Staphylococcus epidermidis - virulence factors and innate ... - Munin

AMPs are probably driven by electrostatic interactions with the negatively charged outer layer of
the bacterial membrane (59-62).
Lactoferrin is a cationic AMP that has been widely studied. Lactoferrin is localized in the
secondary granules of neutrophils as well as tear fluid, saliva and especially breast milk (63). It is
found on the mucosal surface where it is a prominent component of the first line of host defense
against infection (64, 65). Lactoferrin deprives microorganisms of an essential nutrient by
binding iron (66), but it can probably also exert a directly microbicidal effect, presumably via
membrane disruption or by regulation of different parts of the innate immune system (67-69).
Bovine lactoferrins are effective against both Gram-positive and -negative organisms, including
biofilms of S. epidermidis (70-73).
Anionic human AMPs are less common, but an example is the proteolytic product of dermicidin,
DCD-1L, found in sweat (74).
AMPs and synthetic derivates of AMPs are currently under investigation for clinical application
due to their antimicrobial effects (75-80).
Specific aspects in neonates
AMPs in neonates are detectable in early gestation, and levels generally show a positive
correlation to GA (5). Still, there are generally reduced levels of AMPs in cord blood of both
preterm and term born neonates (81).
The therapeutic use of oral bovine lactoferrins with or without adding probiotica (Lactobacillus
rhamnosus GG) to prevent late-onset sepsis and the development of necrotizing enterocolitis
(NEC) in preterm neonates have shown promising results (9, 82). The Cochrane collaboration
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