Phylogenetic analysis of antimicrobial lactic acid bacteria from farmed seabass Dicentrarchus labrax

2012 ◽  
Vol 58 (4) ◽  
pp. 463-474 ◽  
Author(s):  
Ouissal Chahad Bourouni ◽  
Monia El Bour ◽  
Pilar Calo-Mata ◽  
Radhia Mraouna ◽  
Boudabous Abedellatif ◽  
...  

The use of lactic acid bacteria (LAB) in the prevention or reduction of fish diseases is receiving increasing attention. In the present study, 47 LAB strains were isolated from farmed seabass ( Dicentrarchus labrax ) and were phenotypically and phylogenetically analysed by 16S rDNA and randomly amplified polymorphic DNA – polymerase chain reaction (RAPD–PCR). Their antimicrobial effect was tested in vitro against a wide variety of pathogenic and spoilage bacteria. Most of the strains isolated were enterococci belonging to the following species: Enterococcus faecium (59%), Enterococcus faecalis (21%), Enterococcus sanguinicola (4 strains), Enterococcus mundtii (1 strain), Enterococcus pseudoavium (1 strain), and Lactococcus lactis (1 strain). An Aerococcus viridans strain was also isolated. The survey of their antimicrobial susceptibility showed that all isolates were sensitive to vancomycin and exhibited resistance to between 4 and 10 other antibiotics relevant for therapy in human and animal medicine. Different patterns of resistance were noted for skin and intestines isolates. More than 69% (32 strains) of the isolates inhibited the growth of the majority of pathogenic and spoilage bacteria tested, including Listeria monocytogenes , Staphylococcus aureus , Aeromonas hydrophila , Aeromonas salmonicida , Vibrio anguillarum , and Carnobacterium sp. To our knowledge, this is the first report of bioactive enterococcal species isolated from seabass that could potentially inhibit the undesirable bacteria found in food systems.


2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Fernanda Cristina Kandalski Bortolotto ◽  
Maria Helena da Rosa Farfan ◽  
Nathalia Cristina Kleinke Jede ◽  
Gabriela Maia Danielski ◽  
Renata Ernlund Freitas de Macedo

ABSTRACT: Sausages are highly susceptible to microbial spoilage. Lactic acid bacteria (LAB) is the main group of spoilage bacteria in vacuum packed cooked sausages. To control microbial growth natural antimicrobials have been used as food preservatives. The aim of this study was to identify strains of lactic acid bacteria isolated from spoiled commercial Calabresa sausages and use them in an in vitro challenge with the natural antimicrobials, nisin (NI) and ε-poly-L-lysine (ε-PL). Mass spectrometry identification of LAB isolated from sausages using MALDI-TOF revealed a predominance of L. plantarum in the LAB population. RAPD-PCR of L. plantarum strains showed four different genetic profiles. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of NI and ε-PL, alone and in combination, against a pool of different profiles L. plantarum were determined. MIC of NI and ε-PL were 0.468 mg/ L and 75 mg/ L; respectively, whereas MBC of NI and ε-PL were 12.48 mg/L and 150 mg/L, respectively. The combined effect of NI and ε-PL was determined using concentrations at 1/4 and 1/8 of individual MICs. Synergistic effect was confirmed at both concentrations showing a fractional inhibitory concentration index of 0.5 and 0.2, respectively. The combination of NI and ε-PL at a small concentration of 0.05 mg/L and 9.375 mg/L, respectively, showed inhibitory effect towards spoilage L. plantarum Results show the potential of the combined use of NI and ε-PL to control sausage spoilage-associated with lactobacilli.



2019 ◽  
Vol 9 (3) ◽  
pp. 601 ◽  
Author(s):  
Alicia Cervantes-Elizarrarás ◽  
Nelly Cruz-Cansino ◽  
Esther Ramírez-Moreno ◽  
Vicente Vega-Sánchez ◽  
Norma Velázquez-Guadarrama ◽  
...  

Probiotics can act as a natural barrier against several pathogens, such Helicobacter pylori, a bacterium linked to stomach cancer. The aim of the present study was to isolate and identify lactic acid bacteria (LAB) from pulque and aguamiel, and evaluate their probiotic potential and antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. Ten isolates were selected and evaluated for in vitro resistance to antibiotics and gastrointestinal conditions, and antimicrobial activity against E. coli and S. aureus and the effect on H. pylori strains. 16S rRNA identification was performed. Ten potential probiotic isolates were confirmed as belonging to the genera Lactobacillus and Pediococcus. All the strains were susceptible to clinical antibiotics, except to vancomycin. Sixty percent of the isolates exhibited antimicrobial activity against E. coli and S. aureus. The growth of H. pylori ATCC 43504 was suppressed by all the LAB, and the urease activity from all the H. pylori strains was inhibited, which may decrease its chances for survival in the stomach. The results suggest that LAB isolated from pulque and aguamiel could be an option to establish a harmless relationship between the host and H. pylori, helping in their eradication therapy.



