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1.
Nat Commun ; 11(1): 4522, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908144

RESUMO

A unique, protective cell envelope contributes to the broad drug resistance of the nosocomial pathogen Acinetobacter baumannii. Here we use transposon insertion sequencing to identify A. baumannii mutants displaying altered susceptibility to a panel of diverse antibiotics. By examining mutants with antibiotic susceptibility profiles that parallel mutations in characterized genes, we infer the function of multiple uncharacterized envelope proteins, some of which have roles in cell division or cell elongation. Remarkably, mutations affecting a predicted cell wall hydrolase lead to alterations in lipooligosaccharide synthesis. In addition, the analysis of altered susceptibility signatures and antibiotic-induced morphology patterns allows us to predict drug synergies; for example, certain beta-lactams appear to work cooperatively due to their preferential targeting of specific cell wall assembly machineries. Our results indicate that the pathogen may be effectively inhibited by the combined targeting of multiple pathways critical for envelope growth.


Assuntos
Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Infecção Hospitalar/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Parede Celular/metabolismo , Infecção Hospitalar/microbiologia , Análise Mutacional de DNA , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade Microbiana , Mutação
2.
Korean J Parasitol ; 58(4): 445-450, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32871638

RESUMO

Trombiculid "chigger" mites (Acari) are ectoparasites that feed blood on rodents and another animals. A crosssectional survey was conducted in 7 ecosystems of southern Vietnam from 2015 to 2016. Chigger mites were identified with morphological characteristics and assayed by polymerase chain reaction for detection of rickettsiaceae. Overall chigger infestation among rodents was 23.38%. The chigger index among infested rodents was 19.37 and a mean abundance of 4.61. A total of 2,770 chigger mites were identified belonging to 6 species, 3 genera, and 1 family, and pooled into 141 pools (10-20 chiggers per pool). Two pools (1.4%) of the chiggers were positive for Orientia tsutsugamushi. Ricketsia spp. was not detected in any pools of chiggers. Further studies are needed including a larger number and diverse hosts, and environmental factors to assess scrub typhus.


Assuntos
Orientia tsutsugamushi/isolamento & purificação , Roedores/parasitologia , Trombiculidae/microbiologia , Animais , Estudos Transversais , DNA Bacteriano/genética , Orientia tsutsugamushi/genética , Reação em Cadeia da Polimerase/métodos , Tifo por Ácaros/microbiologia , Trombiculidae/genética , Vietnã
3.
Nat Commun ; 11(1): 4379, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873785

RESUMO

The gut microbiome harbors a 'silent reservoir' of antibiotic resistance (AR) genes that is thought to contribute to the emergence of multidrug-resistant pathogens through horizontal gene transfer (HGT). To counteract the spread of AR, it is paramount to know which organisms harbor mobile AR genes and which organisms engage in HGT. Despite methods that characterize the overall abundance of AR genes in the gut, technological limitations of short-read sequencing have precluded linking bacterial taxa to specific mobile genetic elements (MGEs) encoding AR genes. Here, we apply Hi-C, a high-throughput, culture-independent method, to surveil the bacterial carriage of MGEs. We compare two healthy individuals with seven neutropenic patients undergoing hematopoietic stem cell transplantation, who receive multiple courses of antibiotics, and are acutely vulnerable to the threat of multidrug-resistant infections. We find distinct networks of HGT across individuals, though AR and mobile genes are associated with more diverse taxa within the neutropenic patients than the healthy subjects. Our data further suggest that HGT occurs frequently over a several-week period in both cohorts. Whereas most efforts to understand the spread of AR genes have focused on pathogenic species, our findings shed light on the role of the human gut microbiome in this process.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Microbioma Gastrointestinal/genética , Transferência Genética Horizontal , Genes Bacterianos/efeitos dos fármacos , Adulto , Idoso , Antibacterianos/uso terapêutico , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Microbioma Gastrointestinal/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Sequências Repetitivas Dispersas/efeitos dos fármacos , Pessoa de Meia-Idade
4.
BMC Infect Dis ; 20(1): 657, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894079

