In Vitro Antimicrobial Activity of Dermcidin-1L Against Extensively-Drug-Resistant and Pandrug-Resistant Acinetobacter baumannii

Abstract

Background: Acinetobacter baumannii is currently considered one of the greatest causes of nosocomial infection. The rapid emergence and spread of resistance to most conventional antibiotics highlight the need to identify novel antimicrobial agents. Antimicrobial peptides (AMPs) are introduced as potential therapeutic alternatives. Human anionic antimicrobial peptide, dermcidin-1L (DCD-1L), has shown antimicrobial activity against a wide range of nosocomial pathogens; however, it is still unknown whether it exhibits such properties against A. baumannii. Objectives: For the first time, the present study was conducted to examine the antimicrobial activity of DCD-1L against biofilmforming extensively-drug-resistant (XDR) and pandrug-resistant (PDR) isolates of A. baumannii, belonging to different clonal lineages. Methods: Dermcidin-1L was examined in terms of antimicrobial properties against 1 biofilm-forming representative XDR isolate from each clonal lineage and 1 PDR isolate via minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) analyses and time-kill assay. Dermcidin-1L resistance mutation frequency in A. baumannii was also determined. Results: Minimum inhibitory concentration and MBC of DCD-1L against all 8 representative XDR and standard (ATCC 19606) isolates

RETRACTED ARTICLE: Antimicrobial and anti-biofilm potencies of dermcidin-derived peptide DCD-1L against Acinetobacter baumannii: an in vivo wound healing model

“…Interestingly, DCD-1L exhibited an antibacterial effect on the abovementioned pathogens at this concentration range in their study. Likewise, the MIC values of DCD-1L against colistin resistant A. baumannii isolates were in this concentration range [ 21 ]. Colistin is a cationic lipopeptide and bacteria have acquired resistance mechanism to a cationic lipopeptide by reducing the net negative charge of their surface and reducing, consequently, attraction of the positively charged lipopeptide to the surface; so, this resistance mechanism did not influence susceptibility to the negatively charged molecules such as DCD-1L.…”

“…One extensively drug-resistant (XDR)- A. baumannii and one pandrug-resistant (PDR)- A. baumannii with strong biofilm producers which were stored at -80 °C were selected from 100 strains isolated from burn wound infected patients admitted to Shahid Motahari Referral Center of Burn in Tehran, Iran, during 2013–2015 according to our previous study [ 21 ]. The XDR- A. baumannii strain was resistant to all clinically relevant antibiotics except tigecycline and colistin.…”

Peptides with Therapeutic Potential against Acinetobacter baumanii Infections

“…Dermcidin is an anionic AMP encoded by the DCD gene in humans essentially produced in eccrine sweat glands, secreted into a sweat, and further transported to the skin's epidermal surface [130,201]. It has two parts; N-terminal peptide promotes neural cell survival under severe oxidative stress conditions called DCD-1 L [130].…”

“…Dermcidin is an anionic AMP encoded by the DCD gene in humans essentially produced in eccrine sweat glands, secreted into a sweat, and further transported to the skin's epidermal surface [130,201]. It has two parts; N-terminal peptide promotes neural cell survival under severe oxidative stress conditions called DCD-1 L [130]. DCD-1 L, a C-terminal peptide with the net electric charge of À2, is the only anionic anti-Acinetobacter natural AMP found in the literature that shows partial helicity in solution [130,182].…”

“…It has two parts; N-terminal peptide promotes neural cell survival under severe oxidative stress conditions called DCD-1 L [130]. DCD-1 L, a C-terminal peptide with the net electric charge of À2, is the only anionic anti-Acinetobacter natural AMP found in the literature that shows partial helicity in solution [130,182]. Interestingly, in exposure to this AMP, the PDR A. baumannii isolates are twice more susceptible as XDR isolates and the standard strain (ATCC 19606) (MIC = 8 μg/ ml) [131].…”