This study investigated the efficacy of the aqueous fraction obtained after fractionating silage of tilapia (Oreochromis niloticus) and cobia (Rachycentron canadum) in supporting the growth of Escherichia coli and Staphylococcus aureus. The silages were prepared using combinations of citric, formic, and propionic acids. The aqueous fractions, used as test peptones, contained lower levels of total protein. The concentrations of 18 amino acids in all the samples were observed to be lower than those in the commercial peptone. Glutamic acid, lysine, glycine, and aspartic acid were present in higher concentrations than other amino acids, for both types of silage. Biomass production from E. coli culture ranged from 38.4 to 65.9 mg 100 mL?1 for all the tested treatments, while that for S. aureus was from 26.3 to 53.7 mg 100 mL?1. This indicated that products from fish silage were effective for bacterial growth in terms of biomass, by providing the main sources of nitrogen and carbon to facilitate their growth. The tested silages yielded similar efficiency to the commercial peptone. The findings revealed that it is feasible for the fish processing industry to incorporate freeze-dried by-products obtained after fractioning waste silage from the processing of tilapia and cobia. 相似文献
ABSTRACTThe aim of the present study was to evaluate the feasibility of increasing lipid extraction in tilapia (Oreochromis niloticus) waste using different enzymes and to minimize the periods of hydrolysis to evaluate the performance of the lipid fractions. When processing waste tilapia, commercial enzymes were added that were composed of neutrase and alcalase acting at different hydrolysis times to produce the best yields. The treatment proved feasible for obtaining the protein hydrolysates. The type of enzyme and the hydrolysis time determined the degree of fractionation. The enzymes performed well, and the highest efficiency occurred within 2 h of hydrolysis. By fractionating, the obtained by-products can be applied in the preparation of feed, as the lipid fraction treatments yielded significant amounts of polyunsaturated fats and suitable n-6/n-3 ratios. 相似文献
OBJECTIVES: To assess the ability of anthropometric measurements to identify young women at risk of developing diabetes, hypertension and heart disease in the future and to compare cut-off points for common anthropometric measures established with receiver-operating characteristic (ROC) curves with those reported in the literature. DESIGN: Cross-sectional study. SUBJECTS: Eight hundred and two young Mexican women living in semi-urban poverty. MEASUREMENTS/METHODS: The ability of anthropometric measures of fatness and fat distribution (body mass index (BMI), summed skinfold thickness (SST), waist circumference (WC), waist-to-hip ratio (WHR), conicity index (CI), abdominal volume index (AVI)) to predict risk of future disease (pre-diabetes: fasting blood glucose 100-126 mg dl-1; pre-hypertension: systolic blood pressure 120-139 mmHg and/or diastolic blood pressure 80-89 mmHg; hypertriglyceridaemia: triglycerides > or =150 mg dl-1; or a combination of risk factors) was assessed using ROC curve analysis. RESULTS: Twenty-three of the 802 women who were interviewed had incomplete data and 50 (6.4%) were eliminated from the analysis due to hypertension and/or diabetes. Mean age of the remaining 729 women was 29.6 +/- 5.4 years and mean BMI was 27.7 +/- 4.5 kg m-2. There were no significant differences in the area under the ROC curve for BMI, WC, AVI or SST for any of the four outcomes. However, these indices performed significantly better than WHR and CI (P < 0.05). The BMI cut-off points that maximised sensitivity and specificity for the four outcomes were in the range of 27.7-28.4 kg m-2, and for WC were 89.3-91.2 cm. To detect 90% of the cases of any metabolic alteration, the necessary BMI cut-off was 26.1 kg m-2. Younger women (<25 years) were at greater risk than older women for a given BMI increment (P < 0.05). CONCLUSIONS: We found that BMI and WC cut-off points commonly used for the identification of risk of existing disease were also appropriate in this population for the identification of risk in the future among women without diabetes or hypertension. The early identification of at-risk individuals, prior to the onset of disease, is fundamental particularly in the context of a country with scarce resources that is rapidly undergoing nutrition transition. 相似文献
ABSTRACT The phytoplasma "Candidatus Phytoplasma australiense" has been reported from New Zealand and Australia, where it has been associated with a range of host plants, especially since the 1970s. Partial tuf gene sequences of 36 New Zealand (NZ) isolates from four different host genera revealed nine different variants, which clustered into two distinct groups without any obvious correlation with host or geographic region. Phylogenetic analysis of these sequences, together with those available from Australian isolates, revealed three distinct clades: one found solely in Australia, one found solely in NZ, and a third with representatives from both countries. These divisions are consistent with differences observed in the 16-23S rRNA internal transcribed spacer region; therefore, we conclude that they represent three distinct subgroups: tuf 1, tuf 2, and tuf 3. We estimated a time of divergence for the three clades based on a synonymous substitution rate calculated by comparing the complete tuf gene sequence from the Loofah witches'-broom phytoplasma and "Candidatus Phytoplasma australiense". Using a calibration date of 110 million years, the estimated time to a common ancestor for all clades (6 to 9 million years ago) suggests divergence during the Miocene, well after the geological separation of NZ and Australia. 相似文献
