Combined application of bacteriophages with a competitive exclusion culture and carvacrol with organic acids can reduce Campylobacter in primary broiler production

For reducing Campylobacter (C.) in the food production chain and thus the risk to the consumer, the combined application of different measures as a multiple-hurdle approach is currently under discussion. This is the first study to investigate possible synergistic activities in vivo, aiming at reducing intestinal C. jejuni counts by administering (i) bacteriophages (phages) in combination with a competitive exclusion (CE) product and (ii) carvacrol combined with organic acids. The combined application of the two selected phages (Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1) and the CE product significantly reduced C. jejuni loads by 1.0 log10 in cecal and colonic contents as well as in cloacal swabs at the end of the trial (33 and 34 days post hatch). The proportion of bacterial isolates showing reduced phage susceptibility ranged from 10.9% (isolates from cecal content) to 47.8% (isolates from cloacal swabs 32 days post hatch) for the Fletchervirus phage, while all tested isolates remained susceptible to the Firehammervirus phage. The use of carvacrol combined with an organic acid blend (sorbic acid, benzoic acid, propionic acid, and acetic acid) significantly reduced Campylobacter counts by 1.0 log10 in cloacal swabs on day 30 only.

In vivo efficacy of carvacrol on Campylobacter jejuni prevalence in broiler chickens during an entire fattening period

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers.

Occurrence of livestock-associated methicillin-resistant Staphylococcus aureus in Turkey and broiler barns and contamination of air and soil surfaces in their vicinity

The emission of microorganisms, especially resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), from poultry farms is of public interest, and its occurrence and relevance are controversially discussed. So far, there are limited data on this issue. In this study, we investigated the occurrence of livestock-associated (LA)-MRSA inside and outside previously tested MRSA-positive poultry barns in Germany. In total, five turkey and two broiler fattening farms were investigated four and three times, respectively. In a longitudinal study during one fattening period, samples were collected from animals, the animals' environment inside the barn, including the air, and the barns' surroundings, such as ambient air and boot swabs of ground surfaces at different distances from the barn. Moreover, a cross-sectional study was carried out once inside the barns on five turkey and four broiler farms during the last third of the fatting period. In the cross-sectional study, LA-MRSA was detected in the air of most barns (7 of 9, 77.8%), as well as in many samples originating from animals, with detections levels of 50 to 54% in broiler and 62 to 77% in turkey farms. In the longitudinal study, LA-MRSA was found in the ambient air outside two turkey barns and on the ground surface on the downwind side of many (44.4%) turkey and broiler farms. The same spa types of isolates were observed inside and outside the barns. Transmission of MRSA within poultry farms, as well as emission via the airborne route, seems to be possible.

Synthesis of 4-(acylaminomethyl)benzamides and their evaluation as potential anticancer agents

4-(acylaminomethyl)benzamides were prepared in two steps from 4-aminomethylbenzoic acid and assayed in the NCl's primary anti-cancer screen. Eight out of 34 compounds showed interesting antiproliferative activity. From these compounds, three were selected for further in vivo testing. In addition, all the compounds were tested against farnesyltransferase and the cell cycle regulating enzymes cdc2 kinase and cdc25 phosphatase. The compounds proved inactive in these assays, as were some selected compounds in an assay searching for possible interference with the ras/raf interaction in a yeast two-hybrid system.

Increase of the duration of the anticonvulsive activity of a novel NMDA receptor antagonist using poly(butylcyanoacrylate) nanoparticles as a parenteral controlled release system

A novel non-competitive NMDA receptor antagonist MRZ 2/576 is a potent but rather short-acting (5-15 min) anticonvulsant following intravenous administration to mice as estimated by the prevention of maximal electroshock induced convulsions. This is most probably due to a rapid elimination of the drug from the central nervous system by transport processes that are sensitive to probenecid. Intravenous administration of the drug bound to poly(butylcyanoacrylate) nanoparticles coated with polysorbate 80 prolongs the duration of the anticonvulsive activity in mice up to 210 min and after probenecid pre-treatment up to 270 min compared to 150 min with probenecid and MRZ 2/576 alone. The results of this study demonstrate that polysorbate 80 coated poly(butylcyanoacrylate) nanoparticles used so far as a delivery system to the brain for drugs that do not freely penetrate the blood brain barrier can also be used as a parenteral controlled release system to prolong the CNS availability of drugs that have a short duration of action.

Inhibition of IgE-mediated histamine release from human peripheral leukocytes by selective phosphodiesterase inhibitors

Several phosphodiesterase (PDE) inhibitors with the capacity to inhibit the PDE IV isoenzyme produce dose-dependent inhibition of IgE-mediated histamine release (HR) from human peripheral leukocytes in vitro. Inhibition reached a maximum after 20 min of preincubation (IC30: 6-30 microM, IC50: 30-80 microM). Motapizone--a potent inhibitor of the isoenzyme PDE III--was much less effective, thus giving indirect evidence that PDE IV plays a predominant role in the control of cAMP cleavage in human basophils. The inhibiting effect of PDE-III/IV-selective compounds on IgE-mediated HR did not exceed the action of PDE-IV-selective inhibitors. The inhibition of anti-IgE-induced HR by zardaverine (a PDE-III/IV-inhibiting compound) was synergistically enhanced in the combined presence of forskolin or the recently synthesized histamine H2-agonist FRA 19).

Modulation of IgE-mediated histamine release from human leukocytes by a new class of histamine H2-agonists

A new class of phenyl (pyridylalcyl) guanidines, acting as potent histamine H2-agonists, inhibits IgE-mediated human basophil histamine release in a nanomolar range. IC30-level of three substitutes of this group (arpromidine, BUA-75, and FRA-19) were found to be 0.02, 0.015 and 0.008 microM. The inhibition appeared with a fast onset (plateau after 10 min. preincubation) and claimed its maximum (60 +/- 2.9%, 63 +/- 1.8%, and 61 +/- 3.1%, n = 7) with 10 microM of the compounds. H2-mediated inhibition was totally blocked by 10 microM famotidine, a potent histamine H2-antagonist. The amount of anti-IgE or antigen for the initiation of the immunological release influenced the strength of inhibition of H2-agonist FRA-19 (p less than 0.05). Combined preincubation of FRA-19 with zardaverine, a cAMP-specific phosphodiesterase III/IV inhibitor, produced a synergistical inhibitory effect of leukocyte histamine release, which might explained by their different sites of action on intracellular cAMP levels. The capability of histamine to inhibit its own release is mediated by H2-receptors exclusively. New, potent H2-receptor stimulating compounds with positive inotropic effects possess additional potent anti-allergic properties.