Bioengineered Nisin Derivative M17Q Has Enhanced Activity against Staphylococcus epidermidis

Abstract

Staphylococcus epidermidis is frequently implicated in medical device-related infections. As a result of this, novel approaches for control of this opportunistic pathogen are required. We examined the ability of the natural peptide nisin A, produced by Lactococcus lactis, to inhibit S. epidermidis. In addition, a bank of 29 rationally selected bioengineered L. lactis strains were examined with the aim of identifying a nisin derivative with enhanced antimicrobial activity. Agar-based deferred antagonism assays revealed that wild type nisin A inhibited all 18 S. epidermidis strains tested. Larger zones of inhibition than those obtained from the nisin A producing L. lactis strain were observed for each derivative producer against at least one S. epidermidis strain tested. Six derivative producing strains, (VGA, VGT, SGK, M21A, M17Q, AAA), gave larger zones against all 18 strains compared to the wildtype producing strain. The enhanced bioactivity of M17Q was confirmed using well diffusion, minimum inhibitory concentration (MIC) and a broth-based survival assays. Biofilm assays were performed with plastic microtiter plates and medical device substrates (stainless-steel coupons and three catheter materials). The presence of nisin A significantly reduce the amount of biofilm formed on all surfaces. M17Q was significantly better at reducing biofilm production than nisin A on plastic and stainless-steel. Finally, M17Q was significantly better than nisin A at reducing bacterial numbers in a simulated wound fluid. The findings of this study suggest that nisin and bioengineered derivatives warrant further investigation as potential strategies for the control of S. epidermidis.

Application of Lactobacillus helveticus CNRZ 32 to Control the Microbial Contaminants in Cheese by Addition of Bacterial Extracts or by In Situ Production of Bioactive Metabolites

“…decreased the count of the gram positive Staphylococcus sciuri, while Escherichia coli, molds and yeasts were increased. The great activity of this bacteriocin; Nisin was recorded by many researchers [27][28][29][30][31]. The arising count of gram negative bacteria and mycotic growth may be organized by the nutritional competition among microbial populations [32].…”

Bio-Engineered Nisin with Increased Anti-Staphylococcus and Selectively Reduced Anti-Lactococcus Activity for Treatment of Bovine Mastitis

“…Additionally, investigations that involved the in vivo incorporation of tryptophan analogues into nisin in a bid to yield improved or altered-specificity variants revealed that M17W displayed 17-fold less activity than parental nisin A [23]. More recently, a study has demonstrated the enhanced specific activity of nisin A M17Q over nisin A against clinical strains of S. epidermidis, revealing it to be superior at reducing biofilm production on medical device substrates and at reducing bacterial numbers in a simulated wound fluid [37]. The contrasting sensitivity of mastitis-associated S. aureus and industrially relevant lactococci to nisin A M17Q, nisin A T2L and nisin A HTK provides additional data that some bioengineered nisin derivatives exhibit target-specific variations in potency.…”

Recipe for Success: Suggestions and Recommendations for the Isolation and Characterisation of Bacteriocins

“…e stationary microtiter plate method can be used to assess the biofilm growth of target strains [56,77,128,129] (see Protocol S12and Figure S10of the Supplementary Material).…”

“…is assay has successfully demonstrated that nisin A and its bioengineered derivatives can reduce the formation of biofilm both on plastic and medical device material surfaces [56,77,128,129].…”

“…At the late stages of the growth cycle, the build-up of lactic acid can reduce cell viability and create unfavourable conditions. To avoid such conditions which negatively impact the strain and the peptide, the incubation of L. lactis strains is stopped around the 16–20-hour mark and the buffer, β -glycerophosphate, is added to regulate pH [ 56 ]. It is important to consider that the ideal conditions for bacteriocin production may not be the ideal culture conditions.…”