Bovine hypodermosis is a myiasis caused by Hypoderma bovis and Hypoderma lineatum (Diptera, Oestridae) larvae, which has a severe economic impact on the livestock industry. Though myiasis is widespread throughout Italy, no nationwide eradication program has ever been planned, unlike in other European Countries. With a view to setting up a national control program, a pilot study was carried out in Southern Italy on 9939 cattle bred in an area with a high prevalence of cattle hypodermosis, using moxidectin 0.5% pour-on (Cydectin, Fort Dodge) and 1% injectable (Cydectin, Fort Dodge) formulations. At the recommended dosage, moxidectin displayed efficacy levels of 99.9% in the pour-on and 100% in the injectable formulation, whereas the microdose (1 mg per head regardless of body weight) was less effective (65.7%). This trial contributed to a significant reduction in infestation rates in the study area and represented the first step through which a national program for eradicating warble fly infestation in Italy. 相似文献
Preventing tick bites is a fundamental step towards reducing the impact of tick-borne protozoal, bacterial and viral diseases (TBDs) in humans and animals. The aim of this study was to evaluate the efficacy of a combination of imidacloprid 10%/permethrin 50% and of fipronil 10%/S-methoprene 12% against ticks in naturally infected dogs and to assess methodological parameters to calculate drug efficacy on tick immature stages.
From July to August 2004, 45 privately owned dogs of various sexes, ages, breeds, coat length and habits were enrolled in a trial carried out in an area (radius approximately 50 km) in Southern Italy. Three homogeneous groups (both for dog population and tick population) were formed: 15 dogs treated with imidacloprid 10% and permethrin 50% spot-on (group A), 15 dogs treated with fipronil 10% and methoprene 12% spot-on (group B) and 15 untreated dogs (group C). The dogs in each group were then sub-grouped according to their age and weight. Two different treatments were administered (time 0 and +28 days) to groups A and B, and the dogs were checked weekly for tick infestation until day +56 post-treatment (p.t.). Twenty-four areas distributed on the whole body surface were examined for ticks at each follow-up, while only at time 0 and at day +56 p.t., ticks were collected from the dogs and identified.
For the immature stages a semi-quantitative method was adopted and the load of immature stages was evaluated and grouped into four classes up to day +56 p.t. when the mean number of immature ticks (MIT) for each infection class was evaluated.
All the adult ticks collected were identified as brown dog ticks (Rhipicephalus sanguineus). Immature stages were first compared at day +28 p.t.. The efficacy of both products used in groups A and B on adult ticks was high and generally very similar. Conversely, the efficacy of imidacloprid 10% and permethrin 50% against immatures was higher than that of fipronil 10% and methoprene 12% throughout the observation period with statistically significant differences (p < 0.05) at day +28 p.t. (i.e. group A = 98.52%, group B = 72.40%).
On the whole, in analysing the efficacy of both products against adult plus immature ticks, it was found that the combination of imidacloprid 10% and permethrin 50% was more effective than fipronil 10% and methoprene 12%, with the differences being statistically significant at day +28 p.t. (group A = 98.43%, group B = 77.56%). 相似文献
A dot-ELISA test for the detection of anti-BRSV antibodies is described. The objective of this study was the standardisation of a test as a fast, inexpensive and effective alternative to detect anti-BRSV antibodies. Its sensitivity, specificity and usefulness were compared to a commercial ELISA-kit and to the standard serum neutralisation (SN) test. The standardisation of the technique was done using nitrocellulose disks soaked with a viral sample isolated in Brazil, BRSV-25-BR. The best results were obtained when the disks were sensitised with a purified antigen at a concentration of 0.7 microg/disk and the bovine serum was diluted 1: 200. The experiment used 423 samples of bovine serum collected in the main cattle breeding centres in Brazil. The standard SN, dot-ELISA technique and commercial ELISA kits scored 67.8%, 71.8% and 72.3% of the samples as positive, respectively. When compared to the SN test, the standardised dot-ELISA and the commercial ELISA tests presented relative sensitivities of 92.3% and 91.6% and relative specificities of 71.3% and 68.4% respectively. The results demonstrated that the dot-ELISA test is adequate for the objectives proposed by this study, being easy to use and economically viable. Thus, this test represents an alternative for BRSV serological diagnosis in the substitution of SN and commercial ELISA tests, recommendable for utilisation in laboratories with few resources. 相似文献
The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas. 相似文献