Chemical additives have been extensively used to prevent the survival and proliferation of microorganisms, but their safety and impact on human health are under discussion. Since the reduction or ...elimination of pathogens and spoilage microorganisms in food is the foremost priority, the current trends in food processing are focusing on the use of natural compounds, which are considered as safe alternatives and satisfy the consumer preferences for more “green foods.” ...the increased awareness on the safety of food additives and preservatives, and the consumer’s trend to avoid foods containing chemicals, which, in the long-term, may have adverse impact on their health, have generated a significant number of studies and publications on the potential use of various natural substances, recognized as GRAS (Generally Recognized as Safe), to be used as food preservatives. Bacteriocins are peptides, actually microbial toxins, produced from various microorganisms, and so far some of them (e.g., enterocins produced mostly by enterococci) have shown remarkable antimicrobial potential and their application as a natural barrier against pathogens and food spoilage has been proven to be very efficient, when used in the form of purified or semipurified extracts or as protective cultures 9, 10. ...as the developments in food preservation are focusing on the implementation of natural antimicrobials and antioxidants this special issue explores the potential of alternatives to currently used preservatives through the publication of five high-quality articles, which aim to address recent advancements in the field of natural food preservatives and antioxidants. ...this special issue offers to the readers the chance to be informed on the recent advancements related to the antimicrobial and antioxidant properties of natural substances that are of interest for the contemporary food industry.
The occurence and spread of animal-derived methicillin resistant staphylococci (MRS) worldwide is a current problem, especially due to their increasing incidence in food animals and their products, ...with possible contamination of food consumers and handlers. Staphylococci isolated from animals (
n
= 123) were identified with MALDI-TOF mass spectrometry and screened for methicillin/oxacillin/cefoxitin resistance (MR) using the disk diffusion method. Twenty-three phenotypically MRS strains were analysed using PBP2' Latex Agglutination Test Kit to confirm the phenotypic MR and PCR was performed for
mecA
gene detection;
mecA
gene positive strains were furtherly confirmed by means of sequencing. The susceptibility of MRS to 11 partially-purified enterocins (Ent) produced by
E. faecium
,
E. durans
and
E. mundtii
strains of animal, feed/food and environmental origin was checked using agar spot tests. Out of 23 MRS, PBP testing confirmed MR in 17 strains. Three
Staphylococcus epidermidis
and one
S. vitulinus
were
mecA
positive. The majority of MRS, including two
mecA
gene-positive strains
S. epidermidis
R44/1 and P3/Tr2a, were susceptible to the tested enterocins, mainly to Ent7420, EntA(P)/EK13, Ent412, Ent55 and Ent9296 (in the range 100 – 12,800 AU/mL). The most susceptible strains appeared to be the
mecA
gene-positive
S. epidermidis
SE R44/1 and SE P3/Tr2a strains, inhibited by eight enterocins out of 11 tested (100–200 AU/mL). Only four strains (including
mecA
gene positive
S. epidermidis
SE P3/Tr1 and
S. vitulinus
SV K12PL/1) were resistant to the tested antimicrobial substances. These results indicate that the enterocins used offer a promising option for prevention and treatment of bacterial infection caused by MRS in animals.
This book focuses on the effect of natural substances, bioactive compounds and bacteriocins on rabbit production and reproduction, performance, gastrointestinal microbiota, health parameters, and ...metabolic processes in rabbits. Obtained information may help in the utilization of natural additives in human and veterinary healthcare without negative impact on environment and animal welfare. Finally, special attention is given to urgent need for more studies to understand the metabolic processes of natural compounds on a molecular level, to establish the beneficial dose.
The importance of the intestinal microbiota has attracted much interest in recent years particularly with respect to ways in which the microbiota can be manipulated in order to improve health. ...Improving gut health through the use of probiotic microorganisms has become an area of research activity in both human and animal nutrition. However, the amount of research using companion animals is insufficient. The present review evaluates and compares the effects achieved after application of canine-derived probiotic strain
Lactobacillus fermentum
CCM 7421 to healthy dogs as well as to dogs suffering from gastrointestinal disorders. The experiments involved varying duration of application (4 days–14 days), dosage (10
7
–10
9
CFU), form of application (fresh culture or lyophilized from) or combination with natural substances. Results from nine independent studies show the ability of probiotic strains to establish themselves in the canine gastrointestinal tract, alter the composition of intestinal microbiota and metabolites (organic acids), and modulate the physiology (serum biochemical parameters) and immunity parameters in dogs. Almost all observed effects were irrespective of dose or duration of probiotic administration.
Rabbit meat offers excellent nutritive and dietetic properties, but digestive disturbances, mainly during the post-weaning period, induce important economic losses for rabbit farmers ...
