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1.
Food Microbiol ; 110: 104185, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36462831

RESUMO

The aim of the present work was the selection of aromatic plant essential oils (EOs) and/or ethanolic extracts (EEs) to prevent the late blowing defect (LBD) of cheese caused by Clostridium spp. EEs resulted more effective than EOs to inhibit dairy-borne Clostridium spp. in vitro. Savory, hyssop, lavender and tarragon EEs, which showed the lowest minimal inhibitory concentration against Clostridium tyrobutyricum, were selected to study the prevention of LBD caused by this bacterium in cheese. Addition of savory and lavender EEs to cheese milk delayed LBD by 2 weeks, but at the end of ripening these cheeses showed similar clostridial vegetative cells counts, spoilage symptoms and propionic, and butyric acids levels than blown control cheese. Tarragon EE, with the highest content in caffeic acid, also delayed LBD by 2 weeks, but it was more effective to inhibit Clostridium, since cheese with tarragon EE showed minor LBD symptoms, lower vegetative cells count and lower concentrations of propionic and butyric acids than the rest of cheeses made with EEs. This fact could be also attributable to the greater number of antimicrobial terpenes (1,8-cineole, 4-terpineol, α-terpineol, isoelemicin, methyl eugenol, and methyl trans-isoeugenol) detected in this cheese. This is the first report on the application of EEs to control C. tyrobutyricum in cheese.


Assuntos
Queijo , Clostridium tyrobutyricum , Óleos Voláteis , Clostridium , Etanol , Óleos Voláteis/farmacologia , Óleos de Plantas , Butiratos , Extratos Vegetais/farmacologia
2.
Crit Rev Food Sci Nutr ; 57(14): 3084-3103, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-26587821

RESUMO

Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.


Assuntos
Ácido Benzoico/análise , Aromatizantes/análise , Análise de Alimentos , Conservantes de Alimentos/análise , Animais , Alimentos , Humanos
3.
Appl Microbiol Biotechnol ; 100(17): 7665-77, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27216614

RESUMO

In this work, a variety of biochemical properties of Enterococcus faecium CECT 8849, which had been isolated from breast milk, were analyzed. Its acidifying capacity and proteolytic activity were low but, in contrast, remarkable peptidase and esterase activities were observed. Ethanol and 3-hydroxy-2-butanone were the most abundant volatile compounds found in experimental model cheese manufactured with E. faecium CECT 8849. This strain inhibited the growth of several Listeria monocytogenes and Listeria innocua strains in vitro. Enterocin A and B structural genes were detected in E. faecium CECT 8849. Model fermented milk and cheeses were manufactured from milk inoculated or not with L. innocua CECT 8848 (2.5-3 log10 colony forming units mL(-1)) using E. faecium CECT 8849 or Lactococcus lactis ESI 153 as starter cultures. Although E. faecium CECT 8849 controlled Listeria growth in both dairy models, it led to lower reduction in Listeria counts when compared with L. lactis ESI 153.


Assuntos
Queijo/microbiologia , Produtos Fermentados do Leite/microbiologia , Enterococcus faecium/enzimologia , Enterococcus faecium/metabolismo , Esterases/metabolismo , Peptídeo Hidrolases/metabolismo , Compostos Orgânicos Voláteis/análise , Acetoína/metabolismo , Bacteriocinas/genética , Indústria de Laticínios , Enterococcus faecium/genética , Enterococcus faecium/isolamento & purificação , Etanol/análise , Microbiologia de Alimentos , Humanos , Lactococcus lactis/metabolismo , Listeria monocytogenes/crescimento & desenvolvimento , Leite Humano/microbiologia
4.
Zoo Biol ; 35(3): 216-21, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27038075

