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2.
Lett Appl Microbiol ; 76(4)2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37076764

RESUMO

Microbial enumeration by serial dilution is one of the best resources to estimate cellular density for microbiological analysis. However, for metataxonomic analysis, it is not clear if serially diluted samples may accurately be used for metataxonomic analysis to represent species composition in beef samples. In this study, the effect of sampling preparation of beef samples on the bacterial composition was evaluated by the comparison of dilution and exudate. Based on the obtained results, data obtained from the exudate of the samples were more robust in terms of number of generated reads, but no significant differences in terms of biological diversity were observed (P < .05, Wicoxon Test). Besides, both sample preparation procedures evidenced equivalent results of bacterial composition as well as its relative abundances. In conclusion, the use of exudate allows bacterial enumeration and metataxonomic analysis, which is interesting for the point of view of food microbiologists as cellular loads and microbial composition of culturable and unculturable bacteria could be compared.


Assuntos
Microbiota , Animais , Bovinos , Bactérias/genética
3.
J Vis Exp ; (194)2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37092836

RESUMO

Probiotics and prebiotics are of great interest to the food and pharmaceutical industries due to their health benefits. Probiotics are live bacteria that can confer beneficial effects on human and animal wellbeing, while prebiotics are types of nutrients that feed the beneficial gut bacteria. Powder probiotics have gained popularity due to the ease and practicality of their ingestion and incorporation into the diet as a food supplement. However, the drying process interferes with cell viability since high temperatures inactivate probiotic bacteria. In this context, this study aimed to present all the steps involved in the production and physicochemical characterization of a spray-dried probiotic and evaluate the influence of the protectants (simulated skim milk and inulin:maltodextrin association) and drying temperatures in increasing the powder yield and cell viability. The results showed that the simulated skim milk promoted higher probiotic viability at 80 °C. With this protectant, the probiotic viability, moisture content, and water activity (Aw) reduce as long as the inlet temperature increases. The probiotics' viability decreases conversely with the drying temperature. At temperatures close to 120 °C, the dried probiotic showed viability around 90%, a moisture content of 4.6% w/w, and an Aw of 0.26; values adequate to guarantee product stability. In this context, spray-drying temperatures above 120 °C are required to ensure the microbial cells' viability and shelf-life in the powdered preparation and survival during food processing and storage.


Assuntos
Prebióticos , Probióticos , Animais , Humanos , Pós , Viabilidade Microbiana , Bactérias
4.
Forensic Sci Res ; 8(3): 173-184, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38221972

RESUMO

Microorganisms are widespread on the planet being able to adapt, persist, and grow in diverse environments, either rich in nutrient sources or under harsh conditions. The comprehension of the interaction between microorganisms and drugs is relevant for forensic toxicology and forensic chemistry, elucidating potential pathways of microbial metabolism and their implications. Considering the described scenario, this paper aims to provide a comprehensive and critical review of the state of the art of interactions amongst microorganisms and common drugs of abuse. Additionally, other drugs of forensic interest are briefly discussed. This paper outlines the importance of this area of investigation, covering the intersections between forensic microbiology, forensic chemistry, and forensic toxicology applied to drugs of abuse, and it also highlights research potentialities. Key points: Microorganisms are widespread on the planet and grow in a myriad of environments.Microorganisms can often be found in matrices of forensic interest.Drugs can be metabolized or produced (e.g. ethanol) by microorganisms.

5.
Vet Microbiol ; 269: 109431, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35468401

RESUMO

In pig nutrition, antibiotics are used to promote growth and/or to treat diseases in order to improve animal performance. However, due to the potential risk of cross selective pressure for antibiotic resistance among bacterial pathogens, the development of new nutritional additives is needed. Among them, probiotics are of great interest since they could improve the immune response, maintain animal intestinal health, and improve nutritional efficiency. Studies with probiotics have also demonstrated their antimicrobial effects on several pathogenic strains, emphasizing that the form of administration can enhance the beneficial effects. In view of the promising advances in probiotic research, it is opportune to highlight their capacity to modulate health and improve performance at all stages of pig production. Therefore, in this review, we will discuss the benefits of probiotics on physiological, immunological, and clinical aspects during different stages of the pig's life cycle. Specifically, probiotics improve performance during pregnancy, parturition and lactation in sows, they can improve immunohematological parameters and defenses in the growing phase, they can influence the quality of meat in the finishing phase and can also help in the reduction of environmental pollutants.


