scholarly journals Enterococcal Species Associated with Slovak Raw Goat Milk, Their Safety and Susceptibility to Lantibiotics and Durancin ED26E/7

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 681
Author(s):  
Andrea Lauková ◽  
Valentína Focková ◽  
Monika Pogány Pogány Simonová
Keyword(s):  
Biofilm Formation ◽  
Goat Milk ◽  
Surface Protein ◽  
Human Consumption ◽  
Low Grade ◽  
Pathogenic Potential ◽  
Aggregation Substance ◽  
Enterococcal Species ◽  
Traditional Dairy Products ◽  
Original Information

Goat milk has become a popular item of human consumption due to its originality. Enterococci are ubiquitous bacteria, and they can also be found in traditional dairy products. This study focuses on the safety of enterococci from Slovak raw goat milk and on their susceptibility to lantibiotic bacteriocins and durancin ED26E/7, which has not previously been studied. Biofilm formation ability in enterococci, virulence factor genes, enzyme production and antibiotic profile were investigated. Samples of raw goat milk (53) were collected from 283 goats in Slovakia. MALDI-TOF mass spectrometry identified three enterococcal species: Enterococcus faecium, E. hirae and E. mundtii, with dominant occurrence of the species E. faecium. Low-grade biofilm formation ability (0.1 ≤ A570 < 1.0) was found in four strains of E. faecium.Gelatinase, hyaluronidase, aggregation substance and enterococcal surface protein genes were absent in these enterococci. Gene efaAfm (adhesin) was detected in five E. faecium strains. However, it was not detected in biofilm-forming strains. Enterococci detected in Slovak raw goat milk were found not to have pathogenic potential; four strains even produced high amounts of useful β-galactosidase. The strains were susceptible to lantibiotic bacteriocin treatment and to durancin ED26E/7 as well, which represents original information in dairy production.

scholarly journals Lacticaseibacilli and Lactococci from Slovak Raw Goat Milk and their Potential

2021 ◽  
Vol 52 (2) ◽  
pp. 19-28
Author(s):  
A. Lauková ◽  
M. Pogány Simonová ◽  
M. Tomáška ◽  
M. Kološta ◽  
M. Drončovský ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Enzyme Production ◽  
Skim Milk ◽  
Goat Milk ◽  
Inhibition Zone ◽  
Low Ph ◽  
Low Grade ◽  
Inhibition Activity ◽  
Bacteriocin Activity ◽  
Additional Testing

Abstract Strains potential such as bacteriocin activity, biofilm formation ability, growth in skim milk, susceptibility to antibiotics, tolerance to bile and low pH as well as enzyme production was tested in the species Lacticaseibacillus paracasei and Lactococcus lactis detected in Slovak raw goat milk. The strains showed mostly low-grade biofilm formation ability, susceptibility to antibiotics and sufficient tolerance to oxgall/bile. Lacticaseibacillus (Lcb.) paracasei ZM-1, ZM-2 and Lactococcus (Lc.) lactis PD MO 1/8 showed high tolerance to pH 3 (67 %, 83 % and 63 %, respectively). The strains showed bacteriocin activity against the principal indicator Enterococcus avium EA5 (inhibition zone ranging 5–24 mm). A concentrated substance of Lcb. paracasei LPa ML 12/1 (pH 6.3) inhibited EA5 strain (inhibition activity 100 AU ml–1). Lcb. paracasei ZM-1 and ZM-2 also produced a high amount of β-galactosidase (40 nmol). Although the strains indicated their beneficial potential, additional testing is needed; some tests are in processing for further possible application of selected strains in dairy.

scholarly journals Susceptibility to Enterocins and Lantibiotic Bacteriocins of Biofilm-Forming Enterococci Isolated from Slovak Fermented Meat Products Available on the Market

2020 ◽  
Vol 17 (24) ◽  
pp. 9586
Author(s):  
Andrea Lauková ◽  
Anna Kandričáková ◽  
Eva Bino
Keyword(s):  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Food Industry ◽  
Meat Products ◽  
Low Grade ◽  
Enterococcus Hirae ◽  
Conventional Antibiotics ◽  
Enterocin A

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; Enterococcus faecium (8 strains), Enterococcus faecalis (3) and Enterococcus hirae (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.

