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Sydney M Finegold - One of the best experts on this subject based on the ideXlab platform.
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In vitro activity of telithromycin (HMR 3647) against 502 strains of anaerobic bacteria
Journal of Antimicrobial Chemotherapy, 2001Co-Authors: Hannah M. Wexler, Eric Molitoris, Denise Molitoris, Sydney M FinegoldAbstract:: In a previous study, we compared HMR 3004 with azithromycin, clarithromycin, erythromycin and roxithromycin against 502 anaerobic bacteria using NCCLS-approved procedures. This report extends this study by reporting the activity of telithromycin (HMR 3647) against these strains. Telithromycin inhibited 10% of Bacteroides fragilis, 50% of other B. fragilis group organisms and 93% of other Bacteroides spp. Telithromycin inhibited all Porphyromonas spp. and 98% of Prevotella spp. Activity against Bilophila wadsworthia (85-96%) was excellent. Telithromycin was not active against the Fusobacterium mortiferum/varium group. Telithromycin inhibited 100% of Clostridium perfringens, 46-56% of Clostridium difficile and Clostridium ramosum and approximately 90% of non-spore-forming Gram-positive bacilli.
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characterization of Bilophila wadsworthia isolates using pcr fingerprinting
Anaerobe, 1999Co-Authors: M C Claros, Sydney M Finegold, Hunt S Gerardo, Ulrike Schumacher, N Kleinkauf, M. Jacob, Ellie J C Goldstein, Arne C. RodloffAbstract:Abstract Bilophila wadsworthia , an under-appreciated anaerobic organism, was originally described in 1989. Ninety-nine Bilophila wadsworthia isolates, recovered form environmental and clinical specimens in Germany and in Southern California, were examined in this study. Many isolates were recovered in mixed culture with facultative aerobic and other anaerobic bacteria. All isolates were identified by standard laboratory procedures, including gas–liquid chromatography (GLC). A PCR fingerprint assay was established to compare the profiles of clinical and environmental isolates to the type strain (ATCC 49260) and to an environmental (sewage) reference strain (DSM 11045, RZATAU) for intra-species differences. Two primers, one universal primer, M13 core, and one tDNA primer, T3B, were used individually to analyse the strains. Homogeneous PCR fingerprint profiles were found for the majority of strains using the M13 core primer; two PCR groups were determined with T3B, one matching the type strain and one matching the environmental reference strain (DSM 11045, RZATAU). Two urease negative strains, WAL 11470 (blood isolate from California) and TUB 754 (intra-abdominal isolate from Germany) formed unique PCR fingerprint profiles with each of these primers. These results were confirmed by PCR fingerprinting using the T3A primer. These latter results suggest a possible genetic diversity in B. wadsworthia .
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Adherence ofBilophila wadsworthiato Cultured Human Embryonic Intestinal Cells
Anaerobe, 1998Co-Authors: Sharon Hunt Gerardo, Hannah M. Wexler, Manuel M Garcia, Sydney M FinegoldAbstract:Adherence of Bilophila wadsworthia to the cultured human embryonic intestinal cell line, Intestine 407 (Int 407), varied among the strains tested from strongly adherent (76-100% cells positive for one or more adherent bacteria) to non- or weakly adherent (0-25% positive cells). Although negative staining revealed that infrequent cells of an adherent strain, WAL 9077, the adherent type-strain, WAL 7959, and a non-adherent strain, WAL 8448, expressed loosely associated fimbrial structures, a role for these structures in adhesion could not be confirmed with either scanning or thin-section electron micrography. Ruthenium red staining of thin-section preparations and subsequent electron microscopy failed to reveal an extensive extracellular polysaccharide layer. SDS-PAGE analysis of crude outer membrane fractions of WAL 9077 and WAL 8448 demonstrated clear differences in their major and minor outer membrane protein components. Thus, we postulate that the adherence of B. wadsworthia to Int 407 cells is mediated by an outer membrane or cell wall component.
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Recently described clinically important anaerobic bacteria: medical aspects.
