Efficacy of phage therapy in pigs: systematic review and meta-analysis

Limits on the use and efficacy of various antibiotics coupled with negative consumer perception of the practice have together spurred substantial research into compounds that could reduce the use antibiotics to control bacterial diseases in pigs. Bacteriophages are often among such potential compounds, and various groups have examined the efficacy of bacteriophages or bacteriophage products in limiting transmission or colonization of targeted bacteria. The study presented here provides a systematic review of such studies followed by a meta-analysis of aggregated data produced by each study. The data set was limited to inputs (n = 19; 576 total observations) from studies where: 1) live pigs were inoculated with a known quantity of challenge bacteria; 2) challenged animals were treated with a known quantity of phages; 3) concentrations of the challenge bacteria were measured in different tissues/fluids following phage treatment; and 4) SD (or SE to allow calculation of SD) was reported. Concentrations of challenge bacteria were significantly lower in phage-treated pigs versus challenged but untreated pigs (P < 0.0001; effect size = −1.06 1log₁₀ colony-forming units [CFU]/g). The effect size of phage treatment was significantly greater (P < 0.05) in samples collected 48 to 96 h following phage treatment versus those collected ≤ 24 h following phage treatment. Likewise, effect size of phage treatment was significantly greater in piglets versus market-weight pigs. Across observations, phage treatment effect sizes were greatest (P < 0.01) in fecal samples versus ileal or cecal samples. Taken together, these data indicate that phage treatment can significantly reduce the concentrations of targeted bacteria in pigs; scenarios exist, however, where phage treatment could predictably be more or less effective.     

The effect of fentanyl on the end‐tidal sevoflurane concentration needed to prevent motor movement in dogs

ObjectiveThe objectives of this study were to determine the effects of fentanyl on the end-tidal concentration of sevoflurane needed to prevent motor movement (MAC_NM) in response to noxious stimulation, and to evaluate if acute tolerance develops.Study designRandomized cross-over experimental study.AnimalsSix healthy, adult (2–3 years old), intact male, mixed-breed dogs weighing 16.2 ± 1.1 kg.MethodsSix dogs were randomly assigned to receive one of three separate treatments over a 3 week period. After baseline sevoflurane MAC_NM (MAC_NM-B) determination, fentanyl treatments (T) were administered as a loading dose (Ld) and constant rate infusion (CRI) as follows: T1-Ld of 7.5 μg kg^?1 and CRI at 3 μg kg^?1 hour^?1; T2-Ld of 15 μg kg^?1 and CRI at 6.0 μg kg ^?1 hour^?1; T3-Ld of 30 μg kg^?1 and CRI at 12 μg kg^?1 hour^?1. The MAC_NM was defined as the minimum end-tidal sevoflurane concentration preventing motor movement. The first post-treatment MAC_NM (MAC_NM-I) determination was initiated 90 minutes after the start of the CRI, and a second MAC_NM (MAC_NM-II) determination was initiated 3 hours after MAC_NM-I was established.ResultsThe overall least square mean MAC_NM-B for all groups was 2.66%. All treatments decreased (p < 0.05) MAC_NM, and the decrease from baseline was 22%, 35% and 41% for T1, T2 and T3, respectively. Percentage change in T1 differed (p < 0.05) from T2 and T3; however, T2 did not differ from T3. MAC_NM-I was not significantly different from MAC_NM-II within treatments.Conclusions and clinical relevanceFentanyl doses in the range of 3–12 μg kg^?1 hour^?1 significantly decreased the sevoflurane MAC_NM. Clinically significant tolerance to fentanyl did not occur under the study conditions.     

Metabolic fate of 2,4-dichlorophenol and related plant residues in rats

This study compared the metabolic fate of [(14)C]-DCP, [(14)C]-residues from radish plants, and purified [(14)C]-DCP-(acetyl)glucose following oral administration in rats. A rapid excretion of radioactivity in urine occurred for [(14)C]-DCP, [(14)C]-DCP-(acetyl)glucose, and soluble residues, 69, 85, and 69% within 48 h, respectively. Radio-HPLC profiles of 0-24 h urine from rats fed [(14)C]-DCP and [(14)C]-DCP-(acetyl)glucose were close and qualitatively similar to those obtained from plant residues. No trace of native plant residues was detected under the study conditions. The structures of the two major peaks were identified by MS as the glucuronide and the sulfate conjugates of DCP. The characterization of a dehydrated glucuronide conjugate by MS and NMR of DCP was unusual. In contrast to soluble residues, bound residues were mainly excreted in feces, 90% within 48 h, whereas total residues were eliminated in both urine and feces. For total residues, the radioactivity in feces was higher than expected from the percentage of soluble and bound residues in radish plants. This result highlighted that less absorption took place when residues were present in the plant matrix as compared to plant-free residues and DCP.     

