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1.
Anim Front ; 12(4): 46-51, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35974791
2.
Toxins (Basel) ; 11(3)2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893830

RESUMO

In vitro experiments have demonstrated that camel foregut-fluid has the capacity to metabolize indospicine, a natural toxin which causes hepatotoxicosis, but such metabolism is in competition with absorption and outflow of indospicine from the different segments of the digestive system. Six young camels were fed Indigofera spicata (337 µg indospicine/kg BW/day) for 32 days, at which time three camels were euthanized. The remaining camels were monitored for a further 100 days after cessation of this indospicine diet. In a retrospective investigation, relative levels of indospicine foregut-metabolism products were examined by UHPLC-MS/MS in plasma, collected during both accumulation and depletion stages of this experiment. The metabolite 2-aminopimelamic acid could be detected at low levels in almost all plasma samples, whereas 2-aminopimelic acid could not be detected. In the euthanized camels, 2-aminopimelamic acid could be found in all tissues except muscle, whereas 2-aminopimelic acid was only found in the kidney, pancreas, and liver tissues. The clearance rate for these metabolites was considerably greater than for indospicine, which was still present in plasma of the remaining camels 100 days after cessation of Indigofera consumption.


Assuntos
Sistema Digestório/metabolismo , Indigofera , Norleucina/análogos & derivados , Aminoácidos Neutros/sangue , Aminoácidos Neutros/metabolismo , Animais , Camelus , Contaminação de Alimentos , Norleucina/sangue , Norleucina/farmacocinética , Ácidos Pimélicos/sangue , Ácidos Pimélicos/metabolismo , Distribuição Tecidual
3.
J Agric Food Chem ; 65(34): 7528-7534, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28787565

RESUMO

The known accumulation of the hepatotoxin indospicine in tissues of camels and cattle grazing Indigofera pasture plants is unusual in that free amino acids would normally be expected to be degraded during the fermentation processes in these foregut fermenters. In this study, in vitro experiments were carried out to examine the degradability of indospicine of Indigofera spicata by camel and cattle foregut microbiota. In the first experiment, a 48 h in vitro incubation was carried out using foregut fluid samples that were collected from 15 feral camels and also a fistulated cow. Degradability of indospicine ranged between 97% and 99%, with the higher value of 99% for camels. A pooled sample of foregut fluids from three camels that were on a roughage diet was used in a second experiment to examine the time-dependent degradation of indospicine present in the plant materials. Results indicated that camels' foregut fluids have the ability to biodegrade ∼99% of the indospicine in I. spicata within 48 h of incubation and produced 2-aminopimelamic acid and 2-aminopimelic acid. The time-dependent degradation analysis showed rapid indospicine degradation (65 nmol/h) during the first 8-18 h of incubation followed by a slower degradation rate (12 nmol/h) between 18 and 48 h. Indospicine degradation products were also degraded toward the end of the experiment. The results of these in vitro degradation studies suggest that dietary indospicine may undergo extensive degradation in the foregut of the camel, resulting in trace levels after 48 h. The retention time for plant material in the camel foregut varies depending on feed quality, and the results of this study together with the observed accumulation of indospicine in camel tissues suggest that, although indospicine can be degraded by foregut fermentation, this degradation is not complete before the passage of the digesta into the intestine.


Assuntos
Ração Animal/análise , Camelus/metabolismo , Bovinos/metabolismo , Sistema Digestório/metabolismo , Indigofera/metabolismo , Norleucina/análogos & derivados , Ração Animal/toxicidade , Animais , Indigofera/química , Indigofera/toxicidade , Modelos Biológicos , Norleucina/química , Norleucina/metabolismo , Norleucina/toxicidade , Rúmen/metabolismo
4.
J Agric Food Chem ; 64(44): 8447-8453, 2016 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-27737547