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 1997Co-Authors: Sydney M Finegold, Hannele Jousimies-somerAbstract:There is still inadequate information on the role of certain newly described or reclassified anaerobes in disease processes, on their normal sites of carriage, and on their antimicrobial susceptibilities. Herein, we summarize this information (most of the literature reviewed is from the past 5 years, but a few of the articles are approximately 10 years old). Porphyromonas species had seemed to be relatively nonpathogenic, but recent work indicates that this belief is incorrect. P. gingivalis, P levii-like organisms, and P. endodontalis-like organisms have been recovered from a variety of oral and extraoral infections. P. macacae has been recovered from infected cat bite wounds. Sutterella wadsworthensis, recently differentiated from Campylobacter gracilis, has been found in a variety of infections. Bilophila wadsworthia has also been recovered from a wide variety of infections. Newly described anaerobic cocci, gram-positive nonsporeforming rods, and clostridia have also been isolated from various infections.
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In vitro activities of trovafloxacin against 557 strains of anaerobic bacteria.
Antimicrobial Agents and Chemotherapy, 1996Co-Authors: Hannah M. Wexler, Eric Molitoris, Denise Molitoris, Sydney M FinegoldAbstract:The antimicrobial activity of trovafloxacin for 557 strains of anaerobic bacteria was determined by the National Committee for Clinical Laboratory Standards-approved Wadsworth agar dilution technique. The species tested included Bacteroides fragilis (n = 91), other members of the B. fragilis group (n = 130), Campylobacter gracilis (n = 15), other Bacteroides spp. (n = 16), Prevotella spp. (n = 49), Porphyromonas spp. (n = 15), Fusobacterium spp. (n = 62), Bilophila wadsworthia (n = 24), Sutterella wadsworthensis (n = 21), Clostridium spp. (n = 61), Peptostreptococcus spp. (n = 38), and gram-positive non-spore-forming rods (n = 35). Trovafloxacin inhibited all strains of B. fragilis at < or = 0.5 microgram/ml, 99% of other B. fragilis group species at < or = 2 micrograms/ml, and 96% of all anaerobes tested at < or = 2 micrograms/ml.
Alasdair M Cook - One of the best experts on this subject based on the ideXlab platform.
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Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit
2016Co-Authors: Heike Laue, Michael Friedrich, Alasdair M CookAbstract:A dissimilatory sulfite reductase (DSR) was purified from the anaerobic, taurine-degrading bacterium Bilo-phila wadsworthia RZATAU to apparent homogeneity. The enzyme is involved in energy conservation by re-ducing sulfite, which is formed during the degradation of taurine as an electron acceptor, to sulfide. Accord-ing to its UV-visible absorption spectrum with maxima at 392, 410, 583, and 630 nm, the enzyme belongs to the desulfoviridin type of DSRs. The sulfite reductase was isolated as an a2b2gn (n> 2) multimer with a native size of 285 kDa as determined by gel filtration. We have sequenced the genes encoding the a and b subunits (dsrA and dsrB, respectively), which probably constitute one operon. dsrA and dsrB encode polypeptides of 49 (a) and 54 kDa (b) which show significant similarities to the homologous subunits of other DSRs. The dsrB gene product of B. wadsworthia is apparently a fusion protein of dsrB and dsrD. This indicates a possible functional role of DsrD in DSR function because of its presence as a fusion protein as an integral part of the DSR holoenzyme in B. wadsworthia. A phylogenetic analysis using the available Dsr sequences revealed that B. wadsworthia grouped with its closest 16S rDNA relative Desulfovibrio desulfuricans Essex 6. Bilophila wadsworthia is a strictly anaerobic, gram-negative bacterium (2) which belongs to the family Desulfovibrionaceae in the delta subdivision of the Proteobacteria, but does no
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identification of Bilophila wadsworthia by specific pcr which targets the taurine pyruvate aminotransferase gene
Fems Microbiology Letters, 2006Co-Authors: Heike Laue, M C Claros, Ulrike Schumacher, Theo H M Smits, Ralf Hartemink, Alasdair M CookAbstract:The bile-resistant, strictly anaerobic bacterium Bilophila wadsworthia is found in human faecal flora, in human infections and in environmental samples. A specific PCR primer set for the gene encoding the first metabolic enzyme in the degradative pathway for taurine in B. wadsworthia, taurine:pyruvate aminotransferase (tpa), was developed and tested. In addition, enrichment cultures were started from faecal samples of primates and felines and shown to contain B. wadsworthia. These were subcultured on agar media and then identified by PCR fingerprinting. PCR for tpa was successful in all positive enrichment cultures and showed no amplification signal in a variety of other bacterial species. Therefore, this PCR method could be a promising tool for rapid detection of B. wadsworthia in biological samples.