RESUMO

Understanding the behavior of endangered species is crucial to improve the management tools to breed animals in captivity and, thus, to increase the success of ex situ conservation programs. In this study, we monitored suckling behavior of 26 cubs born between 2008 and 2012 at "El Acebuche" Iberian Lynx Breeding Centre. The cubs devoted 251 ± 19.7 min (mean ± SE) to lactation on the day of birth, while mothers spent 426 ± 27 min (mean ± SE) nursing their offspring. The time cubs spent suckling decreased exponentially as they grown, until they were fully weaned at 65 ± 2.6 days. The onset of weaning (first intake of solid food) occurred at 54 ± 1.35 days (mean ± SE). Thus, the strict lactation period occupied most of the overall lactation period. Both suckling and maternal behavior were affected by litter size. In twins and triplets, the competition between siblings caused a decrease in the time spent suckling, in spite of the mothers spending more time nursing their young. Finally, no significant differences were found in time spent suckling between littermates or depending on the sex of the cub. Lactation appeared to play a key role in the nutrition of the Iberian lynx and should therefore be conveniently managed in captive breeding programs of this threatened species. Zoo Biol. 35:216-221, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Animais de Zoológico/fisiologia , Espécies em Perigo de Extinção , Lactação/fisiologia , Lynx/fisiologia , Comportamento Materno/fisiologia , Animais , Animais Lactentes , Feminino , Fatores de Tempo , Desmame
5.
J Anim Ecol ; 83(4): 934-42, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24720673

RESUMO

Food availability is considered a major factor determining spacing behaviour in territorial species, especially for females. Theoretically, spatial overlap (considered the opposite of territoriality) and food availability are related in a nonlinear manner (hypothesized inverted-U function), with high overlap levels at the extremes of a food availability gradient and low overlap at intermediate levels of this gradient. Similar patterns are expected for encounter frequencies owing to its expected correlation with spatial overlap. However, these predictions have rarely been tested in highly structured social systems on a broad gradient of food availability, which implicitly requires experimental manipulation. We test these predictions in a solitary, territorial and trophic specialist, the Iberian lynx Lynx pardinus, taking advantage of a three-decade data set of spatial behaviour in different scenarios of food availability (i.e. rabbit density). In contrast with expectations, home range overlap among resident females was low (median overlap index = 0.08, range 0-0.57) and core area overlap was nearly nil (median overlap index = 0, range 0-0.22) throughout the entire gradient of prey availability. Furthermore, spatial associations between pairs of females were negligible regardless marked variation in prey availability. Therefore, we did not find support for a model of flexible lynx territoriality driven by food availability. Our results suggest that the exclusive use of space in the Iberian lynx was not related to food. Lack of influence of prey availability on lynx territoriality may be adaptive to cope with the consequences of frequent drought-induced periods of prey scarcity or other disturbance typically affecting wild rabbit populations in Mediterranean environments. Thus, lynx would adopt an obstinate strategy of territoriality that consists in defending exclusive areas across a broad range of resource availability ensuring an exclusive access to the minimum amount of prey necessary for survival and eventually reproduction even during periods of prey scarcity. However, we found signs that territoriality was influenced by lynx density in a nonlinear fashion. Our results suggest the occurrence of population regulation through territoriality in this species.


Assuntos
Lynx/fisiologia , Modelos Biológicos , Comportamento Predatório , Territorialidade , Animais , Feminino , Cadeia Alimentar , Estações do Ano , Espanha
6.
Zoo Biol ; 33(5): 381-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25081419

RESUMO

Knowledge on the growth and early development patterns of endangered species can become a useful conservation tool because it may allow detecting anomalous growth in newborns, both in captivity breeding and in the wild. We studied the growth and early development of 40 Iberian lynx (Lynx pardinus) cubs belonging to 21 litters born in captivity between 2005 and 2012 at "El Acebuche" Iberian Lynx Breeding Centre. This is the first study on growth in this critically endangered species. The Iberian lynx cubs were not fully developed at birth. During the first 3 weeks of life, cubs underwent many of the physical changes that allowed them to improve their interaction with the environment, such as the opening of eye and auditory channels, teeth eruptions, and the ability to walk. When the cubs were 1 month old, they were ready to leave the den and develop new behaviors such as the exploration of their environment, play, or hunt. Three different models had been fitted to the body mass growth of the Iberian lynx. The von Bertalanffy curve provided the best fit. The asymptotic adult mass was the only parameter that differed between males and females (males being 8% larger), due to the higher growth rate of males. The adult weight of hand-reared cubs (i.e., those abandoned at born) did not differ from that of cubs reared by their mothers. Both growth and development showed differences from other lynx species.


