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1.
BMC Public Health ; 24(1): 461, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355456

RESUMO

BACKGROUND: The COVID-19 pandemic, extreme weather events, and the Russian invasion of Ukraine have highlighted global food system vulnerabilities and a lack of preparedness and prospective planning for increasingly complex disruptions. This has spurred an interest in food system resilience. Despite the elevated interest in food system resilience, there is a lack of comparative analyses of national-level food system resilience efforts. An improved understanding of the food system resilience landscape can support and inform future policies, programs, and planning. METHODS: We conducted a cross-country comparison of national-level food system resilience activities from Australia, Aotearoa New Zealand, Sweden, and the United States. We developed upon and adapted the resilience framework proposed by Harris and Spiegel to compare actions derived from thirteen national food system resilience documents. We coded the documents based on the actions taken by the governments including: the food system resilience attributes utilized, the part of the food supply chain, the specific shocks or stressors, the implementation level, the temporal focus of action, and the expected impact on food security. We analyzed and compared countries' coded categories and subcategories, and category combinations. RESULTS: The results showed that these countries are addressing some of the same issues, are using multi-pronged policy actions to address food system resilience issues, and are focused on both retrospective reviews and prospective models of disruptive events to inform their decisions. Some work has been done towards preparing for climate change and other natural disasters, and less preparing has been done for other shocks or stressors. CONCLUSIONS: This paper develops and applies a framework rooted in literature to understand the content of national-level food system resilience documents. The analysis identified potential gaps, concentrations, and themes in national food systems resilience. The framework can be applied to augment existing policy, create new policy, as well as to supplement and complement other existing frameworks.


Assuntos
Resiliência Psicológica , Humanos , Países Desenvolvidos , Pandemias/prevenção & controle , Estudos Retrospectivos , Abastecimento de Alimentos
2.
BMC Infect Dis ; 18(1): 377, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-30086729

RESUMO

BACKGROUND: The emergence and spread of antibiotic resistant micro-organisms is a global concern, which is largely attributable to inaccurate prescribing of antibiotics to patients presenting with non-bacterial infections. The use of 'omics' technologies for discovery of novel infection related biomarkers combined with novel treatment algorithms offers possibilities for rapidly distinguishing between bacterial and viral infections. This distinction can be particularly important for patients suffering from lower respiratory tract infections (LRTI) and/or sepsis as they represent a significant burden to healthcare systems. Here we present the study details of the TAILORED-Treatment study, an observational, prospective, multi-centre study aiming to generate a multi-parametric model, combining host and pathogen data, for distinguishing between bacterial and viral aetiologies in children and adults with LRTI and/or sepsis. METHODS: A total number of 1200 paediatric and adult patients aged 1 month and older with LRTI and/or sepsis or a non-infectious disease are recruited from Emergency Departments and hospital wards of seven Dutch and Israeli medical centres. A panel of three experienced physicians adjudicate a reference standard diagnosis for all patients (i.e., bacterial or viral infection) using all available clinical and laboratory information, including a 28-day follow-up assessment. Nasal swabs and blood samples are collected for multi-omics investigations including host RNA and protein biomarkers, nasal microbiota profiling, host genomic profiling and bacterial proteomics. Simplified data is entered into a custom-built database in order to develop a multi-parametric model and diagnostic tools for differentiating between bacterial and viral infections. The predictions from the model will be compared with the consensus diagnosis in order to determine its accuracy. DISCUSSION: The TAILORED-Treatment study will provide new insights into the interplay between the host and micro-organisms. New host- or pathogen-related biomarkers will be used to generate a multi-parametric model for distinguishing between bacterial and viral infections. This model will be helpful to better guide antimicrobial therapy for patients with LRTI and sepsis. This study has the potential to improve patient care, reduce unnecessary antibiotic prescribing and will contribute positively to institutional, national and international healthcare economics. TRIAL REGISTRATION: NCT02025699 . Registration Date: January, 1, 2014.