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biochemical and molecular characterization of taurine pyruvate aminotransferase from the anaerobe Bilophila wadsworthia
FEBS Journal, 2000Co-Authors: Heike Laue, Alasdair M CookAbstract:Bilophila wadsworthia RZATAU is a Gram-negative bacterium which converts the sulfonate taurine (2-aminoethanesulfonate) to ammonia, acetate and sulfide in an anaerobic respiration. Taurine:pyruvate aminotransferase (Tpa) catalyses the initial metabolic reaction yielding alanine and sulfoacetaldehyde. We purified Tpa 72-fold to apparent homogeneity with an overall yield of 89%. The purified enzyme did not require addition of pyridoxal 5 0 -phosphate, but highly active enzyme was only obtained by addition of pyridoxal 5 0 -phosphate to all buffers during purification. SDS/PAGE revealed a single protein band with a molecular mass of 51 kDa. The apparent molecular mass of the native enzyme was 197 kDa as determined by gel filtration, which indicates a homotetrameric structure. The kinetic constants for taurine were: Kma 7.1 mm, Vmaxa 1.20 nmol·s 21 , and for pyruvate: Kma 0.82 mm, Vmaxa 0.17 nmol·s 21 . The purified enzyme was able to transaminate hypotaurine (2-aminosulfinate), taurine, b-alanine and with low activity cysteine and 3-aminopropanesulfonate. In addition to pyruvate, 2-ketobutyrate and oxaloacetate were utilized as amino group acceptors. We have sequenced the encoding gene (tpa). It encoded a 50-kDa peptide, which revealed 33% identity to diaminopelargonate aminotransferase from Bacillus subtilis.
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taurine reduction powers rapid growth of Bilophila wadsworthia a liquid minimal salts medium for clinical research
Anaerobe, 1999Co-Authors: Heike Laue, Ulrike Schumacher, Alasdair M CookAbstract:Abstract Clinical isolates of Bilophila wadsworthia grew rapidly (1–3 days) in the liquid taurine-minimal-salts medium developed for B. wadsworthia RZATAU, whereas growth on Bacteroides Bile Esculin Agar takes up to 1 week. Though rapid growth of B. wadsworthia was achieved, and no other pure cultures grew, the medium was not selective for the organism in human faeces or in intra-abdominal specimens. We hope, however, that our understanding of the physiological and biochemical characteristics of the organism supplies a tool for further research.
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taurine reduction in anaerobic respiration of Bilophila wadsworthia rzatau
Applied and Environmental Microbiology, 1997Co-Authors: Heike Laue, Karin Denger, Alasdair M CookAbstract:Organosulfonates are important natural and man-made compounds, but until recently (T. J. Lie, T. Pitta, E. R. Leadbetter, W. Godchaux III, and J. R. Leadbetter. Arch. Microbiol. 166:204-210, 1996), they were not believed to be dissimilated under anoxic conditions. We also chose to test whether alkane- and arenesulfonates could serve as electron sinks in respiratory metabolism. We generated 60 anoxic enrichment cultures in mineral salts medium which included several potential electron donors and a single organic sulfonate as an electron sink, and we used material from anaerobic digestors in communal sewage works as inocula. None of the four aromatic sulfonates, the three unsubstituted alkanesulfonates, or the N-sulfonate tested gave positive enrichment cultures requiring both the electron donor and electron sink for growth. Nine cultures utilizing the natural products taurine, cysteate, or isethionate were considered positive for growth, and all formed sulfide. Two clearly different pure cultures were examined. Putative Desulfovibrio sp. strain RZACYSA, with lactate as the electron donor, utilized sulfate, aminomethanesulfonate, taurine, isethionate, and cysteate, converting the latter to ammonia, acetate, and sulfide. Strain RZATAU was identified by 16S rDNA analysis as Bilophila wadsworthia. In the presence of, e.g., formate as the electron donor, it utilized, e.g., cysteate and isethionate and converted taurine quantitatively to cell material and products identified as ammonia, acetate, and sulfide. Sulfite and thiosulfate, but not sulfate, were utilized as electron sinks, as was nitrate, when lactate was provided as the electron donor and carbon source. A growth requirement for 1,4-naphthoquinone indicates a menaquinone electron carrier, and the presence of cytochrome c supports the presence of an electron transport chain. Pyruvate-dependent disappearance of taurine from cell extracts, as well as formation of alanine and release of ammonia and acetate, was detected. We suspected that sulfite is an intermediate, and we detected desulfoviridin (sulfite reductase). We thus believe that sulfonate reduction is one aspect of a respiratory system transferring electrons from, e.g., formate to sulfite reductase via an electron transport system which presumably generates a proton gradient across the cell membrane.
