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1.
Eur J Nutr ; 60(7): 4069-4082, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33974128

ABSTRACT

PURPOSE: We aimed to validate myfood24-Germany, a web-based 24-h dietary recall (24HDR), by comparing its performance with a weighed dietary record (WDR) and biomarkers. METHODS: 97 adults (77% female) completed a 3-day WDR with a 24-h urine collection on day 3, followed by at least one 24HDR with myfood24-Germany (corresponding to day 3 of the WDR). Intake of energy and 32 nutrients assessed by myfood24-Germany and the WDR for the same day were compared (method comparison). Intakes of protein and potassium assessed by myfood24-Germany/WDR were compared with intake estimated from urinary biomarkers for protein and potassium (biomarker comparison). RESULTS: In the method comparison, significant correlations were found for energy and all tested nutrients (range 0.45-0.87). There was no significant difference between both methods in the assessed mean energy and macronutrient intake. However, myfood24-Germany underestimated mean intake of 15 nutrients. In the biomarker comparison, protein intake reported by myfood24-Germany/WDR was on average 10%/8% lower than estimated by biomarker. There was no significant difference in mean potassium intake assessed by myfood24-Germany/WDR and biomarker. However, a shared bias in the assessment of potassium intake was observed for both instruments. Concordance correlation coefficients (pc) and weighted Kappa coefficients (κ) confirmed good agreement with the biomarker estimates for myfood24-Germany/WDR in case of protein (pc = 0.58/0.66, κ = 0.51/0.53) and moderate agreement in case of potassium (pc = 0.44/0.51; κ = 0.30/0.33). CONCLUSION: Our results suggest that myfood24-Germany is of comparable validity to traditional dietary assessment methods.


Subject(s)
Diet , Mental Recall , Biomarkers , Diet Records , Diet Surveys , Energy Intake , Female , Germany , Humans , Internet , Male , Nutrition Assessment , Reproducibility of Results , Surveys and Questionnaires
2.
Curr Opin Clin Nutr Metab Care ; 21(5): 343-351, 2018 09.
Article in English | MEDLINE | ID: mdl-29939967

ABSTRACT

PURPOSE OF REVIEW: A promising direction for improving dietary intake measurement in epidemiologic studies is the combination of short-term and long-term dietary assessment methods using statistical methods. Thereby, web-based instruments are particularly interesting as their application offers several potential advantages such as self-administration and a shorter completion time. The objective of this review is to provide an overview of new web-based short-term instruments and to describe their features. RECENT FINDINGS: A number of web-based short-term dietary assessment tools for application in different countries and age-groups have been developed so far. Particular attention should be paid to the underlying database and the search function of the tool. Moreover, web-based instruments can improve the estimation of portion sizes by offering several options to the user. SUMMARY: Web-based dietary assessment methods are associated with lower costs and reduced burden for participants and researchers, and show a comparable validity with traditional instruments. When there is a need for a web-based tool researcher should consider the adaptation of existing tools rather than developing new instruments. The combination of short-term and long-term instruments seems more feasible with the use of new technology.


Subject(s)
Diet , Eating , Internet , Nutrition Assessment , Costs and Cost Analysis , Databases, Factual , Diet Records , Humans , Mental Recall , Portion Size , Reproducibility of Results , Surveys and Questionnaires
3.
Eur J Immunol ; 43(2): 499-509, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23180650

ABSTRACT

HIV controllers are a valuable source for the identification of HIV-neutralizing antibodies, as chronic infection over decades allows extensive affinity maturation of antibodies for improved Ag recognition. We analyzed a small cohort of elite controllers (ECs) for HIV-neutralizing antibodies using a panel of standardized HIV-1 pseudovirions on TZM-bl cells. An HIV-1 Env-tailored phage display library was generated to select epitopes targeted by neutralizing antibodies in the EC26 plasma sample showing the broadest neutralizing activity. Selected Env fragments were mostly allocated to the membrane proximal external region of gp41. After preabsorbing the EC26 plasma with the selected phage EC26-2A4, we achieved 50% depletion of its neutralizing activity. Furthermore, antibodies affinity-purified with the EC26-2A4 epitope from EC26 plasma showed neutralizing activity, proving that the selected phage indeed contains an epitope targeted by neutralizing plasma antibodies. Epitope fine mapping of the purified plasma antibodies on peptide arrays identified a new epitope overlapping, but clearly distinct, from the prominent 2F5 epitope. Of note, the purified antibodies did not show autoreactivity with cardiolipin, whereas low reactivity with phosphatidylserine comparable to mAb 2F5 was observed. Thus, this new epitope represents a promising candidate for further analysis in view of HIV vaccine development.