Assuntos
Probióticos , Ração Animal/análise , Animais , Bactérias , Feminino , Intestinos , Lactação , Carne , Gravidez , Probióticos/farmacologia , Suínos
7.
Environ Microbiol Rep ; 14(1): 96-109, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34761870

RESUMO

The analysis of drugs in wastewater for forensic purposes has been constantly increasing and the investigation of the potential interaction between drugs or metabolites and sewage microbiota is important. The results demonstrated that cocaine esterase genes were widely distributed in 1142 global wastewater samples collected from 64 countries and linked to several bacterial species. In addition, in silico predictions indicated that carfentanil, 4F-MDMB-BINACA, 5F-MDMB-PICA, MDMB-4en-PINACA and mitragynine might also undergo microbial hydrolysis, in a similar fashion of cocaine degradation by cocaine esterase. In conclusion, it was demonstrated the microbial potential to hydrolyze drugs of abuse in wastewater environments, contributing to the critical evaluation of potential metabolites as biomarkers for microbial and human transformation of drugs in wastewater.


Assuntos
Drogas Ilícitas , Microbiota , Biotransformação , Canabinoides , Hidrolases de Éster Carboxílico , Humanos , Drogas Ilícitas/metabolismo , Águas Residuárias
8.
Appl Microbiol Biotechnol ; 103(1): 69-82, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30362076

RESUMO

The reduction of the price of DNA sequencing has resulted in the emergence of large data sets to handle and analyze, especially in microbial ecosystems, which are characterized by high taxonomic and functional diversities. To assess the properties of these complex ecosystems, a conceptual background of the application of NGS technology and bioinformatics analysis to metagenomics is required. Accordingly, this article presents an overview of the evolution of knowledge of microbial ecology from traditional culture-dependent methods to culture-independent methods and the last frontier in knowledge, metagenomics. Topics that will be covered include sample preparation for NGS, starting with total DNA extraction and library preparation, followed by a brief discussion of the chemistry of NGS to help provide an understanding of which bioinformatics pipeline approach may be helpful for achieving a researcher's goals. The importance of selecting appropriate sequencing coverage and depth parameters to obtain a suitable measure of microbial diversity is discussed. As all DNA sequencing processes produce base-calling errors that compromise data analysis, including genome assembly and microbial functional analysis, dedicated software is presented and conceptually discussed with regard to potential applications in the general microbial ecology field.


Assuntos
Biologia Computacional/métodos , Microbiologia Industrial/métodos , Metagenômica/métodos , Biodiversidade , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/estatística & dados numéricos , Filogenia , Controle de Qualidade
9.
Probiotics Antimicrob Proteins ; 10(1): 71-76, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28432677

RESUMO

Yoghurts are dairy products consumed worldwide and can be supplemented with substances that provide extra health benefits as well as probiotic strains. In this context, the present study aimed to prepare a yoghurt added of juçara (Euterpe edulis M.) pulp and the commercial probiotic strain Lactobacillus acidophilus La5. Moreover, the probiotic survival during storage and after in vitro exposure to simulated gastric and enteric conditions was evaluated. Four formulations of yoghurt were prepared: (a) natural yoghurt, (b) yoghurt added of probiotic, (c) yoghurt added of juçara pulp, and (d) yoghurt added of probiotic culture and juçara pulp. The preparations were evaluated for survival of probiotic strain during storage and its tolerance to gastric and enteric conditions in vitro. The probiotic population in yoghurt remained unchanged during 28 days of storage. In addition, juçara pulp increased the probiotic resistance to simulated gastric and enteric conditions in the first day of storage. These data indicate that juçara pulp is a potential ingredient for the production of probiotic yoghurts.


