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1.
J Environ Sci Health B ; 58(12): 711-717, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37897369

RESUMO

Foodborne pathogen Campylobacter jejuni has been associated with ruminants. The objectives of this experiment were to determine C. jejuni survivability in mixed in vitro rumen microbial populations and the impact on methane production with or without methane inhibitors 2-bromosulfonate (BES) and/or sodium nitrate. When inoculated into rumen microbial populations without or with 0.5 mM BES, 5.0 mM nitrate or their combination, C. jejuni viability decreased from 4.7 ± 0.1 log10 colony forming units (CFU)/mL after 24 h. Loss of C. jejuni viability was greater (P < 0.05) when incubated under 100% CO2 compared to 50% H2:50% CO2, decreasing 1.46 versus 1.15 log units, respectively. C. jejuni viability was also decreased (P < 0.05) by more than 0.43 log units by the anti-methanogen treatments. Rumen microbial populations produced less methane (P = 0.05) when incubated with than without C. jejuni regardless of whether under 100% CO2 or 50% H2:50% CO2. For either gas phase, nitrate was decreased (13.2 versus 37.9%) by the anti-methanogen treatments versus controls although not always significant. C. jejuni-inoculated populations metabolized 16.4% more (P < 0.05) nitrate under H2:CO2 versus 100% CO2. Apparently, C. jejuni can compete for H2 with methanogens but has limited survivability under rumen conditions.


Assuntos
Campylobacter jejuni , Animais , Bovinos , Campylobacter jejuni/metabolismo , Nitratos/farmacologia , Nitratos/metabolismo , Dióxido de Carbono/metabolismo , Metano/metabolismo , Rúmen
2.
Skin Pharmacol Physiol ; 27(1): 9-17, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23887477

RESUMO

BACKGROUND/PURPOSE: Modern men have changed their beauty and grooming habits, which has resulted in an increasing demand for cosmetics for men. However, very little information is available about the dermatological needs of male skin. Therefore, the aim of this present clinical study was to conduct the first systematic assessment of the skin physiology of men with special attention to lifetime changes. METHODS: A total of 150 healthy male subjects (aged 20-70 years) were selected following strict criteria, including age, sun behavior and smoking habits. Transepidermal water loss (TEWL), hydration level, sebum production and pH values were measured with worldwide-acknowledged biophysical measuring methods at the forehead, cheek, neck, volar forearm and dorsum of hand. RESULTS: TEWL and sebum production vary by localization, but generally not with increasing age, whereas stratum corneum (SC) hydration decreases significantly at the face and neck. The greatest decrease was assessed at the forehead. Skin surface pH significantly increases with aging in the face. CONCLUSION: The present study assigns for the first time systematic reference values for standardized biophysical measuring methods and localizations reflecting the skin physiology of men in relation to age. The results show that the physiology of male skin partly changes with aging. While SC hydration and skin surface pH are affected by the subject's age, TEWL and sebum production show only minor variations.


Assuntos
Envelhecimento/fisiologia , Envelhecimento da Pele/fisiologia , Adulto , Idoso , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Sebo/metabolismo , Pele/metabolismo , Fumar , Raios Ultravioleta , Água/metabolismo , Adulto Jovem
3.
Skin Res Technol ; 20(2): 127-35, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23889488

RESUMO

BACKGROUND: Previous studies have shown that the clinical genesis and onset of facial wrinkles as well as the morphology of the extracellular matrix differ between the sexes. The aim of this present clinical study was to do the first systematic assessment of gender-related differences in skin elasticity, with special focus on age-related changes. MATERIAL AND METHODS: 300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behavior or smoking habits. Skin mechanical properties were assessed at the cheek, neck, volar forearm and dorsum of the hand using a non-invasive suction device. RESULTS: Data analysis shows a significant negative correlation for all parameters and subject's age. At young age results of the relative parameters are higher for women, whereas absolute parameters are higher for men. Parameters referring to the recovery phase change stronger with aging. DISCUSSION: The present study verifies the progressive decline of the skin mechanical properties with aging. However, the elastic ability of the skin to recover after stretching is more strongly affected by the aging process than the firmness of the skin. Further, the mechanical properties change differently in men and woman over lifetime.