RESUMO

Ingestion of indospicine-contaminated camel and horse meat has caused fatal liver injury to dogs in Australia, and it is currently not known if such contaminated meat may pose a human health risk upon dietary exposure. To date, indospicine-related research has tended to focus on analytical aspects, with little information on post-harvest management of indospicine-contaminated meat. In this study, indospicine degradation was investigated in both aqueous solution and also contaminated meat, under a range of conditions. Aqueous solutions of indospicine and indospicine-contaminated camel meat were microwaved (180 °C) or autoclaved (121 °C) with the addition of food-grade additives [0.05% (v/v) acetic acid or 0.05% (w/v) sodium bicarbonate] for 0, 15, 30, and 60 min. An aqueous sodium bicarbonate solution demonstrated the greatest efficacy in degrading indospicine, with complete degradation after 15 min of heating in a microwave or autoclave; concomitant formation of indospicine degradation products, namely, 2-aminopimelamic and 2-aminopimelic acids, was observed. Similar treatment of indospicine-contaminated camel meat with aqueous sodium bicarbonate resulted in 50% degradation after 15 min of heating in an autoclave and 100% degradation after 15 min of heating in a microwave. The results suggest that thermo-alkaline aqueous treatment has potential as a pragmatic post-harvest handling technique in reducing indospicine levels in indospicine-contaminated meat.


Assuntos
Camelus , Contaminação de Alimentos , Carne , Norleucina/análogos & derivados , Aminoácidos Neutros/análise , Animais , Cromatografia Líquida/métodos , Hidrólise , Espectrometria de Massas/métodos , Norleucina/análise , Norleucina/química , Ácidos Pimélicos/análise , Bicarbonato de Sódio/química
5.
Artigo em Inglês | MEDLINE | ID: mdl-27575484

RESUMO

Camel meat production for human consumption and pet food manufacture accounts for a relatively small part of overall red meat production in Australia. Reliable statistical data for the Australian production and consumption of camel meat are not available; however, it is estimated that 300,000 feral camels roam within the desert of central Australia, with an annual usage of more than 3000 camels for human consumption, 2000 for pet food manufacture and a smaller number for live export. Despite a small Australian camel meat production level, the usage of camel meat for pet food has been restricted in recent years due to reports of serious liver disease and death in dogs consuming camel meat. This camel meat was found to contain residues of indospicine, a non-proteinogenic amino acid found in certain Indigofera spp., and associated with mild to severe liver disease in diverse animals after dietary exposure to this hepatotoxin. The extent of indospicine-contaminated Australian camel meat was previously unknown, and this study ascertains the prevalence of such residue in Australian camel meat. In this study, indospicine levels in ex situ (95 samples collected from an abattoir in Queensland) and in situ (197 samples collected from camels after field culling in central Australia) camel meat samples were quantitated using a validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The quantitation results showed 46.7% of the in situ- and 20.0% of the ex situ-collected camel meat samples were contaminated by indospicine (more than the limit of detection (LOD) of 0.05 mg kg-1 fresh weight). The overall indospicine concentration was higher (p < 0.05) in the in situ-collected samples. Indospicine levels detected in the present study are considered to be low; however, a degree of caution must still be exercised, since the tolerable daily intake for indospicine is currently not available for risk estimation.


Assuntos
Produtos Biológicos/análise , Camelus , Contaminação de Alimentos/análise , Carne/análise , Norleucina/análogos & derivados , Animais , Austrália , Cromatografia Líquida de Alta Pressão , Feminino , Masculino , Norleucina/análise , Espectrometria de Massas em Tandem
6.
J Agric Food Chem ; 64(34): 6613-21, 2016 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-27509381

