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1.
Nature ; 627(8005): 915-922, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38480893

ABSTRACT

Scientific exploration of phototrophic bacteria over nearly 200 years has revealed large phylogenetic gaps between known phototrophic groups that limit understanding of how phototrophy evolved and diversified1,2. Here, through Boreal Shield lake water incubations, we cultivated an anoxygenic phototrophic bacterium from a previously unknown order within the Chloroflexota phylum that represents a highly novel transition form in the evolution of photosynthesis. Unlike all other known phototrophs, this bacterium uses a type I reaction centre (RCI) for light energy conversion yet belongs to the same bacterial phylum as organisms that use a type II reaction centre (RCII) for phototrophy. Using physiological, phylogenomic and environmental metatranscriptomic data, we demonstrate active RCI-utilizing metabolism by the strain alongside usage of chlorosomes3 and bacteriochlorophylls4 related to those of RCII-utilizing Chloroflexota members. Despite using different reaction centres, our phylogenomic data provide strong evidence that RCI-utilizing and RCII-utilizing Chloroflexia members inherited phototrophy from a most recent common phototrophic ancestor. The Chloroflexota phylum preserves an evolutionary record of the use of contrasting phototrophic modes among genetically related bacteria, giving new context for exploring the diversification of phototrophy on Earth.


Subject(s)
Bacteria , Photosystem I Protein Complex , Phototrophic Processes , Bacteria/chemistry , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Bacteriochlorophylls/metabolism , Lakes/microbiology , Photosynthesis , Photosystem I Protein Complex/metabolism , Phylogeny , Anaerobiosis , Photosystem II Protein Complex/metabolism , Gene Expression Profiling
2.
ISME J ; 14(11): 2732-2747, 2020 11.
Article in English | MEDLINE | ID: mdl-32747714

ABSTRACT

Aquatic environments with high levels of dissolved ferrous iron and low levels of sulfate serve as an important systems for exploring biogeochemical processes relevant to the early Earth. Boreal Shield lakes, which number in the tens of millions globally, commonly develop seasonally anoxic waters that become iron rich and sulfate poor, yet the iron-sulfur microbiology of these systems has been poorly examined. Here we use genome-resolved metagenomics and enrichment cultivation to explore the metabolic diversity and ecology of anoxygenic photosynthesis and iron/sulfur cycling in the anoxic water columns of three Boreal Shield lakes. We recovered four high-completeness and low-contamination draft genome bins assigned to the class Chlorobia (formerly phylum Chlorobi) from environmental metagenome data and enriched two novel sulfide-oxidizing species, also from the Chlorobia. The sequenced genomes of both enriched species, including the novel "Candidatus Chlorobium canadense", encoded the cyc2 gene that is associated with photoferrotrophy among cultured Chlorobia members, along with genes for phototrophic sulfide oxidation. One environmental genome bin also encoded cyc2. Despite the presence of cyc2 in the corresponding draft genome, we were unable to induce photoferrotrophy in "Ca. Chlorobium canadense". Genomic potential for phototrophic sulfide oxidation was more commonly detected than cyc2 among environmental genome bins of Chlorobia, and metagenome and cultivation data suggested the potential for cryptic sulfur cycling to fuel sulfide-based growth. Overall, our results provide an important basis for further probing the functional role of cyc2 and indicate that anoxygenic photoautotrophs in Boreal Shield lakes could have underexplored photophysiology pertinent to understanding Earth's early microbial communities.


Subject(s)
Chlorobi , Lakes , Chlorobi/genetics , Iron , Oxidation-Reduction , Photosynthesis , Sulfur
3.
Br Dent J ; 226(3): 180-182, 2019 02 08.
Article in English | MEDLINE | ID: mdl-30734740

ABSTRACT

The objective of this case report is to illustrate the diagnosis and classification of periodontitis, according to the 2017 classification system, as recommended in the British Society of Periodontology (BSP) implementation plan. A 37-year-old female was diagnosed with periodontitis (molar-incisor pattern), stage III, grade C, currently unstable. Several issues pertinent to the diagnosis of localised forms of periodontitis in young patients are discussed in relation to the current and previous classification systems. Periodontitis can be limited to a few sites and this case highlights the importance of the careful application of the basic periodontal examination (BPE).


Subject(s)
Periodontal Diseases , Periodontitis , Adult , Female , Humans , Incisor , Molar
4.
Br Dent J ; 226(2): 98-100, 2019 01 25.
Article in English | MEDLINE | ID: mdl-30679831

ABSTRACT

The objective of this case report is to illustrate the diagnosis and classification of periodontitis according to the 2017 classification system as recommended in the British Society of Periodontology (BSP) implementation plan. We describe a case of a patient who was diagnosed with 'localised periodontitis; stage II, grade B; currently unstable'. The present case report presents an example for the application of the new classification system and illustrates how the new classification system captures disease severity, extent and disease susceptibility by staging and grading periodontitis.


