Gram-negative, coccoid, non-motile bacteria that are catalase-, urease- and indole-negative, facultatively anaerobic and oxidase-positive were isolated from the bovine rumen using an improved selective medium for members of the Pasteurellaceae. All strains produced significant amounts of succinic acid under anaerobic conditions with glucose as substrate. Phenotypic characterization and multilocus sequence analysis (MLSA) using 16S rRNA, rpoB, infB and recN genes were performed on seven independent isolates. All four genes showed high sequence similarity to their counterparts in the genome sequence of the patent strain MBEL55E, but less than 95 % 16S rRNA gene sequence similarity to any other species of the Pasteurellaceae. Genetically these strains form a very homogeneous group in individual as well as combined phylogenetic trees, clearly separated from other genera of the family from which they can also be separated based on phenotypic markers. Genome relatedness as deduced from the recN gene showed high interspecies similarities, but again low similarity to any of the established genera of the family. No toxicity towards bovine, human or fish cells was observed and no RTX toxin genes were detected in members of the new taxon. Based on phylogenetic clustering in the MLSA analysis, the low genetic similarity to other genera and the phenotypic distinction, we suggest to classify these bovine rumen isolates as Basfia succiniciproducens gen. nov., sp. nov. The type strain is JF4016T (=DSM 22022T =CCUG 57335T).

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-Mycoplasma hyopneumoniae is the etiological agent of enzootic pneumonia in swine.Various reports indicate that different strains are circulating in the swine population. We investigated the variety of M. hyopneumoniae strains by a newly developed genetic typing method based on the polyserine repeat motif of the LppS homolog P146. PCR amplification using M. hyopneumoniae specific, conserved primers flanking the region encoding the repeat motif, followed by sequencing and cluster analysis was carried out. The study included strains isolated from different geographic regions as well as lysates from lung swabs from a series of pig farms in Switzerland. High diversity of M. hyopneumoniae was observed but farms being in close geographic or operative contact generally seemed to be affected by the same strains. Moreover, analysis of multiple samples from single pig farms indicated that these harbored the same, farm-specific strain. The results indicate that multiple strains of M. hyopneumoniae are found in the swine population but that specific strains or clones are responsible for local outbreaks. The method presented is a highly reproducible epidemiologic tool allowing direct typing of M. hyopneumoniae from clinical material without prior isolation and cultivation of strains. enzootic pneumonia / epidemiology / LppS / P146

The simultaneous determination of interleukin-2 (IL-2) and gamma interferon (IFN-␥) in Quanti-FERON-TB test plasma supernatants permitted the detection of shifts in Mycobacterium tuberculosis-specific T-cell signatures. A subset of the 84 subjects tested revealed a significantly elevated IL-2/IFN-␥ ratio, which may be a marker for the successful elimination of M. tuberculosis infection.In countries with low tuberculosis (TB) incidence rates, such as Switzerland, targeted testing for latent Mycobacterium tuberculosis infection (LTBI) among risk groups, such as health care workers (HCW), is an important measure for preventing active TB disease (3, 7). Occupational health programs are increasingly turning to gamma interferon (IFN-␥) release assays (IGRA), such as the QuantiFERON-TB Gold in-tube test (QFT test; Cellestis Inc., Australia), to screen employees for LTBI (4,5,9). Diel et al. prospectively followed QFT testpositive, recent-TB contacts who had refused isoniazid treatment. All contacts who subsequently developed active TB disease within the follow-up period were strong responders in the QFT assay, with IFN-␥ plasma levels above the 10-IU/ml upper limit for the test's enzyme-linked immunosorbent assay (ELISA) (6). These results suggest that a correlation exists between the amount of IFN-␥ released upon M. tuberculosis-specific stimulation of CD4 ϩ T cells and the probability of developing active TB disease.A dynamic relationship between antigen load and distinct IFN-␥ and interleukin-2 (IL-2) profiles of antigen-specific CD4ϩ T cells has been demonstrated in viral infections (10). Typically, antigen clearance is associated with IL-2-dominant functional T-cell signatures. In contrast, high antigen loads are associated with IFN-␥-dominant functional T-cell signatures (10). A similar relationship between the IFN-␥ and IL-2 profiles of M. tuberculosis-specific T cells and antigenic load was reported in patients who were treated for active TB disease (1,2,8). Simultaneous measurement of IFN-␥ and IL-2 secretion at the single-cell level revealed a codominance of CD4 ϩ T cells that secrete only IFN-␥ and those that secrete both IFN-␥ and IL-2 in patients with active TB disease. A shift to dominance of CD4 ϩ T cells secreting both IFN-␥ and IL-2 and of newly detectable CD4 ϩ T cells secreting only IL-2 has been demonstrated both during and following TB treatment. Thus, three main functional patterns were observed: a dominant IL-2 response, a multifunctional (IL-2 and IFN-␥) response, and a dominant IFN-␥ response. Determination of the levels of IL-2 and IFN-␥ secretion has been proposed as an adequate marker for clinical monitoring (10). The net result of functional T-cell signatures would be detectable by assessing the M. tuberculosisspecific IL-2/IFN-␥ ratio in QFT test plasma supernatants. Thus, the simultaneous analysis of both IFN-␥ and IL-2 in QFT test plasma supernatants might provide (i) a more precise basis for assessing an individual's risk of developing active TB disease and (ii) information concerning t...

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