scholarly journals The effect of activation of the lactoperoxidase system and souring on certain potential human pathogens in cows' milk

1997 ◽  
Vol 68 (4) ◽  
Author(s):  
J.G.K. Kangumba ◽  
E.H. Venter ◽  
J.A.W. Coetzer
Keyword(s):  
Rural Communities ◽  
Alternative Methods ◽  
Human Consumption ◽  
Socioeconomic Conditions ◽  
Human Pathogens ◽  
Pathogenic Potential ◽  
E Coli ◽  
Lactoperoxidase System ◽  
Potential Alternative ◽  
System Activation

Conventional methods of ensuring the safety and soundness of cows' milk for human consumption, such as pasteurisation, are not always practical in poor socioeconomic conditions or in rural communities that lack modern amenities. Activation of lactoperoxidase (LP) system and souring of milk were investigated as potential alternative methods to sustain the safety of milk by inhibiting certain microorganisms with known pathogenic potential. The activation of the LP-system inhibited the growth of Staphylococcus aureus and Escherichia coli by the order of 2 log values. The inhibition of Brucella abortus was negligible. The replication of Coxiella burnetti in milk was not disturbed even after 17 h of LP-system activation at 20 oC, but the outcome of the LP-system treatment on Mycobacterium bovis could not be determined as the conventional culturing technique used to grow this organism did not allow full recovery. Souring inhibited the growth of S. aureus and E. coli also by the order of 2 log values. From the results obtained in this investigation are concluded that the activation of the LP-system and souring can be used to inhibit the growth of S. aureus and E. coli in cows' milk, thereby increasing its safety.

scholarly journals Glycation of Host Proteins Increases Pathogenic Potential of Porphyromonas gingivalis

2021 ◽  
Vol 22 (21) ◽  
pp. 12084
Author(s):  
Michał Śmiga ◽  
John W. Smalley ◽  
Paulina Ślęzak ◽  
Jason L. Brown ◽  
Klaudia Siemińska ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Disease Process ◽  
Human Keratinocytes ◽  
Bacterial Biofilm ◽  
Pathogenic Potential ◽  
Glycated Proteins ◽  
Sds Page

The non-enzymatic addition of glucose (glycation) to circulatory and tissue proteins is a ubiquitous pathophysiological consequence of hyperglycemia in diabetes. Given the high incidence of periodontitis and diabetes and the emerging link between these conditions, it is of crucial importance to define the basic virulence mechanisms employed by periodontopathogens such as Porphyromonas gingivalis in mediating the disease process. The aim of this study was to determine whether glycated proteins are more easily utilized by P. gingivalis to stimulate growth and promote the pathogenic potential of this bacterium. We analyzed the properties of three commonly encountered proteins in the periodontal environment that are known to become glycated and that may serve as either protein substrates or easily accessible heme sources. In vitro glycated proteins were characterized using colorimetric assays, mass spectrometry, far- and near-UV circular dichroism and UV–visible spectroscopic analyses and SDS-PAGE. The interaction of glycated hemoglobin, serum albumin and type one collagen with P. gingivalis cells or HmuY protein was examined using spectroscopic methods, SDS-PAGE and co-culturing P. gingivalis with human keratinocytes. We found that glycation increases the ability of P. gingivalis to acquire heme from hemoglobin, mostly due to heme sequestration by the HmuY hemophore-like protein. We also found an increase in biofilm formation on glycated collagen-coated abiotic surfaces. We conclude that glycation might promote the virulence of P. gingivalis by making heme more available from hemoglobin and facilitating bacterial biofilm formation, thus increasing P. gingivalis pathogenic potential in vivo.

scholarly journals Complex Nature of Enterococcal Pheromone-Responsive Plasmids

2010 ◽  
Vol 59 (2) ◽  
pp. 79-87 ◽  
Author(s):  
EWA WARDAL ◽  
EWA SADOWY ◽  
WALERIA HRYNIEWICZ
Keyword(s):  
Sex Pheromones ◽  
Complex Nature ◽  
Pheromone Response ◽  
Small Peptides ◽  
Resistance Determinants ◽  
Aggregation Substance ◽  
Enterococcal Species ◽  
Stable Maintenance ◽  
And Function ◽  
Great Complexity

