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Paul J. Planet - One of the best experts on this subject based on the ideXlab platform.
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complete genome sequence of aggregatibacter Haemophilus aphrophilus nj8700
Journal of Bacteriology, 2009Co-Authors: Maria Pia Di Bonaventura, Rob Desalle, Mihai Pop, Niranjan Nagarajan, David H. Figurski, Daniel H. Fine, Jeffrey B. Kaplan, Paul J. PlanetAbstract:Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus) (11) is well known as an etiologic agent in infectious endocarditis caused by gram-negative bacteria (7). Most often, however, it is found as a nonpathogenic, commensal resident of dental plaque and the oropharyngeal flora. The complete genome sequence of A. aphrophilus NJ8700 was achieved using a hybrid approach of a shotgun sequencing strategy combined with 454 pyrosequencing (two runs). The 454 sequences were assembled with the Newbler assembler (454 Life Sciences), and the Sanger reads were added to the resulting contigs using MUMmer (8) and custom scripts. The contigs were linked together into scaffolds using Bambus (15), and gaps between contigs were closed by direct sequencing using a technique described by N. Nagarajan et al. (submitted for publication), achieving a 25-fold coverage. Automated annotation was done at the Institute for Genomic Research/J. Craig Venter Institute through the Annotation Engine Service. The A. aphrophilus NJ8700 genome is 2,313,035 bp in length, with a GC content of 42.23% and 2,320 predicted coding sequences. Approximately 88.4% of nucleotides are predicted to encode proteins. The genome contains 57 tRNAs, including one gene for tRNASec (AAP_1961), and five rRNA nontandem cistrons. Like other Pasteurellaceae (3, 4), the genome has four RNA subunit genes (rpoA, rpoB, rpoC, and rpoZ; AAP_2188, AAP_1813, AAP_1812, and AAP_1427), and five sigma factor genes (AAP_1594, AAP_1967, AAP_2019, AAP_2021, and AAP_2324). The A. aphrophilus NJ8700 genome contains genes encoding a type VI secretion system (T6SS) (AAP_1851 to -1862, AAP_2123), which is the first instance of its presence in a member of the Pasteurellaceae (1, 2, 9, 10, 16, 17, 20). There are several open reading frames (ORFs) similar to vgrG (AAP_0259, AAP_0279 to -0281, AAP_0288, AAP_292, AAP_1540, AAP_1541, AAP_2121) that encode other possible substrates. The flp-tad cluster (AAP_0177 to -0190) is similar to the tad locus involved in the rough colony phenotype in Aggregatibacter actinomycetemcomitans (12, 13, 14, 21). Also present is a locus required for the assembly of type IVa pili, including pilF, pilA, pilB, pilC, and pilD (AAP_0008, AAP_1464 to -1467). The A. aphrophilus genome contains genes encoding several adhesins that may participate in host colonization (EmaA, AAP_0065; Aae, AAP_0152; YadA and Hia, AAP_0523 and AAP_0527). Genes for the production of PGA (poly-N-acetylglucosamine), i.e., hmsD, pgaC, pgaB, and pgaA (AAP_1678 to -1681); N-acetylneuraminate lyase (nanA, AAP_A0548); and the dspB enzyme that degrades PGA (AAP_0383 and AAP_0384), all implicated in biofilm formation, are present (6). A. aphrophilus NJ8700 has several loci implicated in iron utilization, including one for a predicted hemoglobin binding protein, hgpA (AAP_1269), and a hemoglobin/transferrin binding receptor (AAP_2099). Genes for the hemophore receptor HasR (AAP_1311) and a heme utilization protein (AAP_2308) are present. A gene for the TbpA (transferrin binding protein; AAP_1194, AAP_1226) may signal an ability to use transferrin. A. aphrophilus carries genes encoding potential siderophore receptors (AAP_0347, AAP_0905), a TonB-dependent hemoglobin/transferrin/lactoferrin family receptor (AAP_1145), and a receptor for ferrienterochelin/colicins (AAP_1677). Two ORFs may encode chelatin transporters (AAP_1146 to -1149; AAP_783 to -785), along with the ferric-dicitrate transport system (fecBCDE, AAP_1294 to-1297). The genome harbors the genes coding for the Fur regulator (AAP_0360) and periplasmic-binding transport systems: the afe locus (AAP_0393, AAP_0395 to -0397), the hit locus (AAP_1640, AAP_1644 to -1654), and afu loci (AAP_0695 to -0697, AAP_1193 to -1196) (5, 18, 19, 22). There are three regions of the bacterial chromosome where phage/prophage gene clusters were identified, including the accA-GMP gene intergenic region (acetyl coenzyme A carboxylase, AAP_0460; GMP synthase, AAP_0517), which harbors a prophage (M. Di Bonaventura et al., submitted for publication).
