BACKGROUND: Antimicrobial resistance (AMR) is nowadays a major emerging challenge for public health worldwide. The over- and misuse of antibiotics, including those for cell culture, are promoting AMR while also encouraging the research and employment of alternative drugs. The addition of antibiotics to the cell media is strongly recommended in sperm preservation, being gentamicin the most used for boar semen. Because of its continued use, several bacterial strains present in boar semen have developed resistance to this antibiotic. Antimicrobial peptides and proteins (AMPPs) are promising candidates as alternative antibiotics because their mechanism of action is less likely to promote AMR. In the present study, we tested two AMPPs (lysozyme and nisin; 50 and 500 µg/mL) as possible substitutes of gentamicin for boar semen preservation up to 48 h of storage. RESULTS: We found that both AMPPs improved sperm plasma membrane and acrosome integrity during semen storage. The highest concentration tested for lysozyme also kept the remaining sperm parameters unaltered, at 48 h of semen storage, and reduced the bacterial load at comparable levels of the samples supplemented with gentamicin (p > 0.05). On the other hand, while nisin (500 µg/mL) reduced the total Enterobacteriaceae counts, it also decreased the rapid and progressive sperm population and the seminal oxidation-reduction potential (p < 0.05). CONCLUSIONS: The protective effect of lysozyme on sperm function together with its antimicrobial activity and inborn presence in body fluids, including semen and cervical mucus, makes this enzyme a promising antimicrobial agent for boar semen preservation.

• Klíčová slova
• Antimicrobial resistance, Boar semen, Gentamicin, Lysozyme, Nisin, Sperm function,
• MeSH
• akrozom účinky léků   MeSH
• antibakteriální látky * farmakologie   MeSH
• antimikrobiální peptidy farmakologie   MeSH
• buněčná membrána účinky léků   MeSH
• gentamiciny farmakologie   MeSH
• muramidasa * farmakologie   MeSH
• nisin * farmakologie   MeSH
• prasata MeSH
• sperma účinky léků   MeSH
• spermie účinky léků   MeSH
• uchování spermatu * veterinární   metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky * MeSH
• antimikrobiální peptidy MeSH
• gentamiciny MeSH
• muramidasa * MeSH
• nisin * MeSH

Lactobacillus plantarum NMD-17 separated from koumiss could produce a bacteriocin named plantaricin MX against Gram-positive bacteria and Gram-negative bacteria. The bacteriocin synthesis of L. plantarum NMD-17 was remarkably induced in co-cultivation with Lactobacillus reuteri NMD-86 as the increase of cell numbers and AI-2 activity, and the expressions of luxS encoding signal AI-2 synthetase, plnB encoding histidine protein kinase, plnD encoding response regulator, and plnE and plnF encoding structural genes of bacteriocin were significantly upregulated in co-cultivation, showing that the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation may be regulated by LuxS/AI-2-mediated quorum sensing system. In order to further demonstrate the role of LuxS/AI-2-mediated quorum sensing system in the bacteriocin synthesis of L. plantarum NMD-17, plasmids pUC18 and pMD18-T simple were used as the skeleton to construct the suicide plasmids pUC18-UF-tet-DF and pMD18-T simple-plnB-tet-plnD for luxS and plnB-plnD gene deletion, respectively. luxS and plnB-plnD gene knockout mutants were successfully obtained by homologous recombination. luxS gene knockout mutant lost its AI-2 synthesis ability, suggesting that LuxS protein encoded by luxS gene is key enzyme for AI-2 synthesis. plnB-plnD gene knockout mutant lost the ability to synthesize bacteriocin against Salmonella typhimurium ATCC14028, indicating that plnB-plnD gene was a necessary gene for bacteriocin synthesis of L. plantarum NMD-17. Bacteriocin synthesis, cell numbers, and AI-2 activity of luxS or plnB-plnD gene knockout mutants in co-cultivation with L. reuteri NMD-86 were obviously lower than those of wild-type strain in co-cultivation at 6-9 h (P < 0.01). The results showed that LuxS/AI-2-mediated quorum sensing system played an important role in the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation.