Heike Laue - One of the best experts on this subject based on the ideXlab platform.
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Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit
2016Co-Authors: Heike Laue, Michael Friedrich, Alasdair M CookAbstract:A dissimilatory sulfite reductase (DSR) was purified from the anaerobic, taurine-degrading bacterium Bilo-phila wadsworthia RZATAU to apparent homogeneity. The enzyme is involved in energy conservation by re-ducing sulfite, which is formed during the degradation of taurine as an electron acceptor, to sulfide. Accord-ing to its UV-visible absorption spectrum with maxima at 392, 410, 583, and 630 nm, the enzyme belongs to the desulfoviridin type of DSRs. The sulfite reductase was isolated as an a2b2gn (n> 2) multimer with a native size of 285 kDa as determined by gel filtration. We have sequenced the genes encoding the a and b subunits (dsrA and dsrB, respectively), which probably constitute one operon. dsrA and dsrB encode polypeptides of 49 (a) and 54 kDa (b) which show significant similarities to the homologous subunits of other DSRs. The dsrB gene product of B. wadsworthia is apparently a fusion protein of dsrB and dsrD. This indicates a possible functional role of DsrD in DSR function because of its presence as a fusion protein as an integral part of the DSR holoenzyme in B. wadsworthia. A phylogenetic analysis using the available Dsr sequences revealed that B. wadsworthia grouped with its closest 16S rDNA relative Desulfovibrio desulfuricans Essex 6. Bilophila wadsworthia is a strictly anaerobic, gram-negative bacterium (2) which belongs to the family Desulfovibrionaceae in the delta subdivision of the Proteobacteria, but does no
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identification of Bilophila wadsworthia by specific pcr which targets the taurine pyruvate aminotransferase gene
Fems Microbiology Letters, 2006Co-Authors: Heike Laue, M C Claros, Ulrike Schumacher, Theo H M Smits, Ralf Hartemink, Alasdair M CookAbstract:The bile-resistant, strictly anaerobic bacterium Bilophila wadsworthia is found in human faecal flora, in human infections and in environmental samples. A specific PCR primer set for the gene encoding the first metabolic enzyme in the degradative pathway for taurine in B. wadsworthia, taurine:pyruvate aminotransferase (tpa), was developed and tested. In addition, enrichment cultures were started from faecal samples of primates and felines and shown to contain B. wadsworthia. These were subcultured on agar media and then identified by PCR fingerprinting. PCR for tpa was successful in all positive enrichment cultures and showed no amplification signal in a variety of other bacterial species. Therefore, this PCR method could be a promising tool for rapid detection of B. wadsworthia in biological samples.
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biochemical and molecular characterization of taurine pyruvate aminotransferase from the anaerobe Bilophila wadsworthia
FEBS Journal, 2000Co-Authors: Heike Laue, Alasdair M CookAbstract:Bilophila wadsworthia RZATAU is a Gram-negative bacterium which converts the sulfonate taurine (2-aminoethanesulfonate) to ammonia, acetate and sulfide in an anaerobic respiration. Taurine:pyruvate aminotransferase (Tpa) catalyses the initial metabolic reaction yielding alanine and sulfoacetaldehyde. We purified Tpa 72-fold to apparent homogeneity with an overall yield of 89%. The purified enzyme did not require addition of pyridoxal 5 0 -phosphate, but highly active enzyme was only obtained by addition of pyridoxal 5 0 -phosphate to all buffers during purification. SDS/PAGE revealed a single protein band with a molecular mass of 51 kDa. The apparent molecular mass of the native enzyme was 197 kDa as determined by gel filtration, which indicates a homotetrameric structure. The kinetic constants for taurine were: Kma 7.1 mm, Vmaxa 1.20 nmol·s 21 , and for pyruvate: Kma 0.82 mm, Vmaxa 0.17 nmol·s 21 . The purified enzyme was able to transaminate hypotaurine (2-aminosulfinate), taurine, b-alanine and with low activity cysteine and 3-aminopropanesulfonate. In addition to pyruvate, 2-ketobutyrate and oxaloacetate were utilized as amino group acceptors. We have sequenced the encoding gene (tpa). It encoded a 50-kDa peptide, which revealed 33% identity to diaminopelargonate aminotransferase from Bacillus subtilis.
