RESUMO
Preterm birth (PTB), defined as birth occurring before 37 weeks of pregnancy, affects 5-18% of pregnancies and is the leading cause of neonatal morbidity and mortality worldwide. Although PTB is considered a syndrome, infection-induced inflammation accounts for up to 50% of all cases. Despite the effort to reduce the incidence of PTB, it continues to rise worldwide and current approaches for preventing or treating PTB are largely unsatisfactory. Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. It is well known that probiotics can modulate the host immune system exerting a potent anti-inflammatory activity. The main aim of this work was to evaluate the capacity of the probiotic Lactobacillus kefiri (Lk48) to prevent preterm birth in mice. C57BL/6 female mice were treated with Lk48 or vehicle a week before and during pregnancy and were challenged with LPS (10 µg), a dose known to induce PTB on gestational day 16. Percentages of PTB as well as stillbirth were evaluated. We observed that oral administration of Lk48 significantly reduced the occurrence of LPS-induced PTB and stillbirth as well as improved post-natal development. This protective effect was associated with a reduction in leucocyte infiltration and reduced inflammation-induced damage in reproductive tissue. Besides, Lk48 treatment also modulated the diversity of vaginal microbiota. Our results demonstrated that prophylactic consumption of probiotic L. kefiri prevented LPS-induced PTB and still birth in mice and opens new avenues for exploring novel and promising strategies for preventing PTB in humans.
Assuntos
Endotoxinas/toxicidade , Lactobacillus/química , Nascimento Prematuro/prevenção & controle , Probióticos/administração & dosagem , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Nascimento Prematuro/induzido quimicamente , Nascimento Prematuro/patologia , NatimortoRESUMO
The effect of bioprotective extracts (BEs) from Latilactobacillus curvatus CRL705 and Lactobacillus acidophilus CRL641 against Latilactobacillus sakei CRL1407 was evaluated in a refrigerated meat model system under vacuum and aerobic conditions at 4 and 10 °C. As shown by culturing, the BE-1 from L. acidophilus completely inhibited the spoilage strain, while that from Lat. Curvatus CRL705 (BE-2) and its combination with BE-1 exerted a bacteriostatic effect. The antimicrobial activity and exopolysaccharide production correlated with the efficacy of inhibitory treatment while final pH decrease was higher in control samples. When flow cytometry was applied, a lack of correlation with plate counting was found; counts under the detection limit for BE-1 at 21 and 28 days at 4 and 10 °C represented between 64.15 and 73.70% of dead cells. Thus, the concurrence of lactic acid bacteria as biocontrol agents and the use of more accurate tools to prevent the growth of deteriorating species will contribute to the extension of fresh meat shelf-life without quality loss.
Assuntos
Conservantes de Alimentos/farmacologia , Lactobacillaceae/efeitos dos fármacos , Lactobacillus acidophilus/química , Lactobacillus/química , Carne/microbiologia , Animais , Embalagem de Alimentos , Conservação de Alimentos/instrumentação , Conservação de Alimentos/métodos , Conservantes de Alimentos/química , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/metabolismo , Refrigeração , VácuoRESUMO
This study aimed to investigate the effect of Lactobacillus plantarum DPP8 and Lactobacillus acidophilus C7282 in feed supplementation on growth performance, Salmonella invasion, inflammation, and mediating signaling in broilers infected with Salmonella Typhimurium (S. Typhimurium). A total of 240 broilers at day old were randomly allocated into four groups, orally infected with S. Typhimurium and supplemented with individual or combined Lactobacilli DPP8 and C7282 at doses of 0 (control), 1010 (individual), or 2.0 × 1010 (combination) cfu/kg of diet for 21 d. The results showed that supplementing Lactobacilli improved (p 0.05) feed intake and body weight gain and decreased (p 0.05) S. Typhimurium load in the caecum, harder gland, spleen and bursa of Fabricius. Also, the supplements decreased (p 0.05) interleukin (1/2/4), tumor necrosis factor and interferon in the serum, enhanced (p 0.05) interleukin 10, and downregulated gene expressions of inflammatory mediators including Janus kinase (Jak2/3), signal transducer and activator of transcription protein (STAT3/4/5/6) in the intestinal mucosa. In contrast, diets containing DPP8 exhibited greater effects on the inhibition of the pathogen and inflammatory response than C7282. The obtained data suggest that Lactobacilli C7282 and DPP8 can be used as feed additives to inhibit colonization and translocation of S. Typhimurium and inflammatory responses via downregulating Jak/STAT signaling in broilers.(AU)
Assuntos
Animais , Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Lactobacillus/química , Intoxicação Alimentar por Salmonella , Salmonella typhimuriumRESUMO
This study aimed to investigate the effect of Lactobacillus plantarum DPP8 and Lactobacillus acidophilus C7282 in feed supplementation on growth performance, Salmonella invasion, inflammation, and mediating signaling in broilers infected with Salmonella Typhimurium (S. Typhimurium). A total of 240 broilers at day old were randomly allocated into four groups, orally infected with S. Typhimurium and supplemented with individual or combined Lactobacilli DPP8 and C7282 at doses of 0 (control), 1010 (individual), or 2.0 × 1010 (combination) cfu/kg of diet for 21 d. The results showed that supplementing Lactobacilli improved (p 0.05) feed intake and body weight gain and decreased (p 0.05) S. Typhimurium load in the caecum, harder gland, spleen and bursa of Fabricius. Also, the supplements decreased (p 0.05) interleukin (1/2/4), tumor necrosis factor and interferon in the serum, enhanced (p 0.05) interleukin 10, and downregulated gene expressions of inflammatory mediators including Janus kinase (Jak2/3), signal transducer and activator of transcription protein (STAT3/4/5/6) in the intestinal mucosa. In contrast, diets containing DPP8 exhibited greater effects on the inhibition of the pathogen and inflammatory response than C7282. The obtained data suggest that Lactobacilli C7282 and DPP8 can be used as feed additives to inhibit colonization and translocation of S. Typhimurium and inflammatory responses via downregulating Jak/STAT signaling in broilers.
