RNAIII-inhibiting peptide enhances healing of wounds infected with methicillin-resistant Staphylococcus aureus.
Quorum sensing is a mechanism through which a bacterial population receives input from neighboring cells and elicits an appropriate response to enable survival within the host. Inhibiting quorum sensing by RNAIII-inhibiting peptide (RIP) has been demonstrated as a very effective mode of prevention and therapy for device-associated staphylococcal infections and was tested here for healing of wounds that are otherwise resistant to conventional antibiotics. Wounds, established through the panniculus carnosus of BALB/c mice, were inoculated with 5 x 10(7) CFU of methicillin-resistant Staphylococcus aureus. Mice were treated with Allevyn, RIP-soaked Allevyn (containing 20 microg RIP), daily intraperitoneal teicoplanin (7 mg/kg of body weight), Allevyn and teicoplanin, and RIP-soaked Allevyn and daily intraperitoneal teicoplanin. The main outcome measures were quantitative bacterial culture and histological examination with assessment of microvessel density and of vascular endothelial growth factor (VEGF) expression in tissue sections. Treatment with RIP-soaked Allevyn together with teicoplanin injection greatly reduced the bacterial load to 13 CFU/g (control untreated animals had 10(8) CFU/g bacteria). All other treatments were also significantly effective but only reduced the bacterial load to about 10(3) CFU/ml. Histological examination indicated that only treatment with RIP-soaked Allevyn with teicoplanin injection restored epithelial, granulation, and collagen scores, as well as microvessel density and VEGF expression, to the levels found with uninfected mice. In conclusion, we observed that RIP may be useful for the management of infected wounds and that it could represent an exciting and future alternative to the conventional antibiotics, at present considered the gold-standard treatments for methicillin-resistant S. aureus infections.
Simonetti
Oriana
O
Department of Dermatology, Università Politecnica delle Marche, Ancona, Italy. o.simonetti@univpm.it
Cirioni
Oscar
O
Ghiselli
Roberto
R
Goteri
Gaia
G
Scalise
Alessandro
A
Orlando
Fiorenza
F
Silvestri
Carmela
C
Riva
Alessandra
A
Saba
Vittorio
V
Madanahally
Kiran D
KD
Offidani
Annamaria
A
Balaban
Naomi
N
Scalise
Giorgio
G
Giacometti
Andrea
A
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000494:pharmacology / Q000627:therapeutic use*; D053038:Quorum Sensing / Q000187:drug effects; D012329:RNA, Bacterial / Q000037:antagonists & inhibitors*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D013530:Surgical Wound Infection / Q000188:drug therapy* / Q000382:microbiology; D017334:Teicoplanin / Q000627:therapeutic use; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D010455:Peptides; D012329:RNA, Bacterial; C096035:RNAIII, Staphylococcus aureus; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D017334:Teicoplanin