Severe necrotizing pneumonia associated with Sheisha Smoking in a 14 year old child

Abstract

Necrotizing pneumonia is a rare complication of bacterial lung infection .Its cause is due
to either a virulence factor of the microorganism or predisposing factor of the host. An association between
necrotizing pneumonia and Panton –Valentine Leucocidin (PVL) –secreting S.aureus was first recognized
in 1999 (1) .Few years later clinical features of the disease was described by Gillet et al (2) .Risk factors
were then well -recognized by 2007 (3) The disease causes a devastating complications such as diffuse
pulmonary inflammation ,septic shock and respiratory failure .Staphylococcus aureus strains that produce
Panton –Valentine leukocidin have been reported to cause rapidly progressive necrosis of the lung tissue in
young immunocompitent patients .Furthermore, recent studies have shown the risk of disease progression
is associated with underlying medical conditions (4)
Staphylococcus is related to the Micrococcaceae family , Staphylococcus- derived from Greek “stapyle”
(bunch of grapes). Virulence factors of S. aureus includes enzymes : catalase (counters host defences)
;coagulase ,;hyaluronidase ;lipases; B lactasamase (antibiotic resistance).Toxins : enterotoxin, TSST
and epidermolytic toxin.The effects of smoking on staphylococcus virulence was studied among cigarette
smokers. Methicillin-resistant Staphylococcus aureus (MRSA)colonizes the nasopharynx and is thus
exposed to inhalants .MRSA exposed to cigarette smoke extract (CSE-MRSA) was more resistant to
macrophage killing (4 fold )It also demonstrated a reduced susceptibility to cell lysis and modification of
the surface charge of MRSA and eventually impairing the binding of particles with charge similar to that
of AMPs by 90% and increased adherence and invasion of epithelial cells ( 5) .