RESUMO

BACKGROUND: Tuberculosis is still a significant diagnostic and therapeutic challenge with high proportion of smear- and culture- negative incidences worldwide. The conventional diagnostic tests are time-consuming and have a low sensitivity. Digital PCR is a novel technology which can detect target sequences with relatively low abundance and obtain the absolute copy numbers of the targets. METHODS: We assessed the accuracy of dPCR in TB diagnosis using more than 250 specimens, and for the first time, we selected M.tuberculosis-specific IS1081 in addition to widely used IS6110 as the amplification targets for dPCR. The quantification of target DNA was calculated using QuantaSoft Version 1.7.4.0917 (BioRad), and SPSS version 13.0 software (SPSS Inc., Chicago, IL, USA) was used for statistical analyses. RESULTS: IS6110-dPCR was more sensitive than IS1081, with the sensitivity and specificity accounting for 40.6 and 93.4% respectively. When we classified the TB patients by personal factors for high copy number of M.tuberculosis derived DNA in plasma: bilateral TB, extrapulmonary TB and disseminated TB, the sensitivity of both IS6110- and IS1081- dPCR was the highest in patients with disseminated TB (IS6110, 100%; IS1081, 68.8%), while their sensitivity was a bit higher in patients with extrapulmonary TB (IS6110, 50.0%; IS1081, 39.3%) than that in bilateral TB (IS6110, 43.3%; IS1081, 33.3%). Compared with traditional TB diagnostic tests, joint detection IS6110 & IS1081-dPCR was not as sensitive as smear microscope or mycobacterial culture, but it was higher than IS6110 qPCR (p < 0.05) and was able to detect 47.4% of smear-negative TB patients. CONCLUSION: Our study suggested that plasma IS6110-dPCR is a rapid, moderate accurate and less-invasive method to detect M.tuberculosis DNA in plasma of TB patients and IS6110 & IS1081-dPCR has a potential to aid diagnosis of smear-negative TB.


Assuntos
Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Tuberculose Pulmonar/diagnóstico , Adolescente , Adulto , Idoso , DNA Bacteriano/sangue , Confiabilidade dos Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
5.
Plant Dis ; 104(10): 2606-2612, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32813613

RESUMO

The 16SrIV-A phytoplasmas are associated with the devastating disease lethal yellowing (LY) of palms. In Tabasco (Mexico), the death of Cocos nucifera, Adonidia merrillii, and Attalea butyracea palms have been suspected to be associated with LY based on symptomatology. Samples from the trunk of both symptomatic and nonsymptomatic palms were collected in three different environments: two species of palms within a rural zone and the other within an urban zone. DNA was extracted to perform a nested PCR with phytoplasma primers P1/P7-LY16SF/R16R2. A 1,345-bp fragment was amplified from the DNA extracted from each of the 29 LY-symptomatic palms sampled. Phytoplasma identification was achieved by amplicon sequencing and virtual restriction fragment length polymorphism analyses. Three 16SrIV phytoplasma subgroups were detected: 16SrIV-A in C. nucifera, 16SrIV-B in A. merrillii, and 16SrIV-D in C. nucifera, A. merrillii, and A. butyracea. Phylogenetic analysis showed also that the three phytoplasma strains found in the palm species clustered with phytoplasmas reported in the literature in the three subgroups identified. This is the first report of phytoplasmas associated with these palm species in Tabasco.


Assuntos
Phytoplasma/genética , DNA Bacteriano/genética , México , Filogenia , Doenças das Plantas
6.
PLoS One ; 15(8): e0236054, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750053