Antioxidant Activity and Characterization of Phenolic Compounds from Bacaba ( Oenocarpus bacaba Mart.) Fruit by HPLC-DAD-MS(n)

The phytochemicals in fruits have been shown to be major bioactive compounds with regard to health benefits. Bacaba ( Oenocarpus bacaba Mart.) is a native palm fruit from the Brazilian savannah and Amazon rainforest that plays an important role in the diet of rural communities and is also a source of income for poor people. This paper reports the characterization and analyses of phenolics from bacaba fruit extract. The total phenolic content of bacaba fruit amounted to 1759.27 ± 1.01 mg GAE/100 g, the flavonoid content was 1134.32 ± 0.03 mg CTE/100 g, and the anthocyanin content was 34.69 ± 0.00 mg cyn-3-glc/100 g. The antioxidant activity was evaluated through different assays [ORAC, FRAP, DPPH, TEAC, and cellular antioxidant assay (CAA) assays] and revealed a significant antioxidant capacity for bacaba in comparison to the data available in the literature. The assignment of the phenolic compounds using HPLC-DAD-MS(n) was based on the evaluation of their UV-vis absorption maxima (λ(max)) and mass spectral analyses, and 14 compounds were tentatively identified. The results suggest that bacaba fruits are a promising source of phenolics.     

A potential biomarker of androgen exposure in European bullhead (Cottus sp.) kidney

The aim of this study was to identify a signal that could be used as an androgen exposure indicator in the European bullhead (Cottus sp.). For this purpose, the ultra-structure of the kidney was characterized to identify normal structure of this organ, and histological changes previously described in the kidney of breeding male bullheads were quantified using the kidney epithelium height (KEH) assay previously developed and validated for the stickleback. In the next step, the effect of trenbolone acetate (TbA), a model androgen, was assessed to identify potential androgenic regulation of bullhead kidney hypertrophy. Measurement of KEH performed on adult non-breeding male and female bullheads exposed for 14 and 21 days to 0, 1.26 and 6.50 μg/L showed that kidney hypertrophy is induced in a dose-dependent manner, confirming the hypothesis that the European bullhead possesses a potential biomarker of androgen exposure. Combined with the wide distribution of the European bullhead in European countries and the potential of this fish species for environmental toxicology studies in field and laboratory conditions, the hypothesis of a potential biomarker of androgen exposure offers interesting perspectives for the use of the bullhead as a relevant sentinel fish species in monitoring studies. Inducibility was observed with high exposure concentrations of TbA. Further studies are needed to identify molecular signals that could be more sensitive than KEH.     

Evaluation of specificity of tuberculosis diagnostic assays in caprine flocks under different epidemiological situations

The aim of this study was to evaluate the specificity of the most widely used tuberculosis (TB) diagnostic tests, single intradermal tuberculin (SIT) and single comparative intradermal tuberculin (SCIT) tests and interferon-gamma (IFN-γ) assay in 937 animals from eight TB-free caprine flocks under different epidemiological situations. Maximum specificity was found using SCIT test (99.4-100% depending on the interpretation criteria) while SIT test and IFN-γ assay showed a slightly lower overall specificity (97.6-99.2% and 96.4-98.4% respectively). Specificity of the SIT test in a Corynebacterium pseudotuberculosis infected flock was significantly (P<0.05) lower if a severe interpretation criterion was applied. Similarly, specificity values of SIT test and particularly IFN-γ assay in a paratuberculosis (PTB)-vaccinated flock were lower than those observed in non-vaccinated flocks. Higher proportion of false positive reactors to TB tests (SIT and IFN-γ assay) were observed among animals positive in the PTB-ELISA in PTB vaccinated flock. These results demonstrate that TB diagnostic tests show an adequate specificity when performed in goats from TB-free flocks in most situations. However, certain factors such as C. pseudotuberculosis infection and paratuberculosis vaccination can have a negative impact in the most sensitive tests.