Molecular Characterisation of Bacteriophage K Towards Applications for the Biocontrol of Pathogenic Staphylococci

End of project reportThe aim of this work was to characterise staphylococcal bacteriophage (a bacterial virus) and to assess their potential as therapeutic agents against pathogenic strains of Staphylococcus aureus, particularly mastitis-causing strains. The project included the use of two newly isolated phage CS1 and DW2, and an existing polyvalent phage. The new phage were isolated from the farmyard and characterised by electron microscopy and restriction analysis. Both phage were shown to belong to the Siphoviridae family and were lytic for representatives of all three clonal groups of Irish mastitis-associated staphylococci. A cocktail of three phage (CS1, DW2 and K) at 108 (plaque forming units) PFU/ml was infused into cows teats in animal trials. The lack of an increase in somatic cell counts in milks indicated strongly that the phage did not irritate the animal. In addition, the most potent phage used in this study, phage K, was further studied by genome sequencing, which revealed a linear DNA genome of 127,395 base pairs, which encodes 118 putative ORFs (open reading frames)

The Experience of the Automotive Industry in Industrial Policies of Selected Governments

We shall not define precisely industrial policy other than to note that the cases we intend to examine involve some form of general, integrated, economic policy that, among other things, includes industry-specific measures that have had direct or indirect consequences for other countries through trade or investment links. Many other characteristics, including program integration; abridgment of private business governance, perhaps involving varying degrees of compulsion or subsidy; non-market incentives; and subordination of the market mechanism, may or may not be present in the industrial policies discussed. Very often specific protection of favored industries is a major instrument of industrial policy; nearly always, the other measures employed also create changes in international competitiveness. Not all such factors, or objectives, need be present to constitute industrial policy for our purposes

Detection of an SO2 plume over Sapporo, Japan from the eruption of Mt. Kasatochi using a balloon sounding technique

During the month of August 2008, 10 ozonesondes were launched from Hokkaido University in Sapporo, Japan as part of a study to examine regional pollution during the Olympic period. Seven of these soundings included a second instrument with a filter designed to remove SO2 from the intake air stream. SO2 interferes with the normal chemistry of the electrochemical cell (ECC) method for ozone detection, with the net result being that each molecule of SO2 registers as minus one molecule of O3. Thus the unfiltered sonde reports [O3] - [SO2] while the filtered sonde reports [O3]. Laboratory tests prior to launch indicate that the SO2 filter is ~87% effective, while destroying little to no O3. The difference between the filtered and unfiltered readings is ~[SO2]. We demonstrate the effectiveness of this technique in the lower and middle troposphere by examining profiles both with and without SO2 present. Ozone Monitoring Instrument (OMI) SO2 data (Krotkov et al., 2006, 2008) and trajectories from the NASA Goddard Trajectory model (Schoeberl & Sparling, 1995) connect the SO2 detected by our balloon borne instruments over Hokkaido, Japan 21 – 22 August to the plume from the volcanic eruption of Mt. Kasatochi 7 – 9 August

Ariel - Volume 2 Number 6

Editors Richard J. Bonanno Robin A. Edwards Associate Editors Steven Ager Stephen Flynn Shep Dickman Tom Williams Lay-out Editor Eugenia Miller Contributing Editors Michael J. Blecker W. Cherry Light James J. Nocon Lynne Porter Editors Emeritus Delvyn C. Case, Jr. Paul M. Fernhof

Update on the development of a novel dry cow therapy using a bismuth-based intramammary teat seal in combination with the bacteriocin lacticin 3147

peer-reviewedPublic concerns over the widespread prophylactic use of antibiotics have led to a search for alternatives to dry cow therapy for the prevention of intramammary infections. A popular alternative is to infuse a teat seal at drying-off. The teat seal is a viscous non-antibiotic formulation and when it is infused into the teat canal and the teat sinus it forms an internal seal that provides a physical barrier to invasion by mastitis-causing pathogens. Enhancement of teat seal formulations may be achieved using non-antibiotic additives such as bacteriocins, potent proteins produced by some bacteria that have the ability to kill other microorganisms. This paper traces the history of investigations at Moorepark Research Centre into the efficacy of teat seal plus lacticin 3147, a bacteriocin produced by Lactococcus lactis DPC3147, in the prevention of intramammary infections in dry cows. Indications from on-going investigations are that a dry cow formulation combining the two products has considerable potential as a non-antibiotic prophylactic product

