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David N. Fredricks - One of the best experts on this subject based on the ideXlab platform.
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bacterial communities associated with abnormal nugent score in postmenopausal versus premenopausal women
The Journal of Infectious Diseases, 2021Co-Authors: Caroline Mitchell, Sujatha Srinivasan, Tina L. Fiedler, Susan D Reed, Noah G Hoffman, D J Valint, Sean Proll, Kathy Agnew, Katherine A Guthrie, David N. FredricksAbstract:The Nugent score is the reference standard for bacterial vaginosis (BV) diagnosis but has not been validated in postmenopausal women. We compared relative abundances from 16S ribosomal RNA gene sequencing of vaginal microbiota with Nugent score in cohorts of premenopausal (n = 220) and postmenopausal (n = 144) women. In premenopausal women, 33 taxa were significantly correlated with Nugent score, including the classic BV-associated taxa Gardnerella, Atopobium, Sneathia, Megasphaera, and Prevotella. In postmenopausal women, 11 taxa were significantly associated with Nugent score, including Prevotella but no other BV-associated genera. High Nugent scores should not be used to infer BV in postmenopausal women.
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association between vaginal bacterial microbiota and vaginal yeast colonization
The Journal of Infectious Diseases, 2021Co-Authors: Mckenna C Eastment, David N. Fredricks, Sujatha Srinivasan, Tina L. Fiedler, Jennifer E Balkus, Barbra A Richardson, Joshua Kimani, Omu Anzala, Jane R SchwebkeAbstract:BACKGROUND Vaginal yeast is frequently found with Lactobacillus-dominant microbiota. The relationship between vaginal yeast and other bacteria has not been well characterized. METHODS These analyses utilized data from the Preventing Vaginal Infections trial. Relative abundance of vaginal bacteria from 16S ribosomal ribonucleic acid gene amplicon sequencing and quantities of 10 vaginal bacteria using taxon-directed polymerase chain reaction assays were compared at visits with and without detection of yeast on microscopy, culture, or both. RESULTS Higher relative abundances of Megasphaera species type 1 (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.52-0.95), Megasphaera species type 2 (RR, 0.81; 95% CI, 0.67-0.98), and Mageeibacillus indolicus (RR, 0.46; 95% CI, 0.25-0.83) were associated with lower risk of detecting yeast. In contrast, higher relative abundances of Bifidobacterium bifidum, Aerococcus christensenii, Lactobacillus mucosae, Streptococcus equinus/infantarius/lutentiensis, Prevotella bivia, Dialister propionicifaciens, and Lactobacillus crispatus/helveticus were associated with yeast detection. Taxon-directed assays confirmed that increasing quantities of both Megasphaera species and M indolicus were associated with lower risk of detecting yeast, whereas increasing quantities of L crispatus were associated with higher risk of detecting yeast. CONCLUSIONS Despite an analysis that examined associations between multiple vaginal bacteria and the presence of yeast, only a small number of vaginal bacteria were strongly and significantly associated with the presence or absence of yeast.
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vaginal and extra vaginal bacterial colonization and risk for incident bacterial vaginosis in a population of women who have sex with men
The Journal of Infectious Diseases, 2020Co-Authors: David N. Fredricks, Sujatha Srinivasan, Tina L. Fiedler, Sean Proll, Anna Plantinga, Antoinette Oot, Andrew Wiser, Jeanne M. MarrazzoAbstract:Bacterial vaginosis (BV) is a common cause of vaginal discharge and associated with vaginal acquisition of BV-associated bacteria (BVAB). We used quantitative PCR assays to determine if presence or concentrations of BVAB in the mouth, anus, vagina, or labia prior to BV predict risk of incident BV in 72 women who have sex with men. Baseline vaginal and extra-vaginal colonization with Gardnerella spp., Megasphaera spp., Sneathia spp., BVAB-2, Dialister sp. type 2. and other BVAB was more common among subjects with incident BV. Prior colonization with BVAB is a consistent risk for BV.