RESUMO

Livestock industries have maintained a keen interest in pasture legumes because of the high protein content and nutritive value. Leguminous Indigofera plant species have been considered as having high feeding values to be utilized as pasture, but the occurrence of the toxic constituent indospicine in some species has restricted this utility. Indospicine has caused both primary and secondary hepatotoxicosis and also reproductive losses, but has only previously been determined in a small number of Indigofera species. This paper validates a high-throughput ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine the indospicine content of various Indigofera species found in Australian pasture. Twelve species of Indigofera together with Indigastrum parviflorum plants were collected and analyzed. Of the 84 samples analyzed, *I. spicata (the asterisk indicates a naturalized species) contained the highest indospicine level (1003 ± 328 mg/kg DM, n = 4) followed by I. linnaei (755 ± 490 mg/kg DM, n = 51). Indospicine was not detected in 9 of the remaining 11 species and at only low levels (<10 mg/kg DM) in 2 of 8 I. colutea specimens and in 1 of 5 I. linifolia specimens. Indospicine concentrations were below quantitation levels for other Indigofera spp. (I. adesmiifolia, I. georgei, I. hirsuta, I. leucotricha, *I. oblongifolia, I. australis, and I. trita) and Indigastrum parviflorum. One of the more significant findings to emerge from this study is that the indospicine content of I. linnaei is highly variable (from 159 to 2128 mg/kg DM, n = 51) and differs across both regions and seasons. Its first regrowth after spring rain has a higher (p < 0.01) indospicine content than growth following more substantial summer rain. The species collected include the predominant Indigofera in Australia pasture, and of these, only *I. spicata and I. linnaei contain high enough levels of indospicine to pose a potential toxic threat to grazing herbivores.


Assuntos
Indigofera/química , Norleucina/análogos & derivados , Toxinas Biológicas/análise , Austrália , Cromatografia Líquida de Alta Pressão , Indigofera/toxicidade , Norleucina/análise , Estações do Ano , Espectrometria de Massas em Tandem
7.
J Agric Food Chem ; 64(34): 6622-9, 2016 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-27477889

RESUMO

Indospicine (l-2-amino-6-amidinohexanoic acid) is a natural hepatotoxin found in all parts of some Indigofera plants such as Indigofera linnaei and Indigofera spicata. Several studies have documented a susceptibility to this hepatotoxin in different species of animals, including cattle, sheep, dogs, and rats, which are associated with mild to severe liver disease after prolonged ingestion. However, there is little published data on the effects of this hepatotoxin in camels, even though Indigofera plants are known to be palatable to camels in central Australia. The secondary poisoning of dogs after prolonged dietary exposure to residual indospicine in camel muscle has raised additional food safety concerns. In this study, a feeding experiment was conducted to investigate the in vivo accumulation, excretion, distribution, and histopathological effects of dietary indospicine on camels. Six young camels (2-4 years old), weighing 270-390 kg, were fed daily a roughage diet consisting of Rhodes grass hay and lucerne chaff, supplemented with Indigofera and steam-flaked barley. Indigofera (I. spicata) was offered at 597 mg DM/kg body weight (bw)/day, designed to deliver 337 µg indospicine/kg bw/day, and fed for a period of 32 days. Blood and muscle biopsies were collected over the period of the study. Concentrations of indospicine in the plasma and muscle biopsy samples were quantitated by validated ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The highest concentrations in plasma (1.01 mg/L) and muscle (2.63 mg/kg fresh weight (fw)) were found at necropsy (day 33). Other tissues were also collected at necropsy, and analysis showed ubiquitous distribution of indospicine, with the highest indospicine accumulation detected in the pancreas (4.86 ± 0.56 mg/kg fw) and liver (3.60 ± 1.34 mg/kg fw), followed by the muscle, heart, and kidney. Histopathological examination of liver tissue showed multiple small foci of predominantly mononuclear inflammatory cells. After cessation of Indigofera intake, indospicine present in plasma in the remaining three camels had a longer terminal elimination half-life (18.6 days) than muscle (15.9 days), and both demonstrated monoexponential decreases.