Subject(s)
Antibodies, Neutralizing/immunology , Epitopes/immunology , HIV Antibodies/immunology , HIV Envelope Protein gp41/immunology , HIV Infections/immunology , HIV-1/immunology , Antibodies, Monoclonal/immunology , Antibody Affinity/immunology , Bacteriophages/immunology , Broadly Neutralizing Antibodies , HIV Infections/virology , Humans , Immunoglobulin G/immunology , Peptide Library
4.
J Virol ; 85(15): 7594-602, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21632763

ABSTRACT

Human APOBEC3 cytidine deaminases target and edit single-stranded DNA, which can be of viral, mitochondrial, or nuclear origin. Retrovirus genomes, such as human immunodeficiency virus (HIV) genomes deficient in the vif gene and the hepatitis B virus genome, are particularly vulnerable. The genomes of some DNA viruses, such as human papillomaviruses, can be edited in vivo and in transfection experiments. Accordingly, herpesviruses should be no exception. This is indeed the case for herpes simplex virus 1 (HSV-1) in tissue culture, where APOBEC3C (A3C) overexpression can reduce virus titers and the particle/PFU ratio ∼10-fold. Nonetheless, A3A, A3G, and AICDA can edit what is presumably a small fraction of HSV genomes in an experimental setting without seriously impacting the viral titer. Hyperediting was found in HSV genomes recovered from 4/8 uncultured buccal lesions. The phenomenon is not restricted to HSV, since hyperedited Epstein-Barr virus (EBV) genomes were readily recovered from 4/5 established cell lines, indicating that episomes are vulnerable to editing. These findings suggest that the widely expressed A3C cytidine deaminase can function as a restriction factor for some human herpesviruses. That the A3C gene is not induced by type I interferons begs the question whether some herpesviruses encode A3C antagonists.


Subject(s)
Cytosine Deaminase/metabolism , Genome, Viral , Herpesvirus 1, Human/genetics , Herpesvirus 4, Human/genetics , APOBEC Deaminases , Animals , Base Sequence , Chlorocebus aethiops , Cytidine Deaminase , Cytosine Deaminase/genetics , DNA/genetics , HeLa Cells , Herpesvirus 1, Human/physiology , Herpesvirus 4, Human/physiology , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Vero Cells , Virus Replication
5.
Nutrients ; 14(18)2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36145138

ABSTRACT

As consumption of commercial complementary food (CCF) during infancy and toddlerhood is common, the aim of the present study was to describe the current (2020) German market of CCF products targeted at infants and toddlers with a special focus on ingredients, macronutrients, and the practice of nutrient fortification. Information on age declarations, ingredients, energy and nutrient contents, and nutrient fortification was obtained in a market survey by contacting the producers and searching manufacturers' websites. Each product was assigned to 1 of 13 product categories (menus, milk−cereal−meal, fruit−cereal−meal, oil, vegetables, meat, fish, fruits, cereals, snack foods, pouches, desserts, beverages). Descriptive statistics were used. We identified 1057 CF products on the German market (infants' CCF (<12 months): n = 829; toddlers' CCF (>12 months): n = 228)). The highest protein content (% of energy content, %E) was found in meat products. In pouches, beverages, cereal fruit meals, and fruits, more than 50% of energy came from total sugar. The highest median salt content was found in toddlers' menus and desserts. Around one-third of infants' CCF products and one quarter of toddlers' products were fortified with nutrients. Vitamin B1 (thiamin) was the most frequently fortified nutrient, followed by vitamin C, iron, calcium, and vitamin D. Apple was the type of fruit listed most often in products with fruits, whereas carrot was the most frequent vegetable among CCF with vegetables. In particular, the high total sugar content of most CCFs currently available on the German market may promote unhealthy dietary habits. Parents need to be advised about the optimal selection of products.