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interaction between lactobacilli bacterial vaginosis associated bacteria and hiv type 1 rna and dna genital shedding in u s and kenyan women
AIDS Research and Human Retroviruses, 2013Co-Authors: Caroline Mitchell, David N. Fredricks, Jennifer E Balkus, Congzhou Liu, Jennifer Mckernanmullin, Lisa M Frenkel, Christina Mwachari, Amneris E Luque, Susan E CohnAbstract:Abstract Bacterial vaginosis has been associated with genital HIV-1 shedding; however, the effect of specific vaginal bacterial species has not been assessed. We tested cervicovaginal lavage from HIV-1-seropositive women for common Lactobacillus species: L. crispatus, L. jensenii, and seven BV-associated species: BVAB1, BVAB2, BVAB3, Leptotrichia, Sneathia, Megasphaera, and Atopobium spp. using quantitative PCR. We used linear and Poisson regression to evaluate associations between vaginal bacteria and genital HIV-1 RNA and DNA. Specimens from 54 U.S. (310 visits) and 50 Kenyan women (137 visits) were evaluated. Controlling for plasma viral load, U.S. and Kenyan women had similar rates of HIV-1 RNA (19% of visits vs. 24%; IRR=0.95; 95% CI 0.61, 1.49) and DNA shedding (79% vs. 76%; IRR=0.90; 0.78, 1.05). At visits during antiretroviral therapy (ART), the likelihood of detection of HIV-1 RNA shedding was greater with BVAB3 (IRR=3.16; 95% CI 1.36, 7.32), Leptotrichia, or Sneathia (IRR=2.13; 1.02, 4.72), and ...
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changes in vaginal bacterial concentrations with intravaginal metronidazole therapy for bacterial vaginosis as assessed by quantitative pcr
Journal of Clinical Microbiology, 2009Co-Authors: David N. Fredricks, Tina L. Fiedler, Katherine K Thomas, Caroline Mitchell, Jeanne M. MarrazzoAbstract:Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3- to 4-log reductions in median bacterial loads of BVAB1 (P = 0.02), BVAB2 (P = 0.0004), BVAB3 (P = 0.03), a Megasphaera-like bacterium (P < 0.0001), Atopobium species (P < 0.0001), Leptotrichia/Sneathia species (P = 0.0002), and Gardnerella vaginalis (P < 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2, Leptotrichia/Sneathia species, Atopobium species, Gardnerella vaginalis, and a Megasphaera-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.
Jeanne M. Marrazzo - One of the best experts on this subject based on the ideXlab platform.
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vaginal and extra vaginal bacterial colonization and risk for incident bacterial vaginosis in a population of women who have sex with men
The Journal of Infectious Diseases, 2020Co-Authors: David N. Fredricks, Sujatha Srinivasan, Tina L. Fiedler, Sean Proll, Anna Plantinga, Antoinette Oot, Andrew Wiser, Jeanne M. MarrazzoAbstract:Bacterial vaginosis (BV) is a common cause of vaginal discharge and associated with vaginal acquisition of BV-associated bacteria (BVAB). We used quantitative PCR assays to determine if presence or concentrations of BVAB in the mouth, anus, vagina, or labia prior to BV predict risk of incident BV in 72 women who have sex with men. Baseline vaginal and extra-vaginal colonization with Gardnerella spp., Megasphaera spp., Sneathia spp., BVAB-2, Dialister sp. type 2. and other BVAB was more common among subjects with incident BV. Prior colonization with BVAB is a consistent risk for BV.
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p2 11 association between genital herpes simpex virus type 2 shedding and presence of bacterial vaginosis associated bacteria
Sexually Transmitted Infections, 2017Co-Authors: Christine Johnston, Sujatha Srinivasan, Sean Proll, Amalia Magaret, Krista Yuhas, James P Hughes, Christina M Kohler, Dana Varon, Thepthara N Pholsena, Jeanne M. MarrazzoAbstract:Introduction Herpes simplex virus type 2 (HSV-2) infection increases the risk of bacterial vaginosis (BV). We hypothesised that the biologic mechanism of this association is that genital HSV-2 shedding increases inflammation, resulting in increased presence and quantity of BV-associated bacteria (BVAB). Methods HSV-2 seropositive women with a clinical history of BV in the past 12 months collected daily genital swabs for HSV detection and vaginal swabs for Nugent score and analysis of the microbiome for 28 days. BV was defined as Nugent score>=7. Quantitative PCR (qPCR) with species specific primers for Lactobacillus crispatus, L. iners, L. jensenii, Gardnerella vaginalis,Megasphaera and BVAB-2 were performed. HSV was detected using real-time qPCR. The presence of each bacterial species was compared on days with and without HSV shedding using Poisson regression. Results Forty-eight women (median age 40; 48% white) with a median of 2 genital HSV-2 recurrences in the prior year (range 0–12) were enrolled for a total of 1277 days of observation. Genital HSV shedding was detected on 134 (10%) days. Of 960 days with Nugent score available, BV was present on 351 (37%) days. The risk of BV was not significantly different in the presence of HSV shedding (RR=0.84, 95% CI=0.66–1.07). Several bacterial species appeared to be detected more frequently on days with HSV shedding as compared to days without shedding (L. crispatus: 53% vs. 44%, L. jensenii: 56% vs. 49%, Megasphaera: 58% vs. 41%, BVAB-2: 49% vs. 37% of days, respectively), although these findings were not statistically significant. The study is 80% completed; data for at least 12 additional women is anticipated, which will provide additional statistical power. Conclusion Genital HSV-2 shedding may be associated with dynamic shifts in the vaginal microbial community and may increase the presence of BVAB. A study to assess whether the use of suppressive treatment for HSV (daily valacyclovir) decreases the presence of BVAB, or BV (twice weekly metronidazole) decreases HSV shedding, is ongoing.