Assuntos
Animais de Zoológico/crescimento & desenvolvimento , Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção , Lynx/crescimento & desenvolvimento , Animais , Peso Corporal/fisiologia , Feminino , Masculino , Modelos Biológicos , Fatores Sexuais , Espanha
7.
Int J Food Microbiol ; 411: 110547, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38150774

RESUMO

Some lactic acid bacteria (LAB) have the ability to synthesize riboflavin, a trait linked to the presence of ribG, ribB, ribA and ribH genes located in the rib operon. Previous screening of riboflavin producers identified several LAB strains belonging to different species with this ability, but none of them surpassed 0.25 mg/L production of the vitamin. In this study, we explored two strategies to obtain riboflavin-overproducing strains: by roseoflavin selection of mutants, and by the transformation of selected strains with plasmids pNZ:TuR.rib or pNZ:TuB.rib containing the genes ribG, ribB, ribA and ribH from Lactococcus cremoris MG1363. The resulting riboflavin-overproducing strains were able to produce yields between 0.5 and 6 mg/L in culture media and several of them were selected for the fermentation of soy beverages. Riboflavin in bio-enriched soy beverages was evaluated by direct fluorescence measurement and high-performance liquid chromatography-fluorescence analysis. Soy beverages fermented with the recombinant strains Lactococcus cremoris ESI 277 pNZ:TuB.rib and Lactococcus lactis INIA 12 pNZ:TuR.rib showed the highest riboflavin yields (>5 mg/L) after 24 h fermentation. On the other hand, roseoflavin-resistant mutant Limosilactobacillus fermentum INIA P143R2 was able to enrich fermented soy beverages with 1.5 mg/L riboflavin. Riboflavin-overproducing LAB strains constitute a good option for riboflavin enrichment of soy beverages by fermentation and the commercialization of such beverages could be very useful to prevent riboflavin deficiency.


Assuntos
Lactobacillales , Lactococcus lactis , Leite de Soja , Lactobacillales/metabolismo , Riboflavina/metabolismo , Fermentação , Lactococcus lactis/genética
8.
Foods ; 13(14)2024 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-39063379

RESUMO

Adjunct cultures originating from artisanal cheese environments may play an important role in recreating and developing traditional cheese flavours, thanks to their enzymatic activities, involved in different metabolic pathways that occur during cheese ripening. In this work, Ligilactobacillus salivarius SP36, a strain isolated from an old cheese seal, was added as an adjunct culture to the cheese's raw milk, and its effect on the microbiological, physical-chemical and sensory characteristics of the cheese was studied. The use of L. salivarius SP36 in cheese manufacturing had no significant (p > 0.05) effect on the cheese microbiota, gross composition (fat percentage, protein, total solids, moisture and NaCl concentration), colour or texture of the cheese. However, L. salivarius SP36 increased (p < 0.01) the formation of 25 volatile compounds, including 10 esters, 1 aldehyde, 8 alcohols and 6 carboxylic acids. In addition, cheeses made with L. salivarius SP36 received higher scores (p < 0.01) for aroma intensity and quality than control cheeses. L. salivarius SP36 proved to be a good candidate as an adjunct culture for cheesemaking, since it improved the cheese flavour by making it more intense and recovering typical sensorial notes of traditional cheeses.