Subject(s)
Calcium , Energy Intake , Animals , Ascorbic Acid , Germany , Humans , Infant Food , Iron , Sugars , Thiamine , Vegetables , Vitamin D
6.
Nutrients ; 12(1)2020 Jan 06.
Article in English | MEDLINE | ID: mdl-31935885

ABSTRACT

Our aim was to develop and evaluate a German adaptation of myfood24, a fully automated, web-based 24-h dietary recall (24HDR). To complete a self-administered 24HDR with myfood24, users have to search and enter consumed foods within the underlying database by a free text search. The adaptation process thus mainly consisted of the development of an appropriate food database. myfood24-Germany was evaluated in 92 adults aged 17-78 years (study 1). Participants completed four non-consecutive 24HDRs and answered an evaluation questionnaire after the final recall. The System Usability Scale Score (SUS Score, 0-100) was calculated. Users' search behavior was examined with screen recordings in 15 adults aged 20-60 years (study 2). Participants had to enter three sample meals presented as food packaging or pictures. The final database included 11,501 food items (7203 generic and 4298 branded items) with up to 131 nutrients. In study 1, the median completion time for a 24HDR was 15 min. The median SUS score of 78 indicated good usability. The majority of participants considered the overall user-friendliness as good (46%) or very good (21%), and 75% were willing to use myfood24-Germany regularly. Both studies showed that finding and choosing an appropriate item within the database was a major challenge. A German version of myfood24 was successfully developed. The user evaluation indicated a short completion time, good usability and acceptability of the tool, and confirmed its feasibility for repeated short-term application.


Subject(s)
Databases, Factual , Diet Surveys/methods , Diet , Feeding Behavior , Internet , Adolescent , Adult , Aged , Diet Records , Female , Germany , Humans , Male , Meals , Mental Recall , Middle Aged , Nutrition Assessment , Young Adult
7.
Int J Artif Organs ; 32(9): 611-20, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19856273

ABSTRACT

PURPOSE: Identification of putative new virulence factors as additional targets for therapeutic approaches alternative to antibiotic treatment of multi-resistant enterococcal infections. METHODS: The EF3314 gene, coding for a putative surface-exposed antigen, was identified by the analysis of the Enterococcus faecalis V583 genome for LPXTG-motif cell wall anchor surface protein genes. A non-polar EF3314 gene deletion mutant in the E. faecalis 12030 human clinical isolate was obtained. The wild type and the isogenic mutant strain were investigated for biofilm formation, adherence to Hela cells, survival in human macrophages and a Caenorhabditis elegans infection model. The aminoterminal portion of the EF3314 protein was overexpressed in E. coli to obtain mouse polyclonal antibodies for use in Western blotting and immunolocalization experiments. RESULTS: The EF3314 gene has an unusually high GC content (46.88% vs. an average of 37.5% in the E. faecalis chromosome) and encodes a protein of 1744 amino acids that presents a series of 14 imperfect repeats of 90 amino acids covering almost the entire length of the protein. Its global organization is similar to the alpha-like protein family of group B streptococci, enterococcal surface protein Esp and biofilm associated protein Bap from S. aureus. The EF3314 gene was always present and specific for E. faecalis strains of human, food and animal origin. Differences in size depended on variable numbers of repeats in the repetitive region. CONCLUSIONS: EF3314 is a newly described, surface exposed protein that contributes to the virulence properties of E. faecalis.


Subject(s)
Bacterial Proteins/metabolism , Cell Wall/metabolism , Enterococcus faecalis/pathogenicity , Virulence Factors/metabolism , Amino Acid Sequence , Animals , Bacterial Adhesion , Bacterial Proteins/genetics , Base Composition , Biofilms , Caenorhabditis elegans , Disease Models, Animal , Enterococcus faecalis/genetics , Enterococcus faecalis/growth & development , Enterococcus faecalis/metabolism , Epithelial Cells/microbiology , Gene Expression Regulation, Bacterial , Gram-Positive Bacterial Infections/microbiology , HeLa Cells , Humans , Macrophages/microbiology , Molecular Sequence Data , Mutation , Time Factors , Virulence , Virulence Factors/genetics
8.
PLoS One ; 13(5): e0197131, 2018.
Article in English | MEDLINE | ID: mdl-29791516