Assuntos
Euterpe/microbiologia , Aditivos Alimentares/análise , Lactobacillus acidophilus/crescimento & desenvolvimento , Iogurte/análise , Animais , Bovinos , Euterpe/metabolismo , Fermentação , Manipulação de Alimentos , Lactobacillus acidophilus/metabolismo , Viabilidade Microbiana , Leite/química , Leite/microbiologia , Iogurte/microbiologia
10.
J Dairy Res ; 83(1): 115-24, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26608755

RESUMO

Lactic acid bacteria (LAB) can be isolated from different sources such as milk and cheese, and the lipolytic, proteolytic and glycolytic enzymes of LAB are important in cheese preservation and in flavour production. Moreover, LAB produce several antimicrobial compounds which make these bacteria interesting for food biopreservation. These characteristics stimulate the search of new strains with technological potential. From 156 milk and cheese samples from cow, buffalo and goat, 815 isolates were obtained on selective agars for LAB. Pure cultures were evaluated for antimicrobial activities by agar antagonism tests and for proteolytic activity on milk proteins by cultivation on agar plates. The most proteolytic isolates were also tested by cultivation in skim milk followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the fermented milk. Among the 815 tested isolates, three of them identified as Streptococcus uberis (strains FT86, FT126 and FT190) were bacteriocin producers, whereas four other ones identified as Weissella confusa FT424, W. hellenica FT476, Leuconostoc citreum FT671 and Lactobacillus plantarum FT723 showed high antifungal activity in preliminary assays. Complementary analyses showed that the most antifungal strain was L. plantarum FT723 that inhibited Penicillium expansum in modified MRS agar (De Man, Rogosa, Sharpe, without acetate) and fermented milk model, however no inhibition was observed against Yarrowia lipolytica. The proteolytic capacities of three highly proteolytic isolates identified as Enterococcus faecalis (strains FT132 and FT522) and Lactobacillus paracasei FT700 were confirmed by SDS-PAGE, as visualized by the digestion of caseins and whey proteins (ß-lactoglobulin and α-lactalbumin). These results suggest potential applications of these isolates or their activities (proteolytic activity or production of antimicrobials) in dairy foods production.


Assuntos
Bactérias/classificação , Búfalos , Bovinos , Queijo/microbiologia , Cabras , Leite/microbiologia , Animais , Antibacterianos , Antibiose/fisiologia , Bactérias/metabolismo , Brasil , Microbiologia de Alimentos
11.
Braz J Microbiol ; 46(1): 231-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26221112

RESUMO

Listeria monocytogenes is a foodborne pathogen able to adhere and to form biofilms in several materials commonly present in food processing plants. The aim of this study was to evaluate the resistance of Listeria monocytogenes attached to abiotic surface, after treatment with sanitizers, by culture method, microscopy and Quantitative Real Time Polymerase Chain Reaction (qPCR). Biofilms of L. monocytogenes were obtained in stainless steel coupons immersed in Brain Heart Infusion Broth, under agitation at 37 °C for 24 h. The methods selected for this study were based on plate count, microscopic count with the aid of viability dyes (CTC-DAPI), and qPCR. Results of culture method showed that peroxyacetic acid was efficient to kill sessile L. monocytogenes populations, while sodium hypochlorite was only partially effective to kill attached L. monocytogenes (p < 0.05). When, viability dyes (CTC/DAPI) combined with fluorescence microscopy and qPCR were used and lower counts were found after treatments (p < 0.05). Selective quantification of viable cells of L. monocytogenes by qPCR using EMA revelead that the pre-treatment with EMA was not appropriate since it also inhibited amplification of DNA from live cells by ca. 2 log. Thus, the use of CTC counts was the best method to count viable cells in biofilms.


Assuntos
Carga Bacteriana/métodos , Biofilmes/efeitos dos fármacos , Desinfetantes/farmacologia , Microbiologia Ambiental , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/fisiologia , Viabilidade Microbiana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Listeria monocytogenes/isolamento & purificação , Microscopia , Reação em Cadeia da Polimerase em Tempo Real , Temperatura , Tempo
12.
Int J Food Microbiol ; 173: 81-8, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24412962

RESUMO

Carnobacterium maltaromaticum C2, isolated from Brazilian smoked fish (Surubim, Pseudoplatystoma sp.), was found to exert antimicrobial activity against Listeria monocytogenes, an important foodborne pathogen. In this study, the bacteriocins produced by C. maltaromaticum C2 were purified via an extraction with XAD-16 resin, a C18 solid phase extraction, followed by reversed-phase fast protein liquid chromatography. The purified active fractions were characterized using tandem mass spectrometry, permitting the identification of multiple bacteriocins. Carnobacteriocins BM1, B1, and a variant of carnobacteriocin B2 were all found, providing much of the antilisterial activity. Additionally, we herein report the first isolation of the previously predicted antimicrobial peptide carnobacteriocin X. Moreover, C. maltaromaticum C2 produces a novel two-component lantibiotic, termed carnolysin, homologous to enterococcal cytolysin. This lantibiotic is antimicrobially inactive when tested against the non-bacteriocinogenic strain C. maltaromaticum A9b-, likely requiring an additional proteolytic cleavage to reach maturity.