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taurine reduction powers rapid growth of Bilophila wadsworthia a liquid minimal salts medium for clinical research
Anaerobe, 1999Co-Authors: Heike Laue, Ulrike Schumacher, Alasdair M CookAbstract:Abstract Clinical isolates of Bilophila wadsworthia grew rapidly (1–3 days) in the liquid taurine-minimal-salts medium developed for B. wadsworthia RZATAU, whereas growth on Bacteroides Bile Esculin Agar takes up to 1 week. Though rapid growth of B. wadsworthia was achieved, and no other pure cultures grew, the medium was not selective for the organism in human faeces or in intra-abdominal specimens. We hope, however, that our understanding of the physiological and biochemical characteristics of the organism supplies a tool for further research.
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Bilophila wadsworthia in ear infections a report of three cases
Anaerobe, 1999Co-Authors: U K Schumacher, D Bless, Peter K. Plinkert, Heike Laue, H. WernerAbstract:Abstract During a 3-year period routine anaerobic cultures were examined for the presence of Bilophila wadsworthia . Using taurine-supplemented Bacteroides–Bile–Esculin agar for isolation, we observed three cases of complicated polybacterial ear infections where B. wadsworthia was involved. The first case involved a 69-year-old female patient presenting an otitis externa following stapedectomy where B. wadsworthia was isolated. The second patient, 30-year-old woman, with a 2-decade history of otitis and otorrhoea presented with a cholesteatoma, complicated by brain abscess formation and B. wadsworthia was isolated from the purulent ear secretion as well as from the abscess material. The third case, a 39-year-old male patient suffering from cholesteatoma presented with otorrhoea and otalgia, B. wadsworthia was isolated from purulent ear secretion. In all cases, B. wadsworthia was part of mixed aerobic–anaerobic infections. Because this species was not found in 200 ear swabs from 100 healthy volunteers and was not detectable in throat swabs or saliva from of these patients, an exogenous origin of these outer and middle ear infections as well as an infection by fecal contamination seems more probable than ascending infections from the pharynx or the ear canal.
Hannah M. Wexler - One of the best experts on this subject based on the ideXlab platform.
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Isolation and characterization of porins from Desulfovibrio piger and Bilophila wadsworthia: structure and gene sequencing
Archives of Microbiology, 2008Co-Authors: Ofir Avidan, Elena Kaltageser, Izabella Pechatnikov, Alla Shainskaya, Hannah M. Wexler, Yeshayahu NitzanAbstract:The outer membrane proteins of Desulfovibrio piger and Bilophila wadsworthia (Omp-DP and Omp-BW, respectively) and the genes encoding them ( omp-DP and omp-BW ) were isolated and characterized. Native Omp-DP and Omp-BW form a trimeric structure of approximately 120 kDa. These proteins disaggregated into monomers with a molecular weight of approximately 53 kDa after heating at 95°C for 10 min. The pore-forming abilities of these oligomeric proteins demonstrated that they form small nonspecific channels with an exclusion limit of 260–300 Da. The omp-DP and omp-BW genes were cloned and sequenced. Sequence analyses revealed an open reading frame of 1,512 bp for omp-DP and 1,440 bp for omp-BW . The mature Omp-DP protein consisted of 480 amino acids and had a calculated MW of 53,290 Da. The mature Omp-BW protein consisted of 456 amino acids and had a calculated MW of 50.050 Da. Alignment of Omp-DP with Omp-BW revealed 54% homology, whereas alignment with other known porins showed a low level of homology. Analysis of the secondary structures indicated that both proteins span the outer membrane 18 times with amphipathic β-strands. This research presents porins which were isolated and characterized for the first time from bacteria belonging to the Desulfovibrionaceae family.
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In vitro activity of telithromycin (HMR 3647) against 502 strains of anaerobic bacteria
Journal of Antimicrobial Chemotherapy, 2001Co-Authors: Hannah M. Wexler, Eric Molitoris, Denise Molitoris, Sydney M FinegoldAbstract:: In a previous study, we compared HMR 3004 with azithromycin, clarithromycin, erythromycin and roxithromycin against 502 anaerobic bacteria using NCCLS-approved procedures. This report extends this study by reporting the activity of telithromycin (HMR 3647) against these strains. Telithromycin inhibited 10% of Bacteroides fragilis, 50% of other B. fragilis group organisms and 93% of other Bacteroides spp. Telithromycin inhibited all Porphyromonas spp. and 98% of Prevotella spp. Activity against Bilophila wadsworthia (85-96%) was excellent. Telithromycin was not active against the Fusobacterium mortiferum/varium group. Telithromycin inhibited 100% of Clostridium perfringens, 46-56% of Clostridium difficile and Clostridium ramosum and approximately 90% of non-spore-forming Gram-positive bacilli.
