Partial characterisation of enterocin KP produced by Enterococcus faecalis KP, a cheese isolate (original) (raw)
Related papers
Journal of Applied Microbiology, 1998
. Enterocin 81, a bacteriocin produced by Enterococcus faecium WHE 81 previously isolated from cheese, exhibited a very narrow spectrum of activity, which is mainly directed against enterococci and Listeria spp. including Listeria monocytogenes. Enterocin 81 activity, which was extremely rapid with maximal effect achieved within 30 min, could not be detected after treatment with various proteolytic enzymes. This activity was bactericidal in nature and induced an important efflux of intracellular material, which was visualized under electron microscopy as filaments coming out of L. monocytogenes cells. However, enterocin 81 did not display bacterial lysis on sensitive cells, as no changes in cell morphology were detected following the bactericidal action. Furthermore, this bacteriocin was shown to be equally active at pH values ranging from 4·0 to 8·0, which, along with the narrow activity spectrum, are two factors of paramount interest with regards to possible use of this bacteriocin in fermented foods.
Applied and Environmental Microbiology, 2009
Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversedphase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains.
Turkish Journal of Biology, 2013
In this study, the occurrence of enterocin genes, virulence factors, and antibiotic resistance in the bacteriocin-producer Enterococcus faecium EYT17, EYT31, and EYT39 strains was investigated. Polymerase chain reaction (PCR) studies showed that all of the E. faecium strains carried the enterocin A and B structural genes (entA and entB), while E. faecium EYT17 and EYT31 strains also carried the enterocin P structural gene (entP). None of the strains exhibited β-haemolysis or gelatinase activity. PCR analysis revealed that EYT17, EYT31, and EYT39 strains were clear of potential virulence determinants, except for ccf and efaAfm. The ccf gene was found in all of them. The efaAfm gene was only found in the EYT17 strain. All of the strains were found sensitive to ampicillin, chloramphenicol, gentamicin, norfloxacin, penicillin, streptomycin, tetracycline, sulphamethoxazole/trimethoprim, and vancomycin by disc diffusion method. E. faecium strains only exhibited intermediary resistance to erythromycin (15 µg). The results of this study showed that the multiple enterocin-producer E. faecium EYT17, EYT31, and EYT39 strains are safe and these strains may be used for food preservation.
European Food Research and Technology, 2012
Strong bacteriocins, or bacteriocins with a wide range of activity against pathogens and spoilage microorganisms, are actively sought for use as natural food preservatives. This work reports the inhibitory activity of 96 enterococcal isolates from two Iranian, raw milk cheeses against Wve indicator organisms (including Listeria innocua). Forty-eight isolates inhibited at least one indicator in spot agar assays. Of these, 20 isolates corresponding to 15 diVerent strains were shown to produce bacteriocinlike substances in liquid cultures. PCR analysis revealed the genes coding for enterocins (enterococcal bacteriocins) A, B, P or X, or their combinations, in all but one of these 15 strains. In addition, the gene coding for enterocin 31 was detected in two strains. No ampliWcation was obtained in one strain when using speciWc primers for all 13 bacteriocin genes sought. Three diVerent enterocin genes were identi-Wed in most strains and four in one strain. Although the concomitant production of bacteriocins is still to be veri-Wed, producers of multiple enterocins could be of great technological potential as protective cultures in the cheese industry.
Polish Journal of Microbiology
The purpose of this study was to determine the antimicrobial activity and the occurrence of bacteriocin structural genes in Enterococcus spp. isolated from different cheeses and also investigate of their some virulence factors. Enterococcus strains were isolated from 33 different cheeses. Enterococcus faecium (6 strains) and Enterococcus faecalis (5 strains) enterocin-producing strains were identified by 16S rDNA analyses. entA, entB, entP and entX structural genes were detected in some isolates. Multiple enterocin structural genes were found in 7 strains. None of the tested enterococci demonstrated β-haemolytic activity and only one strain has gelatinase activity. Six strains showed multiple antibiotic resistance patterns and in addition, vanA and several virulence genes were detected in many strains. Only E. faecalis MBE1-9 showed tyrosine decarboxylase activity and tdc gene was only detected in this strain.
