, including of the skin and other soft tissues, bones, bloodstream, and respiratory tract. The history of S. aureus treatment is marked by the development of resistance to each new class of antistaphylococcal antimicrobial drugs, including the penicillins, sulfonamides, tetracyclines, glycopeptides, and others, complicating therapy. S. aureus isolates identified in the 1960s were sometimes resistant to methicillin, a ß-lactam antimicrobial active initially against a majority S. aureus strains. These MRSA isolates, resistant to nearly all ß-lactam antimicrobials, were first largely confined to the health care environment and the patients who attended it. However, in the mid-1990s, new strains, known as community-associated (CA-) MRSA strains, emerged. CA-MRSA organisms, compared with health care-associated (HA-) MRSA strain types, are more often susceptible to multiple classes of non ß-lactam antimicrobials. While infections caused by methicillin-susceptible S. aureus (MSSA) strains are usually treated with drugs in the ß-lactam class, such as cephalosporins, oxacillin or nafcillin, MRSA infections are treated with drugs in other antimicrobial classes. The glycopeptide drug vancomycin, and in some countries teicoplanin, is the most common drug used to treat severe MRSA infections. There are now other classes of antimicrobials available to treat staphylococcal infections, including several that have been approved after 2009. The antimicrobial management of invasive and noninvasive S. aureus infections in the ambulatory and in-patient settings is the topic of this review. Also discussed are common adverse effects of antistaphylococcal antimicrobial agents, advantages of one agent over another for specific clinical syndromes, and the use of adjunctive therapies such as surgery and intravenous immunoglobulin. We have detailed considerations in the therapy of noninvasive and invasive S. aureus infections. This is followed by sections on specific clinical infectious syndromes including skin and soft tissue infections, bacteremia, endocarditis and intravascular infections, pneumonia, osteomyelitis and vertebral discitis, epidural abscess, septic arthritis, pyomyositis, mastitis, necrotizing fasciitis, orbital infections, endophthalmitis, parotitis, staphylococcal toxinoses, urogenital infections, and central nervous system infections.

Central nervous system invasion by community-acquired meticillin-resistant Staphylococcus aureus

We report a case of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) bacteraemia with cavernous sinus thrombosis, meningitis and brain abscess in a previously healthy American, who was employed in Belgium. We consecutively reviewed all published cases of CA-MRSA with central nervous system (CNS) involvement. A total of 12 similar cases were found, of which 11 were published in the last 4 years. Predominantly, young previously healthy subjects were affected (median age 28 years). The cases involved brain abscesses (5/12), disseminated disease (4/12), cavernous sinus thrombosis (2/12) and other (1/12). Infection origins were superficial skin infections (5/12), mostly of the face, sinusitis (1/12), otitis media (1/12), other or unknown (5/12). Although, in our review of the literature patients treated with linezolid had a better outcome compared to patients treated with vancomycin, the latter is still the mainstay of therapy for CNS infections associated with MRSA.

Evaluation of Nisin F in the Treatment of Subcutaneous Skin Infections, as Monitored by Using a Bioluminescent Strain of Staphylococcus aureus

The potential of nisin F as an antimicrobial agent in treating subcutaneous skin infections was tested in vivo by infecting C57BL/6 mice with a bioluminescent strain of Staphylococcus aureus (Xen 36). Strain Xen 36 has the luxABCDE operon located on a native plasmid. Mice were grouped into four groups: Infected with strain Xen 36 and treated with nisin F, infected with strain Xen 36 and treated with saline (placebo), not infected and treated with nisin (control) and not infected and not treated (control). The immune systems of the mice were suppressed with deksamethasone. Mice were treated with either nisin F or sterile physiological saline 24 and 48 h after infection with subcutaneously injected S. aureus Xen 36 (4 × 10(6) CFU). Histology and bioluminescent flux measurements revealed no significant difference between infected mice treated with nisin and saline, respectively. However, infected mice treated with nisin F had an increased number of polymorphonuclear cells when compared with infected mice treated with saline. Also, not infected mice treated with nisin F had an influx of polymorphonuclear cells. Nisin F is thus ineffective in combating deep dermal staphylococcal infections. The apparent immune modulation of nisin when subcutaneously injected has to be investigated.