ABSTRACT

BACKGROUND: Restrained Eating, i.e. the tendency to restrict dietary intake to control body-weight, often emerges during adolescence and may result in changes in circadian eating patterns. OBJECTIVE: The objective of the present investigation was to determine the cross-sectional relevance of restrained eating for characteristics of circadian eating pattern in adolescents and whether changes in restrained eating are accompanied by concurrent changes in circadian eating pattern over the course of adolescence. METHODS: Two questionnaires assessing restrained eating (Score 0-30) with parallel 3-day weighed dietary records from two different time points were available from 209 (♂:101, ♀:108) 11-18 year old adolescents of the DONALD study. Mixed linear regression models were used to analyze whether restrained eating was associated with eating occasion frequency, snack frequency and morning and evening energy intake [in % of daily energy intake, %E]. Linear regression models were used to examine whether changes in restrained eating were associated with changes in the mentioned variables. RESULTS: Among girls, greater restrained eating was cross-sectionally associated with higher morning energy intake (p = 0.03). Further, there was a tendency towards lower evening energy intake with higher levels of restrained eating for the whole sample (p = 0.06). No cross-sectional associations were found with eating occasion or snack frequency. Each one-point increase in restrained eating during adolescence was related to a concurrent decrease in eating occasion frequency by 0.04 (95% CI -0.08; -0.01, p = 0.02) and in evening energy intake by 0.36%E (95% CI -0.70; -0.03, p = 0.04). A tendency towards decreasing snack frequency with increasing restrained eating was observed (ß = -0.03, 95% CI -0.07; 0.00, p = 0.07). No association was found between changes in restrained eating and concurrent changes in morning energy intake. CONCLUSION: We found indications for cross-sectional and prospective associations between restrained eating and chronobiological aspects of food intake in adolescents. Our results suggest that restrained eating should be considered a relevant determinant of circadian eating patterns.


Subject(s)
Feeding Behavior , Adolescent , Child , Circadian Rhythm , Cross-Sectional Studies , Energy Intake , Fasting , Female , Humans , Male , Prospective Studies
9.
Int J Food Microbiol ; 117(1): 36-42, 2007 Jun 10.
Article in English | MEDLINE | ID: mdl-17462770

ABSTRACT

Growth and stress adaptation of an autolytic strain of Lactobacillus delbrueckii subsp. lactis FAM-10991 was studied during pH-controlled batch fermentations. After an initial growth to an optical density at 650 nm of 0.8 under controlled optimal growth conditions (pH 5.5, 37 degrees C, no salt), exponentially growing cells were exposed to salt at concentrations from 1 to 3.5%, and temperatures between 48 and 53.5 degrees C, without pH control or with pH controlled at 5.5 or 4.5. Autolysis was induced by salt concentrations of 2.5 or 3.5% and suppressed at 53.5 degrees C or pH 4.5. Salt at concentrations of 2.5 or 3.5% or a temperature of 53.5 degrees C, without pH control or with pH controlled at 5.5, significantly enhanced (p<0.05) survival of lyophilization as compared with the survival of cells in control cultures or cultures with salt at concentration of 1 and 1.5%. The former conditions increased survival by 125- and 200-fold, respectively. However, no correlation was found between autolytic activity and survival of lyophilization. Cultures grown with salt at 2.5% gave high yields of viable cells in broths before and after lyophilization, with numbers being 27-fold higher than with control cultures, but with autolytic activity that was 2.5-fold higher than in cells from control cultures.


Subject(s)
Food Microbiology , Food Preservation/methods , Lactobacillus delbrueckii/growth & development , Osmotic Pressure , Salts/pharmacology , Adaptation, Physiological , Biomass , Dose-Response Relationship, Drug , Hydrogen-Ion Concentration , Lactobacillus delbrueckii/physiology , Temperature
10.
BMC Microbiol ; 6: 60, 2006 Jul 11.
Article in English | MEDLINE | ID: mdl-16834772

ABSTRACT

BACKGROUND: Biofilm formation in E. faecalis is presumed to play an important role in a number of enterococcal infections. We have previously identified a genetic locus provisionally named bop that is involved in maltose metabolism and biofilm formation. A transposon insertion into the second gene of the locus (bopB) resulted in loss of biofilm formation, while the non-polar deletion of this gene, together with parts of the flanking genes (bopA and bopC) resulted in increased biofilm formation. A polar effect of the transposon insertion on a transcriptional regulator (bopD) was responsible for the reduced biofilm formation of the transposon mutant. RESULTS: The amount of biofilm formed is related to the presence of maltose or glucose in the growth medium. While the wild-type strain was able to produce biofilm in medium containing either glucose or maltose, two mutants of this locus showed opposite effects. When grown in medium containing 1% glucose, the transposon mutant showed reduced biofilm formation (9%), while the deletion mutant produced more biofilm (110%) than the wild-type. When grown in medium containing 1% maltose, the transposon mutant was able to produce more biofilm than the wild-type strain (111%), while the deletion mutant did not produce biofilm (4%). Biofilm formation was not affected by the presence of several other sugar sources. In a gastrointestinal colonization model, the biofilm-negative mutant was delayed in colonization of the mouse intestinal tract. CONCLUSION: The biofilm-positive phenotype of the wild-type strain seems to be associated with colonization of enterococci in the gut and the presence of oligosaccharides in food may influence biofilm formation and therefore colonization of enterococci in the gastrointestinal system.