Assuntos
Infecções Bacterianas/diagnóstico , Infecções Respiratórias/diagnóstico , Sepse/diagnóstico , Viroses/diagnóstico , Adolescente , Adulto , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos , Infecções Bacterianas/tratamento farmacológico , Biomarcadores/análise , Biomarcadores/sangue , Criança , Pré-Escolar , Diagnóstico Diferencial , Serviço Hospitalar de Emergência , Feminino , Hospitalização/estatística & dados numéricos , Interações Hospedeiro-Parasita , Humanos , Lactente , Masculino , Microbiota , Estudos Prospectivos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Fatores de Risco , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/virologia , Viroses/tratamento farmacológico , Adulto Jovem
3.
Eur J Clin Microbiol Infect Dis ; 36(2): 351-359, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27744605

RESUMO

Fifty-two Pseudomonas strains that were difficult to identify at the species level in the phenotypic routine characterizations employed by clinical microbiology laboratories were selected for genotypic-based analysis. Species level identifications were done initially by partial sequencing of the DNA dependent RNA polymerase sub-unit D gene (rpoD). Two other gene sequences, for the small sub-unit ribosonal RNA (16S rRNA) and for DNA gyrase sub-unit B (gyrB) were added in a multilocus sequence analysis (MLSA) study to confirm the species identifications. These sequences were analyzed with a collection of reference sequences from the type strains of 161 Pseudomonas species within an in-house multi-locus sequence analysis database. Whole-cell matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses of these strains complemented the DNA sequenced-based phylogenetic analyses and were observed to be in accordance with the results of the sequence data. Twenty-three out of 52 strains were assigned to 12 recognized species not commonly detected in clinical specimens and 29 (56 %) were considered representatives of at least ten putative new species. Most strains were distributed within the P. fluorescens and P. aeruginosa lineages. The value of rpoD sequences in species-level identifications for Pseudomonas is emphasized. The correct species identifications of clinical strains is essential for establishing the intrinsic antibiotic resistance patterns and improved treatment plans.


Assuntos
Filogenia , Infecções por Pseudomonas/microbiologia , Pseudomonas/classificação , Pseudomonas/isolamento & purificação , Análise por Conglomerados , DNA Girase/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , RNA Polimerases Dirigidas por DNA/genética , Genótipo , Humanos , Tipagem de Sequências Multilocus , Fenótipo , Pseudomonas/química , Pseudomonas/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
4.
Int J Syst Evol Microbiol ; 64(Pt 2): 392-399, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24065772

RESUMO

Four Gram-staining-negative, catalase- and oxidase-positive, pale-orange pigmented bacterial strains (435-08(T), 47B-3-09, 412R-09(T) and 60B-3-09) were isolated from diseased rainbow trout. Analysis of their 16S rRNA gene sequences suggested their adscription to the genus Flavobacterium. Strains formed two phylogenetic groups represented by strains 435-08(T) and 47B-3-09 (group A), and strains 412R-09(T) and 60B-3-09 (group B) displaying 16S rRNA sequence similarities greater than 99.8-99.9% within their respective groups. Strain 435-08(T) exhibited the highest levels of similarity with Flavobacterium aquidurense WB-1.1.56(T) (98.6% sequence similarity) and strain 412R-09(T) with Flavobacterium frigidimaris KUC-1(T) and Flavobacterium aquidurense WB-1.1.56(T) (98.9% and 98.6% sequence similarity, respectively). DNA-DNA hybridization studies showed low levels of relatedness between strain 435-08(T) and strain 412R-09(T) and between both strains and the most closely related species of the genus Flavobacterium. The genomic DNA G+C contents of strains 435-08(T) and 412R-09(T) were 36.2 and 34.3 mol%, respectively. The predominant respiratory quinone of both strains was MK-6 and the major fatty acids were iso-C(15 : 0), C(16 : 1)ω7c and C(15 : 0). The two groups of strains could be distinguished from each other and from related species of the genus Flavobacterium by a number of phenotypic properties. Phylogenetic, genotypic and phenotypic evidence indicated that strains of groups A and B represent two novel species of the genus Flavobacterium, for which the names Flavobacterium tructae sp. nov. (type strain 435-08(T) = CECT 7791(T) = CCUG 60100(T)) and Flavobacterium piscis sp. nov. (type strain 412R-09(T) = CECT 7911(T) = CCUG 60099(T)) are proposed.


