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1.
Proc Biol Sci ; 289(1974): 20220532, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35506222

RESUMO

Rapid exaggeration of host and pathogen traits via arms race dynamics is one possible outcome of host-pathogen coevolution. However, the exaggerated traits are expected to incur costs in terms of resource investment in other life-history traits. The current study investigated the costs associated with evolved traits in a host-pathogen coevolution system. We used the Drosophila melanogaster (host)-Pseudomonas entomophila (pathogen) system to experimentally derive two selection regimes, one where the host and pathogen both coevolved, and the other, where only the host evolved against a non-evolving pathogen. After 17 generations of selection, we found that hosts from both selected populations had better post-infection survivorship than controls. Even though the coevolving populations tended to have better survivorship post-infection, we found no clear evidence that the two selection regimes were significantly different from each other. There was weak evidence for the coevolving pathogens being more virulent than the ancestral pathogen. We found no major cost of increased post-infection survivorship. The costs were not different between the coevolving hosts and the hosts evolving against a non-evolving pathogen. We found no evolved costs in the coevolving pathogens. Thus, our results suggest that increased host immunity and pathogen virulence may not be costly.


Assuntos
Drosophila melanogaster , Sobrevivência , Animais , Pseudomonas , Sobrevida
2.
Artigo em Inglês | MEDLINE | ID: mdl-35507398

RESUMO

We described the comparative genomic analysis of Pseudomonas panacis DSM 18529T and Pseudomonas marginalis DSM 13124T of the genus Pseudomonas to define the taxonomic assignment. When conducting this analysis, genomic information for 203 type strains was available in the NCBI genome database. The ANI, AAI and isDDH data were higher than the threshold values between Pseudomonas panacis DSM 18529T and Pseudomonas marginalis DSM 13124T. Whole-genome comparisons show 97 % average nucleotide identity, 98 % average amino acid identity and 75 % in silico DNA-DNA hybridization values. Pseudomonas marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980) have priority over the name Pseudomonas panacis Park et al. 2005, therefore nomenclatural authorities propose that Pseudomonas panacis Park et al. 2005 is a later heterotypic synonym of Pseudomonas marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980). The type strain is ATCC 10844T (=DSM 13124T=NCPPB 667T).


Assuntos
Ácidos Graxos , Pseudomonas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Filogenia , Pseudomonas/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
3.
Microbiol Spectr ; 10(2): e0002522, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35416714

RESUMO

Acanthamoeba species are among the most ubiquitous protists that are widespread in soil and water and act as both a replicative niche and vectors for dispersal. They are the most important human intracellular pathogens, causing Acanthamoeba keratitis (AK) and severely damaging the human cornea. The sympatric lifestyle within the host and amoeba-resisting microorganisms (ARMs) promotes horizontal gene transfer (HGT). However, the genomic diversity of only A. castellanii and A. polyphaga has been widely studied, and the pathogenic mechanisms remain unknown. Thus, we examined 7 clinically pathogenic strains by comparative genomic, phylogenetic, and rhizome gene mosaicism analyses to explore amoeba-symbiont interactions that possibly contribute to pathogenesis. Genetic characterization and phylogenetic analysis showed differences in functional characteristics between the "open" state of T3 and T4 isolates, which may contribute to the differences in virulence and pathogenicity. Through comparative genomic analysis, we identified potential genes related to virulence, such as metalloprotease, laminin-binding protein, and HSP, that were specific to the genus Acanthamoeba. Then, analysis of putative sequence trafficking between Acanthamoeba and Pandoraviruses or Acanthamoeba castellanii medusaviruses provided the best hits with viral genes; among bacteria, Pseudomonas had the most significant numbers. The most parsimonious evolutionary scenarios were between Acanthamoeba and endosymbionts; nevertheless, in most cases, the scenarios are more complex. In addition, the differences in exchanged genes were limited to the same family. In brief, this study provided extensive data to suggest the existence of HGT between Acanthamoeba and ARMs, explaining the occurrence of diseases and challenging Darwin's concept of eukaryotic evolution. IMPORTANCE Acanthamoeba has the ability to cause serious blinding keratitis. Although the prevalence of this phenomenon has increased in recent years, our knowledge of the underlying opportunistic pathogenic mechanism maybe remains incomplete. In this study, we highlighted the importance of Pseudomonas in the pathogenesis pathway using comprehensive a whole genomics approach of clinical isolates. The horizontal gene transfer events help to explain how endosymbionts contribute Acanthamoeba to act as an opportunistic pathogen. Our study opens up several potential avenues for future research on the differences in pathogenicity and interactions among clinical strains.