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Adherence ofBilophila wadsworthiato Cultured Human Embryonic Intestinal Cells
Anaerobe, 1998Co-Authors: Sharon Hunt Gerardo, Hannah M. Wexler, Manuel M Garcia, Sydney M FinegoldAbstract:Adherence of Bilophila wadsworthia to the cultured human embryonic intestinal cell line, Intestine 407 (Int 407), varied among the strains tested from strongly adherent (76-100% cells positive for one or more adherent bacteria) to non- or weakly adherent (0-25% positive cells). Although negative staining revealed that infrequent cells of an adherent strain, WAL 9077, the adherent type-strain, WAL 7959, and a non-adherent strain, WAL 8448, expressed loosely associated fimbrial structures, a role for these structures in adhesion could not be confirmed with either scanning or thin-section electron micrography. Ruthenium red staining of thin-section preparations and subsequent electron microscopy failed to reveal an extensive extracellular polysaccharide layer. SDS-PAGE analysis of crude outer membrane fractions of WAL 9077 and WAL 8448 demonstrated clear differences in their major and minor outer membrane protein components. Thus, we postulate that the adherence of B. wadsworthia to Int 407 cells is mediated by an outer membrane or cell wall component.
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In vitro activities of trovafloxacin against 557 strains of anaerobic bacteria.
Antimicrobial Agents and Chemotherapy, 1996Co-Authors: Hannah M. Wexler, Eric Molitoris, Denise Molitoris, Sydney M FinegoldAbstract:The antimicrobial activity of trovafloxacin for 557 strains of anaerobic bacteria was determined by the National Committee for Clinical Laboratory Standards-approved Wadsworth agar dilution technique. The species tested included Bacteroides fragilis (n = 91), other members of the B. fragilis group (n = 130), Campylobacter gracilis (n = 15), other Bacteroides spp. (n = 16), Prevotella spp. (n = 49), Porphyromonas spp. (n = 15), Fusobacterium spp. (n = 62), Bilophila wadsworthia (n = 24), Sutterella wadsworthensis (n = 21), Clostridium spp. (n = 61), Peptostreptococcus spp. (n = 38), and gram-positive non-spore-forming rods (n = 35). Trovafloxacin inhibited all strains of B. fragilis at < or = 0.5 microgram/ml, 99% of other B. fragilis group species at < or = 2 micrograms/ml, and 96% of all anaerobes tested at < or = 2 micrograms/ml.
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Preliminary Study UsingSpecies-Specific Oligonucleotide ProbeforrRNAofBilophila wadsworthia
1994Co-Authors: Hannah M. Wexler, Kenneth H Wilson, M. FinegoldAbstract:Portions ofthe16SRNA fromaurease-positive Bilophila wadsworthia strain weresequenced, andaprobe was constructed. Theprobe was endlabeled with[32PJATP andpolynucleotide kinaseandhybridized on anylon filter (bydotblothybridization) totheimmobilized rRNA of12B.wadsworthia strains andeight other anaerobic isolates. Theprobeefficiently hybridized onlytotheBilophila strains. Cross-reactivity athighRNA levels (2,000 ng)was observed withone strain ofBacteroides thetaiotaomicron andone strain ofBacteroides fragilis (with 10xSETbuffer [20xSETbuffer is0.5M NaCl, 0.03M Tris, and2mM EDTA])butwas notseen atlowerRNA levels or with5x SETbuffer. Whentested against mixedcultures ofaerobic andanaerobic isolates representative ofappendiceal abscess flora, theprobe didnotreact withmixedcultures containing no Bilophila cells andcoulddetecti105 Bilophila CFU/mlwhenthemixture was seededwithBilophila cells. This probeisofpotential use intherapid identification ofpureisolates andinthedirect identification ofB. wadsworthia inclinical specimens.
Ellen Jo Baron - One of the best experts on this subject based on the ideXlab platform.
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Bilophila wadsworthia: a unique Gram-negative anaerobic rod.