Assuntos
Envelhecimento/fisiologia , Palpação/métodos , Estimulação Física/métodos , Envelhecimento da Pele/fisiologia , Fenômenos Fisiológicos da Pele , Adulto , Idoso , Módulo de Elasticidade/fisiologia , Feminino , Dureza/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores Sexuais , Viscosidade , Adulto Jovem
4.
J Food Prot ; 76(7): 1259-63, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23834803

RESUMO

Because challenge models to infect peripheral lymph nodes (PLNs) with Salmonella have not been reported, we performed a series of experiments to develop and refine challenge models to evaluate an intervention applied at the animal level and to provide initial estimates of efficacy of an intervention (i.e., a vaccine) to aid in the design of future studies. In each of four experiments, steers (control or vaccinated) were inoculated with Salmonella strains Montevideo or Newport, and in experiment IV, Salmonella Senftenberg was also used. Calves were euthanized 14 to 42 days postinoculation, and PLNs were collected. In the first experiment, calves were challenged with ∼10¹° Salmonella cells, and few treatment differences were observed 14 days postchallenge. However, by day 21, Salmonella Newport was recovered from fewer vaccinated calves than control calves (P < 0.05). In experiment II, calves were challenged with ∼107 Salmonella cells and, after two necropsies (14 and 28 days postchallenge), only one lymph node was Salmonella positive; therefore, the study was terminated. In experiment III, calves were again challenged with ∼10¹° Salmonella cells, and no significant effect of vaccine was observed in calves challenged with Montevideo or Newport strains. A transdermal route of challenge was explored in experiment IV, using a 10-lancet, allergy testing instrument. Sixteen steers were challenged with either Salmonella Newport or Salmonella Montevideo (Salmonella Newport right legs; Salmonella Montevideo left legs), and all steers were challenged on the lower abdomen with Salmonella Senftenberg. Transdermal inoculation resulted in predictably Salmonella-positive PLNs, and a modest vaccine effect was detected. Because it is well tolerated by the calves and results in predictable and regionally specific Salmonella recovery from PLNs, the transdermal route of challenge may be preferred by researchers wishing to evaluate the impact of interventions designed to reduce the carriage of Salmonella in PLNs.


Assuntos
Vacinas Bacterianas/administração & dosagem , Portador Sadio/veterinária , Doenças dos Bovinos/prevenção & controle , Linfonodos/microbiologia , Salmonelose Animal/prevenção & controle , Animais , Bovinos , Doenças dos Bovinos/imunologia , Humanos , Salmonella/crescimento & desenvolvimento , Infecções por Salmonella/prevenção & controle , Infecções por Salmonella/transmissão , Salmonelose Animal/imunologia , Vacinação , Zoonoses
5.
Int J Cosmet Sci ; 35(5): 477-83, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23713991

RESUMO

OBJECTIVES: Evidence is given that differences in skin physiological properties exist between men and women. However, despite an assessable number of available publications, the results are still inconsistent. Therefore, the aim of this clinical study is the first systematic assessment of gender-related differences in skin physiology in men and women, with a special focus on changes over lifetime. METHODS: A total of 300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behaviour or smoking habits. TEWL, hydration level, sebum production and pH value were measured with worldwide-acknowledged biophysical measuring methods at forehead, cheek, neck, volar forearm and dorsum of hand. RESULTS: Until the age of 50 men's TEWL is significantly lower than the water loss of women of the same age, regardless of the location. With ageing gender-related differences in TEWL assimilate. Young men show higher SC hydration in comparison with women. But, whereas SC hydration is stable or even increasing in women over lifetime, the skin hydration in men is progressively decreasing, beginning at the age of 40. Sebum production in male skin is always higher and stays stable with increasing age, whereas sebum production in women progressively decreases over lifetime. Across all localizations and age groups, the pH value in men is below 5, the pH value of female subjects is, aside from limited expectations, higher than 5. CONCLUSION: Skin physiological distinctions between the sexes exist and are particularly remarkable with regard to sebum production and pH value.