RESUMO

INTRODUCTION: Multi-drug resistance is a major challenge in the control of tuberculosis. Despite newer modalities for diagnosis and treatment, people are still suffering from this disease. Understanding the common gene mutations conferring rifampicin and isoniazid resistance is crucial for the implementation of effective molecular tools at local and national levels. Hence, this study aimed to evaluate the molecular detection of rifampicin and isoniazid-resistant gene mutations in M.tuberculosis isolates in Addis Ababa, Ethiopia. METHOD: Health Center-based cross-sectional study was conducted between January and September 2017 in Addis Ababa, Ethiopia. The collected sputum samples were processed for mycobacterial isolation and Region of difference 9 based polymerase chain reaction for species identification. To characterize the rifampicin and isoniazid-resistant M. tuberculosis isolates, a molecular genetic assay (GenoType MTBDRplus) was used; the assay is based on DNA-STRIP technology. RESULT: Culture positivity was confirmed in 82.6% (190/230) of smear-positive newly diagnosed pulmonary tuberculosis cases enrolled in the study. From 190 isolates 93.2% were sensitive for both rifampicin and isoniazid, and 6.8% of the isolates were resistant to at least one of the tested anti-TB drugs. Gene mutations were observed in all studied multidrug resistance-associated gene loci (rpoB, katG, and inhA). Two isolates exhibited heteroresistance, a mutated, as well as wild type sequences, were detected in the respective strains. MDR-TB case was observed in 1.1% (2/190) of the cases. All the MDR-TB cases were positive for HIV and found to have a history of prior hospital admission. CONCLUSION: In our finding a relatively high prevalence of any drug resistance was observed and the overall prevalence of multidrug-resistant tuberculosis was 1.1%.The majority of drug-resistant isolates demonstrated common mutations. Heteroresistant strains were detected, signaling the existence of an M.tuberculosis population with variable responses to anti-tuberculosis drugs or of mixed infections.


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adolescente , Adulto , Antituberculosos/uso terapêutico , Estudos Transversais , Análise Mutacional de DNA , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Etiópia , Feminino , Genes Bacterianos/genética , Loci Gênicos/genética , Humanos , Isoniazida/farmacologia , Isoniazida/uso terapêutico , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mutação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase , Rifampina/farmacologia , Rifampina/uso terapêutico , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto Jovem
7.
PLoS One ; 15(8): e0237345, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813724

RESUMO

BACKGROUND: Mixed/polyclonal infections due to different genotypes are reported in Tuberculosis. The current study was designed to understand the fate of mixed infections during the course of treatment and follow-up and its role in disease pathogenesis. METHODS: Sputum samples were collected on 0,1,2,3,6,12 and 24 months from 157 treatment-naïve patients, cultures subjected to Drug-Susceptibility-testing (MGIT 960), spoligotyping, MIRU-VNTR and SNP genotyping. All isolated colonies on thin layer agar (7H11) were subjected to spoligotyping. FINDINGS: One thirty three baseline cultures were positive (133/157, 84.7%), 43(32.3%) had mixture of genotypes. Twenty-four of these patients (55.8%) showed change in genotype while six showed different drug-susceptibility patterns while on treatment. Twenty-three (53.5%) patients with polyclonal infections showed resistance to at least one drug compared to 10/90 (11.1%) monoclonal infections (P<0.0001). Eight patients had recurrent TB, two with a new genotype and two with altered phenotypic DST. CONCLUSIONS: The coexistence of different genotypes and change of genotypes during the same disease episode, while on treatment, confirms constancy of polyclonal infections. The composition of the mixture of genotypes and the relative predominance may be missed by culture due to its limit of detection. Polyclonal infections in TB could be a rule rather than exception and challenges the age-old dogma of reactivation/reinfection.


Assuntos
Antituberculosos/farmacologia , Coinfecção/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/genética , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Antituberculosos/uso terapêutico , Técnicas de Tipagem Bacteriana , Evolução Clonal , Coinfecção/epidemiologia , Coinfecção/microbiologia , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Feminino , Seguimentos , Técnicas de Genotipagem , Humanos , Limite de Detecção , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/patogenicidade , Filogenia , Polimorfismo de Nucleotídeo Único , Prevalência , Recidiva , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/epidemiologia , Adulto Jovem
8.
PLoS One ; 15(8): e0236574, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790770

