Effect of NZ2114 against Streptococcus dysgalactiae biofilms and its application in murine mastitis model

Abstract

Bovine mastitis caused by Streptococcus dysgalactiae (S. dysgalactiae) is usually treated with antibiotics, which may potentially increase drug resistance as the abuse. NZ2114, a variant of fungal defensin plectasin, displayed a potent antibacterial activity against S. dysgalactiae. The inhibition/eradication effect of the antimicrobial peptide NZ2114 on the early/mature biofilm of S. dysgalactiae CVCC 3938 was evaluated, as well as the elimination of bacteria in mature biofilms. In this study, NZ2114 displayed potent antibacterial activity against S. dysgalactiae CVCC 3938 and three clinical isolated S. dysgalactiae strains (0.11-0.45 μM). The early biofilm inhibition of S. dysgalactiae CVCC 3938 was 55.5–85.9% after treatment with NZ2114 at concentrations of 1–16 × MIC, which was better than that of vancomycin at the same concentration. The mature biofilm eradication rate was up to 92.7–97.6% with the increasing concentration (2–16 × MIC) of NZ2114, and the eradication rate did not change significantly with further increase of NZ2114 concentration, while the biofilm eradication rate of vancomycin-treated group at the same concentration remained at 92.5%. NZ2114 reduced the number of persister bacteria in biofilm. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) further demonstrated that NZ2114 could effectively reduce the biofilm thickness and bacterial number of S. dysgalactiae CVCC 3938. In vivo therapeutic effect of NZ2114 on murine mastitis model showed that NZ2114 was better than vancomycin in alleviating mammary gland inflammation by regulating cytokines production, inhibiting bacterial proliferation, and reducing the number of mammary gland bacteria. These data suggested that NZ2114 is a potential peptide candidate for the treatment of mastitis.

Efficiency of NZ2114 on Superficial Pyoderma Infected with Staphylococcus pseudintermedius

“…Antimicrobial peptides (AMPs), a class of small molecular peptides that widely exist in nature, are a component of almost all innate biological defense systems [ 8 ], showing advantages of rapid killing, strong membrane penetration, high specificity and low resistance to pathogens compared to other small molecule drugs [ 9 , 10 , 11 ]. AMPs combine the advantages of vaccines’ specificity and antibiotics’ high activity in the iron triangle cooperation form, while avoiding their disadvantages of being energy expending and causing pathogen mutation, drug residues and resistance.…”

Polylactic Glycolic Acid-Mediated Delivery of Plectasin Derivative NZ2114 in Staphylococcus epidermidis Biofilms

“…To further assess the effect of NZ2114-NPs on persister bacteria in mature biofilms, vancomycin (100× MIC) was added to induce biofilm persister [ 16 ]. As shown in Figure 4 B, after incubation with vancomycin (100× MIC) for 24 h, the number of viable bacteria in the biofilm was 5.3 × 10 6 CFU/mL.…”

“…The effect of NZ2114 on the biofilm and internal bacteria was observed according to the previous study [ 16 ]. After NZ2114-NP treatment, samples were incubated with PI and SYTO9 (LIVE/DEAD BacLight Bacterial Viability Kit, ThermoFisher, Shanghai, China) for 15 min and observed by CLSM (Zeiss LSM880, Carl Zeiss, Oberkochen, Germany).…”

“…NZ2114 ( Table 1 ), a derivative of Plectasin, showed an excellent antibacterial activity against Gram-positive bacteria, especially Staphylococcus aureus ( S. aureus ) and Staphylococcus epidermidis ( S. epidermidis ), with the minimum inhibitory concentration (MIC) as low as 4 μg/mL. However, it is not resistant to trypsin and has a low druggability in mature biofilm [ 15 , 16 ]. Therefore, it is urgent to design a reasonable drug delivery system (DDS) to improve the stability of AMP and the accessibility of delivery in biofilm in order to improve the bioavailability of AMP [ 17 , 18 ].…”

In Vitro/Vivo Mechanisms of Antibacterial Peptide NZ2114 against Staphylococcus pseudintermedius and Its Biofilms

“…Antimicrobial peptides have antimicrobial and immunomodulatory effects on bacteria, fungi, viruses, and parasites [10][11][12][13][14]. They possess the advantages of antibiotics in disease therapy such as rapid bactericidal action and the ability to provide vaccines with specific targets in disease prevention, and avoid the disadvantages, such as high variation and resistance in pathogens and high residue in animals [15]. AMPs could synergistically complement vaccines and antibiotics, establishing an iron triangle to effectively block the spread of drug resistance for animal healthcare [15,16].…”