Assuntos
Ração Animal/análise , Camelus/metabolismo , Indigofera/metabolismo , Norleucina/análogos & derivados , Toxinas Biológicas/metabolismo , Ração Animal/toxicidade , Animais , Austrália , Camelus/sangue , Cães , Feminino , Indigofera/química , Rim/química , Rim/metabolismo , Fígado/química , Fígado/metabolismo , Masculino , Carne/análise , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Norleucina/sangue , Norleucina/metabolismo , Toxinas Biológicas/sangue
8.
Br J Nutr ; 116(1): 35-44, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27138530

RESUMO

High-producing dairy cows enter a period of negative energy balance during the first weeks of lactation. Energy intake is usually sufficient to cover the increase in energy requirements for fetal growth during the period before calving, but meeting the demand for energy is often difficult during the early stages of lactation. A catabolic state predominates during the transition period, leading to the mobilisation of energy reserves (NEFA and amino acids) that are utilised mainly by the liver and muscle. Increased uptake of mobilised NEFA by the liver, combined with the limited capacity of hepatocytes to either oxidise fatty acids for energy or to incorporate esterified fatty acids into VLDL results in fatty liver syndrome and ketosis. This metabolic disturbance can affect the general health, and it causes economic losses. Different nutritional strategies have been used to restrict negative effects associated with the energy challenge in transition cows. The provision of choline in the form of rumen-protected choline (RPC) can potentially improve liver function by increasing VLDL exportation from the liver. RPC increases gene expression of microsomal TAG transfer protein and APOB100 that are required for VLDL synthesis and secretion. Studies with RPC have looked at gene expression, metabolic hormones, metabolite profiles, milk production and postpartum reproduction. A reduction in liver fat and enhanced milk production has been observed with RPC supplementation. However, the effects of RPC on health and reproduction are equivocal, which could reflect the lack of sufficient dose-response studies.


Assuntos
Bovinos/fisiologia , Colina/farmacologia , Lactação/fisiologia , Fígado/efeitos dos fármacos , Rúmen/metabolismo , Animais , Colina/administração & dosagem , Feminino , Gravidez
9.
J Basic Microbiol ; 56(5): 580-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26773324

RESUMO

The presence of the toxic amino acid mimosine in Leucaena leucocephala restricts its use as a protein source for ruminants. Rumen bacteria degrade mimosine to 3,4- and 2,3-dihydroxypyridine (DHP), which remain toxic. Synergistes jonesii is believed to be the main bacterium responsible for degradation of these toxic compounds but other bacteria may also be involved. In this study, a commercial inoculum provided by the Queensland's Department of Agriculture, Fisheries, and Forestry was screened for isolation and characterization of mimosine, 3,4- and 2,3-DHP degrading bacterial strains. A new medium for screening of 2,3-DHP degrading bacteria was developed. Molecular and biochemical approaches used in this study revealed four bacterial isolates - Streptococcus lutetiensis, Clostridium butyricum, Lactobacillus vitulinus, and Butyrivibrio fibrisolvens - to be able to completely degrade mimosine within 7 days of incubation. It was also observed that C. butyricum and L. vitulinus were able to partially degrade 2,3-DHP within 12 days of incubation, while S. lutetiensis, was able to fully degrade both 3,4 and 2,3 DHP. Collectively, we concluded that S. jonesii is not the sole bacterium responsible for detoxification of Leucaena. Comprehensive screening of rumen fluid of cattle grazing on Leucaena pastures is needed to identify additional mimosine-detoxifying bacteria and contribute to development of more effective inoculums to be used by farmers against Leucaena toxicity.


Assuntos
Bactérias/metabolismo , Fabaceae/metabolismo , Mimosina/metabolismo , Piridinas/metabolismo , Rúmen/microbiologia , Animais , Bactérias/isolamento & purificação , Bovinos , Fabaceae/toxicidade , Inativação Metabólica
10.
BMC Microbiol ; 14: 314, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25495654