Assuntos
Acanthamoeba , Transferência Genética Horizontal , Acanthamoeba/genética , Acanthamoeba/microbiologia , Genômica , Humanos , Filogenia , Pseudomonas , Fatores de Virulência/genética
4.
Microbiologyopen ; 11(2): e1283, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35478286

RESUMO

Although plant pathogens are traditionally controlled using synthetic agrochemicals, the availability of commercial bactericides is still limited. One potential control strategy could be the use of plant growth-promoting bacteria (PGPB) to suppress pathogens via resource competition or the production of antimicrobial compounds. This study aimed to conduct in vitro and in vivo screening of eight Pseudomonas strains against Ralstonia solanacearum (the causative agent of bacterial wilt) and to investigate underlying mechanisms of potential pathogen suppression. We found that inhibitory effects were Pseudomonas strain-specific, with strain CHA0 showing the highest pathogen suppression. Genomic screening identified 2,4-diacetylphloroglucinol, pyoluteorin, and orfamides A and B secondary metabolite clusters in the genomes of the most inhibitory strains, which were investigated further. Although all these compounds suppressed R. solanacearum growth, only orfamide A was produced in the growth media based on mass spectrometry. Moreover, orfamide variants extracted from Pseudomonas cultures showed high pathogen suppression. Using the "Micro-Tom" tomato cultivar, it was found that CHA0 could reduce bacterial wilt disease incidence with one of the two tested pathogen strains. Together, these findings suggest that a better understanding of Pseudomonas-Ralstonia interactions in the rhizosphere is required to successfully translate in vitro findings into agricultural applications.


Assuntos
Lycopersicon esculentum , Ralstonia solanacearum , Antibacterianos/farmacologia , Antibiose , Lycopersicon esculentum/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas/genética
5.
Arch Microbiol ; 204(5): 249, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35396979

RESUMO

A Gram-stain-negative, aerobic, rod-shaped and motile bacterium, named LAMW06T, was isolated from greenhouse soil in Beijing, China. In the 16S rRNA gene sequence comparison, strain LAMW06T had the highest similarity with Pseudomonas cuatrocienegasensis 1NT. Phylogenetic analysis based on the 16S rRNA and three housekeeping gene sequences (gyrB, rpoB and rpoD) indicated that strain represented a member of the genus Pseudomonas. The genome sequence size of the isolate was 5.5 Mb, with a DNA G + C content of 63.5 mol%. The average nucleotide identity and DNA-DNA hybridization values between strain LAMW06T and closely related members of Pseudomonas borbori R-20821T, Pseudomonas taeanensis MS-3T and P. cuatrocienegasensis 1NT were 90.9%, 82.4%, 81.5% and 43.0%, 25.9%, 24.6% respectively. The major fatty acids contained summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), C18:1 ω7c and C16:0. The primary respiratory quinone was ubiquinone-9. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, six aminophospholipids, six phospholipids, one aminolipid and one glycolipid. According to the genotypic, phylogenetic and chemotaxonomic data, strain LAMW06T represents a novel species within the genus Pseudomonas, for which the name Pseudomonas tumuqii sp. nov. is proposed. The type strain is LAMW06T (= GDMCC 1.2003T = KCTC 72829T).


