scholarly journals Bacteriocin activity of enterococci and presence of genes related to pathogenesis

2012 ◽  
Vol 30 (No. 4) ◽  
pp. 330-335 ◽  
Author(s):  
K. Trivedi ◽  
R. Sedmíková ◽  
R. Karpíšková
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Virulence Genes ◽  
Bacteriocin Production ◽  
Bacteriocin Activity ◽  
Antimicrobial Substances ◽  
Layer Technique ◽  
Genes Encoding ◽  
The Individual

In total 228 enterococci strains isolated from food were studied. Enterococcus faecalis, E. faecium, and E. casseliflavus were found to be the dominant strains while E. durans and E. mundtii were present in a smaller extent. Antimicrobial activity determined by double layer technique revealed that 150 (65.7%) strains showed antimicrobial activity against the individual tested pathogenic strains of Listeria monocytogenes, Staphylococcus aureus, and methicilin resistant S. aureus (MRSA). Cell-free neutralised supernatants (CFNS) were prepared from 150 potential bacteriocin producers. Of these 150, CFNS 107 (71.3%) strains were active in the bacteriocin production against one or more pathogenic strains tested. S. aureus and MRSA were found to be more sensitive to the antimicrobial substances than L. monocytogenes. Multiplex PCR for the detection of seven virulence genes in bacteriocin producing strains showed that 47.6% of strains were able to amplify one or more virulence genes. E. faecalis was the most virulent species. The presence of tyrdc gene was seen in all bacteriocin producing strains. None of the strains carried genes encoding the resistance to vancomycin.  

scholarly journals Production and Extraction Of Antibacterial Bacteriocin from Pediococcus sp. NWD 015

2015 ◽  
Vol 11 (2) ◽  
Author(s):  
N. Nofisulastri ◽  
Zaenal Bachruddin ◽  
Eni Harmayani
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Enterococcus Faecalis ◽  
Storage Time ◽  
Bacteriocin Production ◽  
Proteinase K ◽  
Bacteriocin Activity

objectives were to study the growth pattern of Pediococcus sp. NWD 015 and bacteriocin activity, extractionand characterization of bacteriocin, and to determine the effect of storage time and temperature on bacteriocinactivity. Results showed that the bacteriocin activity increased during growth and reached the highest activity duringstationary phase. The maximum bacteriocin production reached after incubation of the cell for 12 h at 37oC in TGEbroth and decreased after 96 h incubation. Extraction with adsorbtion-desorbtion method could increased a specificactivity of bacteriocin. Bacteriocin from Pediococcus sp. NWD 015 is inactivated by Proteinase-K; however it is stillactive by heat treatment at 121oC for 15 min and over pH 2 – 11. Bacteriocin of Pediococcus sp. NWD 015 was effectiveagaints Enterococcus faecalis, Staphylococcus aureus, Eschericia coli, Listeria monocytogenes but not against Salmonellathypimurium. The molecular weight of bacteriocin is 4.95 kDa.Keywords : Bacteriocins, Pediococcus sp NWD 015.

scholarly journals Occurrence of Enterocin Genes in Enterococci from Slovak Milk Product Žinčica

2019 ◽  
Vol 50 (3) ◽  
pp. 197-202 ◽  
Author(s):  
A. Lauková ◽  
V. Strompfová ◽  
M. Tomáška ◽  
M. Kološta
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Dairy Product ◽  
Inhibition Zone ◽  
The Other ◽  
Milk Product ◽  
Inhibition Activity ◽  
Gene Detection ◽  
P Gene

Abstract Žinčica is a popular Slovak dairy product made from ewes’ milk. It is a by-product resulting during ewes’ lump cheese processing. Microbiota in Žinčica have rarely been studied, especially enterococci; however, they can produce beneficial substances – bacteriocins. In this study, the presence of Enterocins (Ents) genes were analysed in enterococci from Žinčica and partially also the inhibition activity. Samples of Žinčica were collected from different agrofarms producing ewes’ lump cheese (34) in Central Slovakia. In the enterococci tested, Ent P gene was the most frequently detected (in 6 out of 7 enterococci), followed by Ent A and Ent L50B genes. Ent B gene was detected only in E. faecium 30E1. On the other hand, E. faecalis 31E2 did not contain Ent genes, although it showed inhibition activity against the indicator strains Enterococcus avium EA5, Staphylococcus aureus SA5, Listeria monocytogenes CCM4699 (inhibition zone sizing up to 20 mm). E. faecium 30E1 contained genes of four Ents; however, it showed no inhibition activity. Growth of the four indicators was inhibited due to the antimicrobial activity of E. faecium 32E1 with Ent P gene detection. This is the first study reporting on the occurrence of Ent genes in enterococci from Žinčica.

scholarly journals Effect of an Italian propolis on the growth of Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus in milk and whey cheese

