Effect of lantibiotic gallidermin against biogenic amine-producing faecal staphylococci from ostriches and pheasants

Staphylococcins: an update on antimicrobial peptides produced by staphylococci and their diverse potential applications

Staphylococcins are antimicrobial peptides or proteins produced by staphylococci. They can be separated into different classes, depending on their amino acid composition, structural complexity, and steps involved in their production. In this review, an overview of the current knowledge on staphylococcins will be presented with emphasis on the information collected in the last decade, including a brief description of new peptides. Most staphylococcins characterized to date are either lantibiotics or linear class II bacteriocins. Recently, gene clusters coding for production of circular bacteriocins, sactipeptides, and thiopeptides have been mined from the genome of staphylococcal isolates. In contrast to class II bacteriocins, lantibiotics, sactipeptides, and thiopeptides undergo post-translational modifications that can be quite extensive, depending on the peptide. Few staphylococcins inhibit only some staphylococcal species, but most of them have proven to target pathogens belonging to different genera and involved in a variety of infectious diseases of clinical or agronomic importance. Therefore, these peptides exhibit potential application as anti-infective drugs in different areas. This review will also cover this diverse and remarkable potential. To be commercialized, however, staphylococcin production should be cost-effective and result in high bacteriocin yields, which are not generally achieved from the culture supernatant of their native producers. Such low yields make their production quite costly and not suitable at large industrial scale. Efforts already made to overcome this limitation, minimizing costs and time of production of some staphylococcins and employing either chemical synthesis or in vivo biosynthesis, will be addressed in this review as well. KEY POINTS: • Staphylococci produce a variety of antimicrobial peptides known as staphylococcins. • Most staphylococcins are post-translationally modified peptides. • Staphylococcins exhibit potential biotechnological applications. Graphical abstract.

Susceptibility to Bacteriocins in Biofilm-Forming, Variable Staphylococci Isolated from Local Slovak Ewes' Milk Lump Cheeses

Seventeen staphylococci isolated from 54 Slovak local lump cheeses made from ewes’ milk were taxonomically allotted to five species and three clusters/groups involving the following species: Staphylococcus aureus (5 strains), Staphylococcus xylosus (3 strains), Staphylococcus equorum (one strain) Staphylococcus succinus (5 strains) and Staphylococcus simulans (3 strains). Five different species were determined. The aim of the study follows two lines: basic research in connection with staphylococci, and further possible application of the bacteriocins. Identified staphylococci were mostly susceptible to antibiotics (10 out of 14 antibiotics). Strains showed γ-hemolysis (meaning they did not form hemolysis) except for S. aureus SAOS1/1 strain, which formed β-hemolysis. S. aureus SAOS1/1 strain was also DNase positive as did S. aureus SAOS5/2 and SAOS51/3. The other staphylococci were DNase negative. S. aureus SAOS1/1 and SAOS51/3 showed biofilm formation on Congo red agar. However, using quantitative plate assay, 12 strains out of 17 showed low-grade biofilm formation (0.1 ≤ A₅₇₀ < 1), while five strains did not form biofilm (A₅₇₀ < 0.1). The growth of all strains, including those strains resistant to enterocins, was inhibited by nisin and gallidermin, with high inhibition activity resulting in the inhibition zone in size from 1600 up to 102,400 AU/mL (arbitrary unit per milliliter). This study contributes to microbiota colonization associated with raw ewe’s milk lump cheeses; it also indicates bacteriocin treatment benefit, which can be used in prevention and/or elimination of staphylococci.

Characterisation of Faecal Staphylococci from Roe Deer (Capreolus capreolus) and Red Deer (Cervus elaphus) and Their Susceptibility to Gallidermin

Our current knowledge of microbiota in wild ruminants is limited. The goal of this study was to evaluate staphylococcal species in red and roe deer for various attributes (haemolysis, DNase, and urease activities; lactic acid and biofilm production; and antibiotic profile) and their susceptibility to gallidermin. Sixteen staphylococcal strains were identified from faeces of 21 free-living animals (9 adult female Cervus elaphus-red deer and 12 young female Capreolus capreolus-roe deer) sampled by the Polish colleagues in the Strzałowo Forest District, Piska Primaeval Forest. The variability in the species of staphylococci was determined. Seven species (Staphylococcus capitis, S. epidermidis, S. haemolyticus, S. hominis, S. pseudintermedius, S. vitulinus and S. warneri) and five clusters/groups of coagulase-negative staphylococci (CoNS) were identified. The strains were generally not haemolytic and Dnase negative; did not form biofilms or only produced low-grade biofilms; exhibited high levels of lactic acid; were urease positive; and were generally susceptible to antibiotics (only two strains were resistant to multiple antibiotics). However, all of the strains were susceptible to the lantibiotic bacteriocin gallidermin, with a minimal inhibitory concentration of 0.0156 μg (up to 6400 AU/ml in arbitrary units). This is the first study to perform a detailed study of the properties of CoNS from roe and red deer.

Fecal coagulase-negative staphylococci from horses, their species variability, and biofilm formation

The intestinal microbiota has enormous impact on the health and performance of horses. Staphylococci belong in the phylum Firmicutes, and their occurrence, especially of methicillin-resistant strains and species, has been reported in horses previously. Moreover, biofilm formation is one of the virulence factors; it has been not completely studied in fecal coagulase-negative staphylococci (CoNS) from horses. Therefore, this study was focused on biofilm formation by various species of fecal CoNS from horses because it has been never reported before. In addition, their antibiotic profile was tested. Horses (42) of various breeds from Slovakia/Poland were sampled. Variability in the species of CoNS was detected in feces of horses. Thirty-two strains were identified by using the MALDI-TOF system and classified into nine species and three subspecies of CoNS: Staphylococcus capitis, S. cohnii subsp. cohnii, S. cohnii subsp. urealyticus, S. cohnii subsp. casei, S. epidermidis, S. haemolyticus, S. pasteuri, S. sciuri, S. vitulinus, S. warneri, and S. xylosus. The most frequent species was S. vitulinus. Twenty-two strains showed high biofilm production; 10 strains showed low-grade biofilm production. The highest biofilm formation was measured in the species S. xylosus. Eleven strains (of 32) were methicillin-resistant; the others were susceptible to methicillin.