2000 ◽  
Vol 63 (1) ◽  
pp. 71-77 ◽  
Author(s):  
DERRICK A. BAUTISTA ◽  
RONALD B. PEGG ◽  
PHYLLIS J. SHAND

Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, ∼2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. l-Glucose and d-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of d-glucose. Results showed that both l-glucose and d-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, d-glucose, l-glucose, and d-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P < 0.05) slower for the formulation containing d-tagatose than those containing l-or d-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P < 0.20) change in the presence of any of the sugars used in the meat formulations. Compared to the control sample containing d-glucose, the shelf life of the chopped and formed ham containing d-tagatose at 10°C was extended by 7 to 10 days. These results indicate that d-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.



2021 ◽  
Vol 26 (2) ◽  
pp. 2423-2427
Author(s):  
ȘTEFAN BĂTRÎNA ◽  
◽  
NICOLAE CORCIONIVOSCHI ◽  
STEFANA JURCOANE ◽  
MARK LINTON ◽  
...  

Camelina (Camelina sativa L. Crantz) or false flax is an oil crop from the Brassicaceae family. Camelina oil has multiple uses, of which the best known is biofuel production. A motivation for this study was the oil’s high content of omega-3, omega-6 and omega-9 fatty acids, which are known to have an antimicrobial effect. Campylobacter is the most common bacterial cause of human foodborne gastroenteritis in the world. We tested the potential antimicrobial effect of free fatty acids (FFA) from camelina oil against lactic acid bacteria (LAB) and Campylobacter. The in vitro results show that the free fatty acids from camelina oil reduces levels of Campylobacter spp. and increases the levels of LAB showing a potential use of camelina oil as a natural antimicrobial.



Folia Medica ◽  
2021 ◽  
Vol 63 (5) ◽  
pp. 720-725
Author(s):  
Michaela Michaylova ◽  
Tsvetelina Yungareva ◽  
Zoltan Urshev ◽  
Yana Dermendzieva ◽  
Blagovesta Yaneva ◽  
...  

Introduction: The gram-negative bacterium Porphyromonas gingivalis is a major causative agent of periodontitis in adults. It is also associated with disorders of the cardiovascular and endocrine systems, rheumatoid arthritis, pancreatic cancer, and Alzheimer’s disease. Lactic acid bacteria (LAB) present in the oral cavity or introduced as probiotic preparations can support successful treatment of periodontitis due to their antagonism with the pathogen. Aim: The aim of this study was in vitro assessment of the antimicrobial activity of Lactobacillus spp. and Streptococcus thermophilus against P. gingivalis. Materials and methods: The antimicrobial effect of lactobacilli or S. thermophilus from the LBB Culture collection against P. gingivalis DSM 20709 was evaluated with the well diffusion assay on Wilkins Chalgren blood agar. Inhibition of the pathogen was evaluated by measuring the diameter of clear zones around the wells. Results: Application of milk fermented with selected LAB resulted in а bacteriostatic effect. The most active culture was S. thermophilus 187/4, followed by L. delbr. ssp. bulgaricus (LBB.B1054, C3/2 and LBB.B120), L. helveticus LBB.H48/1 and L. rhamnosus I-1/13. The respective reconstituted freeze-dried preparations had a stronger inhibitory effect on the pathogen with the formation of clear bactericidal zones. The effect of milk acidified with lactic acid was apparent with minimal bactericidal zone observed at concentration of 0.1%. The effectiveness of the assay was confirmed with Elgydium and Eludril. Conclusions:P. gingivalis DSM 20709 was sensitive to the metabolites produced in fermented milk by selected strains of L. delbr. ssp. bulgaricus, L. helveticus, L. rhamnosus, and S. thermophilus. Reconstituted freeze dried fermented milk had а stronger inhibitory effect compared to fresh samples. Lactic acid produced by lactic acid bacteria was the key component for inhibition of the pathogen.



