Antibacterial and Antibiofilm Activities of Novel Antimicrobial Peptides against Multidrug-Resistant Enterotoxigenic Escherichia Coli

Abstract

Post-weaning diarrhea due to enterotoxigenic Escherichia coli (ETEC) is a common disease of piglets and causes great economic loss for the swine industry. Over the past few decades, decreasing effectiveness of conventional antibiotics has caused serious problems because of the growing emergence of multidrug-resistant (MDR) pathogens. Various studies have indicated that antimicrobial peptides (AMPs) have potential to serve as an alternative to antibiotics owing to rapid killing action and highly selective toxicity. Our previous studies have shown that AMP GW-Q4 and its derivatives possess effective antibacterial activities against the Gram-negative bacteria. Hence, in the current study, we evaluated the antibacterial efficacy of GW-Q4 and its derivatives against MDR ETEC and their minimal inhibition concentration (MIC) values were determined to be around 2~32 μg/mL. Among them, AMP Q4-15a-1 with the second lowest MIC (4 μg/mL) and the highest minimal hemolysis concentration (MHC, 256 μg/mL), thus showing the greatest selectivity (MHC/MIC = 64) was selected for further investigations. Moreover, Q4-15a-1 showed dose-dependent bactericidal activity against MDR ETEC in time–kill curve assays. According to the cellular localization and membrane integrity analyses using confocal microscopy, Q4-15a-1 can rapidly interact with the bacterial surface, disrupt the membrane and enter cytosol in less than 30 min. Minimum biofilm eradication concentration (MBEC) of Q4-15a-1 is 4× MIC (16 μg/mL), indicating that Q4-15a-1 is effective against MDR ETEC biofilm. Besides, we established an MDR ETEC infection model with intestinal porcine epithelial cell-1 (IPEC-1). In this infection model, 32 μg/mL Q4-15a-1 can completely inhibit ETEC adhesion onto IPEC-1. Overall, these results suggested that Q4-15a-1 may be a promising antibacterial candidate for treatment of weaned piglets infected by MDR ETEC.

Resveratrol alleviates enterotoxigenicEscherichia coliK88-induced damage by regulating SIRT-1 signaling in intestinal porcine epithelial cells

“…6 With the strict ban on antibiotics in animal feed, different kinds of antibiotic substitutes, such as antimicrobial peptides, organic acids, oligosaccharides, and plant extracts, are gaining more and more attention. [7][8][9][10][11][12] Resveratrol (RES), trans-3,4′,5-trihydroxystilbene, is a phenolic botanical compound existing in various plants, such as peanuts, grapes, and berries. 13 Many in vivo and in vitro studies have shown that resveratrol exerts multiple bioactive properties, including antioxidative, antiinflammatory, anti-stress, and other biological functions.…”

Novel Hybrid Peptide Cathelicidin 2 (1-13)-Thymopentin (TP5) and Its Derived Peptides with Effective Antibacterial, Antibiofilm, and Anti-Adhesion Activities

“…In the previous studies related to an antimicrobial peptide, they mainly focused on the antibacterial, antibiofilm or anti-adhesion effects against gram-negative pathogens, such as enterohaemorrhagic Escherichia coli (EHEC) and enterotoxigenic E. coli (ETEC) [31][32][33][34], while lacking attention to gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA) that can form biofilms. Herein, we firstly explored the antibacterial spectrum of our anti-inflammatory peptides CTPs, and we mainly paid attention to the antibacterial, antibiofilm, and anti-adhesion activities of CTPs against an MRSA target strain S. aureus ATCC 43300.…”

Effects of dietary cecropin on growth performance, diarrhea rate and intestinal health of nursery Hainan pigs

“…In this study, we found that compared with the CON group, the diarrhea rate was significantly reduced in nursery Hainan piglets fed diets containing 250 mg/kg and 500 mg/kg CAP ( p < 0.05, Table 3 ), and the effect was equivalent to that seen in the antibiotic supplementation group. Wu et al (2021) showed that the AMP GW-Q4 had strong antibacterial activity against enterotoxigenic E. coli , and the authors reported that GW-Q4 might be a promising candidate for the treatment of diarrhea in weaned piglets caused by this bacterium. Meanwhile, Liang et al (2022) showed that the AMP gloverin2 exhibited desirable antimicrobial activity against 3 indicator bacteria associated with piglet diarrhea ( E. coli , Salmonella Derby, and C. perfringens ) and also displayed marked potential for the treatment of this condition in piglets.…”