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1.
World J Microbiol Biotechnol ; 37(8): 143, 2021 Jul 30.
Article in English | MEDLINE | ID: mdl-34328568

ABSTRACT

Antifungal and antibacterial activities of twenty-six combinations of lactic acid bacteria, propionibacteria, acetic acid bacteria and dairy yeasts inoculated in whey and milk were investigated. Associations including acetic acid bacteria were shown to suppress growth of the opportunistic yeast Candida albicans in well-diffusion assays. The protective effect of milk fermented with the two most promising consortia was confirmed in Caco-2 cell culture infected with C. albicans. Indeed, these fermented milks, after heat-treatment or not, suppressed lactate dehydrogenase release after 48 h while significant increase in LDH release was observed in the positive control (C. albicans alone) and with fermented milk obtained using commercial yogurt starter cultures. The analysis of volatile compounds in the cell-free supernatant using solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) showed accumulation of significant amount of acetic acid by the consortium composed of Lactobacillus delbrueckii 5, Lactobacillus gallinarum 1, Lentilactobacillus parabuchneri 3, Lacticaseibacillus paracasei 33-4, Acetobacter syzygii 2 and Kluyveromyces marxianus 19, which corresponded to the zone of partial inhibition of C. albicans growth during well-diffusion assays. Interestingly, another part of anti-Candida activity, yielding small and transparent inhibition zones, was linked with the consortium cell fraction. This study showed a correlation between anti-Candida activity and the presence of acetic acid bacteria in dairy associations as well as a significant effect of two dairy associations against C. albicans in a Caco-2 cell model. These two associations may be promising consortia for developing functional dairy products with antagonistic action against candidiasis agents.


Subject(s)
Candida/growth & development , Cultured Milk Products/microbiology , Lactobacillales/metabolism , Milk/microbiology , Animals , Antibiosis , Caco-2 Cells , Cattle , Cultured Milk Products/analysis , Fermentation , Gas Chromatography-Mass Spectrometry , Humans , Lactobacillales/chemistry , Lactobacillales/classification , Milk/chemistry
2.
Int J Food Microbiol ; 322: 108574, 2020 Jun 02.
Article in English | MEDLINE | ID: mdl-32151821

ABSTRACT

Fungi are commonly identified as the cause for dairy food spoilage. This can lead to substantial economic losses for the dairy industry as well as consumer dissatisfaction. In this context, biopreservation of fermented dairy products using lactic acid bacteria, propionibacteria and fungi capable of producing a large range of antifungal metabolites is of major interest. In a previous study, extensive screening was performed in vitro and in situ to select 3 dairy fermentates (derived from Acidipropionibacterium jensenii CIRM-BIA1774, Lactobacillus rhamnosus CIRM-BIA1952 and Mucor lanceolatus UBOCC-A-109193, respectively) with antifungal activity. The aim of the present study was to determine the main compounds responsible for this antifungal activity. Fifty-six known antifungal compounds as well as volatiles were targeted using different analytical methods (conventional LC and GC, GC-MS, LC-QToF). The most abundant antifungal compounds in P. jensenii-, L. rhamnosus- and M. lanceolatus-derived fermentates corresponded to propionic and acetic acids, lactic and acetic acids, and butyric acid, respectively. Many other antifungal compounds (organic acids, free fatty acids, volatile compounds) were identified but at lower levels. In addition, an untargeted approach using nano LC-MS/MS identified a 9-amino acid peptide derived from αs2-casein in the L. rhamnosus-derived fermentate. This peptide inhibited M. racemosus and R. mucilaginosa in vitro. This study provides new insights on the molecules involved in antifungal activities of food-grade microorganism fermentates which could be used as antifungal ingredients in the dairy industry.