RESUMO

Management practices such as tillage, crop rotation, irrigation, organic and inorganic inputs application are known to influence diversity and function of soil microbial populations. In this study, we investigated the effect of conventional versus organic farming systems at low and high input levels on structure and diversity of prokaryotic microbial communities. Soil samples were collected from the ongoing long-term farming system comparison trials established in 2007 at Chuka and Thika in Kenya. Physicochemical parameters for each sample were analyzed. Total DNA and RNA amplicons of variable region (V4-V7) of the 16S rRNA gene were generated on an Illumina platform using the manufacturer's instructions. Diversity indices and statistical analysis were done using QIIME2 and R packages, respectively. A total of 29,778,886 high quality reads were obtained and assigned to 16,176 OTUs at 97% genetic distance across both 16S rDNA and 16S rRNA cDNA datasets. The results pointed out a histrionic difference in OTUs based on 16S rDNA and 16S rRNA cDNA. Precisely, while 16S rDNA clustered by site, 16S rRNA cDNA clustered by farming systems. In both sites and systems, dominant phylotypes were affiliated to phylum Actinobacteria, Proteobacteria and Acidobacteria. Conventional farming systems showed a higher species richness and diversity compared to organic farming systems, whilst 16S rRNA cDNA datasets were similar. Physiochemical factors were associated differently depending on rRNA and rDNA. Soil pH, electrical conductivity, organic carbon, nitrogen, potassium, aluminium, zinc, iron, boron and micro-aggregates showed a significant influence on the observed microbial diversity. The observed higher species diversity in the conventional farming systems can be attributed to the integration of synthetic and organic agricultural inputs. These results show that the type of inputs used in a farming system not only affect the soil chemistry but also the microbial population dynamics and eventually the functional roles of these microbes.


Assuntos
Agricultura/métodos , Microbiologia do Solo , Acidobacteria/genética , Acidobacteria/isolamento & purificação , DNA Bacteriano/genética , Quênia , Microbiota , Agricultura Orgânica/métodos , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética
9.
Int J Syst Evol Microbiol ; 70(8): 4576-4582, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32735207

RESUMO

A strain of an obligately anaerobic, Gram-stain-negative rod-shaped bacterium is described by phenotypical, biochemical and genotypical characterization. This strain A2879T was isolated from an abscess swab of a patient sampled during routine care at hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequence) revealed the strain to belong to the genus Prevotella, but to be distant from recognized species, with the closest relationship to Prevotella veroralis. Unambiguous identification also proved possible by MALDI-TOF MS. The genomic DNA G+C content was 41.5 mol%. Strain A2879T was moderately saccharolytic and proteolytic. The most abundant cellular long-chain fatty acids were anteiso-C15 : 0 and iso-C15 : 0. In view of these data, strain A2879T is considered to represent a novel species within the genus Prevotella, for which the name Prevotella vespertina sp. nov. is proposed. The type strain is A2879T (=DSM 108027T=CCOS 1233T=CCUG72808T). As this strain has been isolated from a clinical sample, it is considered relevant for human medicine and health in general, and in particular for the fields of clinical microbiology and infectious diseases. This description will enable routine and research laboratories alike to easily identify the novel taxon, allowing its role in the context of human health and disease or microbiota to be further elucidated.


Assuntos
Abscesso/microbiologia , Filogenia , Prevotella/classificação , Adulto , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Alemanha , Humanos , Masculino , Prevotella/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
10.
Proc Natl Acad Sci U S A ; 117(33): 20202-20210, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747578

RESUMO

In biology, it is often critical to determine the identity of an organism and phenotypic traits of interest. Whole-genome sequencing can be useful for this but has limited power for trait prediction. However, we can take advantage of the inherent information content of phenotypes to bypass these limitations. We demonstrate, in clinical and environmental bacterial isolates, that growth dynamics in standardized conditions can differentiate between genotypes, even among strains from the same species. We find that for pairs of isolates, there is little correlation between genetic distance, according to phylogenetic analysis, and phenotypic distance, as determined by growth dynamics. This absence of correlation underscores the challenge in using genomics to infer phenotypes and vice versa. Bypassing this complexity, we show that growth dynamics alone can robustly predict antibiotic responses. These findings are a foundation for a method to identify traits not easily traced to a genetic mechanism.