• Klíčová slova
• Bacteriocin, Co-cultivation, Gene knockout, Lactobacillus plantarum, LuxS-mediated quorum sensing system,
• MeSH
• bakteriální proteiny metabolismus   MeSH
• bakteriociny * metabolismus   MeSH
• Lactobacillus plantarum * genetika   MeSH
• Lactobacillus fyziologie   MeSH
• lidé MeSH
• plazmidy MeSH
• quorum sensing MeSH
• regulace genové exprese u bakterií MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• bakteriociny * MeSH

The beneficial influence of bacteriocin-producing, probiotic, mostly non-autochthonous bacteria has already been reported in various animals. However, their use in horses provides limited information, and results with autochthonous bacteria have not been reported. Therefore, the main objective of this model study was to test the effect of autochthonous, bacteriocin-producing faecal strain Enterococcus faecium EF 412 application in horses. One gram of freeze-dried EF 412 strain (109 CFU/mL for 21 days) was applied to horses in a small feed ball. Clinically healthy horses (12), Slovak warm-blood breed of various ages (5-13 years), were involved in a 35-day-long experiment, also functioning as control for themselves. They were stabled in separate boxes (university property), fed twice a day (hay, whole oats or grazed) with water access ad libitum. Sampling was performed at the start of the experiment, i.e. at days 0/1, 21 (3 weeks of EF 412 application) and at day 35 (2 weeks of EF 412 cessation). EF 412 colonized GIT of horses was 3.54 ± 0.75 CFU/g (log 10) at day 21. The eggs of the nematode Strongylus spp. were not found in horses after EF 412 application, and Eimeria spp. oocysts were similarly not found. The other microbiota were not reduced as evaluated by the use of standard method. Using next-generation sequencing, at phylum level, phyla Bacteroidetes and Firmicutes dominated and at family level, they were Bacteroidales BS11 and S24-7 gut goups and Lentisphaerae. In horses, the increasing tendency in phagocytic activity was noted after EF 412 application. Biochemical parameters were in the physiological range. Total protein value was significantly decreased at day 21 compared with day 0/1 as well as with day 35 (P < 0.05). Cholesterol and triglycerides were influenced (decreased) at day 21 compared with day 0/1 and day 35. Neither nematode eggs Strongylus spp. nor Eimeria spp. oocysts were found in faeces after EF 412 application. Autochthonous, faecal strain E. faecium EF 412 showed promising application potential.

• Klíčová slova
• Beneficial strain, Biochemical parameters, Health, Horses, Microbiota, Parasites,
• MeSH
• bakteriociny * metabolismus   MeSH
• Enterococcus faecium * metabolismus   MeSH
• feces mikrobiologie   MeSH
• koně MeSH
• kontrola infekčních nemocí MeSH
• mikrobiota * MeSH
• probiotika * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriociny * MeSH

Fonticins are phage tail-like bacteriocins produced by the Gram-negative bacterium Pragia fontium from the family Budviciaceae. This bacterium produces contractile-type particles that adsorb on the surface of sensitive bacteria and penetrate the cell wall, probably during contraction, in a way similar to the type VI secretion system. We characterized the pore-forming activity of fonticins using both living cells and in vitro model membranes. Using a potassium leakage assay, we show that fonticins are able to permeabilize sensitive cells. On black lipid membranes, single-pore conductance is about 0.78 nS in 1 M NaCl and appears to be linearly dependent on the increasing molar strength of NaCl solution, which is a property of considerably large pores. In agreement with these findings, fonticins are not ion selective for Na+, K+, and Cl-. Polyethylene glycol 3350 (PEG 3350) molecules of about 3.5 nm in diameter can enter the fonticin pore lumen, whereas the larger molecules cannot pass the pore. The size of fonticin pores was confirmed by transmission electron microscopy. The terminal membrane-piercing complex of the fonticin tube probably creates a selective barrier restricting passage of macromolecules. IMPORTANCE Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins. According to some theories, related particles were initially adapted for passage of double-stranded DNA (dsDNA) molecules, but fonticins changed their function during the evolution; they are able to form large pores through the bacterial envelope of Gram-negative bacteria. As various pore-forming proteins are extensively used for nanopore sequencing and stochastic sensing, we decided to investigate the pore-forming properties of fonticin protein complexes on artificial lipid membranes. Our research revealed remarkable structural properties of these particles that may have a potential application as a nanodevice.