Assuntos
Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bacteriocinas/farmacologia , Carnobacterium/química , Listeria monocytogenes/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Bacteriocinas/química , Bacteriocinas/isolamento & purificação , Brasil , Peixes/microbiologia
13.
Anaerobe ; 22: 57-63, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23792229

RESUMO

This study aimed to identify a bacteriocinogenic Lactobacillus isolate (FT259) obtained from Brazilian semi-hard Minas type cheese and to evaluate its probiotic and antimicrobial potentials. The strain was identified by biochemical tests (at genus level), and by 16S rDNA sequencing combined with recA gene amplification (for species). To determine the inhibitory spectrum towards food borne pathogens and lactic acid bacteria, the spot-on-the-lawn assay was carried out. Moreover, the proteinaceous nature of the antimicrobial compound produced was evaluated by susceptibility to degradation by proteolytic enzymes. The isolated strain was tested for survival in acidified culture media (pH 2.0, 2.5 and 3.5), in vitro tolerance to bile salts and viability under gastric conditions. Adhesion of Lactobacillus paraplantarum FT259 to Caco-2 cells was evaluated by surface plate count on De Man, Rogosa, and Sharpe (MRS) agar and also by FISH method (fluorescent in situ hybridization) with the aid of Eub338 probe for fluorescence microscopy analysis. The isolate was identified as L. paraplantarum FT259 and it produced bacteriocins that inhibited the growth of Listeria monocytogenes, Listeria innocua and several lactic acid bacteria. It was also observed that L. paraplantarum FT259 tolerated exposure to pH 3.5, and bile salts 0.3% for up to 180 min. In experiments with simulated gastric juice, viable cells of L. paraplantarum FT259 decreased from 8.6 log CFU/mL to 3.5 log CFU/mL after 180 min. For the same strain, in studies with Caco-2 cells, 74% of adhesion was observed through plate count and FISH assays. It was also demonstrated isolated FT259 was susceptible to the majority the antibiotics tested. Overall, the results indicated L. paraplantarum FT259 is a potential probiotic and the production of bacteriocin may be an interesting feature for food applications.


Assuntos
Antibacterianos/análise , Bacteriocinas/análise , Queijo/microbiologia , Lactobacillus plantarum/genética , Lactobacillus plantarum/isolamento & purificação , Probióticos/classificação , Estômago/microbiologia , Aderência Bacteriana , Sequência de Bases , Brasil , Células CACO-2/microbiologia , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Lactobacillus plantarum/efeitos dos fármacos , Listeria/efeitos dos fármacos , Viabilidade Microbiana , Especificidade da Espécie
14.
Probiotics Antimicrob Proteins ; 5(3): 153-64, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26782984

RESUMO

In this report, Listeria monocytogenes isolates were evaluated for their ability to form biofilms, for adhesion/invasion of eukaryotic cells and for differential expression of internalin A (inl A) gene, which is related to virulence potential. The presence of bacteriocins of lactic acid bacteria and incubation at 5 °C were the main factors that influenced biofilm formation by L. monocytogenes, in comparison with BHI (control). In general, adhesion and invasion of Caco-2 cells were significantly lower in low pH (4.5), in incubation at 5 °C and in the presence of Oxgall 0.3 %. On the other hand, two L. monocytogenes isolates (INCQS 353 and Reg 26c) showed higher invasion rates when cultivated in the presence of NaCl 5 % (P < 0.05). One L. monocytogenes isolate (H-2) showed the strongest ability to form biofilm and to invade Caco-2 cells, under selected conditions, suggesting there is a relationship between biofilm formation and virulence potential. For all isolates, expression of inl A gene was down-regulated by the presence of bacteriocins, Oxgall 0.3 %, pH 4.5 and incubation at 5 °C. Nonetheless, for one L. monocytogenes isolate (HU 471), expression of inl A gene was eight times higher in the presence of sucrose, indicating that food components can increase the infectiveness of L. monocytogenes.