Pheromone-responsive plasmids constitute a unique group of approximately 20 plasmids identified, as yet, only among enterococcal species. Several of their representatives, e.g. pAD1, pCF10, pPD1 and pAM373 have been extensively studied. These plasmids possess a sophisticated conjugation mechanism based on response to sex pheromones--small peptides produced by plasmid-free recipient cells. Detailed analysis of regulation and function of the pheromone response process revealed its great complexity and dual role--in plasmid conjugation and modulation of enterococcal virulence. Among other functional modules identified in pheromone plasmids, the stabilization/partition systems play a crucial role in stable maintenance of the plasmid molecule in host bacteria. Among them, the par locus of pAD1 is one of the exceptional RNA addiction systems. Pheromone-responsive plasmids contribute also to enterococcal phenotype being an important vehicle of antibiotic resistance in this genus. Both types of acquired vancomycin resistance determinants, vanA and vanB, as well many other resistant phenotypes, were found to be located on these plasmids. They also encode two basic agents of enterococcal virulence, i.e. aggregation substance (AS) and cytolysin. AS participates in mating-pair formation during conjugation but can also facilitate the adherence ofenterococci to human tissues during infection. The second protein, cytolysin, displays hemolytic activity and helps to invade eukaryotic cells. There are still many aspects of the nature of pheromone plasmids that remain unclear and more detailed studies are needed to understand their uniqueness and complexity.

Bap-dependent biofilm formation by pathogenic species of Staphylococcus: evidence of horizontal gene transfer?

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2465-2475 ◽  
Author(s):  
M. Ángeles Tormo ◽  
Erwin Knecht ◽  
Friedrich Götz ◽  
Iñigo Lasa ◽  
José R. Penadés
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Biofilm Formation ◽  
Sequence Similarity ◽  
Surface Protein ◽  
Pathogenicity Island ◽  
Alternative Mechanism ◽  
Coagulase Negative Staphylococci ◽  
High Sequence Similarity ◽  
Staphylococcus Simulans

The biofilm-associated protein (Bap) is a surface protein implicated in biofilm formation by Staphylococcus aureus isolated from chronic mastitis infections. The bap gene is carried in a putative composite transposon inserted in SaPIbov2, a mobile staphylococcal pathogenicity island. In this study, bap orthologue genes from several staphylococcal species, including Staphylococcus epidermidis, Staphylococcus chromogenes, Staphylococcus xylosus, Staphylococcus simulans and Staphylococcus hyicus, were identified, cloned and sequenced. Sequence analysis comparison of the bap gene from these species revealed a very high sequence similarity, suggesting the horizontal gene transfer of SaPIbov2 amongst them. However, sequence analyses of the flanking region revealed that the bap gene of these species was not contained in the SaPIbov2 pathogenicity island. Although they did not contain the icaADBC operon, all the coagulase-negative staphylococcal isolates harbouring bap were strong biofilm producers. Disruption of the bap gene in S. epidermidis abolished its capacity to form a biofilm, whereas heterologous complementation of a biofilm-negative strain of S. aureus with the Bap protein from S. epidermidis bestowed the capacity to form a biofilm on a polystyrene surface. Altogether, these results demonstrate that Bap orthologues from coagulase-negative staphylococci induce an alternative mechanism of biofilm formation that is independent of the PIA/PNAG exopolysaccharide.

scholarly journals Cytotoxicity of Protein-Carbon Nanotubes on J774 Macrophages Is a Functionalization Grade-Dependent Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Silvia Lorena Montes-Fonseca ◽  
Blanca Sánchez-Ramírez ◽  
Antonia Luna-Velasco ◽  
Carlos Arzate-Quintana ◽  
Macrina Beatriz Silva-Cazares ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cytotoxic Effect ◽  
Surface Protein ◽  
Low Grade ◽  
High Grade ◽  
Dependent Effect ◽  
Chemical Substances ◽  
Raman And Infrared Spectroscopy