9.
Appl Environ Microbiol ; 79(4): 1277-83, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23241980

RESUMO

Biogenic amines may reach concentrations of public health concern in some cheeses. To minimize biogenic amine buildup in raw milk cheese, high-pressure treatments of 400 or 600 MPa for 5 min were applied on days 21 and 35 of ripening. On day 60, counts of lactic acid bacteria, enterococci, and lactobacilli were 1 to 2 log units lower in cheeses treated at 400 MPa and 4 to 6 log units lower in cheeses treated at 600 MPa than in control cheese. At that time, aminopeptidase activity was 16 to 75% lower in cheeses treated at 400 MPa and 56 to 81% lower in cheeses treated at 600 MPa than in control cheese, while the total free amino acid concentration was 35 to 53% higher in cheeses treated at 400 MPa and 3 to 15% higher in cheeses treated at 600 MPa, and decarboxylase activity was 86 to 96% lower in cheeses treated at 400 MPa and 93 to 100% lower in cheeses treated at 600 MPa. Tyramine, putrescine, and cadaverine were the most abundant amines in control cheese. The total biogenic amine concentration on day 60, which reached a maximum of 1.089 mg/g dry matter in control cheese, was 27 to 33% lower in cheeses treated at 400 MPa and 40 to 65% lower in cheeses treated at 600 MPa. On day 240, total biogenic amines attained a concentration of 3.690 mg/g dry matter in control cheese and contents 11 to 45% lower in cheeses treated at 400 MPa and 73 to 76% lower in cheeses treated at 600 MPa. Over 80% of the histidine and 95% of the tyrosine had been converted into histamine and tyramine in control cheese by day 60. Substrate depletion played an important role in the rate of biogenic amine buildup, becoming a limiting factor in the case of some amino acids.


Assuntos
Aminas Biogênicas/análise , Carboxiliases/metabolismo , Queijo/microbiologia , Desinfecção/métodos , Pressão Hidrostática , Leite/química , Leite/microbiologia , Animais , Carga Bacteriana , Tecnologia de Alimentos/métodos , Lactobacillales/isolamento & purificação , Fatores de Tempo
10.
Oecologia ; 173(3): 753-66, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23579570

RESUMO

We compared movement patterns and rhythms of activity of a top predator, the Iberian lynx Lynx pardinus, a mesopredator, the red fox Vulpes vulpes, and their shared principal prey, the rabbit Oryctolagus cuniculus, in relation to moon phases. Because the three species are mostly nocturnal and crepuscular, we hypothesized that the shared prey would reduce its activity at most risky moon phases (i.e. during the brightest nights), but that fox, an intraguild prey of lynx, would avoid lynx activity peaks at the same time. Rabbits generally moved further from their core areas on darkest nights (i.e. new moon), using direct movements which minimize predation risk. Though rabbits responded to the increased predation risk by reducing their activity during the full moon, this response may require several days, and the moon effect we observed on the rabbits had, therefore, a temporal gap. Lynx activity patterns may be at least partially mirroring rabbit activity: around new moons, when rabbits moved furthest and were more active, lynxes reduced their travelling distances and their movements were concentrated in the core areas of their home ranges, which generally correspond to areas of high density of rabbits. Red foxes were more active during the darkest nights, when both the conditions for rabbit hunting were the best and lynxes moved less. On the one hand, foxes increased their activity when rabbits were further from their core areas and moved with more discrete displacements; on the other hand, fox activity in relation to the moon seemed to reduce dangerous encounters with its intraguild predator.


Assuntos
Comportamento Animal/fisiologia , Cadeia Alimentar , Raposas/fisiologia , Lynx/fisiologia , Lua , Coelhos/fisiologia , Animais , Modelos Lineares , Atividade Motora/fisiologia , Comportamento Predatório/fisiologia , Espanha , Fatores de Tempo
11.
Food Res Int ; 163: 112222, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36596151

RESUMO

Lytic bacteriophages (phages) offer a great potential as biocontrol agents for spoilage Clostridium tyrobutyricum, responsible for butyric acid fermentation in semi-hard and hard ripened cheeses, resulting in late gas blowing defect. With this aim, we have isolated, identified and characterized new lytic phages of C. tyrobutyricum, and have evaluated their efficacy to control cheese late blowing by adding them to manufacture milk. Silage, soil, milk and cheese from dairy farms were screened for anti-clostridial phages, obtaining 96 isolates active against C. tyrobutyricum. According to host range, source and plaque morphology, we obtained 20 phage profiles, 8 of them (represented by phages FA3, FA21, FA29, FA52, FA58, FA67, FA70 and FA88) showing a wider host range and high quality lysis, which were further characterized. Selected isolates showed a non-contractile tail, belonging to the Siphoviridae family, and were grouped into 3 restriction profiles. Viable phages were detected after storage in sodium-magnesium buffer (SM buffer), skim milk and acidified skim milk (pH 5) for 7 d at 4 °C, 12 °C and 37 °C, although a decline in infectivity was observed in some cases. Good phage survival was also detected during semi-hard cheese manufacture and ripening (60 d), and cheese lactococci counts, pH, dry matter values, and volatile compounds were not affected by phage addition. In semi-hard cheese, phage FA67 impaired the early germination of C. tyrobutyricum spores and caused a significant decrease in clostridial vegetative cells counts at 14 d of ripening, delaying by 2 weeks the consumption of lactic acid, formation of butyric acid and appearance of late blowing symptoms, compared to the spoilt control cheese without the phage. This is the first report on the application of phage to control C. tyrobutyricum in cheese.