Assuntos
Pseudomonas , Solo , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Hibridização de Ácido Nucleico , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Arch Microbiol ; 204(5): 272, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35445985

RESUMO

A psychrotolerant bacterial strain of Pseudomonas sp. (P. palleroniana GBPI_508), isolated from the Indian Himalayan region, is studied for analyzing its potential for degrading bisphenol A (BPA). Response surface methodology using Box-Behnken design was used to statistically optimize the environmental factors during BPA degradation and the maximum degradation (97%) was obtained at optimum conditions of mineral salt media pH 9, experimental temperature 25 °C, an inoculum volume of 10% (v/v), and agitation speed 130 rpm at the BPA concentration 270 mg L-1. The Monod model was used for understanding bacterial degradation kinetics, and 37.5 mg-1 half saturation coefficient (KS) and 0.989 regression coefficient (R2) were obtained. Besides, the utmost specific growth rate µmax was witnessed as 0.080 h-1 with the GBPI_508 during BPA degradation. Metabolic intermediates detected in this study by GC-MS were identified as valeric acid, propionic acid, diglycolic acid, and phenol. The psychrotolerant bacterial strain of Pseudomonas sp. (P. palleroniana GBPI_508), isolated from the Indian Himalayan region has shown good potential for remediation of BPA at variable conditions.


Assuntos
Compostos Benzidrílicos , Microbiologia do Solo , Compostos Benzidrílicos/metabolismo , Biodegradação Ambiental , Fenóis , Pseudomonas/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-35442877

RESUMO

A Gram-stain-negative, aerobic and non-spore-forming bacterial strain, designated 20TX0172T, was isolated from a rotting onion bulb in Texas, USA. The results of phylogenetic analysis based on the 16S rRNA sequence indicated that the novel strain represented a member of the genus Pseudomonas and had the greatest sequence similarities with Pseudomonas kilonensis 520-20T (99.3 %), Pseudomonas corrugata CFBP 2431T (99.2 %), and Pseudomonas viciae 11K1T (99.2 %) but the 16S rRNA phylogenetic tree displayed a monophyletic clade with Pseudomonas mediterranea CFBP 5447T. In the phylogenetic trees based on sequences of four housekeeping genes (gap1, gltA, gyrB and rpoD), the novel strain formed a separate branch, indicating that the strain was distinct phylogenetically from known species of the genus Pseudomonas. The genome-sequence-derived average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the novel isolate and P. mediterranea DSM 16733T were 86.7 and 32.7 %, respectively. These values were below the accepted species cutoff threshold of 96 % ANI and 70 % dDDH, affirming that the strain represented a novel species. The genome size of the novel species was 5.98 Mbp with a DNA G+C content of 60.8 mol%. On the basis of phenotypic and genotypic characteristics, strain 20TX0172T represents a novel species of the genus Pseudomonas. The name Pseudomonas uvaldensis sp. nov. is proposed. The type strain is 20TX0172T (=NCIMB 15426T=CIP 112022T).


Assuntos
Genes Bacterianos , Cebolas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Cebolas/microbiologia , Filogenia , Pseudomonas , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
8.
Curr Microbiol ; 79(6): 169, 2022 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-35460384

RESUMO

A plant growth-promoting Rhizobacteria (PGPR) Pseudomonas aeruginosa (NG61) isolated from rhizosphere of Sunflower plant. The isolate was identified by 16S rRNA gene sequencing (Accession no. MK455763). NG61 showed various plant growth promotion and biocontrol activities like, Phosphate solubilisation, Nitrogen fixation, Ammonia production, IAA production, siderophore production, HCN production. The whole genome sequence of Pseudomonas aeruginosa (NG61) was reported and analysed. The estimated genome size was 6537180 bp with 66.18% of G+C content. The genome encoded 6186 protein-coding genes, 6252 genes were predicted, 66RNA genes. Phylogenetic tree showed that the P. aeruginosa( NG61) was closely related to P.aeruginosa strain DSM 50071. The annotated draft genome has been deposited at the NCBI database under the accession number PRJNA707114 BioProject and BioSample: SAMN18174979. The analysis of genome sequence of P. aeruginosa (NG61) showed various genes encoding plant growth promotion and biocontrol activities.