RESUMO

BACKGROUND: Forestomach fermentation in Australian marsupials such as wallabies and kangaroos, though analogous to rumen fermentation, results in lower methane emissions. Insights into hydrogenotrophy in these systems could help in devising strategies to reduce ruminal methanogenesis. Reductive acetogenesis may be a significant hydrogen sink in these systems and previous molecular analyses have revealed a novel diversity of putative acetogens in the tammar wallaby forestomach. RESULTS: Methanogen-inhibited enrichment cultures prepared from tammar wallaby forestomach contents consumed hydrogen and produced primarily acetate. Functional gene (formyltetrahydrofolate synthetase and acetyl-CoA synthase) analyses revealed a restricted diversity of Clostridiales species as the putative acetogens in the cultures. A new acetogen (growth on H2/CO2 with acetate as primary end product) designated isolate TWA4, was obtained from the cultures. Isolate TWA4 classified within the Lachnospiraceae and demonstrated >97% rrs identity to previously isolated kangaroo acetogens. Isolate TWA4 was a potent hydrogenotroph and demonstrated excellent mixotrophic growth (concomitant consumption of hydrogen during heterotrophic growth) with glycerol. Mixotrophic growth of isolate TWA4 on glycerol resulted in increased cell densities and acetate production compared to autotrophic growth. Co-cultures with an autotrophic methanogen Methanobrevibacter smithii revealed that isolate TWA4 performed reductive acetogenesis under high hydrogen concentration (>5 mM), but not at low concentrations. Under heterotrophic growth conditions, isolate TWA4 did not significantly stimulate methanogenesis in a co-culture with M. smithii contrary to the expectation for organisms growing fermentatively. CONCLUSIONS: The unique properties of tammar wallaby acetogens might be contributing factors to reduced methanogen numbers and methane emissions from tammar wallaby forestomach fermentation, compared to ruminal fermentation. The macropod forestomach may be a useful source of acetogens for future strategies to reduce methane emissions from ruminants, particularly if these strategies also include some level of methane suppression and/or acetogen stimulation, for example by harnessing mixotrophic growth capabilities.


Assuntos
Acetatos/metabolismo , Bactérias Anaeróbias/isolamento & purificação , Bactérias Anaeróbias/metabolismo , Bactérias Gram-Positivas/isolamento & purificação , Bactérias Gram-Positivas/metabolismo , Macropodidae/microbiologia , Estômago/microbiologia , Animais , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Genes de RNAr , Glicerol/metabolismo , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/genética , Hidrogênio/metabolismo , Dados de Sequência Molecular , Análise de Sequência de DNA
11.
Poult Sci ; 93(9): 2337-46, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25002548

RESUMO

The aim of this work was to test the potential use of plant-derived extracts and compounds to control Campylobacter jejuni in broiler chickens. Over a 7-wk feeding period, birds were fed a commercial diet with or without plant extracts (Acacia decurrens, Eremophila glabra), essential oil [lemon myrtle oil (LMO)], plant secondary compounds [terpinene-4-ol and α-tops (including α-terpineol, cineole, and terpinene-4-ol)], and the antibiotic virginiamycin. Traditional culture and real-time quantitative PCR techniques were used to enumerate the numbers of C. jejuni in chicken fecal and cecal samples. In addition, BW and feed intake were recorded weekly for the calculation of BW gain and feed conversion ratio. The mean log10 counts of C. jejuni were similar (P > 0.05) across treatments. However, significantly lower levels of fecal Campylobacter counts (P < 0.05) were recorded at d 41 for the α-tops treatment by culture methods. No differences (P > 0.05) in BW gain were obtained for dietary supplementation, except for the E. glabra extract, which had a negative impact (P < 0.001) on BW, resulting in sporadic death. Results from this study suggest that supplemental natural compounds used in the current study did not reduce the shedding of C. jejuni to desired levels.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter jejuni/efeitos dos fármacos , Galinhas , Suplementos Nutricionais , Extratos Vegetais , Doenças das Aves Domésticas/prevenção & controle , Virginiamicina/farmacologia , Acacia/química , Ração Animal/análise , Animais , Antibacterianos/farmacologia , Derrame de Bactérias/efeitos dos fármacos , Infecções por Campylobacter/prevenção & controle , Ceco/microbiologia , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Eremophila (Planta)/química , Fezes/microbiologia , Masculino , Doenças das Aves Domésticas/microbiologia , Distribuição Aleatória
12.
Trop Anim Health Prod ; 46(7): 1161-6, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24898095