Subject(s)
Biofilms/growth & development , Enterococcus faecalis/growth & development , Gastrointestinal Tract/microbiology , Oligosaccharides/metabolism , Animals , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Culture Media , DNA Transposable Elements , Enterococcus faecalis/genetics , Enterococcus faecalis/ultrastructure , Female , Gene Deletion , Gene Expression Regulation, Bacterial , Maltose/metabolism , Mice , Mice, Inbred BALB C , Microscopy, Electron, Scanning , Mutagenesis, Insertional
11.
Med Klin (Munich) ; 100(11): 744-6, 2005 Nov 15.
Article in German | MEDLINE | ID: mdl-16328183

ABSTRACT

Kaposi's sarcoma in HIV-infected patients is a sign of progressive immunodeficiency. It is therefore classified as an AIDS-defining disease according to the CDC classification of 1993. Before antiretroviral therapy became available, disseminated Kaposi's sarcoma was a common therapeutic problem in HIV-infected patients. Therapeutic interventions were limited and in spite of interferon, irradiation or cytostatic drugs, chances of a definitive healing were minimal.Today, disseminated Kaposi's sarcoma is rare even in specialized clinics for infectious diseases. An exception are patients who are not aware of their HIV serostatus until they are diagnosed HIV-positive and who present already with a progressive immunodeficiency.


Subject(s)
HIV Infections/complications , Sarcoma, Kaposi/complications , Skin Neoplasms/complications , Aged , Aged, 80 and over , Antiretroviral Therapy, Highly Active , Biopsy , Diagnosis, Differential , HIV Infections/diagnosis , HIV Infections/drug therapy , Humans , Male , Sarcoma, Kaposi/diagnosis , Sarcoma, Kaposi/pathology , Skin/pathology , Skin Neoplasms/diagnosis , Skin Neoplasms/pathology , Venous Insufficiency/diagnosis
12.
PLoS One ; 7(12): e51715, 2012.
Article in English | MEDLINE | ID: mdl-23300558

ABSTRACT

BACKGROUND: Infections with HIV still represent a major human health problem worldwide and a vaccine is the only long-term option to fight efficiently against this virus. Standardized assessments of HIV-specific immune responses in vaccine trials are essential for prioritizing vaccine candidates in preclinical and clinical stages of development. With respect to neutralizing antibodies, assays with HIV-1 Env-pseudotyped viruses are a high priority. To cover the increasing demands of HIV pseudoviruses, a complete cell culture and transfection automation system has been developed. METHODOLOGY/PRINCIPAL FINDINGS: The automation system for HIV pseudovirus production comprises a modified Tecan-based Cellerity system. It covers an area of 5×3 meters and includes a robot platform, a cell counting machine, a CO(2) incubator for cell cultivation and a media refrigerator. The processes for cell handling, transfection and pseudovirus production have been implemented according to manual standard operating procedures and are controlled and scheduled autonomously by the system. The system is housed in a biosafety level II cabinet that guarantees protection of personnel, environment and the product. HIV pseudovirus stocks in a scale from 140 ml to 1000 ml have been produced on the automated system. Parallel manual production of HIV pseudoviruses and comparisons (bridging assays) confirmed that the automated produced pseudoviruses were of equivalent quality as those produced manually. In addition, the automated method was fully validated according to Good Clinical Laboratory Practice (GCLP) guidelines, including the validation parameters accuracy, precision, robustness and specificity. CONCLUSIONS: An automated HIV pseudovirus production system has been successfully established. It allows the high quality production of HIV pseudoviruses under GCLP conditions. In its present form, the installed module enables the production of 1000 ml of virus-containing cell culture supernatant per week. Thus, this novel automation facilitates standardized large-scale productions of HIV pseudoviruses for ongoing and upcoming HIV vaccine trials.