Assuntos
Flavobacterium/classificação , Oncorhynchus mykiss/microbiologia , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacterium/genética , Flavobacterium/isolamento & purificação , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espanha , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
J Hosp Infect ; 145: 165-173, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286237

RESUMO

BACKGROUND: Population-based sewage surveillance has emerged as a promising approach for studying the prevalence of antibiotic resistance in pathogens. AIM: To determine the temporal prevalence of cefotaxime-resistant Escherichia coli in sewage from five sewage treatment plants located in Bergen city, to determine whether ESBL- and carbapenemase-producing E. coli are consistently disseminated in the receiving environment through sewage. METHOD: A total of 569 cefotaxime-resistant E. coli were isolated over a period of 19 months (August 2020 to February 2022) using ECC CHROMagar™ plates from 82 samples, antibiotic sensitivity profiles were determined, using Sensititre™ plates. The draft genome sequences were determined, using Illumina MiSeq-based sequencing. Complete genome sequences were determined, using Oxford Nanopore-based sequencing. FINDINGS: All 569 strains obtained from influent (N=461) and effluent (N=108) were multi-drug resistant. Most of the sequenced strains (52 of 61) carried blaCTX-M-15 (38.5%) and blaCTX-M-27 (34.6%). The most prevalent sequence types (STs) for ESBL-carrying strains were ST131 (32.8%) and ST38 (21.3%). All CTX-M-27-carrying ST131 strains belonged to clade A or C1, while CTX-M-15-harbouring strains were present in all the clades. Five OXA-244-producing ST38 strains, genetically similar to epidemic-causing strains from Western Norway, France and the Netherlands, were isolated only from raw and treated sewage of the treatment plant receiving hospital sewage. CONCLUSION: This is the first study showing persistent dissemination of OXA-244-producing ST38 clones through sewage in Norway, demonstrating that hospital sewage is the likely source of OXA-244-producing ST38 clones reaching the receiving environment.


Assuntos
Proteínas de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Escherichia coli , Humanos , Escherichia coli/genética , Esgotos , Infecções por Escherichia coli/epidemiologia , beta-Lactamases/genética , Antibacterianos , Cefotaxima , Hospitais , Testes de Sensibilidade Microbiana
6.
Glob Food Sec ; 37: 100693, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37155430

RESUMO

In Honduras, as in many settings between 2020 and 2022, food security was affected by the COVID-19 pandemic, climate change, and conflicts-what some refer to as "The Three Cs." These challenges have had overlapping impacts on food supply chains, food assistance programs, food prices, household purchasing power, physical access to food, and food acceptability. This article applies a food system disruption analysis-adapted from a fault tree analysis originally developed for a municipal context in the United States-to the context of Honduras to systematically examine how the Three Cs affected food availability, accessibility, and acceptability. This article demonstrates the value of approaching food security through a disruption analysis, especially for settings impacted by multiple, interconnected, ongoing crises.

7.
Int J Syst Evol Microbiol ; 62(Pt 12): 2934-2940, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22268076

RESUMO

A taxonomic study was carried out on five Gram-staining-negative, catalase- and oxidase-positive, rod-shaped bacteria isolated from the gills and livers of five diseased rainbow trout. The five novel isolates were designated strains 687B-08(T), 445-08, 452-08, 453B-08 and 967B-08. In phylogenetic analyses based on 16S rRNA gene sequences, the five novel strains appeared almost identical (99.0-100 % sequence similarity) and to belong to the genus Chryseobacterium. Strain 687B-08(T) (the strain selected to represent the five novel isolates) was found to be most closely related to Chryseobacterium oncorhynchi 701B-08(T) (98.9% sequence similarity), Chryseobacterium ureilyticum F-Fue-04IIIaaaa(T) (98.6%), Chryseobacterium indologenes ATCC 29897(T) (98.3%), Chryseobacterium jejuense JS17-8(T) (98.1%) and Chryseobacterium gleum ATCC 35910(T) (98.1%). In DNA-DNA hybridizations, DNA-DNA relatedness values of 99-100% were recorded between the five novel strains. Lower DNA-DNA relatedness values (21-57%) were recorded between strain 687B-08(T) and C. oncorhynchi 701B-08(T), C. ureilyticum F-Fue-04IIIaaaa(T) and the type strains of other closely related, established species of the genus Chryseobacterium. The predominant respiratory quinone of strain 687B-08(T) was MK-6 and the major cellular fatty acids were iso-C(15:0), iso-C(17:1)ω9c, iso-C(17:0) 3-OH and C(16:1)ω6c. The G+C content of the genomic DNA of strain 687B-08(T) was 38.6 mol%. Based on the phenotypic and genotypic evidence, the five novel strains isolated from rainbow trout represent a single, novel species of the genus Chryseobacterium, for which the name Chryseobacterium viscerum sp. nov. is proposed. The type strain is 687B-08(T) ( = CECT 7793(T)  = CCUG 60103(T)).