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GENOME ANNOUNCEMENT Complete Genome Sequence of Aggregatibacter (Haemophilus)
2009Co-Authors: Maria Pia, Di Bonaventura, Rob Desalle, Mihai Pop, Niranjan Nagarajan, David H. Figurski, Daniel H. Fine, Jeffrey B. Kaplan, Paul J. PlanetAbstract:We report the finished and annotated genome sequence of Aggregatibacter aphrophilus strain NJ8700, a strain isolated from the oral flora of a healthy individual, and discuss characteristics that may affect its dual roles in human health and disease. This strain has a rough appearance, and its genome contains genes encoding a type VI secretion system and several factors that may participate in host colonization. Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus) (11) is well known as an etiologic agent in infectious endocarditis caused by gram-negative bacteria (7). Most often, however, it is found as a nonpathogenic, commensal resident of dental plaque and the oropharyngeal flora. The complete genome sequence of A. aphrophilus NJ8700 was achieved using a hybrid approach of a shotgun sequencing strategy combined with 454 pyrosequencing (two runs). The 454 sequences were assembled with the Newbler assembler (454 Life Sciences), and the Sanger reads were added to the resulting contigs using MUMmer (8) and custom scripts. The contigs were linke
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genome announcement complete genome sequence of aggregatibacter Haemophilus aphrophilus nj8700
2009Co-Authors: Maria Pia Di Bonaventura, Rob Desalle, Mihai Pop, Niranjan Nagarajan, David H. Figurski, Daniel H. Fine, Jeffrey B. Kaplan, Paul J. PlanetAbstract:Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus) (11) is well known as an etiologic agent in infectious endocarditis caused by gram-negative bacteria (7). Most often, however, it is found as a nonpathogenic, commensal resident of dental plaque and the oropharyngeal flora. The complete genome sequence of A. aphrophilus NJ8700 was achieved using a hybrid approach of a shotgun sequencing strategy combined with 454 pyrosequencing (two runs). The 454 sequences were assembled with the Newbler assembler (454 Life Sciences), and the Sanger reads were added to the resulting contigs using MUMmer (8) and custom scripts. The contigs were linked together into scaffolds using Bambus (15), and gaps between contigs were closed by direct sequencing using a technique described by N. Nagarajan et al. (submitted for publication), achieving a 25-fold coverage. Automated annotation was done at the Institute for Genomic Research/J. Craig Venter Institute through the Annotation Engine Service. The A. aphrophilus NJ8700 genome is 2,313,035 bp in length, with a GC content of 42.23% and 2,320 predicted coding sequences. Approximately 88.4% of nucleotides are predicted to encode proteins. The genome contains 57 tRNAs, including
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nonspecific adherence by actinobacillus actinomycetemcomitans requires genes widespread in bacteria and archaea
Journal of Bacteriology, 2000Co-Authors: Scott C Kachlany, Rob Desalle, Daniel H. Fine, Paul J. Planet, Mrinal K Bhattacharjee, Evyenia Kollia, David H. FigurskiAbstract:Actinobacillus actinomycetemcomitans is a gram-negative bacterium associated with several human diseases (8, 36, 47). The most predominant of these is known as localized juvenile periodontitis, a severe disease of adolescents that is characterized by bone and tissue destruction and ultimately loss of teeth if untreated. A. actinomycetemcomitans is also a member of a clinically important group of bacteria implicated in infective endocarditis (39). These bacteria are referred to as the HACEK group (Haemophilus aphrophilus, A. actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) (9). Vegetative growths and inflammation of the heart valves caused by the HACEK bacteria result in serious complications owing to the formation of bacterial masses on the valves. A. actinomycetemcomitans expresses several potential virulence factors (8), but only the RTX-type leukotoxin has been studied in detail at the molecular and genetic levels (14, 24). Other possible factors include a cytolethal distending toxin, iron and hemin binding proteins, a trypsin-like protease, an OmpA family member, capsular polysaccharide biosynthetic