Bacteriocin Production Of Enterococcus Species Isolated From Milk And Some Cheese Samples
Enterococci can be used as a starter or probiotic culture in the food industry. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, some probiotic characteristics such as antimicrobial activity and antibiotic susceptibility were investigated.Twenty-three strains of Enterococcus species isolated from Raw milk (7 strains), Karish cheese (8 strains), Domiati cheese (5 strains), and Ras cheese (3 strains) were studied for the capability to produce bacteriocin and antibiotic susceptibility.The seven studied antibiotics showed a different powerful effect on Enterococcus strains. The most effective antibiotic against 23 Enterococcus strains were amikacin, cefotaxime, and cefoxitin, which inhibited the growth of all tested strains, followed by levofloxacin azlocillin, and cloxacillin which inhibited 21, 19, and 19 strains, respectively, out of 23 studied strains. In addition, colistin showed the lowest powerful effect against all Enterococcus strains studied was resistant to this antibiotic. Antimicrobial activity was confirmed for all 23 strains against B. thuringiensis
Macedonian Veterinary Review, 2015
The study investigated the antimicrobial activity of 13 enterococcal strains (E. faecalis-8, E. faecium-2, E. hirae-2, E. spp.-1) isolated from our traditional cheeses against pathogen microorganisms. Also, it includes the detection of the following enterocin structural genes: enterocin A, enterocin B, enterocin P, enterocin L50A/B, bacteriocin 31, enterocin AS48, enterocin Q, enterocin EJ97 and cytolysin by using PCR method. All isolates inhibited growth of L. monocytogenes and L.innocua. One isolate had a broader antimicrobial activity. None of the isolates showed inhibitory activity against S. enteritidis, E. coli and Y. enterocolitica. The genes enterocin P, cytolysin and enterocin A were the most frequently detected structural genes among the PCR positive strains. No amplification was obtained in two strains E. faecalis-25 and E. faecalis-86. Three different genes were identified in some strains. With the exclusion of strains possessing a virulence factor, such as cytolysin, producers of more than one enterocins could be of a great technological potential as protective cultures in the cheese industry.
Italian Journal of Food Science
The goal of this research was to evaluate the functional properties and safety of antilisterial Enterococcus faecium BT29.11 isolated from Turkish Beyaz cheese. E. faecium BT29.11 showed the highest inhibitory activity against Listeria monocytogenes, followed by Staphylococcus aureus and vancomycin-resistant enterococci. E. faecium BT29.11 was identified by 16S rDNA sequence analysis, and genus- and species-specific PCR. The entA, entB, and entX structural genes were detected in E. faecium BT29.11. It was determined that the BT29.11 strain was a slow acid producer and did not show extracellular proteolytic and lipolytic activity. E. faecium BT29.11 demonstrated good probiotic properties. E. faecium BT29.11 was found to be ɣ-hemolytic, gelatinase-negative, and susceptible to clinically important antibiotics. Only ermC and acm were detected in the BT29.11 strain. E. faecium BT29.11 decreased the growth of L. monocytogenes in ultra-high temperature (UHT) milk. The findings of this rese...
Antibacterial potential of Enterococcus faecium strains isolated from ewes’ milk and cheese
LWT - Food Science and Technology, 2012
The study was conducted to evaluate the antibacterial activity of three bacteriocin-producing Enterococcus faecium strains (TW15, TW20 and TW22) isolated from ewes' milk and cheese sampled in the Patagonian region of Argentina. The strains were tested against spoilage and pathogens microorganisms showing antimicrobial activity towards 4 strains of Listeria monocytogenes, one strain of Listeria innocua and 2 strains of Staphylococcus aureus. E. faecium TW15, E. faecium TW20 and E. faecium TW22 were sensitive to vancomycin. Furthermore, investigation of virulence factors revealed the absence of the genes encoding them. The bacteriocin-like substances (BLISs) produced by the 3 strains were thermostable, pH resistant and can be expressed even in the presence of NaCl (3.0 g/100 g). Moreover, they prove to have a bactericidal mode of action. Results from physicochemical and biochemical characteristics of BLIS produced by these E. faecium strains make them potential candidates to aid in preservation of foods.