RESUMO

The total bacterial community of Fibrobacter succinogenes and Ruminococcus flavefaciens in fibre-enriched culture of the foregut contents of 12 adult feral camels (Camelus dromedaries) fed on native vegetation in Australia was investigated using quantitative PCR. Foregut contents were collected postmortem, pooled and filtered before divided into two fractions. One fraction was used for extraction of DNA, while the other fraction was inoculated straight away into BM 10 contained filter paper (FP), cotton thread (CT) or neutral detergent fibre (NDF) as the sole carbohydrate sources in Hungate tubes. The tubes were incubated anaerobically at 39 °C for 1 week. After a near complete degradation of the FP and CT and extensive turbidity in the NDF, media subculturing was carried out into fresh media tubes. This was repeated twice before genomic DNA was extracted and used for quantification of bacteria. Using an absolute quantification method, the numbers of cells in 1 ml of each sample ranged from 4.07 × 10(6) to 2.73 × 10(9) for total bacteria, 1.34 × 10(3) to 2.17 × 10(5) for F. succinogenes and 5.78 × 10(1) to 3.53 × 10(4) for R. flavefaciens. The mean cell number of F. succinogenes was highest in the FP enrichment medium at approximately 107-fold, whereas for the R. flavefaciens targeted primer, the NDF enrichment media had the highest mean cell number at approximately 4-fold when compared to the rumen content. The data presented here provide evidence of fibre type preference by the two main fibre-degrading bacteria and would help us understand the interaction between fibre type and fibre-degrading microorganisms, which has ramification on camel nutrition at different seasons and environments.


Assuntos
Camelus/microbiologia , Fibras na Dieta/farmacologia , Fibrobacter/crescimento & desenvolvimento , Rúmen/microbiologia , Ruminococcus/crescimento & desenvolvimento , Análise de Variância , Animais , Austrália , Contagem de Células , Celulose/metabolismo , Meios de Cultura/química , Primers do DNA/genética , Fibrobacter/efeitos dos fármacos , RNA Ribossômico 16S/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Ruminococcus/efeitos dos fármacos
13.
J Agric Food Chem ; 62(8): 1974-9, 2014 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-24433171

RESUMO

Indospicine is a hepatotoxic amino acid found in Indigofera plant spp. and is unusual in that it is not incorporated into protein but accumulates as the free amino acid in the tissues (including muscle) of animals consuming these plants. Dogs are particularly sensitive to indospicine, and secondary poisoning of dogs has occurred from the ingestion of indospicine-contaminated horse meat and more recently camel meat. In central Australia, feral camels are known to consume native Indigofera species, but the prevalence of indospicine residues in their tissues has not previously been investigated. In this study, a method was developed and validated with the use of ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to determine the level of indospicine in camel meat samples using isotopically labeled indospicine as an internal standard. UPLC-MS/MS analysis showed that the method is reproducible, with high recovery efficiency and a quantitation limit of 0.1 mg/kg. Camel meat samples from the Simpson Desert were largely contaminated (≈50%) by indospicine with levels up to 3.73 mg/kg (fresh weight) determined. However, the majority of samples (95%) contained less than 1 mg/kg indospicine.


Assuntos
Camelus/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Indigofera/metabolismo , Carne/análise , Músculo Esquelético/química , Norleucina/análogos & derivados , Extratos Vegetais/análise , Espectrometria de Massas em Tandem/métodos , Animais , Austrália , Indigofera/toxicidade , Músculo Esquelético/metabolismo , Norleucina/análise , Norleucina/metabolismo , Norleucina/toxicidade , Extratos Vegetais/metabolismo , Extratos Vegetais/toxicidade
15.
Int J Food Microbiol ; 166(3): 450-7, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-24041998