Efficacy of a teat dip containing the bacteriocin lacticin 3147 to eliminate Gram-positive pathogens associated with bovine mastitis

On most dairy farms teat dips are applied to the teats of cows either before or after milking in order to prevent pathogens from gaining access to the mammary gland via the teat canal. In the present experiments, a natural teat dip was developed using a fermentate containing the live bacterium Lactococcus lactis DPC 3251. This bacterium produces lacticin 3147, a two-component lantibiotic which was previously shown to effectively kill Gram-positive mastitis pathogens. Lacticin 3147 activity in the fermentate was retained at 53% of its original level following storage for 3 weeks at 4°C. In the initial experiments in vitro, 105 colony-forming units/ml (cfu/ml) of either Staphylococcus aureus, Streptococcus dysgalactiae or Streptococcus uberis were introduced into the lacticin-containing fermentate. Neither Staph. aureus nor Str. dysgalactiae could be detected after 30 min or 15 min, respectively, while Str. uberis was reduced approximately 100-fold after 15 min. Following these trials, preliminary experiments were performed in vivo on teats of lactating dairy cows. In these experiments, teats were coated with each of the challenge organisms and then dipped with the lacticin-containing fermented teat dip. Following a dip contact time of 10 min, staphylococci were reduced by 80% when compared with the undipped control teat. Streptococcal challenges were reduced by 97% for Str. dysgalactiae and by 90% for Str. uberis. These trials showed that the teat dip is able to reduce mastitis pathogens on the teats of lactating cows

Intramammary infusion of a live culture of Lactococcus lactis for treatment of bovine mastitis: comparison with antibiotic treatment in field trials

A treatment containing a live food-grade organism, Lactococcus lactis DPC3147, was compared with conventional antibiotic therapy for its potential to treat bovine chronic subclinical or clinical mastitis in two separate field trials. Effects on disease symptoms and bacteriology were monitored in response to infusion with the culture in each trial. In the first trial, the live culture treatment was compared with an intramammary antibiotic (n=11 quarters for each treatment). Results from this small trial demonstrated that the live culture had potential to be as effective at eliminating chronic subclinical infections as an antibiotic treatment. By day 12, 7 of the 11 quarters treated with the live culture were pathogen-free compared with 5 of the 11 antibiotic-treated infected quarters. Somatic cell counts (SCC) remained relatively unchanged regardless of treatment: average log SCC pre- and post-treatment in the lactococci-treated group were 6·33±0·41 (day 0) and 6·27±0·43 cells/ml (day 12) and average log SCC pre- and post-treatment in the antibiotic-treated group were 6·34±0·37 and 6·22±0·46 cells/ml on day 0 and on day 12, respectively. In the second trial, the live culture was compared with an intramammary antibiotic for the treatment of naturally occurring clinical mastitis cases (n=25 quarters for each treatment). Following a 14-d experimental period, similar bacteriological responses were observed in 7 out of 25 live culture treated quarters and 9 out of 25 antibiotic-treated quarters. Additionally, 15 of 25 cases treated with the culture and 18 of 25 cases treated with the antibiotic did not exhibit clinical signs of the disease following treatment. The results of these trials suggest that live culture treatment with Lc. lactis DPC3147 may be as efficacious as common antibiotic treatments in some instances

Microlensing of Globular Clusters as a Probe of Galactic Structure

The spatial distribution of compact dark matter in our Galaxy can be determined in a few years of monitoring Galactic globular clusters for microlensing. Globular clusters are the only dense fields of stars distributed throughout the three-dimensional halo and hence are uniquely suited to probe its structure. The microlensing optical depths towards different clusters have varying contributions from the thin disk, thick disk, bulge, and halo of the Galaxy. Although measuring individual optical depths to all the clusters is a daunting task, we show that interesting Galactic structure information can be extracted with as few as $40$--$120$ events in total for the entire globular cluster system (observable with 2--5 years of monitoring). The globular cluster microlensing is particularly sensitive to the core radius of the halo mass distribution and to the scale length, surface mass density, and radial scale height variations of the thin disk.Comment: 14 pages, 1 figure. Submitted to ApJ Letters. Uses aastex macro