====== Staphylococcus epidermidis ventriculoperitoneal shunt infection ======

[[Staphylococcus epidermidis]] is the most common cause of [[cerebrospinal fluid]] [[shunt infection]]s, causing more than 50% of cases in one series
((Bayston R. Hydrocephalus shunt infections. J Antimicrob Chemother 1994; 34 (Suppl. A): S75–S84.)).



The affinity of S. epidermidis for medical devices, such as [[ventriculoperitoneal shunt]] , has been attributed to its ability to adhere to plastics, with the subsequent formation of biofilm which can reduce efficacy of treatment and cause persistence of infection
((Frebourg NB, Lefebvre S, Baert S et al. PCR‐based assay for discrimination between invasive and contaminating Staphylococcus epidermidis strains. J Clin Microbiol 2000; 38: 877–80.)).

The insertion of medical [[device]]s, such as [[intraventricular]] [[shunt]]s, is often complicated by [[infection]] leading to [[ventriculitis]]. Frequently, such infections result from colonisation and subsequent [[biofilm]] formation on the surfaces of the shunts by [[Staphylococcus epidermidis]]. The [[pathogenesis]] of neurosurgical [[shunt infection]]s is complex with interactions between the pathogen, the device and the unique local immunological environment of the central nervous system (CNS). 

An ability to form biofilm, the main virulence determinant of [[Staphylococcus epidermidis]], facilitates protection of the organism from the host defences while still initiating an immunological response. The presence of the [[blood brain barrier]] (BBB) and the biofilm itself also complicates treatment, which presents many challenges when managing shunt infections. A greater understanding of the interplay between S. epidermidis and the CNS could potentially improve the diagnosis, treatment and management of such infections
((Stevens NT, Greene CM, O'Gara JP, Bayston R, Sattar MT, Farrell M, Humphreys
H. Ventriculoperitoneal shunt-related infections caused by Staphylococcus
epidermidis: pathogenesis and implications for treatment. Br J Neurosurg. 2012
Dec;26(6):792-7. doi: 10.3109/02688697.2011.651514. Epub 2012 Feb 3. Review.
PubMed PMID: 22303864.
)).
----
A study group involved 30 [[child]]ren with [[congenital hydrocephalus]] after [[shunt]] system implantation, whose [[procedure]]s were complicated by S. epidermidis implant infection. Thirty children with congenital hydrocephalus awaiting their first-time shunt implantation formed the control group. The level of [[eosinophil]]s in [[peripheral blood]] was assessed in both groups. [[Cerebrospinal fluid]] (CSF) was examined for protein level, [[pleocytosis]], [[interleukin]]s, [[CCL26]]/[[Eotaxin 3]], [[IL]]-5, IL-6, [[CCL11]]/Eotaxin-1, [[CCL3]]/MIP-1a, and MBP. Three measurements were performed in the study group. The first measurement was obtained at the time of [[shunt infection]] diagnosis, the second one at the time of the first sterile shunt, and the third one at the time of shunt reimplantation. In the control group, blood and CSF samples were taken once, at the time of shunt implantation.

In the clinical material, the highest values of eosinophils in peripheral blood and CSF pleocytosis were observed in the second measurement. It was accompanied by an increase in the majority of analyzed CSF [[interleukin]]s.

[[Cerebrospinal fluid pleocytosis]] observed in the study group of Polis et al., from the Department of Neurosurgery, Polish Mother's Memorial Hospital Research Institute, [[Łódź]], [[Poland]]. shortly after [[CSF]] sterilization is presumably related to an allergic reaction to [[Staphylococcus epidermidis]], the causative agent of [[ventriculoperitoneal shunt infection]]
((Polis B, Polis L, Zeman K, Paśnik J, Nowosławska E. Unexpected eosinophilia in
children affected by hydrocephalus accompanied with shunt infection. Childs Nerv 
Syst. 2018 Jul 21. doi: 10.1007/s00381-018-3908-5. [Epub ahead of print] PubMed
PMID: 30032408.
)).
===== Treatment =====

[[Linezolid]], an oxazolidinone, is active against [[Gram positive]] cocci, and has excellent CSF penetration. Gill et al., present a 22-year-old woman who was cured of a Staphylococcus epidermidis VP shunt infection via [[shunt removal]] and intravenous linezolid
((Gill CJ, Murphy MA, Hamer DH. Treatment of Staphylococcus epidermidis
ventriculo-peritoneal shunt infection with linezolid. J Infect. 2002
Aug;45(2):129-32. PubMed PMID: 12217722.
)).