Assuntos
Fenômenos Fisiológicos da Pele , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Sebo/química , Fatores Sexuais , Estatísticas não Paramétricas , Perda Insensível de Água/fisiologia , Adulto Jovem
6.
Lipids ; 48(7): 749-55, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23609414

RESUMO

The hydrolysis of free fatty acids from lipids is a prerequisite for biohydrogenation, a process that effectively saturates free fatty acids. Anaerovibrio lipolyticus 5s and Butyrivibrio fibrisolvens have long been thought to be the major contributors to ruminal lipolysis; however, Propionibacterium avidum and acnes recently have been identified as contributing lipase activity in the rumen. In order to further characterize the lipase activity of these bacterial populations, each was grown with three different lipid substrates, olive oil, corn oil, and flaxseed oil (3 %). Because different finishing rations contain varying levels of glycogen (a source of free glucose) this study also documented the effects of glucose on lipolysis. P. avidum and A. lipolyticus 5s demonstrated the most rapid rates (P < 0.05) of lipolysis for cultures grown with olive oil and flaxseed oil, respectively. A. lipolyticus, B. fibrisolvens, and P. avidum more effectively hydrolyzed flaxseed oil than olive oil or corn oil, especially in the presence of 0.02 % glucose. Conversely, P. acnes hydrolyzed corn oil more readily than olive oil or flaxseed oil and glucose had no effect on lipolytic rate. Thus, these bacterial species demonstrated different specificities for oil substrates and different sensitivities to glucose.


Assuntos
Butyrivibrio/enzimologia , Glucose/metabolismo , Lipase/metabolismo , Óleos de Plantas/metabolismo , Propionibacterium/enzimologia , Rúmen/microbiologia , Veillonellaceae/enzimologia , Animais , Butyrivibrio/efeitos dos fármacos , Butyrivibrio/crescimento & desenvolvimento , Bovinos , Óleo de Milho/metabolismo , Meios de Cultura , Glucose/farmacologia , Óleo de Semente do Linho/metabolismo , Lipólise/efeitos dos fármacos , Azeite de Oliva , Propionibacterium/efeitos dos fármacos , Propionibacterium/crescimento & desenvolvimento , Rúmen/efeitos dos fármacos , Especificidade por Substrato , Veillonellaceae/efeitos dos fármacos , Veillonellaceae/crescimento & desenvolvimento
7.
J Eur Acad Dermatol Venereol ; 27(5): 601-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22404700

RESUMO

BACKGROUND: Skin and hair appearance is important to body image. Oily skin and oily, impaired hair quality, which can develop in women taking certain types of hormonal contraceptives, may cause psychosocial stress. OBJECTIVES: The aim of the current study was to investigate the effects of an oral monophasic contraceptive (0.03 mg ethinylestradiol/2 mg chlormadinone acetate) for 12 treatment cycles on the pathophysiology of oily skin and oily, impaired hair quality in healthy women. METHODS: We assessed changes in hair and skin parameters at baseline, 12, 24 and 48 weeks, in 60 women aged 18-45 years. Psychological well-being was verified by two subject self-assessments (Hair quality, Hairdex). RESULTS: Data from 31 subjects showed that treatment significantly improved sebum excretion at capillitium and forehead, and the number of terminal hairs. Visual haptic scores revealed significant decreases in capillitium seborrhoea, hair condition/density, capillitium dandruff and irritation/redness. Subject self-assessment confirmed improvements in hair quality. Treatment was well tolerated. CONCLUSION: Chlormadinone acetate in hormonal contraception provides excellent cosmetic and dermatological benefits, which can improve psychosocial well-being.


Assuntos
Acetato de Clormadinona/administração & dosagem , Anticoncepcionais Orais Hormonais/farmacologia , Etinilestradiol/administração & dosagem , Cabelo/efeitos dos fármacos , Pele/efeitos dos fármacos , Feminino , Humanos
8.
Int J Cosmet Sci ; 35(2): 183-90, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23113564

RESUMO

The protection against water loss and the prevention of substances and bacteria penetrating into the body rank as the most important functions of the skin. This so-called 'skin barrier function' is the natural frontier between the inner organism and the environment, and is primarily formed by the epidermis. An impairment of the skin barrier function is often found in diseased and damaged skin. An influence of ageing on skin barrier function is widely accepted, but has not been conclusively evaluated yet. Therefore, the aim of this clinical study was to assess the potential influence of ageing on skin barrier function, including transepidermal water loss (TEWL), stratum corneum hydration, sebum content and pH value. One hundred and fifty healthy women aged 18-80, divided into five age groups with 30 subjects each, were evaluated in this study. TEWL, hydration level, sebum secretion and pH value of hydro-lipid acid film were measured with worldwide acknowledged biophysical measuring methods at cheek, neck, décolleté, volar forearm and dorsum of hand. Whereas TEWL and stratum corneum hydration showed only very low correlation with subject's age, the sebum production decreased significantly with age, resulting in the lowest skin surface lipids levels measured in subjects older than 70 years. The highest skin surface pH was measured in subjects between 50 and 60 years, whereas the eldest age group had the lowest mean pH. The dorsum of the hand was the location with the highest TEWL and lowest stratum corneum hydration in all age groups. The results show that only some parameters related to skin barrier function are influenced by ageing. Whereas sebum production decreases significantly over lifetime and skin surface pH is significantly increased in menopausal woman, TEWL and stratum corneum hydration show only minor variations with ageing.