Subject(s)
AIDS Vaccines/therapeutic use , HIV Antibodies/immunology , HIV Infections/virology , HIV-1/physiology , Virus Replication , env Gene Products, Human Immunodeficiency Virus/metabolism , Automation , HIV Infections/prevention & control , Humans , Viral Load , env Gene Products, Human Immunodeficiency Virus/genetics , env Gene Products, Human Immunodeficiency Virus/immunology
13.
PLoS One ; 7(5): e38068, 2012.
Article in English | MEDLINE | ID: mdl-22666448

ABSTRACT

Although human immunodeficiency type 1 (HIV-1) infection induces strong antibody responses to the viral envelope glycoprotein (Env) only a few of these antibodies possess the capacity to neutralize a broad range of strains. The induction of such antibodies represents an important goal in the development of a preventive vaccine against the infection. Among the broadly neutralizing monoclonal antibodies discovered so far, three (2F5, Z13 and 4E10) target the short and hidden membrane proximal external region (MPER) of the gp41 transmembrane protein. Antibody responses to MPER are rarely observed in HIV-infected individuals or after immunization with Env immunogens. To initiate antibody responses to MPER in its membrane-embedded native conformation, we generated expression plasmids encoding the membrane-anchored ectodomain of gp41 with N-terminal deletions of various sizes. Following transfection of these plasmids, the MPER domains are displayed on the cell surface and incorporated into HIV virus like particles (VLP). Transfected cells displaying MPER mutants bound as efficiently to both 2F5 and 4E10 as cells transfected with a plasmid encoding full-length Env. Mice immunized with VLPs containing the MPER mutants produced MPER-specific antibodies, the levels of which could be increased by the trimerization of the displayed proteins as well as by a DNA prime-VLP boost immunization strategy. Although 2F5 competed for binding to MPER with antibodies in sera of some of the immunized mice, neutralizing activity could not be detected. Whether this is due to inefficient binding of the induced antibodies to MPER in the context of wild type Env or whether the overall MPER-specific antibody response induced by the MPER display mutants is too low to reveal neutralizing activity, remains to be determined.


Subject(s)
Antibodies, Viral/biosynthesis , Antibody Formation/genetics , Cell Membrane/virology , HIV Envelope Protein gp41/chemistry , HIV Envelope Protein gp41/genetics , HIV-1/immunology , Protein Engineering/methods , Amino Acid Sequence , Animals , Antibodies, Viral/immunology , DNA, Viral/immunology , Female , HEK293 Cells , Humans , Immunization, Secondary , Mice , Molecular Sequence Data , Mutation , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/immunology , Vaccines, Virus-Like Particle/immunology
14.
Plant Cell ; 21(2): 507-25, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19218397

ABSTRACT

Acyl-CoA Synthetase (ACOS) genes are related to 4-coumarate:CoA ligase (4CL) but have distinct functions. The Arabidopsis thaliana ACOS5 protein is in clade A of Arabidopsis ACOS proteins, the clade most closely related to 4CL proteins. This clade contains putative nonperoxisomal ACOS enzymes conserved in several angiosperm lineages and in the moss Physcomitrella patens. Although its function is unknown, ACOS5 is preferentially expressed in the flowers of all angiosperms examined. Here, we show that an acos5 mutant produced no pollen in mature anthers and no seeds by self-fertilization and was severely compromised in pollen wall formation apparently lacking sporopollenin or exine. The phenotype was first evident at stage 8 of anther development and correlated with maximum ACOS5 mRNA accumulation in tapetal cells at stages 7 to 8. Green fluorescent protein-ACOS5 fusions showed that ACOS5 is located in the cytoplasm. Recombinant ACOS5 enzyme was active against oleic acid, allowing kinetic constants for ACOS5 substrates to be established. Substrate competition assays indicated broad in vitro preference of the enzyme for medium-chain fatty acids. We propose that ACOS5 encodes an enzyme that participates in a conserved and ancient biochemical pathway required for sporopollenin monomer biosynthesis that may also include the Arabidopsis CYP703A2 and MS2 enzymes.


Subject(s)
Arabidopsis Proteins/physiology , Arabidopsis/metabolism , Biopolymers/biosynthesis , Carotenoids/biosynthesis , Coenzyme A Ligases/genetics , Pollen/growth & development , Alleles , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/analysis , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Binding, Competitive , Biopolymers/chemistry , Carotenoids/chemistry , Coenzyme A Ligases/chemistry , Coenzyme A Ligases/physiology , Cytoplasm/metabolism , Flowers/genetics , Flowers/growth & development , Flowers/metabolism , Green Fluorescent Proteins/analysis , Kinetics , Mutation , Phylogeny , Pollen/metabolism , Recombinant Fusion Proteins/analysis , Substrate Specificity
15.
Parasitol Res ; 100(4): 747-8, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17004096

ABSTRACT

Cerebral malaria, the most frequent complication of falciparum malaria, is usually predicted by an increased count of asexual parasites in peripheral blood. We report a case of a female returnee from Ghana who developed cerebral malaria in spite of parasite clearance in peripheral blood after therapy with atovaquone/proguanil.


