Community acquired Panton-Valentine Leukocidin (PVL) positive Methicilin Resistant Staphylococcal aureus cerebral abscess in an 11-month old boy: a case study

Methicillin-resistant Staphylococcus aureus intracranial abscess: An analytical series and review on molecular, surgical and medical aspects

Purpose

Intracranial abscess caused by methicillin-resistant Staphylococcus aureus (MRSA) is rare and unexplored. The aim of the present study is to examine the prevalence, clinical and molecular characteristics, treatment options and outcome of MRSA intracranial abscess over a period of 6 years.

Patientsand Methods

A total of 21 patients were included in this retrospective study. The demographic and clinical details of all the patients were collected. Molecular typing including staphylococcal cassette chromosome mec typing, spa typing and polymerase chain reaction of Panton-Valentine leucocidin toxin (PVL) gene for the latter 6 isolates was performed.

Results

The paediatric population was the most affected group (33.3%). The primary route of infection was post-operative/trauma in 7 (33.3%) cases. All the patients were treated surgically either by aspiration or excision. Fifteen (71%) patients received anti-MRSA treatment with vancomycin or linezolid, where linezolid-treated patients showed better prognosis. Of the 11 patients who were on follow-up, unfavourable outcome was observed in 3 (27.3%) cases and 8 (72.7%) cases improved. The molecular typing of six isolates revealed four community-associated (CA) MRSA, one each of livestock-associated (LA) and healthcare-associated MRSA with PVL gene noted in all.

Conclusion

We propose that timely diagnosis, surgical intervention and appropriate anti-MRSA treatment would contribute to better outcome. The occurrence of CA-MRSA and LA-MRSA infection in the central nervous system signifies the threat from the community and livestock reservoir, thus drawing attention towards surveillance and tracking to understand the epidemiology and implement infection control measures.

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.