2002 ◽  
Vol 9 (6) ◽  
pp. 1318-1323 ◽  
Author(s):  
L. Villamil ◽  
C. Tafalla ◽  
A. Figueras ◽  
B. Novoa

ABSTRACT In the present work, the effects of several lactic acid bacteria on the immune response of turbot (Scophthalmus maximus) macrophages have been studied both in vitro and in vivo. Out of six lactic acid bacterial strains tested, only heat-killed Lactococcus lactis significantly increased the turbot head kidney macrophage chemiluminescent (CL) response after 24 h of incubation. Nitric oxide (NO) was also significantly enhanced by this bacterium after 72 h of incubation with either viable (103 and 106 cells/ml) or heat-killed (106 cells/ml) bacteria. Viable Leuconostoc mesenteroides (106 cells/ml) was also capable of significantly increasing NO production. Since L. lactis proved to be the strain with more effects on the host immune function, further in vivo and in vitro experiments were conducted with this bacterium. The in vitro capacity of L. lactis to adhere to turbot intestinal mucus was positively confirmed. When orally administered, L. lactis significantly increased the macrophage CL response and the serum NO concentration after 7 days of daily administration. The antibacterial effect of the extracellular products from the six LAB strains against the fish-pathogenic bacterium Vibrio anguillarum was also demonstrated in vitro.



2005 ◽  
Vol 34 (1) ◽  
pp. 91-99 ◽  
Author(s):  
K. Szekér ◽  
J. Beczner ◽  
A. Halász ◽  
Á. Mayer ◽  
J.M. Rezessy-Szabó ◽  
...  


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chatchai Kaewpila ◽  
Pongsatorn Gunun ◽  
Piyawit Kesorn ◽  
Sayan Subepang ◽  
Suwit Thip-uten ◽  
...  

AbstractImproving the nutrition of livestock is an important aspect of global food production sustainability. This study verified whether lactic acid bacteria (LAB) inoculant could promote ensiling characteristics, nutritive value, and in vitro enteric methane (CH4) mitigation of forage sorghum (FS) mixture silage in attacking malnutrition in Zebu beef cattle. The FS at the soft dough stage, Cavalcade hay (CH), and cassava chip (CC) were obtained. The treatments were designed as a 4 × 2 factorial arrangement in a completely randomized design. Factor A was FS prepared without or with CH, CC, and CH + CC. Factor B was untreated or treated with Lactobacillus casei TH14. The results showed that all FS mixture silages preserved well with lower pH values below 4.0 and higher lactic acid contents above 56.4 g/kg dry matter (DM). Adding LAB boosted the lactic acid content of silages. After 24 h and 48 h of in vitro rumen incubation, the CC-treated silage increased in vitro DM digestibility (IVDMD) with increased total gas production and CH4 production. The LAB-treated silage increased IVDMD but decreased CH4 production. Thus, the addition of L. casei TH14 inoculant could improve lactic acid fermentation, in vitro digestibility, and CH4 mitigation in the FS mixture silages.



Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2579
Author(s):  
Carmen-Alina Bolea ◽  
Mihaela Cotârleț ◽  
Elena Enachi ◽  
Vasilica Barbu ◽  
Nicoleta Stănciuc

Two multi-functional powders, in terms of anthocyanins from black rice (Oryza sativa L.) and lactic acid bacteria (Lactobacillus paracasei, L. casei 431®) were obtained through co-microencapsulation into a biopolymer matrix composed of milk proteins and inulin. Two extracts were obtained using black rice flour as a raw material and hot water and ethanol as solvents. Both powders (called P1 for aqueous extract and P2 for ethanolic extract) proved to be rich sources of valuable bioactives, with microencapsulation efficiency up to 80%, both for anthocyanins and lactic acid bacteria. A higher content of anthocyanins was found in P1, of 102.91 ± 1.83 mg cyanindin-3-O-glucoside (C3G)/g dry weight (DW) when compared with only 27.60 ± 17.36 mg C3G/g DW in P2. The morphological analysis revealed the presence of large, thin, and fragile structures, with different sizes. A different pattern of gastric digestion was observed, with a highly protective effect of the matrix in P1 and a maximum decrease in anthocyanins of approximatively 44% in P2. In intestinal juice, the anthocyanins decreased significantly in P2, reaching a maximum of 97% at the end of digestion; whereas in P1, more than 45% from the initial anthocyanins content remained in the microparticles. Overall, the short-term storage stability test revealed a release of bioactive from P2 and a decrease in P1. The viable cells of lactic acid bacteria after 21 days of storage reached 7 log colony forming units (CFU)/g DW.





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