Subject(s)
Antifungal Agents/analysis , Cultured Milk Products/analysis , Food Preservatives/analysis , Antifungal Agents/chemistry , Antifungal Agents/metabolism , Antifungal Agents/pharmacology , Bioreactors , Cultured Milk Products/microbiology , Fermentation , Food Microbiology , Food Preservatives/chemistry , Food Preservatives/metabolism , Food Preservatives/pharmacology , Lacticaseibacillus rhamnosus/isolation & purification , Lacticaseibacillus rhamnosus/metabolism , Mucor/isolation & purification , Mucor/metabolism , Propionibacterium/isolation & purification , Propionibacterium/metabolism , Rhodotorula/drug effects
3.
Food Chem ; 301: 125260, 2019 Dec 15.
Article in English | MEDLINE | ID: mdl-31404803

ABSTRACT

In the context of growing consumer demand for clean label foods, antifungal cultures offer alternatives to chemical preservatives for the reduction of food fungal spoilage. Selected binary combinations of lactobacilli strains were recently successfully used to inhibit Penicillium commune and Mucor racemosus in four dairy products. Our aim was to identify the compounds most likely involved in their antifungal activity. Four chromatographic methods, targeting 56 antifungal compounds as well as volatiles, were combined. Overall, 53 antifungal compounds were detected, of which 33 were in significantly higher amounts in at least one product inoculated with an antifungal culture compared to the controls. They were present at concentrations below their MIC and thus could act in synergy. Among them, the most commonly identified were acetic, hydroxyphenyllactic, phenyllactic, 3-phenylpropanoic, 3-(4-hydroxyphenyl)propanoic and 5-oxopyrrolidine-2-carboxylic acids, diacetyl, acetoin, and an unidentified volatile. This extensive study contributes to improve the knowledge about the action mode of antifungal lactobacilli.


Subject(s)
Biological Products/analysis , Dairy Products/microbiology , Lactobacillus/chemistry , Lactobacillus/physiology , Mucor , Penicillium , Biological Products/metabolism , Lactobacillus/metabolism
4.
Food Microbiol ; 82: 160-170, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31027770

ABSTRACT

In the context of a demand for "preservative-free" food products, biopreservation appears as a promising alternative to either replace or reduce the use of chemical preservatives. The purpose of this study was to evaluate the antifungal activity of a collection of lactic acid bacteria (n = 194), and then to evaluate the applicability and efficacy of selected ones used as bioprotective cultures against mold spoilers in dairy and bakery products. First, lactic acid bacteria were isolated from various Algerian raw milk samples and Amoredj, a traditional fermented product. Secondly, in vitro screening tests against Mucor racemosus UBOCC-A-109155, Penicillium commune UBOCC-A-116003, Yarrowia lipolytica UBOCC-A-216006, Aspergillus tubingensis AN, Aspergillus flavus T5 and Paecilomyces formosus AT allowed for the selection of 3 active strains, namely Lactobacillus plantarum CH1, Lactobacillus paracasei B20 and Leuconostoc mesenteroides L1. In situ tests were then performed to validate their activity in actual products (sour cream and sourdough bread) challenged with fungal spoilers. These tests showed that antifungal LAB could slow the fungal target growth and could be candidates of interest for industrial applications. Finally, organic acids and various antifungal compounds produced in sour cream and sourdough bread by the selected LAB, and thus potentially supporting the observed antifungal activity, were identified and quantified by HPLC and LC-QTOF.


Subject(s)
Antifungal Agents/pharmacology , Dairy Products/microbiology , Food Microbiology , Food Preservatives/pharmacology , Lactobacillales/physiology , Animals , Antibiosis , Antifungal Agents/metabolism , Bread/microbiology , Fermented Foods/microbiology , Food Preservatives/metabolism , Fungi/drug effects , Fungi/growth & development , Lactobacillales/isolation & purification , Lactobacillales/metabolism , Milk/microbiology
5.
Front Microbiol ; 9: 1787, 2018.
Article in English | MEDLINE | ID: mdl-30131783