Assuntos
Envelhecimento/fisiologia , Absorção Cutânea , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem
9.
J Dairy Sci ; 95(9): 5176-5181, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22916923

RESUMO

Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of supplemental glycerol on rumen lipolysis, mixed populations of ruminal bacteria were incubated with 6 or 20% glycerol (vol/vol). After 48-h anaerobic incubation of mixed culture rumen fluid, rates of free fatty acid production (nmol/mL per h) for the 6 and 20% glycerol-supplemented samples were decreased by 80 and 86%, respectively, compared with rates from nonsupplemented control cultures (12.4±1.0; mean ± SE). Conversely, assay of the prominent ruminal lipase-producing bacteria Anaerovibrio lipolyticus 5S, Butyrivibrio fibrisolvens 49, and Propionibacterium species avidum and acnes revealed no effect of 2 or 10% (vol/vol) added glycerol on lipolytic activity by these organisms. Supplementing glycerol at 6% on a vol/vol basis, equivalent to supplementing glycerol at approximately 8 to 15% of diet dry matter, effectively reduced lipolysis. However, the mechanism of glycerol inhibition of ruminal lipolysis remains to be demonstrated.


Assuntos
Glicerol/farmacologia , Lipólise/efeitos dos fármacos , Rúmen/metabolismo , Animais , Líquidos Corporais/metabolismo , Butyrivibrio/metabolismo , Bovinos , Técnicas In Vitro , Propionibacterium/metabolismo , Rúmen/microbiologia
10.
J Food Prot ; 75(3): 573-5, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22410233

RESUMO

The objective of the current research was to determine if feeding the citrus by-products(D) -limonene (DL) and citrus molasses would reduce the concentration and prevalence of Salmonella in weanling pigs experimentally infected with Salmonella Typhimurium. Twenty crossbred weanling pigs (average body weight [BW], 19.9 kg) were randomly assigned to one of four treatments: control, low-dose DL (1.5 ml/kg of BW per day), high-dose DL (3.0 ml/kg of BW per day), and citrus molasses (0.05 kg/kg of BW per day). Treatments were administered in the feed (twice daily) for 7 days, with one-half of the dose administered at each feeding. Fecal samples were collected twice daily (prior to administration of treatment) and cultured for quantitative and qualitative determination of the challenge strain of Salmonella. Upon termination of the study, pigs were euthanized and tissues from the stomach, ileum, cecum, spiral colon, and rectum, as well as luminal contents, were collected. In addition, the popliteal and ileocecal lymph nodes and liver, spleen, and tonsil tissue were collected for qualitative Salmonella culture. No significant treatment differences (P > 0.05) were observed among treatments for fecal concentration or prevalence of Salmonella throughout the 7-day collection period. Likewise, no treatment differences (P > 0.05) were observed for any of the tissue or luminal content samples collected. Salmonella was not cultured from the muscle-bound popliteal lymph node but was cultured from the mesenteric ileocecal lymph nodes. While there were no effects in the current experiment, future research may examine the effect of a lower challenge dose and/or different administration (dose or duration) of the citrus by-products.


Assuntos
Ácido Cítrico/farmacologia , Contaminação de Alimentos/prevenção & controle , Salmonelose Animal/prevenção & controle , Salmonella/efeitos dos fármacos , Doenças dos Suínos/prevenção & controle , Animais , Animais Recém-Nascidos , Citrus/química , Relação Dose-Resposta a Droga , Fezes/microbiologia , Carne/microbiologia , Salmonelose Animal/transmissão , Suínos , Doenças dos Suínos/transmissão , Zoonoses
11.
J Food Prot ; 74(4): 524-30, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21477464