• Klíčová slova
• black lipid membranes, conductance, electric current, electron microscopy, fonticin, membrane pore formation, phage tail-like bacteriocins, single-pore conductance,
• MeSH
• bakteriociny * metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• chlorid sodný metabolismus   MeSH
• Enterobacteriaceae MeSH
• lipidové dvojvrstvy * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriociny * MeSH
• chlorid sodný MeSH
• lipidové dvojvrstvy * MeSH

American foulbrood (AFB) is a devastating disease of honey bees. There remains a gap in the understanding of the interactions between the causative agent and host, so we used shotgun proteomics to gain new insights. Nano-LC-MS/MS analysis preceded visual description and Paenibacillus larvae identification in the same individual sample. A further critical part of our methodology was that larvae before capping were used as the model stage. The identification of the virulence factors SplA, PlCBP49, enolase, and DnaK in all P. larvae-positive samples was consistent with previous studies. Furthermore, the results were consistent with the array of virulence factors identified in an in vitro study of P. larvae exoprotein fractions. Although an S-layer protein and a putative bacteriocin were highlighted as important, the microbial collagenase ColA and InhA were not found in our samples. The most important virulence factor identified was isoform of neutral metalloproteinase (UniProt: V9WB82), a major protein marker responsible for the shift in the PCA biplot. This protein is associated with larval decay and together with other virulence factors (bacteriocin) can play a key role in protection against secondary invaders. Overall, this study provides new knowledge on host-pathogen interactions and a new methodical approach to study the disease.

• Klíčová slova
• Apis mellifera, diagnostics with mass spectrometry, host-pathogen interaction, label-free proteomics, neutral metalloproteinase isoforms,
• MeSH
• bakteriociny * metabolismus   MeSH
• faktory virulence metabolismus   MeSH
• larva MeSH
• Paenibacillus larvae * metabolismus   MeSH
• Paenibacillus * metabolismus   MeSH
• proteomika MeSH
• tandemová hmotnostní spektrometrie MeSH
• včely MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Spojené státy americké MeSH
• Názvy látek
• bakteriociny * MeSH
• faktory virulence MeSH

Young rabbits are susceptible to gastrointestinal diseases caused by bacteria. Enterococcus hirae can be associated with diseases. But enterocins produced by some enterococcal species can prevent/reduce this problem. Therefore, the interaction of enterocin M with a biofilm-forming, autochthonous E. hirae Kr8+ strain was tested in rabbits to assess enterocin potential in vivo. Rabbits (96), aged 35 days, both sexes, meat line M91 breed were divided into four groups, control C and three experimental groups. The rabbits in C received the standard diet, rabbits in experimental group 1 (E1) received 108 CFU/mL of Kr8+, a dose 500 µL/animal/day, E2 received Ent M (50 µL/animal/day), and E3 received both Kr8+ and Ent M in their drinking water over 21 days. The experiment lasted 42 days. Feces and blood were sampled at day 0/1 (at the start of the experiment, fecal mixture of 96 animals, n = 10), at day 21 (five fecal mixtures per group, n = 5), and at day 42 (21 days after additives cessation, the same). At days 21 and 42, four rabbits from each group were slaughtered, and cecum and appendix were sampled for standard microbial analysis. Ent M showed decreased tendency of Kr8+. Using next-generation sequencing, the phyla detected with the highest abundance were Firmicutes, Verrucomicrobia, Bacteroidetes, Tenericutes, Proteobacteria, Cyanobacteria, Saccharibacteria, and Actinobacteria. Interaction of Ent M with some phyla resulted in reduced abundance percentage. At day 21, significantly increased phagocytic activity (PA) was found in E1 and E2 (p < 0.001). Kr8+ did not attack PA and did not stimulate oxidative stress. But Ent M supported PA. The prospective importance of this study lies in beneficial interaction of enterocin in host body.