RESUMO

The aim of this study was to examine the antimicrobial potential of three essential oils (EOs: tea tree oil, lemon myrtle oil and Leptospermum oil), five terpenoid compounds (α-bisabolol, α-terpinene, cineole, nerolidol and terpinen-4-ol) and polyphenol against two strains of Campylobacter jejuni (ACM 3393 and the poultry isolate C338), Campylobacter coli and other Gram negative and Gram positive bacteria. Different formulations of neem oil (Azadirachta indica) with these compounds were also tested for synergistic interaction against all organisms. Antimicrobial activity was determined by the use of disc diffusion and broth dilution assays. All EOs tested were found to have strong antimicrobial activity against Campylobacter spp. with inhibitory concentrations in the range 0.001-1% (v/v). Among the single compounds, terpinen-4-ol showed the highest activity against Campylobacter spp. and other reference strains. Based on the antimicrobial activity and potential commerciality of these agents, lemon myrtle oil, α-tops (α-terpineol+cineole+terpinen-4-ol) and terpinen-4-ol were also evaluated using an in vitro fermentation technique to test antimicrobial activity towards C. jejuni in the microbiota from the chicken-caecum. EO compounds (terpinen-4-ol and α-tops) were antimicrobial towards C. jejuni at high doses (0.05%) without altering the fermentation profile. EOs and terpenoid compounds can have strong anti-Campylobacter activity without adversely affecting the fermentation potential of the chicken-caeca microbiota. EOs and their active compounds may have the potential to control C. jejuni colonisation and abundance in poultry.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Campylobacter jejuni/efeitos dos fármacos , Óleos Voláteis/farmacologia , Terpenos/farmacologia , Animais , Galinhas/microbiologia , Fermentação , Bactérias Gram-Positivas/efeitos dos fármacos , Carne/microbiologia , Testes de Sensibilidade Microbiana
16.
Mol Biol Rep ; 40(1): 369-76, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23065252

RESUMO

We investigated the community structure of bacteria that populate the stomach of the Brumby, a breed of feral horses from the Australian outback. Using a 16S rRNA gene clone library, we identified 155 clones that were assigned to 26 OTUs based on a 99.0 % sequence identity cutoff. Two OTUs represented 73.5 % of clones, while 18 OTUs were each assigned only a single clone. Four major bacterial types were identified in the Brumby stomach: Lactobacillaceae, Streptococcaceae, Veillonellaceae and Pasteurellaceae. The first three groups, which represented 98.1 % of the Brumby stomach library clones, belonged to the bacterial phylum Firmicutes. We found that 49.7 % of clones were related to bacterial species previously identified in the equine hindgut, and that 44.5 % of clones were related to symbiotic bacterial species identified in the mouth or throat of either horses or other mammals. Our results indicated that the composition of mutualistic bacterial communities of feral horses was consistent with other studies on domestic horses. In addition to bacterial sequences, we also identified four plastid 16S rRNA gene sequences, which may help in further characterizing the type of vegetation consumed by Brumby horses in their natural environment.


Assuntos
Bactérias/classificação , Bactérias/genética , Estômago/microbiologia , Animais , Austrália , Cavalos , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S
17.
Appl Environ Microbiol ; 78(24): 8836-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23042173

RESUMO

Foregut digesta from five feral dromedary camels were inoculated into three different enrichment media: cotton thread, filter paper, and neutral detergent fiber. A total of 283 16S rRNA gene sequences were assigned to 33 operational taxonomic units by using 99% species-level identity. LIBSHUFF revealed significant differences in the community composition across all three libraries.


Assuntos
Bactérias/classificação , Bactérias/metabolismo , Biodiversidade , Celulose/metabolismo , Rúmen/microbiologia , Animais , Bactérias/isolamento & purificação , Camelus , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
18.
Microb Ecol ; 64(3): 628-40, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22383121