RESUMO

Strategies aimed at reducing fecal shedding of Salmonella and other foodborne pathogens may be effective for limiting transmission of pathogens from food animals to humans. The objective of this study was to determine the effectiveness of gallium maltolate (GaM) against Salmonella in vitro and to determine whether oral administration of GaM would reduce fecal shedding of Salmonella in cattle. Gallium is a semimetal exhibiting antimicrobial properties against some pathogenic bacteria, including Salmonella, by exploiting their need for iron to survive and replicate. In vitro growth studies were performed in pure cultures of Salmonella and in mixed cultures from ruminal fluid. Inclusion of GaM in culture medium or in mixed cultures of ruminal fluid resulted in a significant reduction in growth of Salmonella, suggesting that GaM may be effective for limiting growth and survival in vivo. Therefore, we subsequently administered two doses of GaM to Holstein steers, experimentally infected them with Salmonella, and quantitatively and qualitatively monitored fecal shedding at 12-h intervals. Sixty hours after beginning treatment, cattle were euthanized, and luminal contents and tissue were aseptically harvested from the rumen, jejunum, spiral colon, cecum, and rectum. The luminal contents were processed for quantitative and qualitative analysis of the challenge strains of Salmonella, and tissue samples were enriched and plated for qualitative analysis. We found no significant differences between control and treated animals in quantitative levels of Salmonella in the feces or the luminal contents. Likewise, we observed no pattern between control and treated animals in the frequency of positive or negative results from enriched feces, luminal contents, or tissue samples. These results suggest that GaM was not effective for reducing Salmonella in cattle.


Assuntos
Antibacterianos/farmacologia , Fezes/microbiologia , Compostos Organometálicos/farmacologia , Pironas/farmacologia , Salmonella/efeitos dos fármacos , Administração Oral , Animais , Bovinos , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Contaminação de Alimentos/prevenção & controle , Masculino , Distribuição Aleatória , Salmonella/crescimento & desenvolvimento
12.
J Anim Sci ; 88(12): 3977-83, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20729286

RESUMO

Dietary components and changes cause shifts in the gastrointestinal microbial ecology that can play a role in animal health and productivity. However, most information about the microbial populations in the gut of livestock species has not been quantitative. In the present study, we utilized a new molecular method, bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP) that can perform diversity analyses of gastrointestinal bacterial populations. In the present study, cattle (n = 6) were fed a basal feedlot diet and were subsequently randomly assigned to 1 of 3 diets (n = 2 cows per diet). In each diet, 0, 25, or 50% of the concentrate portion of the ration was replaced with dried distillers grain (DDGS). Ruminal and fecal bacterial populations were different when animals were fed DDGS compared with controls; ruminal and fecal Firmicute:Bacteroidetes ratios were smaller (P = 0.07) in the 25 and 50% DDG diets compared with controls. Ruminal pH was decreased (P < 0.05) in ruminal fluid from cattle fed diets containing 50% compared with 0% DDGS. Using bTEFAP, the normal microbiota of cattle were examined using modern molecular methods to understand how diets affect gastrointestinal ecology and the gastrointestinal contribution of the microbiome to animal health and production.


Assuntos
Ração Animal/análise , Bactérias/classificação , Dieta/veterinária , Fezes/microbiologia , Rúmen/microbiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bactérias/genética , Bovinos , DNA Bacteriano/genética , Grão Comestível/química
13.
Folia Microbiol (Praha) ; 55(4): 309-11, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20680559

RESUMO

Campylobacter spp. are a leading bacterial cause of human foodborne illness. When cocultured in anaerobic Bolton broth with the hyper-ammonia producing bacterium, Clostridium aminophilum, ammonia accumulation was greater and final growth of Campylobacter jejuni was reduced (CFU>or=1.4 log10/mL) compared to that obtained by pure culture controls. Co-culture with the less active ammonia-producing saccharolytic Prevotella albensis had no effect on final C. jejuni concentrations. When co-cultured similarly except with the addition of 10 micromol/L monensin, monensin-susceptible Cl. aminophilum was reduced by 2 to 4 log10 CFU/mL and concentrations of C. jejuni, which is insensitive to monensin, did not differ from its pure culture control. These results suggest that in the absence of added monensin, the hyper ammonia-producing Cl. aminophilum may be able to outcompete asaccharolytic C. jejuni for amino acid substrates and that this competitive ability was eliminated by addition on monensin.