Assuntos
Chryseobacterium/classificação , Oncorhynchus mykiss/microbiologia , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Chryseobacterium/genética , Chryseobacterium/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/análise , Doenças dos Peixes/microbiologia , Brânquias/microbiologia , Fígado/microbiologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
8.
J Dent Res ; 101(9): 1119-1126, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35403480

RESUMO

Dental pain is a persistent, detrimental public health issue that requires a better understanding of the mechanisms of tooth pain and inflammation in order to develop more effective treatments. Calcitonin gene-related peptide (CGRP) and dental pulp cells are promising candidates for mediating tooth pain and generating reparative dental tissues, respectively, but their behavior in the context of pulpitis remains elusive. The mouse incisor requires Sonic hedgehog (Shh) secreted from sensory nerves to continuously regenerate. However, it is unknown whether sensory nerves also regulate the comparatively nonregenerative mouse molar through CGRP and Shh. This is an important knowledge gap to fill since mouse incisors differ biologically from human teeth, while mouse and human molars are similar. In this work, we identified that molar pulp cells express CGRP receptor and Gli1, a Hedgehog (Hh) signaling protein found to label a dental stem cell population in the mouse incisor. We also observed in a mouse molar injury model that Hh signaling was activated and Shh expression was upregulated in vivo. We then determined in vitro that Shh and CGRP regulate differentiation of primary mouse molar and incisor pulp cells and a human dental pulp stem cell line. Furthermore, conditioned media from stimulated sensory neurons induced Hh signaling activation and inflammatory gene expression in primary molar pulp cells, which was abolished by inhibition of either Shh or CGRP. Our results suggest that CGRP and Shh signaling may promote an inflammatory response after injury in the molar and that activated sensory nerves secrete CGRP and Shh to regulate molar pulp cell expansion and differentiation into odontoblast-like cells for dentin repair. Thus, CGRP/Shh signaling should be considered for new strategies that seek to manage pain or dentin regeneration in the molar.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Polpa Dentária , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Polpa Dentária/metabolismo , Proteínas Hedgehog/metabolismo , Humanos , Incisivo , Camundongos , Neurônios Aferentes/metabolismo , Dor
9.
Mar Genomics ; 40: 13-17, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32420876

RESUMO

Rhodococcus sp. H-CA8f was isolated from marine sediments obtained from the Comau fjord, located in Northern Chilean Patagonia. Whole-genome sequencing was achieved using PacBio RS II platform, comprising one closed, complete chromosome of 6,19 Mbp with a 62.45% G + C content. The chromosome harbours several metabolic pathways providing a wide catabolic potential, where the upper biphenyl route is described. Also, Rhodococcus sp. H-CA8f bears one linear mega-plasmid of 301 Kbp and 62.34% of G + C content, where genomic analyses demonstrated that it is constituted mostly by putative ORFs with unknown functions, representing a novel genetic feature. These genetic characteristics provide relevant insights regarding Chilean marine actinobacterial strains.

