Recently, a new genus of Anaplasmataceae termed “ Candidatus Neoehrlichia” was discovered in ticks and rodents. Here, we report on two patients who suffered from febrile bacteremia due to “ Candidatus Neoehrlichia mikurensis” associated with thrombotic or hemorrhagic events. 16S rRNA and groEL gene sequencing provided evidence of three groups of sequence variants.

"Classical" Whipple's disease (cWD) is caused by Tropheryma whipplei and is characterized by arthropathy, weight loss, and diarrhea. T. whipplei infectious endocarditis (TWIE) is rarely reported, either in the context of cWD or as isolated TWIE without signs of systemic infection. The frequency of TWIE is unknown, and systematic studies are lacking. Here, we performed an observational cohort study on the incidence of T. whipplei infection in explanted heart valves in two German university centers. Cardiac valves from 1,135 patients were analyzed for bacterial infection using conventional culture techniques, PCR amplification of the bacterial 16S rRNA gene, and subsequent sequencing. T. whipplei-positive heart valves were confirmed by specific PCR, fluorescence in situ hybridization, immunohistochemistry, histological examination, and culture for T. whipplei. Bacterial endocarditis was diagnosed in 255 patients, with streptococci, staphylococci, and enterococci being the main pathogens. T. whipplei was the fourth most frequent pathogen, found in 16 (6.3%) cases, and clearly outnumbered Bartonella quintana, Coxiella burnetii, and members of the HACEK group (Haemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae). In this cohort, T. whipplei was the most commonly found pathogen associated with culture-negative infective endocarditis.

In Germany humans with acute granulocytic ehrlichiosis have not yet been described. Here, we characterized three different genes of Anaplasma phagocytophilum strains infecting German Ixodes ricinus ticks in order to test whether they differ from strains in other European countries and the United States. A total of 1,022 I. ricinus ticks were investigated for infection with A. phagocytophilum by nested PCR and sequence analysis. Forty-two (4.1%) ticks were infected. For all positive ticks, parts of the 16S rRNA and groESL genes were sequenced. The complete coding sequence of the ankA gene could be determined in 24 samples. The 16S rRNA and groESL gene sequences were as much as 100% identical to known sequences. Fifteen ankA sequences were >99.37% identical to sequences derived from humans with granulocytic ehrlichiosis in Europe and from a horse with granulocytic ehrlichiosis in Germany. Thus, German I. ricinus ticks most likely harbor A. phagocytophilum strains that can cause disease in humans. Nine additional sequences were clearly different from known ankA sequences. Because these newly described sequences have never been obtained from diseased humans or animals, their biological significance is currently unknown. Based on this unexpected sequence heterogeneity, we propose to use the ankA gene for further phylogenetic analyses of A. phagocytophilum and to investigate the biology and pathogenicity of strains that differ in the ankA gene.

Degradation of long-chain alkanes by Acinetobacter sp. strain ADP1 involves rubredoxin and rubredoxin reductase. We complemented a mutant deficient in alkane utilization and sequenced four open reading frames (ORFs) on the complementing DNA. Each of these ORFs was disrupted by insertional mutagenesis on the chromosome. As determined from sequence comparisons, ORF1 and ORF4 seem to encode a rotamase of the PpiC type and an acyl coenzyme A dehydrogenase, respectively. Disruption of these ORFs does not affect alkane utilization. In contrast, the two other ORFs, alkR and alkM, are essential for growth on alkanes as sole carbon sources. alkR encodes a polypeptide with extensive homology to AraC-XylS-like transcriptional regulators. It is located next to alkM, which encodes the terminal alkane hydroxylase, but is in the opposite orientation. Sequence homologies with other bacterial integral-membrane hydrocarbon hydroxylases suggest that AlkM may be the first member of a new protein family. The genes identified here are not linked to the rubredoxinand rubredoxin reductase-encoding genes on the Acinetobacter sp. strain ADP1 chromosome.