Assuntos
Amônia/metabolismo , Antibiose , Campylobacter jejuni/fisiologia , Clostridium/fisiologia , Animais , Antibacterianos/farmacologia , Campylobacter jejuni/crescimento & desenvolvimento , Clostridium/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Clostridium/metabolismo , Técnicas de Cocultura , Contagem de Colônia Microbiana , Meios de Cultura/química , Humanos , Monensin/farmacologia , Prevotella/crescimento & desenvolvimento , Prevotella/metabolismo , Prevotella/fisiologia
14.
Bioresour Technol ; 101(21): 8469-72, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20580225

RESUMO

Ruminant-derived foods contain high proportions of saturated fats as a result of ruminal biohydrogenation that rapidly saturates and thus limits the availability of free unsaturated fatty acids for assimilation. The objective of this study was to evaluate the effects of glycerol on ruminal free-fatty acid (FFA) production rates and in vitro fermentation kinetics of alfalfa hay. In vitro incubations demonstrated 48% and 77% reductions in rates of FFA accumulation in incubations supplemented with 2% and 20% glycerol as compared to controls. In vitro incubations with alfalfa hay demonstrated that increasing levels of glycerol did not affect NDF digestibility of the hay. Additionally, increasing amounts of glycerol decreased the acetate to propionate ratio in the rumen. These results suggest that inhibiting bacterial fat degradation may promote ruminal passage of total lipid, thereby providing greater proportions of beneficial unsaturated fat for incorporation into beef products.


Assuntos
Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Ácidos Graxos não Esterificados/biossíntese , Fermentação/efeitos dos fármacos , Glicerol/farmacologia , Rúmen/efeitos dos fármacos , Rúmen/microbiologia , Animais , Ácidos Graxos Voláteis/análise , Cinética , Medicago sativa/metabolismo
15.
J Appl Microbiol ; 107(4): 1258-68, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19486394

RESUMO

AIMS: To determine if the purported deaminase inhibitors diphenyliodonium chloride (DIC) and thymol reduce the growth and survivability of Campylobacter. METHODS AND RESULTS: Growth rates of Campylobacter jejuni and Camp. coli were reduced compared to unsupplemented controls during culture in Muellar-Hinton broth supplemented with 0.25 micromol DIC or thymol ml(-1) but not with 0.01 micromol monensin ml(-1) or 1% ethanol. Recovery of Camp. jejuni and Camp. coli was reduced >5 log(10) CFU from controls after 24 h pure culture in Bolton broth supplemented with 0.25 or 1.0 micromol DIC ml(-1) or with 1.0 micromol thymol ml(-1). Similarly, each test Campylobacter strain was reduced >3 log(10) CFU from controls after 24 h mixed culture with porcine faecal microbes in Bolton broth supplemented with 0.25 or 1.0 micromol DIC ml(-1) or with 1.0 micromol thymol ml(-1). Treatments with 0.25 micromol thymol ml(-1), 0.01 micromol monensin ml(-1) or 1% ethanol were less effective. Ammonia production during culture or incubation of cell lysates was reduced by 0.25 or 1.0 micromol DIC ml(-1) but only intermittently reduced, if at all, by the other treatments. CONCLUSIONS: Diphenyliodonium chloride and thymol reduced growth, survivability and ammonia production of Camp. jejuni and Camp. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest a potential physiological characteristic that may be exploited to develop interventions.


Assuntos
Anti-Infecciosos/farmacologia , Compostos de Bifenilo/farmacologia , Campylobacter/efeitos dos fármacos , Oniocompostos/farmacologia , Timol/farmacologia , Amônia/metabolismo , Animais , Campylobacter/crescimento & desenvolvimento , Campylobacter/metabolismo , Sobrevivência Celular , Contagem de Colônia Microbiana , Fezes/microbiologia , Suínos , Fatores de Tempo
16.
Curr Microbiol ; 58(5): 488-92, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19194750