Assuntos
Bacteriófagos , Queijo , Clostridium tyrobutyricum , Ácido Butírico , Clostridium
12.
Ecology ; 103(6): e3654, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35132618

RESUMO

Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications.


Assuntos
Carnívoros , Ecossistema , Animais , Mudança Climática , Mamíferos , Portugal , Coelhos , Roedores
13.
Conserv Biol ; 25(1): 4-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21091768

RESUMO

The Iberian lynx (Lynx pardinus) may be the first charismatic felid to become extinct in a high-income country, despite decades of study and much data that show extinction is highly probable. The International Union for Conservation of Nature categorizes it as critically endangered; about 200 free-ranging individuals remain in two populations in southern Spain. Conservation measures aimed at averting extirpation have been extensively undertaken with 4 of the former 10 Iberian lynx populations recorded 25 years ago. Two of the four populations have been extirpated. The number of individuals in the third population have declined by 83%, and in the fourth the probability of extirpation has increased from 34% to 95%. Major drivers of the pending extinction are the small areas to which conservation measures have been applied; lack of incorporation of evidence-based conservation, scientific monitoring, and adaptive management into conservation efforts; a lack of continuity in recovery efforts, and distrust by conservation agencies of scientific information. In contrast to situations in which conservation and economic objectives conflict, in the case of the Iberian lynx all stakeholders desire the species to be conserved.


Assuntos
Espécies em Perigo de Extinção , Extinção Biológica , Lynx/fisiologia , Animais , Política Ambiental , Feminino , Masculino , População , Espanha
14.
Genes (Basel) ; 11(3)2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32131436

RESUMO

The genus Crocidura represents a remarkable model for the study of chromosome evolution. This is the case of the lesser white-toothed shrew (Crocidura suaveolens), a representative of the Palearctic group. Although continuously distributed from Siberia to Central Europe, C. suaveolens is a rare, habitat-specialist species in the southwesternmost limit of its distributional range, in the Gulf of Cádiz (Iberian Peninsula). In this area, C. suaveolens is restricted to genetically isolated populations associated to the tidal marches of five rivers (Guadiana, Piedras, Odiel, Tinto and Guadalquivir). This particular distributional range provides a unique opportunity to investigate whether genetic differentiation and habitat specialization was accompanied by chromosomal variation. In this context, the main objective of this study was to determinate the chromosomal characteristics of the habitat-specialist C. suaveolens in Southwestern Iberia, as a way to understand the evolutionary history of this species in the Iberian Peninsula. A total of 41 individuals from six different populations across the Gulf of Cádiz were collected and cytogenetically characterized. We detected four different karyotypes, with diploid numbers (2n) ranging from 2n = 40 to 2n = 43. Two of them (2n = 41 and 2n = 43) were characterized by the presence of B-chromosomes. The analysis of karyotype distribution across lineages and populations revealed an association between mtDNA population divergence and chromosomal differentiation. C. suaveolens populations in the Gulf of Cádiz provide a rare example of true karyotypic polymorphism potentially associated to genetic isolation and habitat specialization in which to investigate the evolutionary significance of chromosomal variation in mammals and their contribution to phenotypic and ecological divergence.