10.
Cochrane Database Syst Rev ; (3): CD003519, 2007 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-17636727

RESUMO

BACKGROUND: Mother-infant separation postbirth is common in Western culture. Early skin-to-skin contact (SSC) begins ideally at birth and involves placing the naked baby, covered across the back with a warm blanket, prone on the mother's bare chest. According to mammalian neuroscience, the intimate contact inherent in this place (habitat) evokes neurobehaviors ensuring fulfillment of basic biological needs. This time may represent a psychophysiologically 'sensitive period' for programming future behavior. OBJECTIVES: To assess the effects of early SSC on breastfeeding, behavior, and physiological adaptation in healthy mother-newborn dyads. SEARCH STRATEGY: Cochrane Pregnancy and Childbirth Group's and Neonatal Group's Trials Registers (August 2006), Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 2), MEDLINE (1976 to 2006). SELECTION CRITERIA: Randomized and quasi-randomized clinical trials comparing early SSC with usual hospital care. DATA COLLECTION AND ANALYSIS: We independently assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Thirty studies involving 1925 participants (mother-infant dyads), were included. Data from more than two trials were available for only 8-of-64 outcome measures. We found statistically significant and positive effects of early SSC on breastfeeding at one to four months postbirth (10 trials; 552 participants) (odds ratio (OR) 1.82, 95% confidence interval (CI) 1.08 to 3.07), and breastfeeding duration (seven trials; 324 participants) (weighted mean difference (WMD) 42.55, 95% CI -1.69 to 86.79). Trends were found for improved summary scores for maternal affectionate love/touch during observed breastfeeding (four trials; 314 participants) (standardized mean difference (SMD) 0.52, 95% CI 0.07 to 0.98) and maternal attachment behavior (six trials; 396 participants) (SMD 0.52, 95% CI 0.31 to 0.72) with early SSC. SSC infants cried for a shorter length of time (one trial; 44 participants) (WMD -8.01, 95% CI -8.98 to -7.04). Late preterm infants had better cardio-respiratory stability with early SSC (one trial; 35 participants) (WMD 2.88, 95% CI 0.53 to 5.23). No adverse effects were found. AUTHORS' CONCLUSIONS: Limitations included methodological quality, variations in intervention implementation, and outcome variability. The intervention may benefit breastfeeding outcomes, early mother-infant attachment, infant crying and cardio-respiratory stability, and has no apparent short or long-term negative effects. Further investigation is recommended. To facilitate meta-analysis, future research should be done using outcome measures consistent with those in the studies included here. Published reports should clearly indicate if the intervention was SSC and include means, standard deviations, exact probability values, and data to measure intervention dose.


Assuntos
Aleitamento Materno , Relações Mãe-Filho , Apego ao Objeto , Tato/fisiologia , Feminino , Humanos , Lactente , Recém-Nascido , Mães , Ensaios Clínicos Controlados Aleatórios como Assunto , Pele
11.
Gene ; 236(1): 149-57, 1999 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-10433976

RESUMO

Pseudomonas stutzeri strain AN10 is a naphthalene-degrading strain whose dissimilatory genes are chromosomally encoded. We sequenced a total of 11514bp including the entire naphthalene-degradation upper pathway (nah) of P. stutzeri AN10. Nine open reading frames, nahAaAbAcAdBFCED, encoding the enzymes for the degradation of naphthalene to salicylate, were identified. The nah genes of P. stutzeri AN10 have been compared with genes encoding isofunctional proteins from other Pseudomonas naphthalene-degradation upper pathways. The implications of the sequence homologies to the evolution of aromatic catabolic pathways are discussed. Our findings indicate that this entire catabolic module of P. stutzeri AN10 was recruited from other microorganisms and a short period of time has elapsed after its incorporation within the P. stutzeri AN10 genome. Comparisons also suggest the coexistence of two entire nah upper pathways in a host strain, and further recombination between them. These events could accelerate the evolution of modern catabolic pathways.


Assuntos
Naftalenos/metabolismo , Pseudomonas/metabolismo , Pseudomonas/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Códon , Cosmídeos , Escherichia coli/metabolismo , Evolução Molecular , Modelos Químicos , Modelos Genéticos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Recombinação Genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
12.
Gene ; 245(1): 65-74, 2000 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-10713446

RESUMO

Pseudomonas stutzeri strain AN10 is a naphthalene-degrading strain whose dissimilatory genes are chromosomally encoded. We sequenced the entire naphthalene-degradation lower pathway of P. stutzeri AN10, this being, together with the upper-pathway reported previously (Bosch R. et al., 1999a. Gene 236, 149-157) the first complete DNA sequence for an entire naphthalene-catabolic pathway. Eleven open reading frames were identified. The nahGTHINLOMKJ genes encode enzymes for the metabolism of salicylate to pyruvate and acetyl-CoA, and nahR encodes the NahR regulatory protein. Our findings suggest that catabolic modules were recruited through transposition events and recombination among tnpA-like genes, and subsequent rearrangements and deletions of non-essential DNA fragments allowed the formation of the actual catabolic pathway. Our results also suggest that the genes encoding the xylene/toluene-degradation enzymes of P. putida mt-2 (pWW0) have coexisted with the nah genes of the P. stutzeri AN10 ancestral genome. This could allow the selection, via recombination events among homologous genes, for a combination of genes enabling the metabolism of a given aromatic compound in the ancestral host strain. Such events accelerate the evolution of modern catabolic pathways and provide new genetic material to the environment, ultimately resulting in improved, natural, bioremediation potential.


