BackgroundThe genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a rapid method for the analysis of biological samples. The advantages of this method, compared to conventional techniques, are rapidity, cost-effectiveness, accuracy and suitability for the high-throughput identification of bacteria. Discrepancies between taxonomy and genetic relatedness on the species and biovar level complicate the development of detection and identification assays.ResultsIn this study, the accurate identification of Brucella species using MALDI-TOF-MS was achieved by constructing a Brucella reference library based on multilocus variable-number tandem repeat analysis (MLVA) data. By comparing MS-spectra from Brucella species against a custom-made MALDI-TOF-MS reference library, MALDI-TOF-MS could be used as a rapid identification method for Brucella species. In this way, 99.3% of the 152 isolates tested were identified at the species level, and B. suis biovar 1 and 2 were identified at the level of their biovar. This result demonstrates that for Brucella, even minimal genomic differences between these serovars translate to specific proteomic differences.ConclusionsMALDI-TOF-MS can be developed into a fast and reliable identification method for genetically highly related species when potential taxonomic and genetic inconsistencies are taken into consideration during the generation of the reference library.

Lung infections due to Burkholderia cepacia and Pseudomonas aeruginosa in patients with cystic fibrosis (CF) are common, are associated with respiratory morbidity and are a cause of mortality. Respiratory mucin in CF patients is highly sulphated, which increases its resistance to bacterial degradation. Desulphation increases the susceptibility of mucin to degradation by bacterial glycosidases and proteinases, and subsequent deglycosylation may facilitate bacterial colonisation by increasing available substrates and binding sites. This study determined whether clinical and environmental strains of B. cepacia and I! aeruginosa had the ability to desulphate mucin. Mucin-sulphatase activity was tested by incubating bacterial cell suspensions with 35S-sulphated mucins purified from LSl74T and HT29-MTX human colon carcinoma cell lines. These mucins were also used to test for differences in substrate specificities. Mucin-sulphatase activity was detected in all nine B. cepacia strains and in four of six I! aeruginosa strains. There was strain variability in the level of mucin-sulphatase activity. Aryl-sulphatase activities of Pseudomonas isolates (determined with methylumbelliferyl sulphate) were c. 20-fold higher than those of B. cepacia strains, and were independent of mucin-sulphatase activity. This is the first report to demonstrate desulphation of mucin by B. cepacia and I! aeruginosa. It is concluded that B. cepacia and I! aeruginosa produce one or more cell-bound glycosulphatase(s), in addition to aryl-sulphatase activity. Mucin-sulphatase activity of B. cepacia and I! aeruginosa may contribute to their association with airway infections in patients with cystic fibrosis.

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Pure hops-derived substances were added to unhopped beer. Illumination only produced a sun-struck flavour with cfs-isohumulone, trans-isohumulone and racemic trans-isohumulone. It seems that 3-methyl-butenyl-mercaptan is not or not alone responsible for sun-struck flavour.Tests trials show that trans-isohumulone, cis-tsohumulone, racemic trans-iso humulone, trans-pt-isohumulone and ds-^-isohumulone do not show significant differences in bitter taste and bittering power. Fresh solutions of these bitter acids are not as bitter as solutions which have been kept for a few weeks.Since it is known that the isomerization of compounds in question is not easy as only humulone produces two diastereo-isomers,6toms-isohumulone is crystalline with in.p. namely trans-and cts-isohumulone,* the 08°C. and can thus be purified completely question of their relative bitterness is clearly by recrystallization. The cts-isohumulone important. The interesting point behind is an oil and even the most careful work this is obviously that if one of the two isocannot produce it completely pure. It mers is more bitter, industrial isomerization cannot be distilled without decomposition conditions could be adapted to produce more and partition procedures like chromatoof the more bitter iso-a-acid. graphy or countercurrent distribution, alOver a very wide range of pH, aqueous though producing highly purified material, alkaline isomerization gives the same equilido not yield completely pure substances, brium mixture with a ratio 65-70/30-35 for Indeed, these procedures yield the desired the cts-and /rans-isomers.' Magnesium catasubstance in dilute solution and the evaporalysed isomerization, however, produces a tion of the large excess of solvent always 50-50 mixture.4Photo-isomerization* in leaves some impurities behind. Also, it is methanol leads to a high percentage of the very difficult to remove the last traces of frans-isomer.solvent from an oil like cts-isohumulone. A comparison of bitterness for the two These observations are general for the field • Trans-and ei's-isohumulone are new names for isohumulonc A and D respectively according to the nomenclature proposals ol the Hops Liaison Committee of the E.B.C.

Our study was designed to provide a concise and east-to-apply set of criteria that could be used by NATO nations to evaluate emerging infectious disease threats with respect to their weaponization potential. Our results were unexpected. We believe that a lack of appropriate weighting factors may explain these results and suggest that future studies weigh each of the 12 proposed criteria based on the intended use of the assessment data and other situational factors. We believe that the greatest value of our study lies in a codification of the attributes of a biological weapon.