Subject(s)
Periodontal Diseases , Periodontitis , Humans , Middle Aged , Periodontics
5.
Br Dent J ; 226(1): 16-22, 2019 01 11.
Article in English | MEDLINE | ID: mdl-30631188

ABSTRACT

The 2017 World Workshop Classification system for periodontal and peri-implant diseases and conditions was developed in order to accommodate advances in knowledge derived from both biological and clinical research, that have emerged since the 1999 International Classification of Periodontal Diseases. Importantly, it defines clinical health for the first time, and distinguishes an intact and a reduced periodontium throughout. The term 'aggressive periodontitis' was removed, creating a staging and grading system for periodontitis that is based primarily upon attachment and bone loss and classifies the disease into four stages based on severity (I, II, III or IV) and three grades based on disease susceptibility (A, B or C). The British Society of Periodontology (BSP) convened an implementation group to develop guidance on how the new classification system should be implemented in clinical practice. A particular focus was to describe how the new classification system integrates with established diagnostic parameters and pathways, such as the basic periodontal examination (BPE). This implementation plan focuses on clinical practice; for research, readers are advised to follow the international classification system. In this paper we describe a diagnostic pathway for plaque-induced periodontal diseases that is consistent with established guidance and accommodates the novel 2017 classification system, as recommended by the BSP implementation group. Subsequent case reports will provide examples of the application of this guidance in clinical practice.


Subject(s)
Dental Plaque , Periodontal Diseases , Periodontitis , Humans , Periodontics , Periodontium
6.
Br Dent J ; 226(1): 23-26, 2019 01 11.
Article in English | MEDLINE | ID: mdl-30631190

ABSTRACT

The objective of this case report is to illustrate the diagnosis and classification of periodontitis according to the 2017 classification system as recommended in the British Society of Periodontology (BSP) implementation plan. We describe two cases in the form of a pair of siblings, who developed periodontitis very early in life. A 19-year-old female was diagnosed with 'generalised periodontitis; stage III/grade C; currently unstable'. Her 14-year-old sister was diagnosed with 'localised periodontitis; stage II, grade C; currently unstable'. The present case report presents an example for the application of the new classification system and illustrates the importance of a periodontal check for children and adolescents and/or their relatives.


Subject(s)
Periodontal Diseases , Periodontitis , Adolescent , Adult , Child , Female , Humans , Periodontics , Siblings , Societies , Young Adult
7.
J Assoc Physicians India ; 64(4): 79-80, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27734648

ABSTRACT

Alkaptonuria is an autosomal recessive metabolic disorder characterized by joints and spine involvement, ochronosis and presence of homogentisic acid in urine and its deposition in cartilage, intervertebral disc and other connective tissues, leading to disabling arthritis in elderly individual.


Subject(s)
Alkaptonuria , Ochronosis , Humans
8.
J Assoc Physicians India ; 64(7): 85-86, 2016 07.
Article in English | MEDLINE | ID: mdl-27759355

ABSTRACT

We describe a case of Spondyloepiphyseal Dysplasia Congenita (SEDc) who presented to our rheumatology clinic with complaints of painful swelling of bilateral elbow, knee, distal and proximal interphalangeal joints (DIP and PIP) of hands and small joints of foot. Patient also complained of restriction during extension of bilateral wrist joint and lateral rotation of neck on both sides. He was also unable to walk without support.


Subject(s)
Osteochondrodysplasias/congenital , Adult , Humans , Male , Osteochondrodysplasias/diagnosis , Phenotype
9.
J Assoc Physicians India ; 64(8): 62-66, 2016 08.
Article in English | MEDLINE | ID: mdl-27762111

ABSTRACT

Systemic lupus erythematosus (SLE) mostly affects young women of reproductive age group. SLE patients may conceive as any normal woman but complication may occur in these patients if the disease is active. Pregnancy in SLE may lead to 1. Aggravation of SLE (Lupus flare) 2. Pre-term delivery, intrauterine growth retardation and foetal loss (in presence of antiphospholipid antibodies) 3. Neonatal lupus especially in presence of Anti-Ro / La antibody. For a successful pregnancy, both from maternal and foetal aspects, disease should be quiescent for at least six months before the conception. Lupus patients with pregnancy require specific management to improve the maternal and fetal outcomes. Many safe drugs are available for the management of pregnancy in SLE.


Subject(s)
Lupus Erythematosus, Systemic/therapy , Pregnancy Complications/therapy , Female , Humans , Pregnancy
10.
J Assoc Physicians India ; 64(3): 88-89, 2016 03.
Article in English | MEDLINE | ID: mdl-27731569

ABSTRACT

A case of Pachydermoperiostosis (PDP) presented to us in rheumatology clinic with complaints of enlargement and broadening of bilateral hands and feet, grade IV digital clubbing, coarsening of facial features, excessive sweating of the palms, soles during summers.