Assuntos
Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/genética , Antibacterianos/farmacologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos , Microbiologia Ambiental , Regulação Bacteriana da Expressão Gênica , Polimorfismo de Nucleotídeo Único , Especificidade da Espécie , Fatores de Tempo
11.
PLoS One ; 15(8): e0237232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32776951

RESUMO

Until recently the in utero environment of pregnant women was considered sterile. Recent high-sensitivity molecular techniques and high-throughput sequencing lead to some evidence for a low-biomass microbiome associated with the healthy placenta. Other studies failed to reveal evidence for a consistent presence of bacteria using either culture or molecular based techniques. Comparing conflicting "placental microbiome" studies is complicated by the use of varied and inconsistent protocols. Given this situation, we undertook an evaluation of the in utero environment sterility using several controlled methods, in the same study, to evaluate the presence or absence of bacteria and to explain contradictions present in the literature. Healthy pregnant women (n = 38) were recruited in three maternity wards. Placenta were collected after cesarean section with or without Alexis® and vaginal delivery births. For this study we sampled fetal membranes, umbilical cord and chorionic villi. Bacterial presence was analyzed using bacterial culture and qPCR on 34 fetal membranes, umbilical cord and chorionic villi samples. Shotgun metagenomics was performed on seven chorionic villi samples. We showed that the isolation of meaningful quantities of viable bacteria or bacterial DNA was possible only outside the placenta (fetal membranes and umbilical cords) highlighting the importance of sampling methods in studying the in utero environment. Bacterial communities described by metagenomics analysis were similar in chorionic villi samples and in negative controls and were dependent on the database chosen for the analysis. We conclude that the placenta does not harbor a specific, consistent and functional microbiota.


Assuntos
Bactérias/isolamento & purificação , Vilosidades Coriônicas/microbiologia , Membranas Extraembrionárias/microbiologia , Placenta/microbiologia , Cordão Umbilical/microbiologia , Adulto , Bactérias/genética , Cesárea , Amostra da Vilosidade Coriônica , DNA Bacteriano/análise , DNA Bacteriano/genética , Parto Obstétrico , Feminino , Humanos , Microbiota , Gravidez , Manejo de Espécimes
12.
Mem Inst Oswaldo Cruz ; 115: e200184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785422

RESUMO

BACKGROUND Carrion's disease (CD) is a neglected biphasic illness caused by Bartonella bacilliformis, a Gram-negative bacteria found in the Andean valleys. The spread of resistant strains underlines the need for novel antimicrobials against B. bacilliformis and related bacterial pathogens. OBJECTIVE The main aim of this study was to integrate genomic-scale data to shortlist a set of proteins that could serve as attractive targets for new antimicrobial discovery to combat B. bacilliformis. METHODS We performed a multidimensional genomic scale analysis of potential and relevant targets which includes structural druggability, metabolic analysis and essentiality criteria to select proteins with attractive features for drug discovery. FINDINGS We shortlisted seventeen relevant proteins to develop new drugs against the causative agent of Carrion's disease. Particularly, the protein products of fabI, folA, aroA, trmFO, uppP and murE genes, meet an important number of desirable features that make them attractive targets for new drug development. This data compendium is freely available as a web server (http://target.sbg.qb.fcen.uba.ar/). MAIN CONCLUSION This work represents an effort to reduce the costs in the first phases of B. bacilliformis drug discovery.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Bartonella/tratamento farmacológico , Bartonella bacilliformis/efeitos dos fármacos , Bartonella bacilliformis/genética , Bartonella bacilliformis/isolamento & purificação , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Genômica , Humanos , Reação em Cadeia da Polimerase
13.
Int J Syst Evol Microbiol ; 70(8): 4774-4781, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32744986

RESUMO

Three strains of a Gram-stain-positive, catalase-negative, facultative anaerobic, and coccoid species were isolated from German bulk tank milk. Phylogenetic analyses based on the 16S rRNA gene sequences indicated that the three strains (WS4937T, WS4759 and WS5303) constitute an independent phylogenetic lineage within the family Aerococcaceae with Facklamia hominis CCUG 36813T (93.7-94.1 %) and Eremococcus coleocola M1831/95/2T (93.5 %) as most closely related type species. The unclassified strains demonstrated variable growth with 6.5 % (w/v) NaCl and tolerated pH 6.5-9.5. Growth was observed from 12 to 39 °C. Their cell-wall peptidoglycan belongs to the A1α type (l-Lys-direct) consisting of alanine, glutamic acid and lysine. The predominant fatty acids were C16 : 1 ω9c, C16 : 0 and C18 : 1 ω9c and in the polar lipids profile three glycolipids, a phospholipid, phosphatidylglycerol, phosphoglycolipid and diphosphatidylglycerol were found. The G+C content of strain WS4937T was 37.4 mol% with a genome size of ~3.0 Mb. Based on phylogenetic, phylogenomic and biochemical characterizations, the isolates can be demarcated from all other genera of the family Aerococcaceae and, therefore, the novel genus Fundicoccus gen. nov. is proposed. The type species of the novel genus is Fundicoccus ignavus gen. nov., sp. nov. WS4937T (=DSM 109652T=LMG 31441T).