Three mesophilic bacteria (strains AMX 26BT , UR374_02 and 12-3 T ) isolated respectively from an anaerobic digester, human urine and urban riverside soil were characterized. Cells were Gram-negative, motile, non-sporulating, straight to curved rods with one polar flagellum and had a strictly respiratory metabolism with O 2 as the preferential terminal electron acceptor. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all strains clustered within the Xanthomonadaceae branch of the Proteobacteria. Isolates AMX 26BT and UR374_02 exhibited 100 % 16S rRNA gene sequence similarity and both were related to strain 12-3 T (99?6 % similarity

A 39-year-old woman with tubarian sterility fell ill with acute pelvic inflammatory disease 2 months after transvaginal oocyte recovery. Laparotomy revealed a large tuboovarian abscess, from which Atopobium vaginae, an anaerobic gram-positive coccoid bacterium of hitherto unknown clinical significance, was isolated. The microbial etiology and the risk of pelvic infections following transvaginal punctures are discussed.

In Acinetobacter sp. strain ADP1, alkane degradation depends on at least five essential genes. rubAB andxcpR are constitutively transcribed. Here we describe inducible transcription of alkM, which strictly depends on the presence of the transcriptional activator AlkR. alkRitself is expressed at a low level, while a chromosomally locatedalkM::lacZ fusion is inducible by middle-chain-length alkanes from heptane to undecane, which do not support growth of ADP1, and by long-chain-length alkanes from dodecane to octadecane, which are used as sources of carbon and energy. The putative AlkM substrate 1-dodecene is also an effective inducer. Products of alkane hydroxylase activity like 1-dodecanol prevent induction of alkM expression. alkM is expressed only in stationary phase, suggesting its dependence on at least one other regulatory mechanism.

A mutant of Acinetobacter calcoaceticus ADP1 unable to grow on alkanes was complemented for growth on hexadecane with a DNA fragment encoding a protein with homology to XcpR, a subunit of the general secretion pathway for exoproteins in Pseudomonas aeruginosa. Insertional inactivation of xcpR in A. calcoaceticus ADP1 by transcriptional fusion to lacZ abolishes secretion of lipase and esterase and leads to lack of growth on dodecane and slower growth on hexadecane. We, therefore, propose the participation of a secreted protein in alkane degradation.Acinetobacter calcoaceticus ADP1, also called BD413 (18,28), is able to grow on n-alkanes as sole carbon and energy sources via the -hydroxylation pathway (2). Candidates (n ϭ 2,650) able to grow on minimal medium with lauric acid were obtained by ethyl methanesulfonate mutagenesis and screened for the inability to grow on dodecane, which yielded 27 candidates with a negative phenotype on solid agar plates (11). Mutant WH365 is also unable to grow on hexadecane and fails to secrete lipase and esterase, in contrast to the wild type (20)(21)(22). Extracellular lipase of A. calcoaceticus ADP1, which shows activity towards triglycerides and phospholipids, was monitored on indicator plates with NB medium (Difco) containing 2% (vol/vol) egg yolk (Oxoid), whereas esterase activity was determined on NB medium with 1% (vol/vol) Tween 80. This Tween esterase is supposed to be secreted, but the corresponding gene has not been identified and nothing is known about the biological importance of this activity.Partially Sau3A-digested total DNA from A. calcoaceticus ADP1 was inserted into BamHI-cleaved pWH1274 carrying an origin of replication for Escherichia coli and A. calcoaceticus (16). The resulting gene library was transformed into WH365 by electroporation, and transformants were selected for growth on Luria broth (LB) plates with ampicillin (300 mg/liter). Replica plating on minimal medium with metal 44 (8), hexadecane delivered through the gas phase from a droplet on a filter disk in the lid of the plate, and ampicillin (200 mg/liter) yielded seven candidates. After passage of the plasmids through E. coli DH5␣ (13) and retransformation into WH365, one plasmid, called pWH1590, conferred the ability to grow with hexadecane as the sole carbon source. It contains a 15-kb insertion of contiguous chromosomal DNA, as confirmed by Southern hybridization (data not shown). pWH1590 was digested with HindIII, resulting in nine fragments. Eight of them were ligated with HindIII-restricted pBluescript SKIIϩ (Stratagene), yielding pWH1591 to -98. pWH1597 transformed WH365 to grow on hexadecane and to secrete lipase and esterase. The 2.8-kb insert was sequenced on both strands. It contains three open reading frames (ORFs) (Fig. 1), each of which is preceded by a putative ribosome binding site, as judged by sequence comparison with other Acinetobacter genes (38). Transformation of plasmids obtained from a nested-deletion reaction of pWH1597 mapped the complementing fragment within ORF3 (Fig. 1...