Subject(s)
Osteoarthropathy, Primary Hypertrophic/diagnosis , Periostitis/etiology , Adult , Facial Dermatoses/pathology , Fingers/pathology , Humans , Male , Osteoarthropathy, Primary Hypertrophic/genetics , Osteoarthropathy, Primary Hypertrophic/pathology , Periostitis/pathology , Toes/pathology , Wrist Joint/pathology
11.
Int J Syst Evol Microbiol ; 65(8): 2391-2396, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25908706

ABSTRACT

A novel Gram-stain-positive, coccoid, non-motile bacterium, designated strain AMV4T, was isolated from a soil sample collected from a mud volcano located in the Andaman Islands, India. The colony was pale orange. Strain AMV4T was positive for oxidase, aesculinase, lysine decarboxylase and ornithine decarboxylase activities and negative for amylase, catalase, cellulase, protease, urease and lipase activities. 16S rRNA gene sequence analysis indicated that strain AMV4T was a member of the order Actinomycetales and was closely related to Aquipuribacter hungaricus with a sequence similarity of 97.13% (pairwise alignment). Phylogenetic analyses showed that strain AMV4T clustered with Aquipuribacter hungaricus and was distantly related to the other genera of the family Intrasporangiaceae. DNA-DNA hybridization between strains AMV4T and Aquipuribacter hungaricus IV-75T showed a relatedness of 28%. The predominant cellular fatty acids were iso-C15 : 0 (6.9%), anteiso-C15 : 0 (25.3%), C16 : 0 (12.9%), anteiso-C16 : 0 (5.6%), C18 : 1ω9c (19.8%) and C18 : 3ω6,9,12c (9.1%). The diagnostic diamino acid in the cell-wall peptidoglycan of strain AMV4T was meso-diaminopimelic acid. Strain AMV4T contained MK-10(H4) as the predominant respiratory quinone. The polar lipids consisted of phosphatidylglycerol, one unidentified glycolipid, two unidentified phospholipids and five unidentified lipids. The DNA G+C content of strain AMV4T was 74.3 mol%. Based on data from this taxonomic study using a polyphasic approach, it is proposed that strain AMV4T represents a novel species of the genus Aquipuribacter, with the suggested name Aquipuribacter nitratireducens sp. nov. The type strain is AMV4T ( = CCUG 58430T = DSM 22863T = NBRC 107137T).


Subject(s)
Actinomycetales/classification , Phylogeny , Soil Microbiology , Actinomycetales/genetics , Actinomycetales/isolation & purification , Bacterial Typing Techniques , Base Composition , Cell Wall/chemistry , DNA, Bacterial/genetics , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry , Glycolipids/chemistry , India , Molecular Sequence Data , Nucleic Acid Hybridization , Peptidoglycan/chemistry , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/chemistry
12.
Lett Appl Microbiol ; 58(4): 370-5, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24330032

ABSTRACT

UNLABELLED: To determine the detection limits of the SystemSure Plus, Escherichia coli and Staphylococcus aureus growth curve samples were taken in lag (1 h), log (6 h), stationary (12 h) and death phases (E. coli 144 h, Staph. aureus 72 h). At each time point, the log10 CFU ml(-1) was determined for the dilution where the SystemSure read 0 relative light units (RLU). Average detection limits were E. coli: lag 6·27, log 5·88, stationary 7·45 and death 6·88; Staph. aureus: lag 4·37, log 5·15, stationary 7·88 and death 7·57. Between-run precision was determined with positive control; within-run precision with positive control, lag and log growth for each bacteria. Within-run precision mean RLU (CV): positive control 274 (12%), E. coli lag 1 (63%), log 2173 RLU (19%), Staph. aureus lag 2 (58%) and log 5535 (18%). Between-run precision was 232 (16%). The precision is adequate with most values within the 95% confidence interval. The detection limit varied by 3·51 log10 for Staph. aureus and 1·47 log10 for E. coli. The lowest detection limits were during E. coli log and Staph. aureus lag phases; the highest was during stationary phase. These results suggest that organism identification and growth phase both impact ATP RLU readings. SIGNIFICANCE AND IMPACT OF THE STUDY: Surface hygiene is a critical component of food safety and infection control; increasingly, ATP detection by bioluminescence is used to evaluate surface hygiene and effective cleaning. This is the first study to show that the number of living and potentially infectious bacteria remaining when the device reads zero varies between the different bacterial life cycle phases: lag, log, stationary and death. ATP device users need to be aware of this information to use the devices appropriately.