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changes in vaginal bacterial concentrations with intravaginal metronidazole therapy for bacterial vaginosis as assessed by quantitative pcr
Journal of Clinical Microbiology, 2009Co-Authors: David N. Fredricks, Tina L. Fiedler, Katherine K Thomas, Caroline Mitchell, Jeanne M. MarrazzoAbstract:Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3- to 4-log reductions in median bacterial loads of BVAB1 (P = 0.02), BVAB2 (P = 0.0004), BVAB3 (P = 0.03), a Megasphaera-like bacterium (P < 0.0001), Atopobium species (P < 0.0001), Leptotrichia/Sneathia species (P = 0.0002), and Gardnerella vaginalis (P < 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2, Leptotrichia/Sneathia species, Atopobium species, Gardnerella vaginalis, and a Megasphaera-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.
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Targeted PCR for Detection of Vaginal Bacteria Associated with Bacterial Vaginosis
Journal of clinical microbiology, 2007Co-Authors: David N. Fredricks, Tina L. Fiedler, Katherine K Thomas, Brian B. Oakley, Jeanne M. MarrazzoAbstract:Several novel bacterial species have been detected in subjects with bacterial vaginosis (BV) by using broad-range PCR assays, but this approach is insensitive for detecting minority species. We developed a series of taxon-directed 16S rRNA gene PCR assays for more sensitive detection of key vaginal bacteria. We sought to determine the prevalence of each species in the vagina, its association with BV, and the utility of PCR for the microbiological diagnosis of BV. Targeted PCR assays were developed for 17 vaginal bacterial species and applied to 264 vaginal-fluid samples from 81 subjects with and 183 subjects without BV. The results were compared to those of two widely accepted methods for diagnosing BV, the use of clinical findings (Amsel criteria) and the interpretation of vaginal-fluid Gram stains (Nugent criteria). Leptotrichia/Sneathia, Atopobium vaginae, an Eggerthella-like bacterium, Megasphaera species, and three novel bacteria in the order Clostridiales are among the bacterial species significantly associated with BV. PCR detection of either a Megasphaera species or one of the Clostridiales bacteria yielded a sensitivity of 99% and a specificity of 89% for diagnosis of BV compared to the Amsel clinical criteria and a sensitivity of 95.9% and a specificity of 93.7% compared to the Nugent criteria (Gram stain). PCR detection of one or more fastidious bacterial species is a more reliable indicator of BV than detection of bacteria, such as Gardnerella vaginalis, previously linked to BV, highlighting the potential of PCR for the diagnosis of BV.
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molecular methodology in determining vaginal flora in health and disease its time has come
Current Infectious Disease Reports, 2005Co-Authors: David N. Fredricks, Jeanne M. MarrazzoAbstract:The microbial flora of the human vagina can affect the health of women, their fetuses, and newborns. Conventional cultivation methods fail to detect some fastidious vaginal bacteria, leading to an incomplete census. Recent advances in molecular biology have facilitated the detection and identification of bacteria without cultivation, and the advantages and limitations of this approach are described. Molecular studies of the vaginal flora have discovered many uncultivated bacterial species. For instance, several novel bacteria in the Clostridiales order are highly specific indicators of bacterial vaginosis, and bacteria related to Megasphaera, Leptotrichia, Atopobium, and Dialister species are commonly found in subjects with bacterial vaginosis. A more complete understanding of vaginal microbial populations resulting from the adoption of molecular tools may lead to better strategies to maintain healthy vaginal floras and will create opportunities to explore the role of novel bacteria in reproductive tract diseases.
Tina L. Fiedler - One of the best experts on this subject based on the ideXlab platform.