ABSTRACT

Consumer's demand for naturally preserved food products is growing and the use of bioprotective cultures is an alternative to chemical preservatives or a complementary tool to hurdle technologies to avoid or delay fungal spoilage of dairy products. To develop antifungal cultures for the dairy product biopreservation, experiments were conducted both in vitro and in situ. Firstly, the antifungal activity of 32 strains of lactic acid bacteria (LAB) and propionibacteria was screened alone, and then on combinations based on 5 selected lactobacilli strains. This screening was performed in yogurt and cheese models against four major spoilage fungi previously isolated from contaminated dairy products (Penicillium commune, Mucor racemosus, Galactomyces geotrichum, and Yarrowia lipolytica). Selected combinations were then tested as adjunct cultures in sour cream and semi-hard cheeses produced at a pilot scale to evaluate their antifungal activity during challenge tests against selected fungal targets (P. commune, M. racemosus, and Rhodotorula mucilaginosa) and shelf life tests; and their impact on product organoleptic properties. The screening step allowed selecting two binary combinations, A1 and A3 composed of Lactobacillus plantarum L244 and either Lactobacillus harbinensis L172 or Lactobacillus rhamnosus CIRM-BIA1113, respectively. In situ assays showed that the A1 combination delayed the growth of P. commune, M. racemosus and R. mucilaginosa for 2-24 days on sour cream depending of the antifungal culture inoculum, without effect on organoleptic properties at low inoculum (106 colony-forming units (CFU)/mL). Moreover, the A1 and A3 combinations also delayed the growth of P. commune in semi-hard cheese for 1-6 days and 1 day, respectively. Antifungal cultures neither impacted the growth of starter cultures in both sour cream and cheese nor the products' pH, although post acidification was observed in sour cream supplemented with these combinations at the highest concentrations (2.107 CFU/mL). The combination of both in vitro and in situ screening assays allowed developing 2 antifungal combinations exhibiting significant antifungal activity and providing future prospects for use as bioprotective cultures in dairy products.

6.
J Dairy Sci ; 101(6): 4971-4976, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29605322

ABSTRACT

In this study, we developed a high-throughput antifungal activity screening method using a cheese-mimicking matrix distributed in 24-well plates. This method allowed rapid screening of a large variety of antifungal agent candidates: bacterial fermented ingredients, bacterial isolates, and preservatives. Using the proposed method, we characterized the antifungal activity of 44 lactic acid bacteria (LAB) fermented milk-based ingredients and 23 LAB isolates used as protective cultures against 4 fungal targets (Mucor racemosus, Penicillium commune, Galactomyces geotrichum, and Yarrowia lipolytica). We also used this method to determine the minimum inhibitory concentration of a preservative, natamycin, against 9 fungal targets. The results underlined the strain-dependency of LAB antifungal activity, the strong effect of fermentation substrate on this activity, and the effect of the screening medium on natamycin minimum inhibitory concentration. Our method could achieved a screening rate of 1,600 assays per week and can be implemented to evaluate antifungal activity of microorganisms, fermentation products, or purified compounds compatible with dairy technology.


Subject(s)
Cheese/microbiology , Lactobacillales/isolation & purification , Lactobacillales/physiology , Animals , Antibiosis , Antifungal Agents , Cattle , Fermentation , Food Microbiology , Fungi/drug effects , Fungi/physiology , High-Throughput Screening Assays , Lactobacillales/genetics , Lactobacillales/immunology , Microbial Sensitivity Tests , Milk/microbiology , Natamycin/pharmacology
7.
Microorganisms ; 5(3)2017 Sep 20.
Article in English | MEDLINE | ID: mdl-28930185

ABSTRACT

Many bacteria biosynthesize structurally diverse exopolysaccharides (EPS) and excrete them into their surrounding environment. The EPS functional features have found many applications in industries such as cosmetics and pharmaceutics. In particular, some EPS produced by marine bacteria are composed of uronic acids, neutral sugars, and N-acetylhexosamines, and may also bear some functional sulfate groups. This suggests that they can share common structural features with glycosaminoglycans (GAG) like the two EPS (HE800 and GY785) originating from the deep sea. In an attempt to discover new EPS that may be promising candidates as GAG-mimetics, fifty-one marine bacterial strains originating from deep-sea hydrothermal vents were screened. The analysis of the EPS chemical structure in relation to bacterial species showed that Vibrio, Alteromonas, and Pseudoalteromonas strains were the main producers. Moreover, they produced EPS with distinct structural features, which might be useful for targeting marine bacteria that could possibly produce structurally GAG-mimetic EPS.