Assuntos
Aerococcaceae/classificação , Leite/microbiologia , Filogenia , Aerococcaceae/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
14.
Proc Natl Acad Sci U S A ; 117(31): 18540-18549, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32675239

RESUMO

Once described as mere "bags of enzymes," bacterial cells are in fact highly organized, with many macromolecules exhibiting nonuniform localization patterns. Yet the physical and biochemical mechanisms that govern this spatial heterogeneity remain largely unknown. Here, we identify liquid-liquid phase separation (LLPS) as a mechanism for organizing clusters of RNA polymerase (RNAP) in Escherichia coli Using fluorescence imaging, we show that RNAP quickly transitions from a dispersed to clustered localization pattern as cells enter log phase in nutrient-rich media. RNAP clusters are sensitive to hexanediol, a chemical that dissolves liquid-like compartments in eukaryotic cells. In addition, we find that the transcription antitermination factor NusA forms droplets in vitro and in vivo, suggesting that it may nucleate RNAP clusters. Finally, we use single-molecule tracking to characterize the dynamics of cluster components. Our results indicate that RNAP and NusA molecules move inside clusters, with mobilities faster than a DNA locus but slower than bulk diffusion through the nucleoid. We conclude that RNAP clusters are biomolecular condensates that assemble through LLPS. This work provides direct evidence for LLPS in bacteria and demonstrates that this process can serve as a mechanism for intracellular organization in prokaryotes and eukaryotes alike.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Imagem Individual de Molécula , Fatores de Elongação da Transcrição/genética , Fatores de Elongação da Transcrição/metabolismo
15.
Int J Syst Evol Microbiol ; 70(8): 4515-4522, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32614762

RESUMO

Two strains of lactic acid bacteria, designated Hs20B0-1T and Hs30E4-3T, were isolated from the gut of the damp-wood termite Hodotermopsis sjostedti. These strains were characterized genetically and phenotypically. Strain Hs20B0-1T was related to Lactococcus piscium DSM 6634T showing 96.3 and 84.2 % sequence similarity in 16S rRNA gene and rpoB gene sequences, respectively. Strain Hs30E4-3T was related to Lactococcus plantarum DSM 20686T showing 94.8 and 82.2 % sequence similarity in 16S rRNA gene and rpoB gene sequences, respectively. The 16S rRNA gene sequence similarity between strains Hs20B0-1T and Hs30E4-3T was 95.7 %. Furthermore, genomic comparisons using pairwise average nucleotide identity (ANI) and digital DNA-DNA hybridization (DDH) analyses between strain Hs20B0-1T and L. piscium DSM 6634T resulted in values of 73.5 and 20.1 %, respectively. Strain Hs30E4-3T had 72.8 % ANI similarity and 21.3 % DDH similarity to L. plantarum DSM 20686T. Strains Hs20B0-1T and Hs30E4-3T had 75.4 % ANI similarity and 21.1 % DDH similarity to each other. The cell-wall peptidoglycan types of strains Hs20B0-1T and Hs30E4-3T were A4α, Lys-Asp and A3α, Lys-Thr-Ala, respectively. The two strains, Hs20B0-1T and Hs30E4-3T, are distinguishable from each other and other established Lactococcus species phylogenetically and phenotypically. In conclusion, two novel species of the genus Lactococcus are proposed, namely Lactococcus insecticola Hs20B0-1T (=JCM 33485T=DSM 110147T) and Lactococcus hodotermopsidis Hs30E4-3T (=JCM 33486T=DSM 110148T), respectively.