Assuntos
Cromossomos/genética , Eutérios/genética , Evolução Molecular , Cariótipo , Animais , Cromossomos/classificação , DNA Mitocondrial/genética , Ecossistema , Europa (Continente) , Deriva Genética , Variação Genética/genética , Genética Populacional , Humanos , Cariotipagem , Filogenia , Musaranhos/genética , Sibéria , Áreas Alagadas
15.
Int J Food Microbiol ; 329: 108686, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32516659

RESUMO

Clostridium tyrobutyricum has been identified as a major species associated with the late blowing defect (LBD) of semi-hard and hard cheeses, due to undesirable butyric acid fermentation. To find new strategies to control this spoilage bacterium, we investigated the delivery of a bacteriophage endolysin by a cheese starter culture. The nisin producer Lactococcus lactis subsp. lactis INIA 415 was engineered to produce the CTP1L endolysin, encoded by the virulent bacteriophage ΦCTP1 of C. tyrobutyricum and with a demonstrated lytic activity in vitro, to the cheese matrix. The presence of the nisRK two-component regulatory system in the host strain allowed constitutive expression of the endolysin under the control of the nisA promoter (PnisA), while the use of a signal peptide (SLPmod) led to successful secretion of the active endolysin to the surrounding media. Engineered lysins with a second cell wall binding domain were also tested and shown to have improved lytic activity. Transformation of L. lactis subsp. lactis INIA 415 with endolysin delivery plasmids had a detrimental effect on its ability to produce nisin in milk, but did not affect its acidifying capacity. Transformed L. lactis subsp. lactis INIA 415 were evaluated as starters in cheeses contaminated with spores of C. tyrobutyricum. Evolution of microbiological parameters, pH and dry matter of cheeses were studied, and Clostridium metabolism and LBD in cheeses were monitored by sensory and instrumental analyses during ripening. Cheese made with the parental strain L. lactis subsp. lactis INIA 415 delayed LBD by one month, attributable to the activity of the nisin, but it was not sufficient to arrest the growth of C. tyrobutyricum during ripening completely. The use of the endolysin-producing strains in cheese manufacture as single cultures also delayed the appearance of LBD by one month, attributable to the activity of the endolysin produced in situ during ripening, because nisin activity in these cheeses was very low at day 1 and undetectable from 15 days onwards. Endolysin was more effective than nisin in inhibiting Clostridium growth, since cheeses made with the CTP1L or the chimeric derivative producers only as starters showed lower LBD symptoms, higher lactic acid levels and lower concentrations of propionic and butyric acids (associated with off-flavours) than cheese made with the parental strain. Investigation of different promoters to maximise endolysin production may help to implement CTP1L as a tool to control C. tyrobutyricum by L. lactis cheese starter and reduce LBD even further.


Assuntos
Bacteriófagos , Queijo/microbiologia , Clostridium tyrobutyricum/efeitos dos fármacos , Endopeptidases/genética , Endopeptidases/farmacologia , Microbiologia de Alimentos/métodos , Lactococcus lactis/genética , Bacteriófagos/enzimologia , Bacteriófagos/genética , Lactococcus lactis/enzimologia , Nisina/farmacologia , Organismos Geneticamente Modificados
16.
Appl Environ Microbiol ; 75(3): 875-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19047400

RESUMO

Biodesulfurization was monitored in a recombinant Pseudomonas putida CECT5279 strain. DszB desulfinase activity reached a sharp maximum at the early exponential phase, but it rapidly decreased at later growth phases. A model two-step resting-cell process combining sequentially P. putida cells from the late and early exponential growth phases was designed to significantly increase biodesulfurization.


Assuntos
Pseudomonas putida/metabolismo , Enxofre/metabolismo , Tiofenos/metabolismo , Proteínas de Bactérias/biossíntese , Enzimas/biossíntese , Perfilação da Expressão Gênica
17.
Foodborne Pathog Dis ; 6(5): 577-81, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19388832