Assuntos
Cromossomos Bacterianos/genética , DNA Bacteriano/genética , Evolução Molecular , Naftalenos/metabolismo , Pseudomonas/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Mapeamento Cromossômico , Clonagem Molecular , DNA Bacteriano/química , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Óperon/genética , Regiões Promotoras Genéticas , Pseudomonas/metabolismo , Salicilatos/metabolismo , Análise de Sequência de DNA , Fatores de Transcrição/genética
13.
FEMS Microbiol Lett ; 151(2): 145-53, 1997 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9228747

RESUMO

The nearly complete, PCR-amplified, 16S rRNA gene sequences have been determined from the representative type strains of eight xanthomonad phena, including six validly described species of the genus Xanthomonas and Stenotrophomonas maltophilia. Pairwise sequence comparisons and phylogenetic analysis demonstrated that the xanthomonads comprise a monophyletic lineage-within the gamma-subclass of the Proteobacteria. Although the genus Xanthomonas was observed to comprise a cluster of very closely related species, the observed species-specific primary sequence differences were confirmed through sequencing additional strains belonging to the respective species.


Assuntos
DNA Ribossômico/química , RNA Ribossômico 16S/genética , Xanthomonas/classificação , Sequência de Bases , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Xanthomonas/genética
14.
Microb Ecol ; 39(3): 175-185, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12035094

RESUMO

A BSTRACTThe defense strategy of the aquatic bacterium Pseudomonas sp. MWH1 against flagellate grazing was investigated in chemostat and batch experiments. The influence of predation on the Pseudomonas population was studied in the absence and presence of a potential competitor ( Vibrio sp. CB5), as well as under starvation conditions and in a situation of unlimited growth. In the competition experiment the two bacterial strains were distinguished by immunofluorescence microscopy. When the Pseudomonas strain was cultured in the absence of the predator Ochromonas sp. DS, only mobile single cells were detectable. Grazing by this bacterivorous flagellate resulted in all experiments in the occurrence of a Pseudomonas subpopulation, which grew as floclike, suspended microcolonies. These microcolonies consisted of up to approximately 1,000 cells and were, because of their large size, protected against flagellate grazing. The microcolony subpopulation dominated the total Pseudomonas population in situations of high grazing pressure at a wide range of bacterial growth conditions. Thus, the formation of the microcolonies is interpreted as a successful grazing-defense strategy, which is effective under several growth conditions, allowing for the survival of the strain even when substrate depletion is combined with strong grazing pressure. Batch culture experiments demonstrated that the change in morphology of Pseudomonas sp. MWH1 is not controlled by growth rate, although no formation of microcolonies was observed after the addition of 0.2-&mgr;m-filtered flagellate cultures to Pseudomonas cultures, indicating that a chemical trigger released by the flagellate is not involved in the control of this defense mechanism.

15.
Microb Ecol ; 42(3): 295-305, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12024255

RESUMO

The Baltic Sea is an estuarine ecosystem where denitrification in the low oxic and anoxic parts of the deep water contributes significantly to the nitrogen budget. Seventy-six heterotrophic, denitrifying, strains have been isolated by four cultivation procedures from the water column of the Gotland Deep, the main anoxic basin of the Central Baltic. Phylogenetic positions of representative strains of 10 different genotypes, grouped beforehand by low molecular weight (LMW) RNA profiling, were estimated by 16S rRNA sequence analysis. The 10 genotypes consisted of two members of the alpha subclass of the Proteobacteria and eight members of the gamma subclass. The major fraction of the genotypes was considered to be novel species or even genera. The gamma-Proteobacteria were the most abundant of the denitrifying isolates (96% of the total isolates) with a predominance of Shewanella baltica (77%), whereas the alpha-Proteobacteria were represented by single isolates. The diversity spectrum of Baltic sea denitrifying isolates was rather distinct from that previously described for marine and freshwater environments. Denitrifying bacteria could be isolated from all depths of the water column with the highest diversity and abundance of genotypes detected in samples of the oxic-anoxic interface, the layer of high in situ denitrification. For success of isolation of phylogenetically divers denitrifiers, both sample origin and cultivation procedure were observed to have an impact.