8.
Microorganisms ; 5(3)2017 Jul 08.
Article in English | MEDLINE | ID: mdl-28698479

ABSTRACT

Food spoilage is a major issue for the food industry, leading to food waste, substantial economic losses for manufacturers and consumers, and a negative impact on brand names. Among causes, fungal contamination can be encountered at various stages of the food chain (e.g., post-harvest, during processing or storage). Fungal development leads to food sensory defects varying from visual deterioration to noticeable odor, flavor, or texture changes but can also have negative health impacts via mycotoxin production by some molds. In order to avoid microbial spoilage and thus extend product shelf life, different treatments-including fungicides and chemical preservatives-are used. In parallel, public authorities encourage the food industry to limit the use of these chemical compounds and develop natural methods for food preservation. This is accompanied by a strong societal demand for 'clean label' food products, as consumers are looking for more natural, less severely processed and safer products. In this context, microbial agents corresponding to bioprotective cultures, fermentates, culture-free supernatant or purified molecules, exhibiting antifungal activities represent a growing interest as an alternative to chemical preservation. This review presents the main fungal spoilers encountered in food products, the antifungal microorganisms tested for food bioprotection, and their mechanisms of action. A focus is made in particular on the recent in situ studies and the constraints associated with the use of antifungal microbial agents for food biopreservation.

9.
Rev Peru Med Exp Salud Publica ; 31(2): 380-4, 2014 Apr.
Article in Spanish | MEDLINE | ID: mdl-25123883

ABSTRACT

The case of an adult, 56 year old male is reported, from Sihuas (Ancash) who presented at Hospital Nacional Dos de Mayo with fever, jaundice and anemia. In three days of hospitalization, he developed severe anemia (Hb: 11.8 to 6.7 g / dL) and generalized myalgias associated with a sudden worsening jaundice correlated with elevated bilirubin (TB 3.2 to 19.6 mg / dL direct dominance) and general deterioration. Microbiological smear and culture were positive for Bartonella bacilliformis. Subsequent serology (microagglutination) was positive for Lesptospira serovar Pomona. The patient was given specific antibiotic therapy (ceftriaxone and ciprofloxacin), transfused two units of packed red blood cells, improved clinically and was discharged.


Subject(s)
Bartonella Infections/complications , Leptospirosis/complications , Acute Disease , Humans , Male , Middle Aged , Severity of Illness Index
10.
Rev. peru. med. exp. salud publica ; 31(2): 380-384, abr.-jun. 2014. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: lil-719519

ABSTRACT

Se reporta el caso de un adulto varón de 56 años, procedente de Sihuas (Ancash) que acude al Hospital Nacional Dos de Mayo con cuadro clínico caracterizado por un síndrome ictérico febril anemizante, en cuya evolución tórpida de solo tres días de hospitalizado presenta anemia severa (Hb: 11,8 a 6,7 g/dL) así como mialgias generalizadas asociadas a un empeoramiento brusco de la ictericia correlacionada con elevación de bilirrubinas (BT: 3,2 a 19,6 mg/dL a predominio directo) y deterioro general del paciente; por ello, se realizó la investigación microbiológica donde se encontró frotis y cultivo positivo para Bartonella bacilliformis, posteriormente, la serología (microaglutinación) resultó positiva para Lesptospira serovar Pomona. El paciente recibe tratamiento antibiótico específico (ceftriaxona y ciprofloxacino), se le transfunde dos paquetes globulares, mejora clínicamente y es dado de alta.


The case of an adult, 56 year old male is reported, from Sihuas (Ancash) who presented at Hospital Nacional Dos de Mayo with fever, jaundice and anemia. In three days of hospitalization, he developed severe anemia (Hb: 11.8 to 6.7 g / dL) and generalized myalgias associated with a sudden worsening jaundice correlated with elevated bilirubin (TB 3.2 to 19.6 mg / dL direct dominance) and general deterioration. Microbiological smear and culture were positive for Bartonella bacilliformis. Subsequent serology (microagglutination) was positive for Lesptospira serovar Pomona. The patient was given specific antibiotic therapy (ceftriaxone and ciprofloxacin), transfused two units of packed red blood cells, improved clinically and was discharged.