• Klíčová slova
• Biofilm, Broiler rabbits, Enterocin, Enterococcus hirae, Susceptibility,
• MeSH
• bakteriociny * MeSH
• biofilmy MeSH
• Enterococcus hirae * MeSH
• králíci * MeSH
• prospektivní studie MeSH
• zvířata MeSH
• Check Tag
• králíci * MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriociny * MeSH
• enterocin M MeSH Prohlížeč

Interactions within bacterial communities are frequently mediated by the production of antimicrobial agents. Despite the increasing interest in research of new antimicrobials, studies describing antagonistic interactions among cold-adapted microorganisms are still rare. Our study assessed the antimicrobial interactions of 36 Antarctic Pseudomonas spp. and described the genetic background of these interactions in selected strains. The overall bacteriocinogeny was greater compared to mesophilic Pseudomonas non-aeruginosa species. R-type tailocins were detected on transmission electron micrographs in 16 strains (44.4%); phylogenetic analysis of the corresponding gene clusters revealed that the P. prosekii CCM 8878 tailocin was related to the Rp3 group, whereas the tailocin in Pseudomonas sp. CCM 8880 to the Rp4 group. Soluble antimicrobials were produced by eight strains (22.-2%); gene mining found pyocin L homologues in the genomes of P. prosekii CCM 8881 and CCM 8879 and pyocin S9-like homologues in P. prosekii CCM 8881 and Pseudomonas sp. CCM 8880. Analysis of secretomes confirmed the production of all S- and L-type pyocin genes. Our results suggest that bacteriocin-based inhibition plays an important role in interactions among Antarctic soil bacteria, and these native, cold-adapted microorganisms could be a promising source of new antimicrobials.

• MeSH
• bakteriociny * genetika   MeSH
• fylogeneze MeSH
• Pseudomonas aeruginosa genetika   MeSH
• Pseudomonas MeSH
• pyociny * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Antarktida MeSH
• Názvy látek
• bakteriociny * MeSH
• pyociny * MeSH

A bacteriocin termed plantaricin MX with a broad antimicrobial spectrum was produced by Lactobacillus plantarum NMD-17, which was isolated from Inner Mongolia traditional koumiss of china. Among 300 strains of lactic acid bacteria (LAB) belonging to the genera Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, and Enterococcus, five strains including Lactobacillus reuteri NMD-86, Lactobacillus helveticus NMD-137, Lactococcus lactis NMD-152, Enterococcus faecalis NMD-178, and Enterococcus faecium NMD-219 were revealed to significantly induce the bacteriocin synthesis and greatly increase the cell numbers of Lactobacillus plantarum NMD-17 and activity of AI-2 signaling molecule. Bacteriocin synthesis was not increased by cell-free supernatants and autoclaved cultures of inducing strains, demonstrating that intact cells of inducing strains were essential to the induction of bacteriocin synthesis. The existence of bacteriocin structural plnEF genes and the plnD and luxS genes involved in quorum sensing was confirmed by PCR, and the presence of plnB gene encoding histidine protein kinase was determined by single oligonucleotide nested PCR (Son-PCR). Quantitative real-time PCR demonstrated that plnB, plnD, luxS, plnE, and plnF genes of L. plantarum NMD-17 were upregulated significantly (P < 0.01) in co-cultivation with L. reuteri NMD-86. The results showed that the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation might have a close relationship with LuxS-mediated quorum sensing system.