16.
Syst Appl Microbiol ; 21(1): 135-43, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9741118

RESUMO

Two Gram-positive, obligately anaerobic, lipolytic bacteria, isolates LIP4 and LIP5, were obtained from the rumen contents of juvenile red deer. These mesophilic bacterial strains were capable of hydrolysing the neutral lipids, tallow, tripalmitin and oliver oil, into their constituent free long-chain fatty acid and glycerol moieties. The latter compound was dissimilated by both isolates, with isolate LIP4 producing propionate as the predominant product, while isolate LIP5 produced acetate, ethanol and succinate. The lactate-utilising isolate LIP4 grew on a limited range of saccharide substrates including glucose, fructose and ribose, and exhibited an unusual cell wall structure and morphology. The isolate LIP5 grew upon a wider range of saccharides, but was unable to use lactate as a substrate. Based upon phenotypic and 16S rRNA gene sequence analyses, isolate LIP4 clusters with species in the genus Propionibacterium, while isolate LIP5 is a member of clostridial cluster XIVa.


Assuntos
Bactérias Anaeróbias/isolamento & purificação , Clostridium/isolamento & purificação , Cervos/microbiologia , Metabolismo dos Lipídeos , Propionibacterium/isolamento & purificação , Rúmen/microbiologia , Animais , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/metabolismo , Sequência de Bases , Clostridium/classificação , Clostridium/crescimento & desenvolvimento , Clostridium/metabolismo , Meios de Cultivo Condicionados , DNA Ribossômico/análise , Ecologia , Dados de Sequência Molecular , Filogenia , Propionibacterium/classificação , Propionibacterium/crescimento & desenvolvimento , Propionibacterium/metabolismo , RNA Ribossômico 16S/genética , Rúmen/metabolismo , Alinhamento de Sequência
17.
Syst Appl Microbiol ; 23(4): 487-93, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11249018

RESUMO

The taxonomic status of a gram-negative, oxidase positive rod (strain S1) able to degrade 4-aminobenzenesulfonate was studied using a polyphasic approach. Chemotaxonomic investigations of quinones and polar lipids established the allocation of this strain to the beta-subclass of the Proteobacteria and revealed similarities to Hydrogenophaga palleronii. 16S rRNA sequence comparisons demonstrated that this strain clusters phylogenetically with H. palleronii and H. taeniospiralis, but clearly represents a new species. The fatty acid patterns and substrate utilization profile displayed similarity to the characteristics of the four validly published species of Hydrogenophaga, although clear differentiating characters were also observed. No close similarities between the type strains of H. palleronii and H. taeniospiralis were detected in hybridization experiments with the genomic DNAs. On basis of these results, the new species Hydrogenophaga intermedia sp. nov. is proposed, with the type strain S1T (= DSM 5680).


Assuntos
Betaproteobacteria/classificação , Técnicas de Tipagem Bacteriana , Betaproteobacteria/genética , Betaproteobacteria/metabolismo , Betaproteobacteria/ultraestrutura , Biodegradação Ambiental , Meios de Cultura , DNA Ribossômico/análise , DNA Ribossômico/genética , Evolução Molecular , Bactérias Aeróbias Gram-Negativas/classificação , Bactérias Aeróbias Gram-Negativas/enzimologia , Dados de Sequência Molecular
18.
Syst Appl Microbiol ; 22(1): 68-78, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10188280

RESUMO

Resin acids are tricyclic diterpenes which are synthesized by trees and are a major cause of toxicity of pulp mill effluents. Bacterial strains isolated from three different sources and which grow on resin acids were physiologically characterized. Eleven strains, representating distinct groups, were further characterized physiologically and phylogenetically. The isolates had distinct specificities for use, as growth substrates, of the different resin acids tested. The isolates also used fatty acids but were generally limited in use of other diverse substrates tested. According to their 16S rDNA sequences, the representative isolates are related to members of the genera, Sphingomonas, Zoogloea, Ralstonia, Burkholderia, Pseudomonas and Mycobacterium. Analysis of whole-cell fatty acid profiles generally supported those phylogenetic relationships. However, most of the isolated did not have high similarities to reference strains in the Microbial Identification System database of fatty acid profiles or in the Biolog database of substrate oxidation patterns. Described species of Sphingomonas, Zoolgoea, Burkholderia Pseudomonas, most closely related to the isolates we characterized, failed to grow on, or degrade, resin acids. We propose recognition of Zoogloea resiniphila sp. nov., Pseudomonas vancouverensis sp. nov., P. abietaniphila sp. nov. and P. multiresinivorans sp. nov.