Assuntos
Animais , Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Intoxicação Alimentar por Salmonella , Lactobacillus/química , Salmonella typhimuriumRESUMO
Bacteriocins are ribosomally synthesized peptides with antibacterial activity against food-borne pathogenic bacteria that cause spoilage, possessing important potential for use as a natural preservative in the food industry. The novel bacteriocin BM1300 produced by Lactobacillus crustorum MN047 was identified after purification in this study. It displayed broad-spectrum antibacterial activity against some selected Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) values of BM1300 against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 were 13.4 µg/mL and 6.7 µg/mL, respectively. Moreover, BM1300 showed excellent thermal (between 60 and 120 °C), pH (2-11), and chemical (Tween-40, Tween-80, Triton X-100, and EDTA) stabilities. Time-kill curves revealed that BM1300 exhibited bactericidal activity against S. aureus and E. coli. The scanning and transmission electron microscopy indicated that BM1300 acted by disrupting the cell membrane integrity and increasing cell membrane permeabilization of indicator bacteria. The disruption of cell membrane integrity caused by BM1300 was further demonstrated by the uptake of propidium iodide (PI) and the release of intracellular lactate dehydrogenase (LDH) and nucleic acid and proteins. Moreover, BM1300 affected cell cycle distribution to exert antibacterial activity collaboratively. Meanwhile, BM1300 inhibited the growth of S. aureus and E. coli of beef meat and improved the microbiological quality of beef meat. These findings place BM1300 as a potential biopreservative in the food industry.
Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Lactobacillus/química , Animais , Antibacterianos/classificação , Eritrócitos/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise , Camundongos , Testes de Sensibilidade MicrobianaRESUMO
This work presents the synthesis of platinum nanoparticles supported on S-layer protein/polymeric particle systems, obtained by combining proteins isolated from Lactobacillus kefiri and an aqueous dispersion of acrylic particles. FTIR spectra of the protein/polymer supports did not show changes in the Amide I band of the proteins, suggesting that proteins maintained their conformation after adsorption. The SAXS spectra and DLS results are consistent with the formation of a protein corona around the polymer particles. After combining the supports with the platinum complex and subsequently reducing the combination with hydrogen at mild conditions, we obtained colloidal nanocomposite materials. In these, platinum nanoparticles with diameters around 3 nm located on the surface of the protein/polymer supports were observed by TEM. The obtained nanosystems showed catalytic activity in the reduction of p-nitrophenol with NaBH4 at room temperature with conversions of 100% for reaction times of 50 to 70 min.
Assuntos
Proteínas de Bactérias/química , Glicoproteínas de Membrana/química , Nanopartículas Metálicas/química , Metilmetacrilatos/química , Adsorção , Boroidretos/química , Catálise , Lactobacillus/química , Nanocompostos/química , Nitrofenóis/química , Oxirredução , Platina/químicaRESUMO
The genus Lactobacillus has been widely used in food industry as starter or adjunct culture due to its probiotic features. Its biotechnological features improve the spectrum of uses of lactobacilli, which can affect its applicability directly. In this sense, this literature review gathers information and discusses the biotechnological potential of technological/probiotic lactobacilli aiming to improve food quality and human health. The primary and secondary metabolism generates specific substances, such as organic acids, carbon dioxide, hydrogen peroxide, diacetyl, fatty acids, and bacteriocins, which are determinant due to their probiotic potential, antimicrobial activity, and the development of new food flavors. In order to become industrially and commercially attractive, it is necessary develop a large-scale process with lower production costs.