Subject(s)
Antimalarials/therapeutic use , Atovaquone/therapeutic use , Malaria, Cerebral/drug therapy , Malaria, Cerebral/parasitology , Plasmodium falciparum/drug effects , Proguanil/therapeutic use , Adult , Animals , Artemisinins/therapeutic use , Artesunate , Female , Humans , Plasmodium falciparum/isolation & purification , Quinine/therapeutic use , Sesquiterpenes/therapeutic use
16.
J Infect Dis ; 191(8): 1253-62, 2005 Apr 15.
Article in English | MEDLINE | ID: mdl-15776371

ABSTRACT

Enterococcus faecalis is responsible for a large variety of nosocomial infections. The intestinal barrier is thought to be one of the preferential portals of entry of enterococci, and the ability of E. faecalis to survive within peritoneal macrophages may contribute to spreading to distant sites. We examined the ability of a polysaccharide-expressing (biofilm-positive) E. faecalis strain and an isogenic biofilm-negative mutant to enter and survive within professional and nonprofessional phagocytes. Biofilm-positive bacteria survived longer in all cell systems than did biofilm-negative bacteria, through a process of receptor-mediated endocytosis that is dependent on functional reorganization of microtubules and polymerization of microfilament and on activation of protein kinases but not ATPases or protein phosphatases. We suggest that glycosaminoglycans--specifically heparin, heparan sulfate, and chondroitin sulfate A--are the host receptors for enterococci on professional and, possibly, nonprofessional phagocytes, allowing entry of enterococci into cell compartments where killing mechanisms are inhibited.


Subject(s)
Enterococcus faecalis/physiology , Glycosaminoglycans/metabolism , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/microbiology , Animals , Bacterial Adhesion , Biofilms/growth & development , Cell Line , DNA Transposable Elements/genetics , Dendritic Cells/metabolism , Dendritic Cells/microbiology , Endocytosis , Enterococcus faecalis/genetics , Enterococcus faecalis/growth & development , HeLa Cells , Humans , Mice , Mutation/genetics , Rats , Skin/cytology , Skin/embryology , Skin/immunology
17.
Expert Opin Biol Ther ; 4(9): 1519-31, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15335318

ABSTRACT

Enterococci are one of the leading types of organisms isolated from infections of hospitalised patients and the third most common cause of nosocomial bloodstream infections. They contribute significantly to patient mortality and morbidity, as well as healthcare costs. The emergence of resistance against virtually all clinically available antibiotics and the ability to transfer these resistance determinants to other pathogens demonstrates the urgency for an improved understanding of enterococcal virulence mechanisms, and the development of alternative treatment and prevention options. This article reviews new antimicrobials, vaccine targets, bacteriophage therapy, as well as treatments targeting virulence factors and biofilm, for their potential to treat and/or prevent enterococcal infections. Although clinical isolates often cause serious infections, so-called 'non-pathogenic' strains are used as therapeutics in the form of probiotics. Understanding the differences between true pathogens and beneficial commensals may help to evaluate future treatment and prophylactic options.


Subject(s)
Enterococcus , Gram-Positive Bacterial Infections/therapy , Animals , Anti-Bacterial Agents/therapeutic use , Antigens, Bacterial/immunology , Bacterial Vaccines/immunology , Bacteriophages/physiology , Biofilms , Biological Therapy , Cross Infection/microbiology , Cross Infection/prevention & control , Cross Infection/therapy , Drug Resistance , Enterococcus/drug effects , Enterococcus/immunology , Enterococcus/pathogenicity , Enterococcus/virology , Female , Gram-Positive Bacterial Infections/epidemiology , Gram-Positive Bacterial Infections/physiopathology , Gram-Positive Bacterial Infections/prevention & control , Gram-Positive Bacterial Infections/transmission , Humans , Male , Probiotics/therapeutic use , Vaccination
18.
Vaccine ; 22(7): 822-30, 2004 Feb 17.
Article in English | MEDLINE | ID: mdl-15040934

ABSTRACT

The emergence of resistance against multiple antibiotics and the increasing frequency with which Enterococcus faecalis and Enterococcus faecium are isolated from hospitalized patients underscore the necessity for a better understanding of the virulence mechanisms of this pathogen and the development of alternatives to current antibiotic treatments. The genetic plasticity of enterococci and their ability to rapidly acquire and/or develop resistance against many clinically important antibiotics and to transfer these resistance determinants to other more pathogenic microorganisms makes the search for alternative treatment and preventive options even more important. A capsular polysaccharide antigen has recently been characterized that is the target of opsonic antibodies. A limited number of clinically relevant serotypes exist, and the development of an enterococcal vaccine based on capsular polysaccharides may improve our ability to prevent and treat these infections. Additional enterococcal surface antigens, including ABC transporter proteins and other virulence factors, such as aggregation substance (AS), may also be useful targets for therapeutic antibodies.