RESUMO

Reductive acetogenesis is not competitive with methanogenesis in adult ruminants, whereas acetogenic bacteria are the dominant hydrogenotrophs in the early rumen microbiota. The ecology of hydrogenotrophs in the developing rumen was investigated using young lambs, raised in sterile isolators, and conventional adult sheep. Two lambs were born naturally, left with their dams for 17 h and then placed into a sterile isolator and reared aseptically. They were inoculated with cellulolytic bacteria and later with Methanobrevibacter sp. 87.7 to investigate the effect of methanogen establishment on the rumen acetogen population since they lacked cultivable representatives of methanogens. Putative acetogens were investigated by acetyl-CoA synthase and formyltetrahydrofolate synthetase gene analysis and methanogens by methyl coenzyme reductase A gene analysis. Unexpectedly, a low abundant but diverse population of methanogens (predominantly Methanobrevibacter spp.) was identified in isolated lambs pre-inoculation with Mbb. sp 87.7, which was similar to the community structure in conventional sheep. In contrast, potential acetogen diversity in isolated lambs and conventional sheep was different. Potential acetogens affiliated between the Lachnospiraceae and Clostridiaceae in conventional sheep and with the Blautia genus and the Lachnospiraceae in isolated lambs. The establishment of Mbb. sp. 87.7 (1,000-fold increase in methanogens) did not substantially affect acetogen diversity.


Assuntos
Ácido Acético/metabolismo , Animais Recém-Nascidos/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Metano/metabolismo , Rúmen/microbiologia , Carneiro Doméstico/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos/microbiologia , Assepsia , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Celulose/metabolismo , Ecossistema , Methanobrevibacter/crescimento & desenvolvimento , Dados de Sequência Molecular , Análise de Sequência de DNA , Carneiro Doméstico/microbiologia , Fatores de Tempo
19.
Phytother Res ; 26(2): 186-90, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21604309

RESUMO

Campylobacter jejuni is the most common cause of acute enteritis in humans, with symptoms such as diarrhoea, fever and abdominal cramps. In this study, 115 extracts from 109 Australian plant species were investigated for their antimicrobial activities against two C. jejuni strains using an in vitro broth microdilution assay. Among the plants tested, 107 (93%) extracts showed activity at a concentration between 32 and 1024 µg/mL against at least one C. jejuni strain. Seventeen plant extracts were selected for further testing against another six C. jejuni strains, as well as Campylobacter coli, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Proteus mirabilis and Enterococcus faecalis. The extract from Eucalyptus occidentalis demonstrated the highest antimicrobial activity, with an inhibitory concentration of 32 µg/mL against C. jejuni and B. cereus. This study has shown that extracts of selected Australian plants possess antimicrobial activity against C. jejuni and thus may have application in the control of this organism in live poultry and retail poultry products.


Assuntos
Antibacterianos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas/química , Austrália , Eucalyptus/química , Testes de Sensibilidade Microbiana
20.
Environ Microbiol ; 13(11): 3024-35, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21914099

RESUMO

The molecular diversity of the foregut bacterial community in the dromedary camel (Camelus dromedarius) in Central Australia was investigated through comparative analyses of 16S rRNA gene sequences prepared from the foregut contents of 12 adult feral camels fed on native vegetation. A total of 267 full-length 16S rRNA gene clones were examined, with 151 operational taxonomic units (OTUs) identified at a 99% species-level identity cut-off criterion. The prediction of actual diversity in the foregut of the dromedary camel using the Chaol approach was 238 OTUs, while the richness and evenness of the diversity estimated using Shannon index was 4.84. The majority of bacteria in the current study were affiliated with the bacterial phylum Firmicutes (67% of total clones) and were related to the classes Clostridia, Bacilli and Mollicutes, followed by the Bacteroidetes (25%) that were mostly represented by the family Prevotellaceae. The remaining phyla were represented by Actinobacteria, Chloroflexi, Cynophyta, Lentisphaerae, Planctomycetes, Proteobacteria and Sphirochaetes. Moreover, 11 clones of cultivated bacteria were identified as Brevundimonas sp., Butyrivibrio fibrisolvens, Prevotella sp. and Ruminococcus flavefaciens. The novelty in this foregut environment is remarkable where 97% of the OTUs were distantly related to any known sequence in the public database.


Assuntos
Bactérias/genética , Camelus/microbiologia , Trato Gastrointestinal/microbiologia , Metagenoma , Animais , Austrália , Bactérias/classificação , Biblioteca Gênica , Dados de Sequência Molecular , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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