This study investigated eight types of Slovak dry fermented meat products (salami and sausages) that are available on the market and were produced by three different producers in different regions of ...Slovakia. The total counts of enterococci in these products ranged from 2.0 up to 6.0 cfu/g (log10). Three species were identified among the 15 selected enterococcal strains;
(8 strains),
(3) and
(4). They were hemolysis-negative (γ-hemolysis) with a biofilm-forming ability, which was evaluated as low-grade biofilm formation, susceptible to conventional antibiotics and mainly susceptible to lantibiotic bacteriocins, namely, gallidermin and nisin; they even showed a higher susceptibility to gallidermin than to nisin. They were also susceptible to enterocin-durancin, but most strains showed resistance to enterocin A/P. This study indicated that bacteriocins can play a key role in preventing and/or protecting from undesirable bacterial multiplication or contamination in the food industry and that they have great potential for further experimental applications.
There is a major problem with the rising occurrence of highly virulent and multiply-resistant strains, including methicillin-resistant
Staphylococcus aureus
(MRSA), because of their difficult ...treatment. This study aimed to evaluate the antibacterial and antibiofilm effect of new enterocins (Ent) against potential pathogenic MRSA strains isolated from rabbits. Staphylococci were identified with PCR and screened for methicillin/oxacillin/cefoxitin resistance (MR) using the disk diffusion method and the PBP2’ Latex Agglutination Test Kit. Enzyme production, hemolysis, DNase activity, slime production, and biofilm formation were tested in MRSA strains. The susceptibility of MRSA to eight partially-purified enterocins (Ent) produced by
E. faecium
and
E. durans
strains was checked using agar spot tests. The antibiofilm activity of Ents was tested using a quantitative plate assay. Out of 14 MRSA, PBP testing confirmed MR in 8 strains. The majority of MRSA showed DNase activity and β-hemolysis. Slime production and moderate biofilm formation were observed in all strains. MRSA were susceptible to tested Ents (100–12,800 AU/mL; except Ent4231). The antibiofilm effect of Ents (except Ent4231) was noted in the high range (64.9–97.0%). These results indicate that enterocins offer a promising option for the prevention and treatment of bacterial infections caused by biofilm-forming MRSA.
Aims
To study the local intestinal lymphocyte immunity in mice with trichinellosis affected by probiotic bacteria.
Methods and Results
Enterococcus faecium CCM8558, Enterococcus durans ED26E/7, ...Limosilactobacillus fermentum CCM7421 and Lactiplantibacillus plantarum 17 L/1 were administered daily (109 CFU ml−1) and mice were infected with Trichinella spiralis (400 larvae) on the 7th day of treatment. T. spiralis infection significantly inhibited lymphocyte subpopulations from 5 to 25 days postinfection (dpi). L. fermentum CCM7421 and L. plantarum 17 L/1 restored the CD4+ T cell numbers in the epithelium and lamina propria at the control level from 11 dpi. All strains stimulated the CD8+ T cells numbers in infected mice, which were restored in the lamina propria on 11 dpi and in the epithelium only on 32 dpi. B cells (CD19+) inhibition after T. spiralis infection was not affected by treatment till 25 dpi.
Conclusions
The strain‐specific immunomodulatory effect of tested bacteria was confirmed. L. fermentum CCM7421 and L. plantarum 17 L/1 showed the greatest immunomodulatory potential on CD4+ and CD8+ T lymphocytes in trichinellosis. E. faecium CCM8558 and E. durans ED26E/7 activated only CD8+ T cells in the lamina propria.
Significance and Impact of the Study
Positive modulation of the gut lymphocyte immunity in T. spiralis infection with bacterial strains showed their beneficial effect with the host′s antiparasitic defence.
Significance and Impact of Study
Positive modulation of the gut lymphocyte immunity in T. spiralis infection with bacterial strains showed their beneficial effect with the host′s antiparasitic defence.
Nowadays, developed more precisious identification techniques have allowed to validate newer enterococcal species. Among them, the species
Enterococcus moraviensis
was also validated, at first from ...surface waters
.
However, in this study, characteristics and potential to bacteriocin production by the strain
E. moraviensis
EMo 1-1Nik isolated from buccal mucosa of Slovak warm-blood horse breed has been studied. BLASTn analysis allotted this strain to the species
E. moraviensis
with percentage identity BLASTn 16S rRNA sequence in the strain up to 100% (99.93% similarity with
E. moraviensis
NR113937.1). The strain EMo 1-1Nik has been provided with GenBank accession number MW326085. It is hemolysis-negative (γ-hemolysis), deoxyribonuclease-negative and gelatinase-negative; absent of virulence factor genes, low-grade biofilm-positive (0.133 ± 0.36), mostly susceptible to tested antibiotics. Moreover, 60% of EMo1-1Nik colonies were found as bacteriocin-producing against the principal indicator
Enterococcus avium
EA5. The concentrated substance (CS, pH 4.5) of EMo1-1Nik showed the inhibitory activity against EA5 strain (800 AU/mL); CSs with pH 6.3 and 7.3 reached inhibitory activity 100 AU/mL against EA5 strain. CS was thermo-stable and it does not lost activity after enzymes treatment. Oppositelly, EMo 1-1Nik was susceptible to Mundticin EM 41/3 (800 AU/mL) produced by horse fecal strain
E. mundtii
EM 41/3 and enterocins (up to 51 200 AU/mL). In spite of the preliminary results, it has been shown a potential to produce bacteriocin substance of the safe strain
E. moraviensis
EMo1-1Nik. The additional studies are in processing.
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