15.
FEMS Microbiol Ecol ; 84(1): 110-23, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23167835

RESUMO

A validated in vitro model of the large intestine (TIM-2), set up with human or pig faeces, was used to evaluate the impact of potentially probiotic Lactobacillus amylovorus DSM 16698, administered alone (i), in the presence of prebiotic galactooligosaccharides (GOS) (ii), and co-administered with probiotic Bifidobacterium animalis ssp. lactis Bb-12 (Bb-12) (iii) on GOS degradation, microbial growth (L. amylovorus, lactobacilli, bifidobacteria and total bacteria) and metabolite production. High performance anion exchange chromatography revealed that GOS degradation was more pronounced in TIM-2 inoculated with pig faeces than with human faeces. Denaturing gradient gel electrophoresis profiling of PCR-amplified 16S rRNA genes detected a more complex Lactobacillus spp. community in pig faecal material than in human faecal inoculum. According to 16S rRNA gene-targeted qPCR, GOS stimulated the growth of lactobacilli and bifidobacteria in faecal material from both materials. The cumulative production of short chain fatty acids and ammonia was higher (P < 0.05) for pig than for human faeces. However, lactate accumulation was higher (P < 0.05) in the human model and increased after co-administration with GOS and Bb-12. This study reinforced the notion that differences in microbiota composition between target host organisms need to be considered when animal data are extrapolated to human, as is often done with pre- and probiotic intervention studies.


Assuntos
Bifidobacterium , Colo/microbiologia , Lactobacillus acidophilus , Oligossacarídeos/administração & dosagem , Prebióticos , Probióticos/administração & dosagem , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Bifidobacterium/genética , Cromatografia por Troca Iônica , Eletroforese em Gel de Gradiente Desnaturante , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Galactose/química , Humanos , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Lactobacillus acidophilus/genética , Lactobacillus acidophilus/crescimento & desenvolvimento , Metagenoma , Oligossacarídeos/metabolismo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Sus scrofa
16.
J Food Prot ; 75(6): 1083-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22691476

RESUMO

Lactobacillus sakei 1 is a food isolate that produces a heat-stable antimicrobial peptide (sakacin 1, a class IIa bacteriocin) inhibitory to the opportunistic pathogen Listeria monocytogenes. Bacterial isolates with antimicrobial activity may be useful for food biopreservation and also for developing probiotics. To evaluate the probiotic potential of L. sakei 1, it was tested for (i) in vitro gastric resistance (with synthetic gastric juice adjusted to pH 2.0, 2.5, or 3.0); (ii) survival and bacteriocin production in the presence of bile salts and commercial prebiotics (inulin and oligofructose); (iii) adhesion to Caco-2 cells; and (iv) effect on the adhesion of L. monocytogenes to Caco-2 cells and invasion of these cells by the organism. The results showed that L. sakei 1 survival in gastric environment varied according to pH, with the maximum survival achieved at pH 3.0, despite a 4-log reduction of the population after 3 h. Regarding the bile salt tolerance and influence of prebiotics, it was observed that L. sakei 1 survival rates were similar (P > 0.05) for all de Man Rogosa Sharpe (MRS) broth formulations when tests were done after 4 h of incubation. However, after incubation for 24 h, the survival of L. sakei 1 in MRS broth was reduced by 1.8 log (P < 0.001), when glucose was replaced by either inulin or oligofructose (without Oxgall). L. sakei 1 was unable to deconjugate bile salts, and there was a significant decrease (1.4 log) of the L. sakei 1 population in regular MRS broth plus Oxgall (P < 0.05). In spite of this, tolerance levels of L. sakei 1 to bile salts were similar in regular MRS broth and in MRS broth with oligofructose. Lower bacteriocin production was observed in MRS broth when inulin (3,200 AU/ml) or oligofructose (2,400 AU/ml) was used instead of glucose (6,400 AU/ml). L. sakei 1 adhered to Caco-2 cells, and its cell-free pH-neutralized supernatant containing sakacin 1 led to a significant reduction of in vitro listerial invasion of human intestinal Caco-2 cells.