Anaerobe, 1997Co-Authors: Ellen Jo BaronAbstract:Although comprising less than 0.01% of the normal human gastrointestinal microbiota, Bilophila wadsworthia is the third most common anaerobe recovered from clinical material obtained from patients with perforated and gangrenous appendicitis. Since its discovery in 1988, B. wadsworthia has been recovered from clinical specimens associated with a variety of infections, including sepsis, liver abscesses, cholecystitis, Fournier's gangrene, soft tissue abscesses, empyema, osteomyelitis, Bartholinitis, and hidradenitis suppurativa. In addition, it has been found in the saliva and vaginal fluids of asymptomatic adults and even in the periodontal pockets of dogs. The organism is a saccharolytic, fastidious, and is easily recognized by its strong catalase reaction with 15% H2O2, production of hydrogen sulfide, and growth stimulation by bile (oxgall) and pyruvate. Approximately 75% of strains are urease positive. When grown on pyruvate-containing media, > 85% of strains demonstrate beta-lactamase production. Ribosomal RNA-based phylogenetic studies show Bilophila to be a homogeneous species, most closely related to Desulfovibrio species. Both adherence to human cells and endotoxin have been observed, and preliminary work suggests that environmental iron has a role in expression of outer membrane proteins. Penicillin-binding proteins appear to mediate the organism's susceptibility to at least some beta-lactam agents, which induce spheroplast formation that results in a haze of growth on agar dilution susceptibility test plates which is difficult to interpret. Bilophilastrains are inhibited in vitro by most antibiotics.
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Effect of iron depletion on protein profiles of Bilophila wadsworthia
Clinical Infectious Diseases, 1995Co-Authors: Catherine Daniel, Ellen Jo Baron, René CourcolAbstract:Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in the development of the infectious process. The presence of key nutrients, such as iron, may be important for the expression of virulence factors. Iron is an essential component of a wide variety of biochemical processes in microorganisms, and its availability is of major importance in bacterial pathogenesis. In response to a low level of available iron in vivo, the creation of high-affinity iron-uptake systems and of a number of iron-regulated membrane proteins is induced. Although relationships between iron and virulence factors of aerobes have been better studied, a few such studies have been carried out with regard to anaerobes (mainly Bacteroides fragilis) [ 1, 2]. As discussed by Duerden [3], there is as yet no clear understanding of many of the virulence factors of anaerobes. Little is known about the mechanisms of iron uptake used by anaerobic bacteria, and nothing about those of Bilophila wadsworthia. The purpose of this work was to study the properties of this recently recognized anaerobe in relation to iron metabolism. B. wadsworthia is an anaerobic, gram-negative, asaccharolytic, bileresistant, and strongly catalase-positive bacillus [4]. This bacterium was first isolated from patients with gangrenous and perforative appendicitis. This study sought to determine whether B. wadsworthia expressed iron-regulated outer-membrane proteins (OMPs) in an iron-depleted environment and whether these proteins were immunogenic. Iron-free reagents and materials were used to prepare the ironfree medium. In this work, all glassware was deferrated. Chemicals used to prepare the medium were of highest purity. The medium was one previously described, to which oxgall (2%) and pyruvate (10 mM) were added [5]. The medium components were deferrated with Chelex-100 resin (Bio-Rad Laboratories, Hercules, CA), except for MgSO4, amino acids, and vitamins. Medium without iron contained
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effect of iron depletion on protein profiles of Bilophila wadsworthia
Clinical Infectious Diseases, 1995Co-Authors: Catherine Daniel, Ellen Jo Baron, René CourcolAbstract:Pathogenicity of microorganisms is a multifactorial phenomenon. Host environment plays a role in the development of the infectious process. The presence of key nutrients, such as iron, may be important for the expression of virulence factors. Iron is an essential component of a wide variety of biochemical processes in microorganisms, and its availability is of major importance in bacterial pathogenesis. In response to a low level of available iron in vivo, the creation of high-affinity iron-uptake systems and of a number of iron-regulated membrane proteins is induced. Although relationships between iron and virulence factors of aerobes have been better studied, a few such studies have been carried out with regard to anaerobes (mainly Bacteroides fragilis) [ 1, 2]. As discussed by Duerden [3], there is as yet no clear understanding of many of the virulence