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Francesca Pedonese ◽  
Giada Verani ◽  
Beatrice Torracca ◽  
Barbara Turchi ◽  
Antonio Felicioli ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Dairy Products ◽  
Skim Milk ◽  
Cow’S Milk ◽  
Alcoholic Extract ◽  
Cow's Milk

Propolis antimicrobial activity has been limitedly studied in food, particularly in dairy products. We studied the antimicrobial activity of an alcoholic extract of an Italian propolis in sterile skim milk, pasteurized cow’s milk, and cow’s and goat’s whey cheese (ricotta). Following the determination of the minimal inhibitory concentration on Gram+ and Gram- bacteria, the extract was employed at 2 and 5% (P2, P5), using controls with the same ethanol concentrations (E2, E5) and without any addition. In milk trials, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Pseudomonas fluorescens were tested. P2 and P5 samples registered significant decreases of Gram+ bacteria in skim milk. The same was true for P5 in cows’ milk, but only with S. aureus for P2. Ricotta was inoculated with L. monocytogenes, S. aureus and B. cereus and stored at 8.5°C. In cow’s milk ricotta, L. monocytogenes counts in P5 were always lower than control during the storage time, significantly so from the 14th day. In goat’s ricotta, L. monocytogenes counts in P5 were at least one logarithm lower than E5, whereas the extract didn’t show a significant effect on S. aureus and B. cereus. The antimicrobial activity of propolis, particularly on L. monocytogenes, could be employed in ready-to-eat refrigerated dairy products.

The Antimicrobial Activity of Extracts of the Lichen Cetraria aculeata and Its Protolichesterinic Acid Constituent

2003 ◽  
Vol 58 (11-12) ◽  
pp. 850-854 ◽  
Author(s):  
Ayşen Özdemir Türk ◽  
Meral Yılmaz ◽  
Merih Kıvanç ◽  
Hayrettin Türk
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Aeromonas Hydrophila ◽  
Proteus Vulgaris ◽  
Ethanol Extracts

Abstract In this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen Cetraria aculeata has been investigated. The extracts were tested against twelve bacteria and eight fungi and found active against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Proteus vulgaris, Streptococcus faecalis, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes. No antimicrobial activity against the fungi was detected. It was determined that only one substance in the extracts has antimicrobial activity and it was characterized as protolichesterinic acid. The MICs of the extracts and protolichesterinic acid were also determined.

scholarly journals Synthesis of chalcone-based pyrimidine derivatives and their antimicrobial activity

2021 ◽  
Vol 57 (4) ◽  
pp. 431-437
Author(s):  
D. S. Martsinkevich ◽  
K. F. Chernyavskaya ◽  
V. A. Tarasevich
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Tropicalis ◽  
Good Activity ◽  
Pyrimidine Derivatives ◽  
Antimicrobial Substances

A series of substituted chalcones and pyrimidine derivatives on their base was synthesized. Obtained compounds were tested for antimicrobial activity and ability to increase activity of known antimicrobial substances. Pyrimidine products shown good activity against Staphylococcus aureus and Candida tropicalis. These compounds also could increase activity of modified polyguanidines against Staphylococcus aureus.

scholarly journals AKTIVITAS ANTIMIKROBA BAKTERI ASAM LAKTAT DARI AIR SUSU IBU (ASI) TERHADAP Listeria monocytogenes FNCC 0156

2020 ◽  
Vol 9 (1) ◽  
pp. 96
Author(s):  
Made Juli Antari ◽  
Ni Nyoman Puspawati ◽  
Putu Ari Sandhi Wipradnyadewi
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Breast Milk ◽  
Lactic Acid Bacteria ◽  
Bacteriocin Production ◽  
Diffusion Method ◽  
Contact Method ◽  
Agar Diffusion ◽  
Agar Diffusion Method

The aim of the research was to find the potency of Lactic Acid Bacteria isolated from breast milk on inhibiting Listeria monocytogenes FNCC 0156 and to find the magnitude of lactic acid bacteria from breast milk in inhibiting L. monocytogenes FNCC 0156. This reseach consists of two phase: antimicrobial activity of lactic acid bacteria from breast milk and activity of bacteriocin against L. monocytogenes FNCC 0156. Isolate used in this research was A1, A3, A6, A8, A9, B3, B7, B8, and B10b. Antimicrobial activity of lactic acid bacteria from breast milk against L. monocytogenes FNCC 0156 was performed cell free supernatant, cell free neutral supernatant, and cell free neutral heated supernatant. The test was performed by well-agar diffusion method and contact method. The activity of bacteriocin was carried out according to the optimum incubation time of bacteriocin production in cell free heated neutral supernatant. The highest antimicrobial activity was supernatant treatment by well-agar diffusion method and contact method showed by isolate A1 with inhibition diameter of 10.60 mm and a decrease of 1.66 log cycle. The highest antimicrobial activity was neutral supernatant treatment by well-agar diffusion method and contact method showed by isolate B8 with inhibition diameter of 5.11 mm and increased only by 0.18 log cycle. The highest antimicrobial activity on the heated neutral supernatant treatment by well-agar diffusion method and contact method showed by isolate A6 with inhibition diameter of 0.85 mm and a decrease of 0.48 log cycle. The two isolates of cell free neutral heated supernatant treatment was isolate A6 and isolate B8 suspected to have bacteriocin compounds was then continued with isolation of bacteriocin. The result of the second phase showed that optimum time for bacteriocin production of isolate A6 was 36 hours and B8 was 60 hours. The highest antimicrobial activity of bacteriocin was showen by isolate A6 with an average inhibition diameter of 5.36 mm, followed by B8 with an average inhibition diameter of 2.44 mm. Keywords: lactic acid bacteria, breast milk, Listeria monocytogenes FNCC 0156, antimicrobial activity, bacteriocin