RESUMO

The dicarboxylic acids malate and fumarate increase ruminal pH, reduce methane production, increase propionate and total volatile fatty acid (VFA) production, and reduce lactic acid accumulation in a manner similar to ionophores. These acids stimulate the ruminal bacterium Selenomonas ruminantium to ferment lactate to produce propionate. Thus, dicarboxylic acids have been suggested as nonantibiotic modifiers of the ruminal fermentation, but their impact on ruminal microbial ecology remains unknown. This study was designed to examine what effects these modifiers may have on intestinal pathogen populations such as Escherichia coli O157:H7 and S. enterica Typhimurium prior to their widespread incorporation into cattle rations. Pure cultures of E. coli O157:H7 strain 933 and S. enterica Typhimurium were grown with malate and fumarate added at 0, 1, 5, 10, and 20 mM (v/v; n = 3). Neither dicarboxylic acid inhibited (p > 0.1) the growth rate or final populations of E. coli O157:H7 or S. enterica Typhimurium. Ruminal fluid was collected from cattle (n = 2) and E. coli O157:H7 and S. enterica Typhimurium were added to separate ruminal fermentations incubated for 24 h at 39 degrees C. Fumarate and malate were added at concentrations of 0, 5, 10, and 20 mM (v/v; n = 2) and incubated for 24 h at 39 degrees C. Malate or fumarate addition did not affect (p > 0.1) populations of E. coli O157:H7 or S. enterica Typhimurium. However, the final pH was increased (p < 0.05), the acetate:propionate ratio was decreased (p < 0.05), and the total VFA production was increased (p < 0.05) by > or =10 mM dicarboxylic acid addition. These results confirm that dicarboxylic acids can modify ruminal fermentation, but they do not affect populations of critical foodborne pathogens.


Assuntos
Escherichia coli O157/crescimento & desenvolvimento , Fumaratos/farmacologia , Inibidores do Crescimento/farmacologia , Malatos/farmacologia , Rúmen/microbiologia , Salmonella typhimurium/crescimento & desenvolvimento , Animais , Líquidos Corporais/química , Líquidos Corporais/microbiologia , Bovinos , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Fermentação , Concentração de Íons de Hidrogênio , Salmonella typhimurium/efeitos dos fármacos
17.
Poult Sci ; 88(2): 298-302, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19151343

RESUMO

Laying hens are typically induced to molt to begin a new egg-laying cycle by withdrawing feed for up to 12 to 14 d. Fasted hens are more susceptible to colonization and tissue invasion by Salmonella enterica serovar Enteritidis. Much of this increased incidence in fasted hens is thought to be due to changes in the native intestinal microflora. An alternative to feed withdrawal involves feeding alfalfa meal crumble to hens, which is indigestible by poultry but provides fermentable substrate to the intestinal microbial population and reduces Salmonella colonization of hens compared with feed withdrawal. The present study was designed to quantify differences in the cecal microbial population of hens (n=12) fed a typical layer ration, undergoing feed withdrawal, or being fed alfalfa crumble by using a novel tag bacterial diversity amplification method. Bacteroides, Prevotella, and Clostridium were the most common genera isolated from all treatment groups. Only the ceca of hens undergoing feed withdrawal (n=4) contained Salmonella. The number of genera present was greatest in the alfalfa crumble-fed group and least in the feed withdrawal group (78 vs. 54 genera, respectively). Overall, the microbial diversity was least and Lactobacillius populations were not found in the hens undergoing feed withdrawal, which could explain much of these hens' sensitivity to colonization by Salmonella.


Assuntos
Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana/veterinária , Ceco/microbiologia , Galinhas/microbiologia , Dieta/veterinária , Análise de Sequência de DNA/veterinária , Animais , Bactérias/classificação , Técnicas de Tipagem Bacteriana/métodos , Biodiversidade , Feminino , Técnicas de Amplificação de Ácido Nucleico
18.
J Anim Sci ; 86(4): 882-9, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18156364

RESUMO

This study examined how different methods of applying a fibrolytic enzyme or ammonia affect the nutritive value of Bermudagrass hay and the performance of beef cattle. Fifty Angus x Brangus crossbred steers (mean initial BW 244 +/- 26 kg) were individually fed for ad libitum intake of a 5-wk regrowth of a mixture of Florakirk and Tifton 44 Bermudagrass [Cynodon dactylon (L.) Pers] hay for 84 d with a concentrate supplement (77% soybean hull pellets, 23% cottonseed meal (DM basis) fed at 1% of BW daily. The Bermudagrass was conserved as hay without treatment (control), with NH(3) (30 g/kg of DM), or with a fibrolytic enzyme (16.5 g/t, air-dry basis) that was applied immediately after cutting (Ec), at baling (Eb), or at feeding. Chromic oxide was dosed to steers for 10 consecutive days, and fecal Cr concentrations from the last 5 d were used to estimate apparent total tract digestibility. In situ ruminal DM degradability was measured by incubating ground (4-mm) hay samples in duplicate in each of 2 ruminally cannulated cows having ad libitum access to Bermudagrass hay and 500 g/d of soybean meal. Unlike the enzyme treatment, ammoniation increased (P < 0.001) the CP concentration and reduced (P < 0.001) NDF, hemicellulose, and lignin concentrations of hay. Total DMI was greater (P < 0.05) for steers fed hays treated with Ec or NH(3) than for those fed control hays. All additive treatments increased (P < 0.05) DM digestibility, and NH(3), Ec, and Eb treatments also increased (P < 0.01) NDF digestibility. The initial and final BW, ADG, BCS, G:F, and hip height of the steers were not affected (P > 0.05) by treatment. The wash loss fractions in hays treated with Ec and Eb were lower than that in the control hay, but the potentially degradable fraction, total degradable fraction, and the effective degradability were increased (P < 0.01) by NH(3) treatment. Application at cutting was the most promising method of enzyme treatment, and this treatment was almost as effective as ammonia for enhancing forage quality.