Assuntos
Pseudomonas aeruginosa , Pseudomonas , Bactérias/genética , Genômica , Filogenia , Pseudomonas aeruginosa/genética , RNA Ribossômico 16S , Rizosfera
9.
NPJ Biofilms Microbiomes ; 8(1): 32, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35484166

RESUMO

Bioprospecting of microorganisms suitable for bioremediation of fuel or oil spills is often carried out in contaminated environments such as gas stations or polluted coastal areas. Using next-generation sequencing (NGS) we analyzed the microbiota thriving below the lids of the fuel deposits of diesel and gasoline cars. The microbiome colonizing the tank lids differed from the diversity found in other hydrocarbon-polluted environments, with Proteobacteria being the dominant phylum and without clear differences between gasoline or diesel-fueled vehicles. We observed differential growth when samples were inoculated in cultures with gasoline or diesel as the main carbon source, as well as an increase in the relative abundance of the genus Pseudomonas in diesel. A collection of culturable strains was established, mostly Pseudomonas, Stenotrophomonas, Staphylococcus, and Bacillus genera. Strains belonging to Bacillus, Pseudomonas, Achromobacter, and Isoptericola genera showed a clear diesel degradation pattern when analyzed by GC-MS, suggesting their potential use for bioremediation and a possible new species of Isoptericola was further characterized as hydrocarbon degrader.


Assuntos
Automóveis , Gasolina , Bactérias/genética , Biodegradação Ambiental , Hidrocarbonetos/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo
10.
Int J Mol Sci ; 23(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35457206

RESUMO

Bacterial biofilm represents a multicellular community embedded within an extracellular matrix attached to a surface. This lifestyle confers to bacterial cells protection against hostile environments, such as antibiotic treatment and host immune response in case of infections. The Pseudomonas genus is characterised by species producing strong biofilms difficult to be eradicated and by an extraordinary metabolic versatility which may support energy and carbon/nitrogen assimilation under multiple environmental conditions. Nutrient availability can be perceived by a Pseudomonas biofilm which, in turn, readapts its metabolism to finally tune its own formation and dispersion. A growing number of papers is now focusing on the mechanism of nutrient perception as a possible strategy to weaken the biofilm barrier by environmental cues. One of the most important nutrients is amino acid L-arginine, a crucial metabolite sustaining bacterial growth both as a carbon and a nitrogen source. Under low-oxygen conditions, L-arginine may also serve for ATP production, thus allowing bacteria to survive in anaerobic environments. L-arginine has been associated with biofilms, virulence, and antibiotic resistance. L-arginine is also a key precursor of regulatory molecules such as polyamines, whose involvement in biofilm homeostasis is reported. Given the biomedical and biotechnological relevance of biofilm control, the state of the art on the effects mediated by the L-arginine nutrient on biofilm modulation is presented, with a special focus on the Pseudomonas biofilm. Possible biotechnological and biomedical applications are also discussed.


Assuntos
GMP Cíclico , Pseudomonas aeruginosa , Arginina/metabolismo , Arginina/farmacologia , Proteínas de Bactérias/metabolismo , Biofilmes , Carbono/metabolismo , Carbono/farmacologia , GMP Cíclico/metabolismo , Nitrogênio/metabolismo , Nitrogênio/farmacologia , Nutrientes , Pseudomonas/metabolismo , Pseudomonas aeruginosa/fisiologia
11.
Am J Case Rep ; 23: e935743, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35365592

RESUMO

BACKGROUND Pseudomonas luteola (P. luteola) is a Gram-negative, oxidase-negative is an environmental organism that is isolated from soil, water, and damping areas, and is rarely found as a human pathogen. Most infections in which P. luteola is implicated are associated with a breach in immune barrier, such as indwelling catheters, prosthetic devices, immunocompromised conditions and surgical wounds. CASE REPORT A 9 years old girl, known case of Chron's disease and recurrent urinary tract infections on prophylactic antibiotics, presented with an acute-onset abdominal pain associated with fever reaching 40C and vomiting. She was placed on a peripherally inserted central line for total parenteral nutrition and developed sepsis on the 30th day of admission. Septic workup revealed P. letuola infection with right atrial vegetation. Treatment with Piperacillin/tazobactam yielded an uneventful recovery. CONCLUSIONS P. luteola can be involved in serious infections in susceptible individuals. Serious outcomes may be associated with infective endocarditis especially on a background of valvular prosthesis and central lines. The definitive treatment of catheter related infective endocarditis caused by P. leuteola is the removal of the lines along with an appropriate antibiotic regimen-based AST result.