Assuntos
Bacteriocinas/biossíntese , Ácidos e Sais Biliares/farmacologia , Lactobacillus/fisiologia , Viabilidade Microbiana , Aderência Bacteriana , Ácidos e Sais Biliares/metabolismo , Células CACO-2/microbiologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Inulina/metabolismo , Inulina/farmacologia , Lactobacillus/efeitos dos fármacos , Lactobacillus/metabolismo , Oligossacarídeos/metabolismo , Oligossacarídeos/farmacologia , Probióticos
17.
Int J Food Microbiol ; 149(2): 152-8, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21741105

RESUMO

Probiotic properties of Lactobacillus amylovorus DSM 16698 were previously demonstrated in piglets. Here, its potential as a human probiotic was studied in vitro, using the TIM-1 system, which is fully validated to simulate the human upper gastrointestinal tract. To evaluate the effect of the food matrix composition on the survival of L. amylovorus DSM 16698 in TIM-1, the microorganism was inoculated alone or with prebiotic galactooligosaccharides (GOS), partially skimmed milk (PSM) and/or commercial probiotic Bifidobacterium animalis subsp. lactis Bb-12 (Bb-12). Samples were collected from TIM-1 for six hours, at one-hour intervals and L. amylovorus populations were enumerated on MRS agar plates with confirmation of identity of selected isolates by randomly amplified polymorphic DNA (RAPD) fingerprinting. The cumulative survival for L. amylovorus alone (control) was 30% at the end of the experiment (t=6h). Co-administration of L. amylovorus with GOS, PSM and/or Bb-12 increased its survival in comparison with the control significantly from the 4th hour after ingestion onwards (P<0.05). Furthermore, by the use of High Performance Anion Exchange Chromatography, both L. amylovorus and Bb-12 were observed to promptly degrade GOS compounds in samples collected from TIM-1, as assessed at t=2h. Hence, food matrix composition interfered with survival and growth of L. amylovorus during passage through TIM-1, providing leads towards optimization of probiotic properties in vivo.


Assuntos
Bifidobacterium/crescimento & desenvolvimento , Trato Gastrointestinal/microbiologia , Lactobacillus acidophilus/crescimento & desenvolvimento , Oligossacarídeos/metabolismo , Prebióticos , Probióticos , Animais , Impressões Digitais de DNA , Humanos , Leite/microbiologia , Modelos Biológicos
18.
Int J Food Microbiol ; 146(3): 228-34, 2011 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-21419508

RESUMO

Minimally processed refrigerated ready-to-eat fishes may offer health risk of severe infection to susceptible individuals due to contamination by the psychrotolerant bacterium L. monocytogenes. In this work, inhibition of L. monocytogenes by a plant extract and lactic acid bacteria (LAB) was studied in model fish systems kept at 5 °C for 35 days. For that, fillets of tropical fish "surubim" (Pseudoplatystoma sp.) and hydroalcoholic extract of the plant Lippia sidoides Cham. ("alecrim pimenta") were used. Fish peptone broth (FPB), "surubim" broth and "surubim" homogenate were inoculated with combinations of L. monocytogenes and bacteriocin-producing Carnobacterium maltaromaticum (C2 and A9b(+)) and non bacteriocin-producing C. maltaromaticum (A9b(-)), in the presence or absence of extract of "alecrim pimenta" (EAP). In all model systems, monocultures of L. monocytogenes and carnobacteria reached final populations ≥10(8) CFU/ml after 35 days, except for L. monocytogenes in "surubim" homogenate (10(4) CFU/ml). In FPB, EAP alone and combined with cultures of LAB inhibited L. monocytogenes but carnobacteria without EAP were only weakly antilisterial. In "surubim" broth, EAP alone did not prevent L. monocytogenes growth but cultures of carnobacteria combined or not with EAP inhibited L. monocytogenes, with more pronounced effect being observed for C. maltaromaticum C2, which produced bacteriocin. In "surubim" homogenate, EAP alone and combined with cultures of C. maltaromaticum A9b(-) and A9b(+) were strongly inhibitory to L. monocytogenes, while C. maltaromaticum C2 with EAP caused transient inhibition of L. monocytogenes. No significant inhibition of L. monocytogenes was observed for carnobacteria in "surubim" homogenate without EAP. In conclusion, it was observed that the use of EAP and cultures of carnobacteria have potential to inhibit L. monocytogenes in fish systems and the applications should be carefully studied, considering the influence of food matrix.