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bacterial communities associated with abnormal nugent score in postmenopausal versus premenopausal women
The Journal of Infectious Diseases, 2021Co-Authors: Caroline Mitchell, Sujatha Srinivasan, Tina L. Fiedler, Susan D Reed, Noah G Hoffman, D J Valint, Sean Proll, Kathy Agnew, Katherine A Guthrie, David N. FredricksAbstract:The Nugent score is the reference standard for bacterial vaginosis (BV) diagnosis but has not been validated in postmenopausal women. We compared relative abundances from 16S ribosomal RNA gene sequencing of vaginal microbiota with Nugent score in cohorts of premenopausal (n = 220) and postmenopausal (n = 144) women. In premenopausal women, 33 taxa were significantly correlated with Nugent score, including the classic BV-associated taxa Gardnerella, Atopobium, Sneathia, Megasphaera, and Prevotella. In postmenopausal women, 11 taxa were significantly associated with Nugent score, including Prevotella but no other BV-associated genera. High Nugent scores should not be used to infer BV in postmenopausal women.
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association between vaginal bacterial microbiota and vaginal yeast colonization
The Journal of Infectious Diseases, 2021Co-Authors: Mckenna C Eastment, David N. Fredricks, Sujatha Srinivasan, Tina L. Fiedler, Jennifer E Balkus, Barbra A Richardson, Joshua Kimani, Omu Anzala, Jane R SchwebkeAbstract:BACKGROUND Vaginal yeast is frequently found with Lactobacillus-dominant microbiota. The relationship between vaginal yeast and other bacteria has not been well characterized. METHODS These analyses utilized data from the Preventing Vaginal Infections trial. Relative abundance of vaginal bacteria from 16S ribosomal ribonucleic acid gene amplicon sequencing and quantities of 10 vaginal bacteria using taxon-directed polymerase chain reaction assays were compared at visits with and without detection of yeast on microscopy, culture, or both. RESULTS Higher relative abundances of Megasphaera species type 1 (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.52-0.95), Megasphaera species type 2 (RR, 0.81; 95% CI, 0.67-0.98), and Mageeibacillus indolicus (RR, 0.46; 95% CI, 0.25-0.83) were associated with lower risk of detecting yeast. In contrast, higher relative abundances of Bifidobacterium bifidum, Aerococcus christensenii, Lactobacillus mucosae, Streptococcus equinus/infantarius/lutentiensis, Prevotella bivia, Dialister propionicifaciens, and Lactobacillus crispatus/helveticus were associated with yeast detection. Taxon-directed assays confirmed that increasing quantities of both Megasphaera species and M indolicus were associated with lower risk of detecting yeast, whereas increasing quantities of L crispatus were associated with higher risk of detecting yeast. CONCLUSIONS Despite an analysis that examined associations between multiple vaginal bacteria and the presence of yeast, only a small number of vaginal bacteria were strongly and significantly associated with the presence or absence of yeast.
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vaginal and extra vaginal bacterial colonization and risk for incident bacterial vaginosis in a population of women who have sex with men
The Journal of Infectious Diseases, 2020Co-Authors: David N. Fredricks, Sujatha Srinivasan, Tina L. Fiedler, Sean Proll, Anna Plantinga, Antoinette Oot, Andrew Wiser, Jeanne M. MarrazzoAbstract:Bacterial vaginosis (BV) is a common cause of vaginal discharge and associated with vaginal acquisition of BV-associated bacteria (BVAB). We used quantitative PCR assays to determine if presence or concentrations of BVAB in the mouth, anus, vagina, or labia prior to BV predict risk of incident BV in 72 women who have sex with men. Baseline vaginal and extra-vaginal colonization with Gardnerella spp., Megasphaera spp., Sneathia spp., BVAB-2, Dialister sp. type 2. and other BVAB was more common among subjects with incident BV. Prior colonization with BVAB is a consistent risk for BV.
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Presence and Concentrations of Select Bacterial Vaginosis-Associated Bacteria Are Associated With Increased Risk of Pelvic Inflammatory Disease.
Sexually transmitted diseases, 2020Co-Authors: Catherine L Haggerty, Roberta B Ness, Sujatha Srinivasan, Fouzia Farooq, Gong Tang, Xuezhou Hou, Tina L. Fiedler, Sabina G AsteteAbstract:In a vaginal 16S ribosomal RNA gene quantitative PCR study of 17 pelvic inflammatory disease (PID) cases and 17 controls who tested positive for Chlamydia trachomatis, women who additionally tested positive for Atopobium vaginae, Sneathia spp., Megasphaera spp., Eggerthella-like bacterium or Prevotella amnii were more likely to develop PID.