Subject(s)
Enterococcus , Gram-Positive Bacterial Infections/immunology , Gram-Positive Bacterial Infections/therapy , Animals , Antigens, Bacterial/immunology , Bacterial Translocation , Bacterial Vaccines/immunology , Enterococcus/growth & development , Enterococcus/immunology , Enterococcus/pathogenicity , Gram-Positive Bacterial Infections/prevention & control , Humans , Lipopolysaccharides/chemistry , Lipopolysaccharides/immunology , Virulence Factors
19.
J Infect Dis ; 189(3): 420-30, 2004 Feb 01.
Article in English | MEDLINE | ID: mdl-14745699

ABSTRACT

A biofilm-negative transposon mutant was created from an Enterococcus faecalis strain that produces a lot of biofilm. The transposon had been inserted in the second gene of a locus consisting of 4 open-reading frames, designated bop (biofilm on plastic surfaces). A nonpolar deletion of this gene and of parts of the 2 flanking genes was created; production of biofilm by this deletion mutant was significantly enhanced, compared with that by the wild-type strain. Expression of a downstream gene was significantly lower in the transposon mutant than in the wild-type strain and the biofilm-enhanced deletion mutant. Transformation of this gene into the transposon mutant partially restored production of biofilm. Mice challenged by intravenous injection with the biofilm-negative mutant strain showed significantly reduced numbers of colony-forming units in the blood, compared with mice challenged with the biofilm-enhanced deletion mutant and the wild-type. These results indicate that bop is involved in production of biofilm and probably regulates expression of biofilm in the E. faecalis strain tested.


Subject(s)
Bacteremia/microbiology , Enterococcus faecalis/genetics , Genes, Regulator , Gram-Positive Bacterial Infections/microbiology , Animals , Biofilms/growth & development , Carbohydrate Metabolism , DNA Transposable Elements , Disease Models, Animal , Enterococcus faecalis/pathogenicity , Mice , Mice, Inbred BALB C , Mutation , Open Reading Frames , Virulence/genetics
20.
J Clin Microbiol ; 42(6): 2548-57, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15184433

ABSTRACT

Enterococci possess capsular carbohydrate antigens that are targets of opsonic antibodies. These antigens may be used to develop alternative options for the treatment and prevention of enterococcal infections. The present study was done to analyze the diversity of capsular polysaccharides in Enterococcus faecalis. Four type-specific sera were used in an enzyme-linked immunosorbent assay format to detect polysaccharide antigen extracted from bacterial cell walls. A total of 55% of a collection of 29 E. faecalis strains could be grouped into one of four serogroups. Additional analysis of the strains by opsonophagocytic assays revealed agreement between the results of the two methods for 72% of the isolates. An additional four strains could be assigned to a serogroup on the basis of opsonic killing by sera with antibodies against the four prototypes strains, provisionally named CPS-A to CPS-D. The results of the two methods disagreed for one strain (4%). When the results of both methods were combined, 66% of the strains could be classified. One strain had to be assigned to two serogroups. The assignments to the four serogroups were confirmed by analysis of the genetic organization of the biosynthetic capsular polysaccharide (cps) locus. All strains grouped into serotypes CPS-A and CPS-B possessed only the cpsA and cpsB genes, while all strains grouped into serogroups CPS-C and CPS-D possessed an additional eight or nine genes. Our results suggest the existence of a limited number of E. faecalis capsule serotypes, and we provisionally propose four serotypes, named CPS-A to CPS-D, and the respective prototype strains for these families.


Subject(s)
Bacterial Capsules/immunology , Enterococcus faecalis/immunology , Animals , Bacterial Capsules/genetics , Enterococcus faecalis/genetics , Enzyme-Linked Immunosorbent Assay , Genetic Variation , Humans , Immune Sera/immunology , Phagocytosis , Polymorphism, Restriction Fragment Length , Rabbits
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