Assuntos
Carnobacterium/metabolismo , Peixes/microbiologia , Microbiologia de Alimentos , Listeria monocytogenes/patogenicidade , Extratos Vegetais/farmacologia , Alimentos Marinhos/microbiologia , Animais , Antibiose , Bacteriocinas/farmacologia , Carnobacterium/fisiologia , Contagem de Colônia Microbiana , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos , Conservação de Alimentos , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/fisiologia , Lippia/química , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento
19.
Braz J Microbiol ; 41(1): 6-14, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24031455

RESUMO

Urogenital infections affect millions of people every year worldwide. The treatment of these diseases usually requires the use of antimicrobial agents, and more recently, the use of probiotic lactic acid bacteria (LAB) cultures for the management of vaginal infections has been extensively studied. In this work, 11 vaginal lactobacilli isolates, previously obtained from healthy patients, were studied to screen microorganisms with probiotic properties against Candida spp. The LAB were tested for their ability of auto-aggregation, co-aggregation with C. albicans, C. glabrata, C. krusei, and C. tropicalis, adhesion to Caco-2 epithelial cells and production of lactic acid and hydrogen peroxide (H2O2). All lactobacilli isolates tested were able to auto-aggregate (ranging from 25.3% to 75.4% assessed at 4 hours of incubation) and to co-aggregate with the four Candida species into different degrees; among them L. crispatus showed the highest scores of co-aggregation. The highest amount of lactic acid was produced by L. salivarius (13.9 g/l), followed by L. johnsonii (6.5 g/l), L. acidophilus (5.5 g/l), and L. jensenii (5.4 g/l). All isolates produced H2O2, but the highest levels (3 - 10 mg/l) were observed for L. acidophilus, L. crispatus, L. gasseri, L. johnsonii, and L. vaginalis. Only L. agilis, L. jensenii, L. johnsonii and L. ruminus were able to adhere to epithelial Caco-2 cells. Among the isolates evaluated, L agilis, L. jensenii, L. johnsonii, and L. ruminus exhibited simultaneously several desirable properties as potential probiotic strains justifying future studies to evaluate their technological properties in different pharmaceutical preparations for human use.

20.
Microbiol Immunol ; 53(9): 487-95, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19703242

RESUMO

Vulvovaginal candidiasis, a high prevailing infection worldwide, is mainly caused by Candida albicans. Probiotic Lactobacillus reuteri RC-14 and Lactobacillus rhamnosus GR-1 have been previously shown to be useful as adjuvants in the treatment of women with VVC. In order to demonstrate and better understand the anti-Candida activity of the probiotic microorganisms in an in vitro model simulating vaginal candidiasis, a human vaginal epithelial cell line (VK2/E6E7) was infected with C.albicans 3153a and then challenged with probiotic L. rhamnosus GR-1 and/or L. reuteri RC-14 or their respective CFS (alone or in combination). At each time point (0, 6, 12 and 24 hr), numbers of yeast, lactobacilli and viable VK2/E6E7 cells were determined and, at 0, 6 and 12 hr, the supernatants were measured for cytokine levels. We found that C. albicans induced a significant increase in IL-1alpha and IL-8 production by VK2/E6E7 cells. After lactobacilli challenge, epithelial cells did not alter IL-6, IL-1alpha, RANTES and VEGF levels. However, CFS from the probiotic microorganisms up-regulated IL-8 and IP-10 levels secreted by VK2/E6E7 cells infected with C. albicans. At 24 hr of co-incubation, L. reuteri RC-14 alone and in combination with L. rhamnosus GR-1 decreased the yeast population recoverable from the cells. In conclusion, L. reuteri RC-14 alone and together with L. rhamnosus GR-1 have the potential to inhibit the yeast growth and their CFS may up-regulate IL-8 and IP-10 secretion by VK2/E6E7 cells, which could possibly have played an important role in helping to clear VVC in vivo.


Assuntos
Candida albicans/imunologia , Candidíase Vulvovaginal/imunologia , Lacticaseibacillus rhamnosus/imunologia , Limosilactobacillus reuteri/imunologia , Candida albicans/fisiologia , Candidíase Vulvovaginal/microbiologia , Linhagem Celular , Citocinas/imunologia , Feminino , Humanos , Limosilactobacillus reuteri/fisiologia , Lacticaseibacillus rhamnosus/fisiologia , Modelos Biológicos
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