Assuntos
Bactérias Aeróbias/classificação , Diterpenos/metabolismo , Bactérias Aeróbias/química , Bactérias Aeróbias/isolamento & purificação , DNA Ribossômico/química , Ácidos Graxos/análise , Filogenia , Pseudomonas/classificação , RNA Ribossômico 16S/genética , Zoogloea/classificação
19.
Syst Appl Microbiol ; 21(3): 384-97, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9779605

RESUMO

The almost complete 16S rDNA sequences of twenty nine plant-associated strains, representing species of the genera Erwinia, Pantoea and Enterobacter were determined and compared with those of other members of the Enterobacteriaceae. The species of the genus Erwinia may be divided into three phylogenetic groups. Cluster I represents the true erwinias and comprises E. amylovora, E. mallotivora, E. persicinus, E. psidii, E. rhapontici and E. tracheiphila. We propose to unite the species of cluster II, E. carotovora subsp. atroseptica, E. carotovora subsp. betavasculorum, E. carotovora subsp. carotovora, E. carotovora subsp. odorifera, E. carotovora subsp. wasabiae, E. cacticida, E. chrysanthemi and E. cypripedii in the genus Pectobacterium respectively as P. carotovorum subsp. atrosepticum comb. nov., P. carotovorum subsp. betavasculorum comb. nov., P. carotovorum subsp. carotovorum comb. nov., P. carotovorum subsp. odoriferum comb. nov., P. carotovorum subsp. wasabiae comb. nov., P. cacticidum comb. nov., P. chrysanthemi and P. cypripedii. The species E. alni, E. nigrifluens, E. paradisiaca, E. quercina, E. rubrifaciens and E. salicis, comprising cluster III, are being classified into a new genus Brenneria gen. nov. respectively as B. alni comb. nov., B. nigrifluens comb. nov., B. paradisiaca comb. nov., B. quercina comb. nov., B. rubrifaciens comb. nov. and B. salicis comb. nov. The species of the genus Pantoea, included in this study, form a monophyletic unit (cluster IV), closely related with Erwinia, whereas the three phytopathogenic species of the genus Enterobacter are scattered among the genera Citrobacter and Klebsiella.


Assuntos
Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Filogenia , Doenças das Plantas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Especificidade da Espécie
20.
J Ind Microbiol Biotechnol ; 23(4-5): 353-358, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11423955

RESUMO

We have studied the concerted degradation of two monochlorodibenzofurans by a bacterial consortium, consisting of the chlorodibenzofurans-cometabolizing and chlorosalicylates-excreting strain Sphingomonas sp RW16, and Pseudomonas sp RW10, which mineralized the released chlorosalicylates. Neither of the organisms was able to grow with chlorodibenzofurans alone. Degradation of 2-chloro- and 3-chlorodibenzofuran proceeded to the end products 5-chloro- and 4-chlorosalicylate, respectively, when the initial dioxygenase of Sphingomonas sp RW 16 attacked the unchlorinated aromatic ring of the heterocyclic dibenzofuran molecule. 2-Hydroxypenta-2,4-dienoate, formed upon meta-cleavage of the intermediary chlorotrihydroxybiphenyls, served as a growth substrate for the sphingomonad. Presumably, most of the chlorosalicylates were excreted and degraded further by Pseudomonas sp RW10. Mineralization of both chlorosalicylates proceeded through a converging pathway, via 4-chlorocatechol, and protoanemonin. Chlorosalicylates were mineralized by the pseudomonad only when their concentration in the culture medium was below 1.5 mM. In the case of initial dioxygenation taking place on the chlorinated aromatic ring, salicylate and chlorinated hydroxypentadienoates should be formed. The metabolic fate of putative chlorohydroxypentadienoates is not clear; ie, they may be channeled into unproductive catabolism and, thus, represent the critical point in the breakdown of the carbon of these two chlorodibenzofurans by Sphingomonas sp RW16.

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