Assuntos
Trato Gastrointestinal/microbiologia , Isópteros/microbiologia , Lactococcus/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Lactococcus/isolamento & purificação , Hibridização de Ácido Nucleico , Peptidoglicano/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Madeira
16.
Int J Syst Evol Microbiol ; 70(8): 4562-4568, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32618560

RESUMO

A Gram-stain-negative, yellow-pigmented, non-spore-forming, non-motile, rod-shaped, catalase-positive, strictly aerobic bacterial strain, designated CAU 1491T, was isolated from seawater and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1491T grew optimally at 30 °C, pH 7.5 and in 2.0 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence of CAU 1491T showed that it formed a distinct lineage within the family Flavobacteriaceae as a separate deep branch, with 97.0 % or lower sequence similarity to representatives of the genera Lacinutrix, Gaetbulibacter and Aquibacter. The major cellular fatty acids of strain CAU 1491T were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine and an unidentified phospholipid. The strain contained MK-6 as the sole respiratory quinone. Genome sequencing revealed that strain CAU 1491T has a genome size of 3.13 Mbp and a G+C content of 32.4 mol%. On the basis of the phenotypic, chemotaxonomic and genomic data, strain CAU 1491T represents a new genus and species in the family Flavobacteriaceae for which the name Pontimicrobium aquaticum gen. nov., sp. nov. is proposed. The type strain of Pontimicrobium aquaticum is CAU 1491T (=KCTC 72003T=NBRC 113695T).


Assuntos
Flavobacteriaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
17.
Int J Syst Evol Microbiol ; 70(8): 4591-4601, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658637

RESUMO

Gram-negative, aerobic, chemo-organotrophic and bacteriochlorophyll a-containing bacterial strains, KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152, were isolated from the thalli of Cladonia arbuscula and Cladonia stellaris lichens. Cells from the strains were coccoid and reproduced by binary division. They were motile at the early stages of growth and utilized sugars and alcohols. All strains were psychrophilic and acidophilic, capable of growth between pH 3.5 and 7.5 (optimum, pH 5.5), and at 4-30 °C (optimum, 10-15 °C). The major fatty acids were C18 : 1 ω7c and C18 : 0; the lipids were phosphatidylcholines, phosphatidylethanolamines, phosphatidic acids, phosphatidylglycerol, glycolipids, diphosphatidylglycerol and polar lipids with an unknown structure. The quinone was Q-10. The DNA G+C content was 67.8 mol%. Comparative 16S rRNA gene analysis together with other data, supported that the strains, KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152 belonged to the same species. Whole genome analysis of the strain KEBCLARHB70RT and average amino acid identity values confirmed its distinctive phylogenetic position within the family Acetobacteraceae. Phenotypic, ecological and genomic characteristics distinguished strains KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152 from all genera in the family Acetobacteraceae. Therefore, we propose a novel genus and a novel species, Lichenicoccus roseus gen. nov., sp. nov., for these novel Acetobacteraceae members. Strain KEBCLARHB70RT (=KCTC 72321T=VKM B-3305T) has been designated as the type strain.


Assuntos
Acetobacteraceae/classificação , Líquens/microbiologia , Filogenia , Acetobacteraceae/isolamento & purificação , Técnicas de Tipagem Bacteriana , Bacterioclorofila A , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
18.
Int J Syst Evol Microbiol ; 70(8): 4602-4609, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658638

RESUMO

Two bacterial strains, 50A-KIRBAT and 50C-KIRBAT, were isolated from the same freshwater creek located near Salzburg, Austria. They showed 16S rRNA gene sequence similarities to Aquirufa nivalisilvae of 100 and 99.9 %, respectively. A genome-based phylogenetic reconstruction with amino acid sequences of 119 single-copy genes suggested that the new strains represent two new species of the genus Aquirufa. Pairwise calculated whole-genome average nucleotide identity (gANI) values ranging from 85.4 to 87.5 % confirmed this conclusion. Phenotypic, chemotaxonomic and genomic traits were investigated. Like strains of other Aquirufa species, 50A-KIRBAT and 50C-KIRBAT grew aerobically and chemoorganotrophically, were rod-shaped, red-pigmented and motile, most likely by gliding. They could be distinguished by slight differences in the chemotaxonomic features. We propose to establish for strain 50A-KIRBAT (=CIP 111735T=LMG 31080T) as type strain the name Aquirufa ecclesiirivi and for strain 50C-KIRBAT (=CIP 111736T=LMG 31501T) as type strain the name Aquirufa beregesia. Furthermore, the relationship between the type strains of Aquirufa nivalisilvae (59G-WUEMPELT) and Allopseudarcicella aquatilis (HME7025T) was investigated. Results of polyphasic analyses, especially a gANI value of 97.6 %, as well as the genome-based phylogenetic reconstruction, suggested that Allopseudarcicella aquatilis is a heterotypic synonym of Aquirufa nivalisilvae. According to rule 24b of the International Code of Nomenclature of Prokaryotes we propose to classify strain HME7025 as Aquirufa nivalisilvae and provide an emended description for the latter.