RESUMO

The effect of single-cycle and multiple-cycle high hydrostatic pressure (HHP) treatments on the survival of three Salmonella Enteritidis strains in chicken breast fillets was investigated. The surface of fillets was inoculated with a cocktail of three Salmonella strains at approximately 10(7) colony-forming units (CFU)/g, and held at 4 degrees C for 20 hours before HHP treatments. Reduction of Salmonella counts on tryptic soy agar (TSA) by single-cycle treatments at 300 MPa and 12 degrees C ranged from 0.58 log CFU/g for a 0-minute (no dwell time) cycle to 3.35 log CFU/g for a 20-minute cycle, whereas with 400 MPa treatments the decline ranged from 0.93 log CFU/g to more than 5 log CFU/g, respectively. The 4.8 log unit reduction in Salmonella counts on TSA achieved by a 15-minute treatment at 400 MPa should suffice to eliminate the pathogen naturally present in contaminated chicken meat. When plated on Salmonella Shigella agar (SSA), the reduction of Salmonella counts by single-cycle treatments at 300 MPa and 12 degrees C ranged from 0.69 log CFU/g for a 0-minute cycle to 4.21 log CFU/g for a 20-minute cycle, and with 400 MPa treatments from 1.25 log CFU/g to more than 5 log CFU/g, respectively. From the comparison of Salmonella counts on SSA and TSA it was concluded that not only the lethality but also the proportion of injured Salmonella cells increased with the length of HHP treatments. The use of multiple-cycle treatments instead of single-cycle treatments of the same HHP time for the inactivation of Salmonella Enteritidis inoculated on chicken breast fillets showed to be more advantageous at 400 MPa than at 300 MPa. No recovery of injured Salmonella cells was observed when fillets treated at 300 or 400 MPa for 5 minutes were held for 72 hours at 4 degrees C.


Assuntos
Galinhas/microbiologia , Manipulação de Alimentos/métodos , Pressão Hidrostática , Aves Domésticas/microbiologia , Salmonella enteritidis/crescimento & desenvolvimento , Animais , Contagem de Colônia Microbiana , Desinfecção/métodos
18.
J Food Prot ; 71(4): 811-5, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18468038

RESUMO

The effect of single- and multiple-cycle high-pressure treatments on the survival of Escherichia coli CECT 4972, a strain belonging to the O157:H7 serotype, in ground beef was investigated. Beef patties were inoculated with 10(7) CFU/g E. coli O157:H7, and held at 4 degrees C for 20 h before high-pressure treatments. Reduction of the E. coli O157:H7 population by single-cycle treatments at 400 MPa and 12 degrees C ranged from 0.82 log CFU/g for a 1-min cycle to 4.39 log CFU/g for a 20-min cycle. Multiple-cycle treatments were very effective, with four 1-min cycles at 400 MPa and 12 degrees C reducing the E. coli O157:H7 population by 4.38 log CFU/g, and three 5-min cycles by 4.96 log CFU/g. The color parameter L* increased significantly with high-pressure treatments in the interior and the exterior of beef patties, whereas a* decreased in the interior, and b* increased in the exterior-changes that might diminish consumer acceptance of the product. Kramer shear force and energy were generally higher in pressurized than in control ground beef. Maximum values for these texture parameters, which corresponded to tougher patties, were reached after one 10-min cycle in the case of single-cycle treatments or two 5-min cycles in the case of multiple-cycle treatments. High-pressure treatments had no significant effect on Warner-Bratzler shear force.


Assuntos
Escherichia coli O157/crescimento & desenvolvimento , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Produtos da Carne/microbiologia , Pressão , Animais , Bovinos , Contagem de Colônia Microbiana , Comportamento do Consumidor , Qualidade de Produtos para o Consumidor , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Produtos da Carne/normas , Pigmentação , Temperatura , Fatores de Tempo
19.
Eur J Wildl Res ; 54(2): 171-178, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-32214935