Carbon nanotubes (CNTs) are used as carriers in medicine due to their ability to be functionalized with chemical substances. However, cytotoxicity analysis is required prior to use forin vivomodels. The aim of this study was to evaluate the cytotoxic effect of CNTs functionalized with a 46 kDa surface protein fromEntamoeba histolytica(P46-CNTs) on J774A macrophages. With this purpose, CNTs were synthesized by spray pyrolysis and purified (P-CNTs) using sonication for 48 h. A 46 kDa protein, with a 4.6–5.4 pI range, was isolated fromE. histolyticaHM1:IMSS strain trophozoites using an OFFGEL system. The P-CNTs were functionalized with the purified 46 kDa protein, classified according to their degree of functionalization, and characterized by Raman and Infrared spectroscopy.In vitrocytotoxicity was evaluated by MTT, apoptosis, and morphological assays. The results demonstrated that P46-CNTs exhibited cytotoxicity dependent upon the functionalized grade. Contrary to what was expected, P46-CNTs with a high grade of functionalization were more toxic to J774 macrophages than P46-CNTs with a low grade of functionalization, than P-CNTs, and had a similar level of toxicity as UP-CNT. This suggests that the nature of the functionalized protein plays a key role in the cytotoxicity of these nanoparticles.

scholarly journals Enterococcal Surface Protein Esp Is Important for Biofilm Formation of Enterococcus faecium E1162

2007 ◽  
Vol 189 (22) ◽  
pp. 8233-8240 ◽  
Author(s):  
Esther Heikens ◽  
Marc J. M. Bonten ◽  
Rob J. L. Willems
Keyword(s):  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Deletion Mutant ◽  
Wild Type Strain ◽  
Protein Gene ◽  
Surface Protein ◽  
Essential Factor ◽  
Wild Type ◽  
Surface Protein Gene ◽  
Multiple Antibiotics

ABSTRACT Enterococci have emerged as important nosocomial pathogens with resistance to multiple antibiotics. Adhesion to abiotic materials and biofilm formation on medical devices are considered important virulence properties. A single clonal lineage of Enterococcus faecium, complex 17 (CC17), appears to be a successful nosocomial pathogen, and most CC17 isolates harbor the enterococcal surface protein gene, esp. In this study, we constructed an esp insertion-deletion mutant in a clinical E. faecium CC17 isolate. In addition, initial adherence and biofilm assays were performed. Compared to the wild-type strain, the esp insertion-deletion mutant no longer produced Esp on the cell surface and had significantly lower initial adherence to polystyrene and significantly less biofilm formation, resulting in levels of biofilm comparable to those of an esp-negative isolate. Capacities for initial adherence and biofilm formation were restored in the insertion-deletion mutant by in trans complementation with esp. These results identify Esp as the first documented determinant in E. faecium CC17 with an important role in biofilm formation, which is an essential factor in infection pathogenesis.

Identification of bacterial hazards in the production of artisan fresh cheese in Cuba

2020 ◽  
Vol 87 (2) ◽  
pp. 263-265
Author(s):  
Ailin Martínez ◽  
Nivian Montes de Oca ◽  
Mabelín Armenteros ◽  
Odalys Uffo ◽  
Yamilka Riverón ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Raw Milk ◽  
Foodborne Diseases ◽  
Pathogenic Potential ◽  
Good Manufacturing Practices ◽  
Fresh Cheese ◽  
Isolated Species

AbstractArtisan fresh cheese producing farms from six provinces of Cuba were studied to identify the presence of bacterial hazards and the results are presented in this research communication. The bacterial hazards identified in milk and cheese respectively were: Listeria spp. (9.5 and 18.9%), Bacillus cereus (23.2 and 24.2%), Escherichia coli O157 (12.6 and 13.7%), Salmonella spp. (10.5 and 17.9%), and Staphylococcus aureus (29.5 and 51.6%). Listeria monocytogenes was not detected. Nine Salmonella serotypes corresponding to Salmonella enterica subsp. enterica and Salmonella enterica subsp. arizonae were isolated, whereas Salmonella Anatum was present most often. Biofilm formation by the isolated species and enterotoxin production by S. aureus strains demonstrated the pathogenic potential of the identified bacterial hazards. Results proved the presence of bacterial hazards in the raw milk and cheeses analyzed, so that good manufacturing practices must be accomplished throughout the entire production process in order to avoid the occurrence of foodborne diseases in the population.

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