factors of anaerobes. Little is known about the mechanisms of iron uptake used by anaerobic bacteria, and nothing about those of Bilophila wadsworthia. The purpose of this work was to study the properties of this recently recognized anaerobe in relation to iron metabolism. B. wadsworthia is an anaerobic, gram-negative, asaccharolytic, bileresistant, and strongly catalase-positive bacillus [4]. This bacterium was first isolated from patients with gangrenous and perforative appendicitis. This study sought to determine whether B. wadsworthia expressed iron-regulated outer-membrane proteins (OMPs) in an iron-depleted environment and whether these proteins were immunogenic. Iron-free reagents and materials were used to prepare the ironfree medium. In this work, all glassware was deferrated. Chemicals used to prepare the medium were of highest purity. The medium was one previously described, to which oxgall (2%) and pyruvate (10 mM) were added [5]. The medium components were deferrated with Chelex-100 resin (Bio-Rad Laboratories, Hercules, CA), except for MgSO4, amino acids, and vitamins. Medium without iron contained <0.04 tM Fe+++. Iron was added to a concentration of 100 iM in preparation of the ironcontaining medium. The final pH was adjusted to 7.0-7.1. Four strains of B. wadsworthia originally isolated from appendicitis case specimens were studied, including the reference strain ATCC 49260. They were all incubated for 14 days in 200-mL flask cultures (in media with and without iron) at 37?C in an anaerobic atmosphere. Detection of siderophores in culture supernatants was attempted by means of the method described by Schwyn and Neilands [6]. Preparation of the outer membrane was accomplished according to the method described by Sprott et al. [7]. Cells harvested by centrifugation were disrupted ultrasonically. Unbroken cells were discarded by centrifugation. The supernatant was treated with 2% Triton
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bactericidal activity of selected antimicrobial agents against Bilophila wadsworthia and bacteroides gracilis
Clinical Infectious Diseases, 1993Co-Authors: Ellen Jo Baron, G Ropers, Paula Summanen, René CourcolAbstract:Antimicrobial agents tested were ampicillin/sulbactam (final concentrations, 16/8 tug/mL), ticarcillin/clavulanate (128/2 gg/mL), imipenem (8 gg/mL), cefoxitin (32 ltg/mL), chloramphenicol (16 ,g/mL), clindamycin (4 ,g/mL), and metronidazole (16 ,g/mL). Although all antimicrobial agents tested inhibited growth of all Bilophila strains during the first 24 hours, bactericidal activity was variable; only metronidazole was uniformly bactericidal. Most strains of Bilophila showed 1-2 log increases in growth at 6 hours with clindamycin and chloramphenicol. With chloramphenicol, some Bilophila strains tested showed regrowth starting at 30 hours. B. gracilis strains were generally more susceptible to all agents tested. Metronidazole, ticarcillin/ clavulanate, chloramphenicol, and imipenem were most active. Several strains of B. gracilis were not killed by ampicillin/sulbactam, clindamycin, or cefoxitin. Activity was variable among strains and antimicrobial agents. Bacteroides gracilis and Bilophila wadsworthia are asaccharolytic, nonmotile gram-negative bacilli that form part of the normal flora of the human oral cavity and gastrointestinal tract. Both species are involved in polymicrobic infections [1-3]. B. gracilis has recently been characterized as a microaerobic organism [4], although it originally was thought to be anaerobic and is usually grown under anaerobic conditions. B. wadsworthia requires strictly anaerobic conditions. These species are fastidious; they require supplementary factors for optimal growth in vitro and exhibit characteristic slow colony formation. For these reasons, results of conventional susceptibility tests, which rely on adequate growth in a standardized medium, are difficult to interpret when these species are assayed [5-8]. Results obtained with
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clinical importance of Bilophila wadsworthia
European Journal of Clinical Microbiology & Infectious Diseases, 1992Co-Authors: Sydney M Finegold, Hunt S Gerardo, Paula H Summanen, Ellen Jo BaronAbstract:Bilophila wadsworthia is an anaerobic, gram-negative, asaccharolytic, urease-positive, bile-resistant, catalase-positive bacillus, originally recovered from infections in patients with gangrenous and perforated appendicitis. Additional isolations from clinical specimens, including pleural fluid, joint fluid, blood and pus from a scrotal abscess, mandibular osteomyelitis and axillary hidradenitis suppurativa are described here.Bilophila is found as normal flora in feces and, occasionally, in saliva and in the vagina. Isolates from humans are usually β-lactamase positive and therefore resistant to certain β-lactam antibiotics. Two percent of strains are also resistant to clindamycin.