Assuntos
Cateteres Venosos Centrais , Endocardite Bacteriana , Endocardite , Criança , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/tratamento farmacológico , Feminino , Humanos , Pseudomonas
12.
Food Chem ; 386: 132858, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35367791

RESUMO

This study evaluated the synergistic effects and disinfection mechanism of ultrasound (US, 200 W and 30 kHz) and slightly acidic electrolysed water (SAEW, 60 mg/L and pH of 6.2) treatment and the associated preservation of mirror carp during refrigeration storage (4 °C). US and SAEW alone and US combined with SAEW (US + SAEW) showed the lower water loss of fish. Fish treated with US + SAEW exhibited significantly lower degrees of lipid oxidation and protein degradation (P < 0.05). Microbiological results showed that US + SAEW inhibited the growth of Pseudomonas and activity of endogenous enzymes; also, US + SAEW decreased the relative activities of 2,3,5-triphenyl tetrazolium chloride-dehydrogenase (TTC-dehydrogenase) and ATP-ase in Pseudomonas by 65.89% and 10.26%, respectively. The combination of US + SAEW destroyed the cellular membrane and aggravated the leakage of nucleic acid and protein of Pseudomonas, and effectively inhibited the activity of antioxidant enzyme. This study reports a new industrial method for preserving refrigerated fish.


Assuntos
Carpas , Desinfecção , Ácidos/farmacologia , Animais , Desinfecção/métodos , Oxirredutases , Pseudomonas , Refrigeração , Água/farmacologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-35380531

RESUMO

Here we present the description of a novel Pseudomonas species, designated Pseudomonas rustica sp. nov., which was isolated from raw milk samples obtained from Germany. Results of initial 16S rRNA gene sequence analysis assigned the strain into the genus Pseudomonas and showed Pseudomonas helmanticensis, Pseudomonas neuropathica and Pseudomonas atagonensis to be its closest relatives. Further studies including sequence analysis of the rpoB gene, multi-gene phylogenetic tree reconstruction, whole-genome sequence comparisons, cellular fatty acid analysis and chemotaxonomic characterization showed a clear separation from the known Pseudomonas species. Isolate MBT-4T was closely related to Pseudomonas helmanticensis, 'Pseudomonas crudilactis' and Pseudomonas neuropathica with average nucleotide identities based on blast values of 88.8, 88.8 and 88.6%, respectively. Therefore, the strain can be classified into the Pseudomonas koreensis subgroup of the Pseudomonas fluorescens group. The G+C content of strain MBT-4T was 58.9 mol%. The strain was catalase- and oxidase-positive, while the ß-galactosidase reaction was negative. Growth occurred between 4 and 30 °C and at pH values from pH 6.0 to 8.0. In conclusion, strain MBT-4T belongs to a novel species, for which the name Pseudomonas rustica sp. nov. is proposed. The type strain is MBT-4T (=DSM 112348T=LMG 32241T) and strain MBT-17 is also a representative of this species.


Assuntos
Ácidos Graxos , Leite , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Fazendas , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , Filogenia , Pseudomonas , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
14.
Front Cell Infect Microbiol ; 12: 808800, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35392610