Subject(s)
Humans , Male , Middle Aged , Bartonella Infections/complications , Leptospirosis/complications , Acute Disease , Severity of Illness Index
11.
An. Fac. Med. (Perú) ; 70(2): 103-108, abr.-jun. 2009. tab, graf
Article in Spanish | LILACS, LIPECS | ID: lil-564560

ABSTRACT

Objetivos: Determinar el efecto coadyuvante antihipertensivo y la seguridad del jugo del fruto de maracuyá en pacientes hipertensos en tratamiento con enalapril. Diseño:Ensayo clínico prospectivo piloto, de fase II, aleatorizado, a doble ciego, de grupos paralelos, controlado, de búsqueda de dosis y evaluación del producto. Institución: Instituto de Investigaciones Clínicas, Facultad de Medicina, UNMSM; Hospital NacionalDos de Mayo en Lima; Hospital Belén de Trujillo y Centros de Salud de Moche y Laredo, en la ciudad de Trujillo. Participantes: Pacientes hipertensos. Intervenciones: Los pacientes fueron asignados aleatoriamente a 4 grupos. Todos recibieron enalapril 10 mg/día y, además, el primer grupo recibió placebo y los demás 2, 3 y 4 cápsulas de 500 mg de liofilizado de jugo de maracuyá/día, respectivamente. Principales medidas de resultados: Disminución de la presión arterial. Resultados: Los grupos que recibieron enalapril más maracuyá tuvieron una mejor reducción de la presión sanguínea en comparación con el grupo que recibió enalapril más placebo. El grupo tratado con enalapril más 4 cápsulas de jugo liofilizado de maracuyá/día produjo al final del experimento una reducción de la presión sistólica de 6,73 mmHg y de la presión diastólica de 5,33 mmHg (p menor que 0,05), en comparación con el grupo enalapril más placebo. No se observó efectos adversos por el tratamiento. Conclusiones: El jugo del fruto de P. edulis fue coadyuvante efectivo del enalapril en la disminución de lapresión arterial en pacientes con hipertensión estadio 1, y demostró ser seguro.


Objectives: To determine the adjunctive antihypertensive effect and safety ofpassion fruit juice in patients with hypertension treated with enalapril. Design: prospective pilot clinical trial, phase II, randomized, double blind, parallel group, controlled, dose finding and evaluation of the product. Setiing: Instituto de Investigaciones Clínicas, Facultad de Medicina, UNMSM, Dos de Mayo Hospital in Lima, Hospital Belen de Trujillo and Moche and Laredo Health Centers in Trujillo city. Participants: Patients with arterial hypertension. Interventions: Patients were randomly assigned to four groups, each receiving enalapril 10 mg / day; the first group also received placebo and the other, 2, 3 and 4 groups, 500 mg capsulesof freeze-dried passion fruit juice / day, respectively. Main outcome measures:Reduction in blood pressure. Results: Groups receiving enalapril and passionfruit had better reduction in blood pressure compared with the group receiving enalapril plus placebo. The group treated with enalapril plus 4 capsules of freezedried passion fruit juice / day had a reduction in systolic blood pressure of 6,73 mmHg and diastolic blood pressure of 5,33 mmHg (p minor that 0,05) compared with the enalapril group more placebo. No adverse effects were observed. Conclusions: P. edulis juice fruit was effective adjuvant to enalapril in reducing blood pressure in patients with stage 1 hypertension, with proved safety.


Subject(s)
Humans , Hypertension , Passiflora , Blood Pressure
12.
An. Fac. Med. (Perú) ; 64(4): 255-260, oct. 2003. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: lil-475268

ABSTRACT

Los autores reportan un raro caso de un absceso esplénico crónico, en un paciente varón de 52 años de edad; a quien dos años antes de su ingreso al hospital se le diagnosticó en forma casual diagnóstico por imágenes- un quiste esplénico con paredes calcificadas, estando previamente asintomático. Al momento de su ingreso se presentó con una historia de 12 meses de dolor leve en cuadrante superior izquierdo del abdomen como única manifestación positiva. Luego de una intervención quirúrgica, el diagnóstico correspondió a un absceso esplénico crónico o seudoquiste esplénico por los hallazgos anatomopatológicos. Se describe las características del caso y se revisa la literatura.


Subject(s)
Humans , Spleen , Abdominal Abscess , Cysts , Abdomen
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