Subject(s)
Adenosine Triphosphate/analysis , Bacteria/isolation & purification , Luminescent Measurements/methods , Bacteria/growth & development , Escherichia coli/growth & development , Escherichia coli/isolation & purification , Limit of Detection , Staphylococcus aureus/growth & development , Staphylococcus aureus/isolation & purification
13.
Br Dent J ; 215(3): 104-5, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23928584
14.
Int J Syst Evol Microbiol ; 59(Pt 9): 2333-8, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19620368

ABSTRACT

A spherical-shaped, phototrophic, purple sulfur bacterium was isolated in pure culture from anoxic sediment in a marine aquaculture pond near Bheemli (India). Strain JA142T is Gram-negative and non-motile. It has a requirement for NaCl (optimum of 2% and maximum of 6% w/v NaCl). Intracellular photosynthetic membranes are of the vesicular type. In vivo absorption spectra indicate the presence of bacteriochlorophyll a and carotenoids of the okenone series as photosynthetic pigments. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA142T is related to halophilic purple sulfur bacteria of the genera Thiohalocapsa and Halochromatium, with the highest sequence similarity to Thiohalocapsa halophila DSM 6210T (97.5%). Morphological and physiological characteristics differentiate strain JA142T from other species of the genera Halochromatium and Thiohalocapsa. Strain JA142T is sufficiently different from Thiohalocapsa halophila based on 16S rRNA gene sequence analysis and morphological and physiological characteristics to allow the proposal of a novel species, Thiohalocapsa marina sp. nov., with the type strain JA142T (=JCM 14780T=DSM 19078T).


Subject(s)
Chromatiaceae/classification , Chromatiaceae/isolation & purification , Geologic Sediments , Aquaculture , Bacterial Typing Techniques , Bacteriochlorophyll A/analysis , Carotenoids/analysis , Cell Membrane/ultrastructure , Chromatiaceae/genetics , Chromatiaceae/physiology , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , India , Molecular Sequence Data , Photosynthesis , Phylogeny , Pigments, Biological/biosynthesis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sodium Chloride/metabolism
15.
J Pharm Biomed Anal ; 11(6): 489-93, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8399520

ABSTRACT

The chemical stability of 2',3'-dideoxyinosine has been studied over a wide pH range (0-12). A stability-indicating HPLC method was used to separate the degradation product from the parent drug. The effects of temperature, ionic strength and buffer components on the degradation kinetics were investigated. Furthermore, the influence of some cyclodextrins (alpha-, beta-, HP-beta-, DM-beta- and gamma-cyclodextrin) on the drug stability have been studied.


Subject(s)
Cyclodextrins/chemistry , Didanosine/chemistry , Buffers , Chromatography, High Pressure Liquid , Drug Stability , Hydrogen-Ion Concentration , Kinetics , Osmolar Concentration , Temperature
17.
J Pharm Biomed Anal ; 9(10-12): 1055-60, 1991.
Article in English | MEDLINE | ID: mdl-1822173

ABSTRACT

The effects of cyclodextrins on the chemical stability of several mitomycin antibiotics in an alkaline medium have been investigated. A stability-indicating high-performance liquid chromatographic method was used to determine the overall degradation rate constants. The influence of various parameters such as structural variations of the cyclodextrins and mitomycins, temperature and pH was studied. It appears that complexation is most favourable with gamma-cyclodextrin. All mitomycin-gamma-cyclodextrin complexes degrade at lower rates than those of the free drugs. Moreover, it was shown that gamma-cyclodextrin influences the equilibrium between mitomycin C and its zwitterion mesomer.


Subject(s)
Alkalies/chemistry , Cyclodextrins/chemistry , Mitomycins/chemistry , Buffers , Chromatography, Liquid , Circular Dichroism , Drug Stability , Hydrogen-Ion Concentration , Kinetics , Molecular Structure , Solutions , Spectrophotometry , Temperature
18.
J Hand Surg Am ; 8(6): 942-5, 1983 Nov.
Article in English | MEDLINE | ID: mdl-6643977

ABSTRACT

The lateral antebrachial cutaneous and digital nerves were compared by a histomorphometric method in each patient from a series of patients in whom a digital nerve was grafted with the lateral antebrachial cutaneous nerve as donor. Statistical analysis by the paired Student's test of paired data sets from all patients showed that there was no significant difference between the two nerves in regard to the following parameters: fascicular area, area of the entire nerve bundle, and percent of the nerve bundle occupied by the actual nerve fascicles. These data, together with other observations reported here, strongly support the hypothesis that the lateral antebrachial cutaneous nerve closely resembles the original fascicular pattern of the digital nerve and is, therefore, a highly suitable donor for the digital nerve.


Subject(s)
Fingers/innervation , Nerve Fibers/transplantation , Adult , Child , Female , Forearm/innervation , Humans , Male , Middle Aged , Skin/innervation
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