RESUMO

The Iberian lynx (Lynx pardinus) is the most endangered felid species in the world. Lynx populations have decreased dramatically in size and distribution in the last four decades, thus becoming increasingly vulnerable to catastrophic events such as epizooties. From 1989 to 2000, serum samples were obtained from 48 free-ranging lynx captured in the Doñana National Park (DNP, n = 31) and mountains of Sierra Morena (SM, n = 17) in southern Spain. Samples were tested for antibodies against Toxoplasma gondii, feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), feline/canine parvovirus (FPV/CPV), feline coronavirus, feline immunodeficiency virus (FIV), feline leukaemia virus and canine distemper virus (CDV) and for FeLV p27 antigen, to document baseline exposure levels. Antibodies against T. gondii were detected in 44% of lynx, with a significantly greater prevalence in DNP (61%) than in SM (12%). In DNP, prevalence was significantly higher in adult (81%) than in juvenile and sub-adult (41%) lynx, but no such difference was observed in SM. Low prevalences (≤11%) of minimally positive titres were found for FHV-1, FCV and FPV/CPV. This, combined with the lack of evidence for exposure to CDV, FIV and FeLV, suggests that these lynx populations are naïve and might be vulnerable to a disease outbreak in the future. Because of the reduced size of lynx populations, the documented low level of genetic variation (particularly in the DNP population) coupled with the recently documented state of immune depletion in a majority of necropsied lynx, it is important to better understand the threat and potential impact that disease agents might pose for the conservation of this endangered species. Future surveillance programs must include possible disease reservoir hosts such as domestic cats and dogs and other wild carnivores.

20.
Ginecol. obstet. Méx ; 91(11): 799-804, ene. 2023. tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1557829

RESUMO

Resumen OBJETIVO: Describir los valores ecocardiográficos en pacientes con diagnóstico de preeclampsia con criterios de severidad. MATERIALES Y MÉTODOS: Estudio prospectivo, transversal y descriptivo efectuado en pacientes con diagnóstico de preeclampsia con criterios de severidad. Criterios de inclusión: pacientes mayores de 18 años, con diagnóstico de preeclampsia, hospitalizadas en terapia intensiva entre los meses de junio a septiembre del 2022. Criterios de exclusión: pacientes cardiópatas o con procesos sépticos. A todas las pacientes se les practicó un ecocardiograma. Se describieron las variables relacionadas con la función sistólica y diastólica. RESULTADOS: Se estudiaron 20 pacientes; 6 de ellas requirieron ingreso a cuidados intensivos debido a cifras tensionales superiores a 160-90 mmHg. Se encontraron 6 pacientes con lesión renal (creatinina sérica superior a 1.1 mg/dL) y 4 con síndrome de HELLP. En 6 pacientes se estableció el diagnóstico de disfunción sistólica, 4 de ellas con preeclampsia temprana que cumplieron los criterios de severidad y 2 con preeclampsia tardía y misma característica de disfunción sistólica. De las pacientes con preeclampsia con criterios de severidad 10 tuvieron disfunción diastólica; 7 preeclampsia temprana y 3 preeclampsia tardía. CONCLUSIÓN: A pesar de lo pequeño de la muestra se proporciona una visión detallada de la función sistólica y diastólica de pacientes con preeclampsia con criterios de severidad. Queda claro que la valoración sonográfica cardiaca puede tener implicaciones significativas en el pronóstico y en la atención médica personalizada de cada paciente.


Abstract OBJECTIVE: To describe echocardiographic values in patients with a diagnosis of pre-eclampsia with severity criteria. MATERIALS AND METHODS: Prospective, cross-sectional, descriptive study performed in patients with a diagnosis of pre-eclampsia with severity criteria. Inclusion criteria: patients older than 18 years, with a diagnosis of pre-eclampsia, hospitalized in the intensive care unit between June and September 2022. Exclusion criteria: patients with heart disease or septic processes. All patients underwent echocardiography. Variables related to systolic and diastolic function were described. RESULTS: 20 patients were studied; 6 of them required admission to intensive care due to blood pressure higher than 160-90 mmHg. Six patients were found to have renal damage (serum creatinine greater than 1.1 mg/dL) and 4 with HELLP syndrome. Systolic dysfunction was diagnosed in 6 patients, 4 with early preeclampsia meeting the severity criteria and 2 with late preeclampsia and the same feature of systolic dysfunction. Among patients with pre-eclampsia meeting the severity criteria, 10 had diastolic dysfunction; 7 with early pre-eclampsia and 3 with late pre-eclampsia. CONCLUSION: Despite the small sample size, a detailed view of systolic and diastolic function in patients with pre-eclampsia with severity criteria is provided. It shows that cardiac sonographic assessment may have significant implications for prognosis and personalized medical care for each patient.

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