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changes in vaginal bacterial concentrations with intravaginal metronidazole therapy for bacterial vaginosis as assessed by quantitative pcr
Journal of Clinical Microbiology, 2009Co-Authors: David N. Fredricks, Tina L. Fiedler, Katherine K Thomas, Caroline Mitchell, Jeanne M. MarrazzoAbstract:Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3- to 4-log reductions in median bacterial loads of BVAB1 (P = 0.02), BVAB2 (P = 0.0004), BVAB3 (P = 0.03), a Megasphaera-like bacterium (P < 0.0001), Atopobium species (P < 0.0001), Leptotrichia/Sneathia species (P = 0.0002), and Gardnerella vaginalis (P < 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2, Leptotrichia/Sneathia species, Atopobium species, Gardnerella vaginalis, and a Megasphaera-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.
Florence Fenollar - One of the best experts on this subject based on the ideXlab platform.
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Megasphaera vaginalis sp nov and anaerococcus vaginimassiliensis sp nov new bacteria isolated from vagina of french woman with bacterial vaginosis
new microbes and new infections, 2020Co-Authors: Alexia Bordigoni, E K Yimagou, Cheikh Ibrahima Lo, Khoudia Diop, Berangere Nicaise, Christelle Desnues, Florence FenollarAbstract:Abstract Using the culturomics method, two strains were isolated, identified and characterized following the taxonogenomics concept. Megasphaera vaginalis sp. nov. strain Marseille-P4512 (= CSURP4512) and Anaerococcus vaginimassiliensis sp. nov. strain Marseille-P4857 (= CSURP4857) were isolated from the vagina of a French woman. The phylogenic tree, phenotypic criteria and genomic analysis described here clearly show that these two bacteria are different from previously known bacterial species with standing in nomenclature and new members of Firmicutes phylum.
Wolfgang Buckel - One of the best experts on this subject based on the ideXlab platform.
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reduction of ferredoxin or oxygen by flavin based electron bifurcation in Megasphaera elsdenii
FEBS Journal, 2015Co-Authors: Nilanjan Pal Chowdhury, Wolfgang Buckel, Jorg KahntAbstract:: Over 50 years ago, it was reported that, in the anaerobic rumen bacterium Megasphaera elsdenii, the reduction of crotonyl-CoA to butyryl-CoA by NADH involved an electron transferring flavoprotein (Etf) as mediator [Baldwin RL, Milligan LP (1964) Biochim Biophys Acta 92, 421-432]. Purification and spectroscopic characterization revealed that this Etf contained 2 FAD, whereas, in the Etfs from aerobic and facultative bacteria, one FAD is replaced by AMP. Recently we detected a similar system in the related anaerobe Acidaminococcus fermentans that differed in the requirement of additional ferredoxin as electron acceptor. The whole process was established as flavin-based electron bifurcation in which the exergonic reduction of crotonyl-CoA by NADH mediated by Etf + butyryl-CoA dehydrogenase (Bcd) was coupled to the endergonic reduction of ferredoxin also by NADH. In the present study, we demonstrate that, under anaerobic conditions, Etf + Bcd from M. elsdenii bifurcate as efficiently as Etf + Bcd from A. fermentans. Under the aerobic conditions used in the study by Baldwin and Milligan and in the presence of catalytic amounts of crotonyl-CoA or butyryl-CoA, however, Etf + Bcd act as NADH oxidase producing superoxide and H2 O2 , whereas ferredoxin is not required. We hypothesize that, during bifurcation, oxygen replaces ferredoxin to yield superoxide. In addition, the formed butyryl-CoA is re-oxidized by a second oxygen molecule to crotonyl-CoA, resulting in a stoichiometry of 2 NADH consumed and 2 H2 O2 formed. As a result of the production of reactive oxygen species, electron bifurcation can be regarded as an Achilles' heel of anaerobes when exposed to air.
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an enzyme complex of propionyl coa dehydrogenase and electron transferring flavoprotein
2003Co-Authors: Marc Hetzel, Matthias Brock, BERNARD THOMAS GOLDING, Antonio J Pierik, Thorsten Selmer, Wolfgang BuckelAbstract:dimeric propionyl-CoA dehydrogenase subunit is similar to those of butyryl-CoA dehydrogenases from several clostridia and related anaerobes (up to 55% sequence identity). The N-termini of the b and c subunits share 40% and 35% sequence identities with those of the A and B subunits of the ETF from Megasphaera elsdenii, respectively, and up to 60% with those of putative ETFs from other anaerobes. Acryloyl-CoA reductase from C. propionicum has been characterized as a soluble enzyme, with kinetic properties perfectly adapted to the requirements of the organism. The enzyme appears not to be involved in anaerobic respiration with NADH or reduced ferredoxin as electron donors. There is no relationship to the trans-2-enoyl-CoA reductases from various organisms or the recently described acryloylCoA reductase activity of propionyl-CoA synthase from Chloroflexus aurantiacus.