Assuntos
Cytophagaceae/classificação , Água Doce/microbiologia , Filogenia , Áustria , Técnicas de Tipagem Bacteriana , Composição de Bases , Cytophagaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Int J Syst Evol Microbiol ; 70(8): 4537-4543, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32667871

RESUMO

A novel actinobacterium, designated strain HNM0687T, was isolated from mangrove soil samples collected from Hainan Province, PR China and its polyphasic taxonomy was studied. Based on the results of 16S rRNA gene sequence analysis, strain HNM0687T was closely related to Gordonia bronchialis NBRC 16047T (98.7 %), Gordonia rhizosphera NBRC 16068T (98.2 %), Gordonia oryzae RS15-1ST (97.9 %), Gordonia polyisoprenivorans NBRC 16320T (97.7 %) and Gordonia sediminis AMA 120T (97.7 %). Genome-based comparisons revealed a clear distinction in average nucleotide identity values between strain HNM0687T and its closely related strains (74.4-78.3 %). Strain HNM0687T contained meso-diaminopimelic acid, arabinose and galactose in whole-cell hydrolysates. Mycolic acid was present. The menaquinones of strain HNM0687T were MK-9(H2) and MK-7(H2). The phospholipids of the isolate were composed of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were C16 : 0, C16 : 1 ω7c/C16 : 1 ω6c, C18 : 010-methyl (TBSA), C18 : 0 and C18 : 1 ω9c. Based on its genotypic, chemotaxonomic and phenotypic characteristics, it is concluded that strain HNM0687T represents a novel species of the genus Gordonia for which the name Gordonia mangrovi sp. nov. is proposed. The type strain is HNM0687T (=CCTCC AA 2019074 T=KCTC 49383 T).


Assuntos
Gordonia (Bactéria)/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Gordonia (Bactéria)/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/química
20.
Int J Syst Evol Microbiol ; 70(8): 4616-4622, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32667873

RESUMO

Two Gram-stain-negative, facultative anaerobic and non-motile bacteria, strains R11T and S1162T, were isolated from soil in the Republic of Korea. Both strains were catalase- and oxidase-positive and contained menaquinone-7 as the major isoprenoid quinone. Strain R11T contained summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), iso-C15:0, C16:0 and iso-C17:0 3-OH as major fatty acids and phosphatidylethanolamine, an unidentified aminophospholipid and an unidentified aminolipid as major polar lipids; while strain S1162T contained summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), iso-C15:0, iso-C17:0 3-OH, C16:0 and summed feature 9 (10-methyl C16:0 and/or iso-C17:1 ω9c) as major fatty acids and phosphatidylethanolamine and an unidentified aminophospholipid as major polar lipids. The DNA G+C contents of strains R11T and S1162T calculated from their whole genomes were 42.7 and 42.9 mol%, respectively. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain R11T formed a phylogenetic lineage with Mucilaginibacter jinjuensis YC7004T and strain S1162T formed a distinct phyletic lineage from closely related type strains within the genus Mucilaginibacter. Strains R11T and S1162T were most closely related to M. jinjuensis YC7004T and Mucilaginibacter panaciglaebae BXN5-31T with 97.78 and 97.23% 16S rRNA gene sequence similarities, respectively. On the basis of phenotypic, chemotaxonomic and molecular analysis, strains R11T and S1162T represent two novel species of the genus Mucilaginibacter, for which the names Mucilaginibacter agri sp. nov. and Mucilaginibacter humi sp. nov. are proposed, respectively. The type strains of M. agri and M. humi are R11T (=KACC 21228T=JCM 33472T) and S1162T (=KACC 21669T=JCM 33916T), respectively.


Assuntos
Bacteroidetes/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
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