Assuntos
Amônia/farmacologia , Bovinos/crescimento & desenvolvimento , Bovinos/metabolismo , Digestão , Ingestão de Energia/efeitos dos fármacos , Enzimas/farmacologia , Rúmen/metabolismo , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Cynodon , Masculino , Valor Nutritivo , Distribuição Aleatória
19.
Int J Cosmet Sci ; 29(2): 131-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18489334

RESUMO

It is generally stated that drinking plenty of water has a positive influence on skin condition. However, there is no published scientific study that has investigated this matter. The aim of our exploratory 'before-after' study was to evaluate the in vivo influence of drinking more than 2 L of mineral water or ordinary tap water per day on skin physiology. Ninety-three healthy subjects were included in our prospective study. After an initial run-in phase of 2 weeks to monitor individual drinking habits, subjects had to drink 2.25 L day(-1) of either mineral water (n = 53) or tap water (n = 40) for 4 weeks. Bioengineering in vivo measurements on the volar forearm included sonographic evaluation of skin thickness and density, determination of skin surface pH, assessment of skin surface morphology, and measurement of finger circumference. Eighty-six subjects completed the study. In the mineral water group measurements revealed a statistically significant decrease in skin density. Skin thickness increased slightly, albeit not at a statistically significant level. However, when separately analysing those individuals from the mineral water group, who had routinely drunken comparably little before the start of the study, their skin thickness increased at a statistically significant level. Skin surface pH remained almost unchanged in the physiologically optimal range. In the tap water group, skin density increased significantly, while skin thickness decreased significantly. Skin surface pH decreased at a statistically significant level. While in the mineral water group finger circumference decreased significantly, measurements in the tap water group revealed a statistically significant increase. Objective skin surface morphology did not change in any group. In summary, drinking more than 2 L of water per day can have a significant impact on skin physiology. The exact effects within the skin seem to differ depending on the nature of the water ingested. Randomized, controlled, double-blind follow-up trials are warranted to confirm the findings of our exploratory pilot study.

20.
J Chem Phys ; 125(24): 244509, 2006 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-17199357

RESUMO

The nuclear magnetic resonance (NMR) spectra for the I=3/2 23Na cation dissolved into filamentous bacteriophage Pf1 solutions display line splittings and relaxation times consistent with an interaction between the 23Na nuclear quadrupole moment and the electric field gradient produced by the negatively charged Pf1 particles. The 23Na NMR line splittings and relaxation rates corresponding to magnetization recovery and single, double, and triple quantum coherence decays are measured in Pf1 solutions and compared to theoretical values. The deviation of the observed dc spectral density J0 from the equal first harmonic J(omega0) and second harmonic J(2omega0) values as J(omega0)=J(2omega0) not equal to J0 in these solutions suggests that ion migration in the electric field gradient of the Pf1 particles produces an anisotropic relaxation mechanism. Correlation functions and thus spectral densities for this process are calculated from solutions to the Fokker-Planck equation for radial motion in an electric potential and used to estimate measured relaxation rates. Appropriate electric potentials are generated from the solutions to the Poisson-Boltzmann equation for a charged Pf1 particle in aqueous phase, functions that lead to theoretical estimates of NMR line splittings consistent with experimental observations.


Assuntos
Bacteriófago Pf1/química , Espectroscopia de Ressonância Magnética/métodos , Modelos Biológicos , Modelos Químicos , Modelos Moleculares , Sódio/química , Simulação por Computador , Soluções , Marcadores de Spin , Temperatura
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