proteins, catalase, and a GroEL-like protein (5, 12, 13, 23, 26, 28, 35, 41, 43, 46). However, their potential roles in pathogenesis are unknown. A. actinomycetemcomitans is also able to invade epithelial cells, and the bacteria can be transferred between cells (8, 27). A striking and characteristic property of fresh clinical isolates of A. actinomycetemcomitans is their ability to form tenacious biofilms on solid surfaces, including glass, plastics, and hydroxyapatite (6, 21, 30). This property is very likely required for pathogenesis by allowing for colonization of teeth in an environment of continuous salivary flow. Clinical isolates form rough-appearing colonies, autoaggregate, and express bundles of fimbria-like structures that may be important for adherence and colonization (18, 30, 34). Genetic analysis of rough, adherent strains has proven to be difficult. The distinctive adherence property of clinical strains is easily lost, as nonadherent, smooth-colony variants readily emerge during subculture (7, 45). In addition, while DNA can be introduced into A. actinomycetemcomitans by transformation (37) or conjugation (11), the efficiency of DNA transfer into rough, adherent strains is too low for standard transposon mutagenesis protocols involving suicide vectors. Recently we reported the development of transposon IS903φkan, which carries a cryptic kanamycin resistance gene that can be activated upon insertion of the transposon into an expressed gene, and we have demonstrated its utility in the direct selection of random insertions in genetically recalcitrant bacteria, such as A. actinomycetemcomitans (38). Here we report the use of IS903φkan to obtain adherence-defective mutants of A. actinomycetemcomitans CU1000, a well-characterized rough clinical isolate (7, 20, 30). Genetic and nucleotide sequence analyses of these mutants have allowed us to identify a locus of seven novel genes that are required for tenacious adherence, autoaggregation, and the production of bundled fibers. Examination of genome sequences of Bacteria and Archaea revealed that surprisingly diverse microorganisms are predicted to carry tad-related genes. We discuss the likely function of these genes and the significance of their widespread occurrence.
Weichuan Hsieh - One of the best experts on this subject based on the ideXlab platform.
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Haemophilus aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess in a patient with liver cirrhosis
Journal of Infection, 1997Co-Authors: Chienching Hung, Poren Hsueh, Yeechun Chen, Chitai Fang, Shanchwen Chang, Kwentay Luh, Weichuan HsiehAbstract:Haemophilus aphrophilus is rarely implicated as an aetiology of spinal epidural abscess. A 73-year-old woman with liver cirrhosis who developed H. aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess is presented. Without surgical decompression, she was successfully treated with cefotaxime for 3 weeks, followed by maintenance with ciprofloxacin for another 10 weeks. The clinical features of eight previously reported cases of vertebral osteomyelitis without epidural abscess due to H. aphrophilus are reviewed.
Ingar Olsen - One of the best experts on this subject based on the ideXlab platform.
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determination of acids in whole lipopolysaccharide and in free lipid a from actinobacillus actinomycetemcomitans and Haemophilus aphrophilus
Journal of Chromatography A, 1998Co-Authors: Ilia Brondz, Ingar OlsenAbstract:Acids from whole lipopolysaccharide and free lipid A of the closely related bacteria Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus were determined by gas chromatography and gas chromatography-mass spectrometry. In whole lipopolysaccharide, 3-hydroxymyristic acid was most abundant, followed by myristic and 3-deoxy-D-manno-2-octulosonic acid. In the lipid A moiety, myristic acid dominated, followed by 3-hydroxymyristic acid. The acid composition of whole lipopolysaccharide and free lipid A from A. actinomycetemcomitans and H. aphrophilus was not so specific as to allow taxonomic differentiation between these bacteria. If fatty acids of lipopolysaccharide are essential for expression of endotoxicity, the present results suggested no marked difference in the endotoxic activities of A. actinomycetemcomitans and H. aphrophilus.