Virulence gene profiles inStaphylococcus aureusisolated from cows with subclinical mastitis in eastern Poland

2016 ◽  
Vol 83 (2) ◽  
pp. 228-235 ◽  
Author(s):  
Barbara Kot ◽  
Piotr Szweda ◽  
Aneta Frankowska-Maciejewska ◽  
Małgorzata Piechota ◽  
Katarzyna Wolska
Keyword(s):  
Staphylococcus Aureus ◽  
Serine Protease ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Subclinical Mastitis ◽  
Staph Aureus ◽  
Gene Profiles ◽  
Enterotoxin Genes ◽  
Genes Encoding

Staphylococcus aureusis arguably the most important pathogen involved in bovine mastitis. The aim of this study was to determine the virulence gene profiles of 124Staph. aureusisolates from subclinical mastitis in cows in eastern Poland. The presence of 30 virulence genes encoding adhesins, proteases and superantigenic toxins was investigated by PCR. The 17 different combinations of adhesin genes were identified. Occurrence ofeno(91·1%) andfib(82·3%) genes was found to be common. The frequency of other adhesion genesfnbA, fnbB, ebpswere 14·5, 50, 25%, respectively, and forcnaandbbpwere 1·6%. TheetAandetDgenes, encoding exfoliative toxins, were present in genomes of 5·6 and 8·9% isolates, respectively. ThesplAandsspA, encoding serine protease, were detected in above 90% isolates. The most frequent enterotoxin genes weresei(21%),sem(19·4%),sen(19·4%),seg(18·5%) andseo(13·7%). Thetstgene was harboured by 2·4% isolates. The 19 combinations of the superantigenic toxin genes were obtained and found in 35·5% of isolates. Three of them (seg, sei, sem, sen, seo; sec, seg, sei, sem, sen, seoandseg, sei, sem, sen) were the most frequent and found in 16·1% of the isolates. The most common virulotype, present in 17·7% of the isolates, wasfib, eno, fnbB, splA, splE, sspA. The results indicate the variation in the presence of virulence genes inStaph. aureusisolates and considerable diversity of isolates that are able to cause mastitis in cows.

Prevalence of bacteriocin activities and bacteriocin-encoding genes in enterococcal clinical isolates in Iran

2012 ◽  
Vol 58 (4) ◽  
pp. 359-368 ◽  
Author(s):  
Maryam Hassan ◽  
Dzung B. Diep ◽  
Yousef Javadzadeh ◽  
Siavash Dastmalchi ◽  
Ingolf F. Nes ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Clinical Isolates ◽  
Proteinase K ◽  
Structural Genes ◽  
High Antimicrobial Activity ◽  
Antimicrobial Substances ◽  
Genes Encoding ◽  
Pcr Method ◽  
Enterocin A ◽  
Bacteriocin Genes

The aim of the project was to isolate and characterize bacteriocin-producing enterococci, as well as determine the prevalence of enterocin structural genes in 187 enterococcal clinical isolates from the northwest of Iran. The isolates were screened for antibacterial activity against 15 different indicator strains. The proteinaceous nature of the antimicrobial substances was confirmed by sensitivity to proteinase K; their stability to heat treatment was tested at 60 °C and 100 °C for 20 and 10 min, respectively. The PCR method was applied to detect previously identified enterocin genes. Our results showed that 38 (20.3%) of the enterococcal isolates were considered to be potential bacteriocinogenic strains. Furthermore, genes encoding diverse bacteriocin are highly distributed among clinical enterococci, and the strains with multi-bacteriocin genes displayed high antimicrobial activity. Enterocin A, enterolysin A, and enterocin L50A/B were the most abundant structural genes detected in bacteriocinogenic strains. This work is the first survey on the prevalence of bacteriocin genes among clinical enterococci in Iran that has isolated a strain with high antimicrobial activity and sensitivity to clinically relevant antibiotics.

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