Assuntos
Biotecnologia , Qualidade dos Alimentos , Ácido Láctico/metabolismo , Lactobacillus/metabolismo , Probióticos/metabolismo , Humanos , Ácido Láctico/química , Lactobacillus/química , Probióticos/químicaRESUMO
BACKGROUND: Bacteriocins produced by lactic acid bacteria (LAB) can be considered as viable alternatives for food safety and quality, once these peptides present antimicrobial activity against foodborne pathogens and spoilage bacteria. Fermented foods, such as artisanal sausages and cured meats, are relevant sources of LAB strains capable of producing novel bacteriocins, with particular interest by the food industry. RESULTS: Three LAB strains (firstly named as Lactobacillus curvatus 12, L. curvatus 36 and Weissella viridescens 23) were obtained from calabresa by presenting promising bacteriocinogenic activity, distinct genetic profiles (rep-PCR, RAPD, bacteriocin-related genes) and wide inhibitory spectrum. Among these strains, L. curvatus 12 presented higher bacteriocin production, reaching 25,000 AU/mL after incubation at 25, 30 and 37 °C and 6, 9 and 12 h. Partially purified bacteriocins from L. curvatus 12 kept their inhibitory activity after elution with isopropanol at 60% (v/v). Bacteriocins produced by this strain were purified by HPLC and sequenced, resulting in four peptides with 3102.79, 2631.40, 1967.06 and 2588.31 Da, without homology to known bacteriocins. CONCLUSIONS: LAB isolates obtained from calabresa presented high inhibitory activity. Among these isolates, bacteriocins produced by L. curvatus 12, now named as L. curvatus UFV-NPAC1, presented the highest inhibitory performance and the purification procedures revealed four peptides with sequences not described for bacteriocins to date.
Assuntos
Antibiose , Bacteriocinas/isolamento & purificação , Alimentos Fermentados/microbiologia , Lactobacillales/química , Lactobacillus/química , Listeria monocytogenes , Produtos da Carne/microbiologia , Bacteriocinas/genética , Meios de Cultura , Microbiologia de Alimentos , Lactobacillales/isolamento & purificação , Lactobacillus/isolamento & purificaçãoRESUMO
BACKGROUND: This study assessed the survival of the fruit-derived and freeze-dried L. plantarum 49, L. brevis 59, L. paracasei 108, L. fermentum 111 and L. pentosus 129 strains during frozen storage and when incorporated into apple, orange, and grape juice stored under refrigeration. Physicochemical parameters of juices containing the freeze-dried Lactobacillus strains and the survival of the test strains in the fruit juices during in vitro digestion were also evaluated. RESULTS: No decreases in survival rates (log N/log N0) of the freeze-dried cells were observed in up to 1 month of storage. The survival rates of the freeze-dried strains L. plantarum 49 and L. paracasei 108 were > 0.75 in up to 4 months of storage. All freeze-dried strains exhibited survival rates of >0.75 in up to 2 weeks of storage in apple juice; only L. plantarum 49 and L. paracasei 108 showed similar survival rates in orange and grape juices in up to 2 weeks of storage. The contents of the monitored organic acids or sugars during storage varied depending on the added strain and the type of fruit juice. At the end of in vitro digestion, L. brevis 59, L. paracasei 108 and L. fermentum 111 showed survival rates of >0.80 in apple juice. CONCLUSION: Apple juice was the best substrate for the survival of the tested freeze-dried Lactobacillus strains over time. L. paracasei 108 and L. plantarum 49 were the strains presenting the best performance for incorporation in potentially probiotic fruit juices. © 2018 Society of Chemical Industry.
Assuntos
Citrus sinensis/microbiologia , Sucos de Frutas e Vegetais/microbiologia , Lactobacillus/crescimento & desenvolvimento , Malus/microbiologia , Probióticos/química , Vitis/microbiologia , Citrus sinensis/química , Aditivos Alimentares/química , Liofilização , Frutas/química , Frutas/microbiologia , Sucos de Frutas e Vegetais/análise , Lactobacillus/química , Malus/química , Viabilidade Microbiana , Vitis/químicaRESUMO
Industrial ethanol fermentation is subject to bacterial contamination that causes significant economic losses in ethanol fuel plants. Chronic contamination has been associated with biofilms that are normally more resistant to antimicrobials and cleaning efforts than planktonic cells. In this study, contaminant species of Lactobacillus isolated from biofilms (source of sessile cells) and wine (source of planktonic cells) from industrial and pilot-scale fermentations were compared regarding their ability to form biofilms and their sensitivity to different antimicrobials. Fifty lactobacilli were isolated and the most abundant species were Lactobacillus casei, Lactobacillus fermentum and Lactobacillus plantarum. The majority of the isolates (87.8%) were able to produce biofilms in pure culture. The capability to form biofilms and sensitivity to virginiamycin, monensin and beta-acids from hops, showed inter- and intra-specific variability. In the pilot-scale fermentation, Lactobacillus brevis, L. casei and the majority of L. plantarum isolates were less sensitive to beta-acids than their counterparts from wine; L. brevis isolates from biofilms were also less sensitive to monensin when compared to the wine isolates. Biofilm formation and sensitivity to beta-acids showed a positive and negative correlation for L. casei and L. plantarum, respectively.