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intra injector methylation of free fatty acids from aerobically and anaerobically cultured actinobacillus actinomycetemcomitans and Haemophilus aphrophilus
Journal of Chromatography B: Biomedical Sciences and Applications, 1992Co-Authors: Ilia Brondz, Ingar OlsenAbstract:Free fatty acids from the type strains of anaerobically and aerobically broth-cultured Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus cells were Soxhlet-extracted with hexane. The fatty acids were identified and quantified by gas chromatography and gas chromatography—mass spectrometry after intra-injector derivatization with trimethylanilinium hydroxide. This derivatization method, which we propose as suitable for routine use in clinical microbiology, is fast, accurate and sensitive, with low toxicity. Whereas the fatty acid content of A. actinomycetemcomitans was affected by the cultivation atmosphere, i.e. C16:1, decreased under aerobic growth and C16:0 increased, that of the closely related H. aphrophilus was more stable.
Mogens Kilian - One of the best experts on this subject based on the ideXlab platform.
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reclassification of actinobacillus actinomycetemcomitans Haemophilus aphrophilus Haemophilus paraphrophilus and Haemophilus segnis as aggregatibacter actinomycetemcomitans gen nov comb nov aggregatibacter aphrophilus comb nov and aggregatibacter segn
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Niels Norskovlauritsen, Mogens KilianAbstract:The aim of this study was to reinvestigate the relationships and the generic affiliations of the species Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Haemophilus paraphrophilus and Haemophilus segnis. The nicotinamide phosphoribosyltransferase gene (nadV) conferring V factor-independent growth was identified in Haemophilus aphrophilus. The gene encodes a polypeptide of 462 amino acids that shows 74.5 % amino acid sequence identity to the corresponding enzyme from Actinobacillus actinomycetemcomitans. Ten isolates of Haemophilus paraphrophilus all carried a nadV pseudogene. DNA from Haemophilus aphrophilus was able to transform Haemophilus paraphrophilus into the NAD-independent phenotype. The transformants carried a full-length nadV inserted in the former locus of the pseudogene. The DNA-DNA relatedness between the type strains of Haemophilus aphrophilus and Haemophilus paraphrophilus was 77 %. We conclude that the division into two species Haemophilus aphrophilus and Haemophilus paraphrophilus is not justified and that Haemophilus paraphrophilus should be considered a later heterotypic synonym of Haemophilus aphrophilus. Forty strains of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus and Haemophilus segnis were investigated by multilocus sequence analysis. The 40 strains form a monophyletic group clearly separate from other evolutionary lineages of the family Pasteurellaceae. We propose the transfer of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus and Haemophilus segnis to a new genus Aggregatibacter gen. nov. as Aggregatibacter actinomycetemcomitans comb. nov. (the type species; type strain ATCC 33384(T)=CCUG 13227(T)=CIP 52.106(T)=DSM 8324(T)=NCTC 9710(T)), Aggregatibacter aphrophilus comb. nov. (type strain ATCC 33389(T)=CCUG 3715(T)=CIP 70.73(T)=NCTC 5906(T)) and Aggregatibacter segnis comb. nov. (type strain HK316(T)=ATCC 33393(T)=CCUG 10787(T)=CCUG 12838(T)=CIP 103292(T)=NCTC 10977(T)). The species of the genus Aggregatibacter are independent of X factor and variably dependent on V factor for growth in vitro.
Chunming Lee - One of the best experts on this subject based on the ideXlab platform.
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Haemophilus aphrophilus brain abscess a case report
Journal of Microbiology Immunology and Infection, 2002Co-Authors: Paotsuan Kao, Hsiangkuang Tseng, Chunming LeeAbstract:Haemophilus aphrophilus infection is rare, and the organism is infrequently implicated in serious infection. We report a case of a 61-year-old patient who experienced left hemiparesis with dizziness. Computed tomography of the brain demonstrated a lesion with ring enhancement in the right frontotemporal region. Craniotomy was performed, abscess was drained, and H. aphrophilus was isolated. Following the surgical procedure and further antibiotic treatment, the patient recovered completely.