• MeSH
• bakteriální proteiny * genetika   MeSH
• bakteriociny * genetika   MeSH
• kumys * mikrobiologie   MeSH
• Lactobacillales * fyziologie   MeSH
• Lactobacillus plantarum * genetika   MeSH
• lyasy štěpící vazby C-S * genetika   MeSH
• mikrobiální interakce * fyziologie   MeSH
• quorum sensing genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny * MeSH
• bakteriociny * MeSH
• LuxS protein, Bacteria MeSH Prohlížeč
• lyasy štěpící vazby C-S * MeSH

Enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing E. coli (STEC) strains are the causative agents of severe foodborne diseases in both humans and animals. In this study, porcine pathogenic E. coli strains (n = 277) as well as porcine commensal strains (n = 188) were tested for their susceptibilities to 34 bacteriocin monoproducers to identify the most suitable bacteriocin types inhibiting porcine pathogens. Under in vitro conditions, the set of pathogenic E. coli strains was found to be significantly more susceptible to the majority of tested bacteriocins than commensal E. coli. Based on the production of bacteriocins with specific activity against pathogens, three potentially probiotic commensal E. coli strains of human origin were selected. These strains were found to be able to outcompete ETEC strains expressing F4 or F18 fimbriae in liquid culture and also decreased the severity and duration of diarrhea in piglets during experimental ETEC infection as well as pathogen numbers on the last day of in vivo experimentation. While the extents of the probiotic effect were different for each strain, the cocktail of all three strains showed the most pronounced beneficial effects, suggesting synergy between the tested E. coli strains. IMPORTANCE Increasing levels of antibiotic resistance among bacteria also increase the need for alternatives to conventional antibiotic treatment. Pathogenic Escherichia coli represents a major diarrheic infectious agent of piglets in their postweaning period; however, available measures to control these infections are limited. This study describes three novel E. coli strains producing antimicrobial compounds (bacteriocins) that actively inhibit a majority of toxigenic E. coli strains. The beneficial effect of three potentially probiotic E. coli strains was demonstrated under both in vitro and in vivo conditions. The novel probiotic candidates may be used as prophylaxis during piglets' postweaning period to overcome common infections caused by E. coli.

• Klíčová slova
• E. coli, ETEC, Escherichia, STEC, bacteriocin, pig, probiotic,
• MeSH
• bakteriální toxiny * metabolismus   MeSH
• bakteriociny metabolismus   terapeutické užití   MeSH
• Escherichia coli * účinky léků   genetika   metabolismus   MeSH
• faktory virulence genetika   MeSH
• feces mikrobiologie   MeSH
• infekce vyvolané Escherichia coli mikrobiologie   prevence a kontrola   veterinární   MeSH
• nemoci prasat mikrobiologie   prevence a kontrola   MeSH
• prasata MeSH
• probiotika terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie veterinární MeSH
• Názvy látek
• bakteriální toxiny * MeSH
• bakteriociny MeSH
• faktory virulence MeSH

INTRODUCTION: The emergence and spread of antibiotic resistance among pathogenic bacteria drives the search for alternative antimicrobial therapies. Bacteriocins represent a potential alternative to antibiotic treatment. In contrast to antibiotics, bacteriocins are peptides or proteins that have relatively narrow spectra of antibacterial activities and are produced by a wide range of bacterial species. Bacteriocins of Escherichia coli are historically classified as microcins and colicins, and, until now, more than 30 different bacteriocin types have been identified and characterized. AREAS COVERED: We performed bibliographical searches of online databases to review the literature regarding bacteriocins produced by E. coli with respect to their occurrence, bacteriocin role in bacterial colonization and pathogenicity, and application of their antimicrobial effect. EXPERT OPINION: The potential use of bacteriocins for applications in human and animal medicine and the food industry includes (i) the use of bacteriocin-producing probiotic strains, (ii) recombinant production in plants and application in food, and (iii) application of purified bacteriocins.

• Klíčová slova
• Antimicrobials, E. coli, Escherichia, Shigella, bacteriocin, colicin, diarrhea, microcin, probiotic, virulence,
• MeSH
• antibakteriální látky biosyntéza   izolace a purifikace   farmakologie   MeSH
• bakteriociny biosyntéza   izolace a purifikace   farmakologie   MeSH
• Escherichia coli metabolismus   MeSH
• koliciny biosyntéza   izolace a purifikace   farmakologie   MeSH
• lidé MeSH
• probiotika farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• bakteriociny MeSH
• koliciny MeSH
• microcin MeSH Prohlížeč