RESUMO

Pseudomonas plecoglossicida is an aerobic Gram-negative bacterium, which is the pathogen of "Visceral white spot disease" in large yellow croaker. P. plecoglossicida is a temperature-dependent bacterial pathogen in fish, which not only reduces the yield of large yellow croaker but also causes continuous transmission of the disease, seriously endangering the healthy development of fisheries. In this study, a mutant strain of fusA was constructed using homologous recombination technology. The results showed that knockout of P. plecoglossicida fusA significantly affected the ability of growth, adhesion, and biofilm formation. Temperature, pH, H2O2, heavy metals, and the iron-chelating agent were used to treat the wild type of P. plecoglossicida; the results showed that the expression of fusA was significantly reduced at 4°C, 12°C, and 37°C. The expression of fusA was significantly increased at pH 4 and 5. Cu2+ has a significant inducing effect on the expression of fusA, but Pb2+ has no obvious effect; the expression of fusA was significantly upregulated under different concentrations of H2O2. The expression of the fusA gene was significantly upregulated in the 0.5~4-µmol/l iron-chelating agent. The expression level of the fusA gene was significantly upregulated after the logarithmic phase. It was suggested that fusA included in the TBDR family not only was involved in the transport of ferredoxin but also played important roles in the pathogenicity and environment adaptation of P. plecoglossicida.


Assuntos
Doenças dos Peixes , Perciformes , Infecções por Pseudomonas , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Quelantes , Ferredoxinas , Doenças dos Peixes/microbiologia , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Ferro/metabolismo , Perciformes/metabolismo , Perciformes/microbiologia , Pseudomonas , Infecções por Pseudomonas/microbiologia , Virulência
15.
Water Res ; 216: 118328, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35364354

RESUMO

Legionella pneumophila is a natural inhabitant of water systems. From there, it can be transmitted to humans by aerosolization resulting in severe pneumonia. Most large outbreaks are caused by cooling towers colonized with L. pneumophila. The resident microbiota of the cooling tower is a key determinant for the colonization and growth of L. pneumophila. In our preceding study, the genus Pseudomonas correlated negatively with the presence of L. pneumophila in cooling towers, but it was not clear which species was responsible. Therefore, we identified the Pseudomonas species inhabiting 14 cooling towers using a Pseudomonas-specific 16S rRNA amplicon sequencing strategy. We found that cooling towers that are free of L. pneumophila contained a high relative abundance of members from the Pseudomonas alcaliphila/oleovorans phylogenetic cluster. P. alcaliphila JCM 10630 inhibited the growth of L. pneumophila on agar plates. Analysis of the P. alcaliphila genome revealed the presence of a gene cluster predicted to produce toxoflavin. L. pneumophila growth was inhibited by pure toxoflavin and by extracts from P. alcaliphila culture found to contain toxoflavin by liquid chromatography coupled with mass spectrometry. In addition, toxoflavin inhibits the growth of Vermameoba vermiformis, a host cell of L. pneumophila. Our study indicates that P. alcaliphila may be important to restrict growth of L. pneumophila in water systems through the production of toxoflavin. A sufficiently high concentration of toxoflavin is likely not achieved in the bulk water but might have a local inhibitory effect such as near or in biofilms.


Assuntos
Legionella pneumophila , Legionella , Humanos , Legionella/genética , Legionella pneumophila/genética , Filogenia , Pseudomonas/genética , Pirimidinonas , RNA Ribossômico 16S/genética , Triazinas , Água , Microbiologia da Água
16.
ACS Synth Biol ; 11(4): 1650-1657, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35389616

RESUMO

Pseudomonas is a large genus that inhabits diverse environments due to its distinct metabolic versatility. Its applications range from environmental to industrial biotechnology. Molecular tools that allow precise and efficient genetic manipulation are required to understand and harness its full potential. Here, we report the development of a highly efficient adenine base editing system, i.e., dxABE-PS, for Pseudomonas species. The system allows A:T → G:C transition with up to 100% efficiency along a broad target spectrum because we use xCas9 3.7, which recognizes NG PAM. To enhance the dxABE-PS utility, we develop a prediction workflow for protein dysfunction using ABE, namely, DABE-CSP (dysfunction via ABE through CRISPOR-SIFT prediction). We applied DABE-CSP to inactivate several genes in Pseudomonas putida KT2440 to accumulate a nylon precursor, i.e., muconic acid from catechol with 100% yield. Moreover, we expanded the ABE to non-model Pseudomonas species by developing an nxABE system for P. chengduensisDY56-96, isolated from sediment samples from the seamount area in the West Pacific Ocean. Taken together, the establishment of the ABE systems along with DABE-CSP will fast-track research on Pseudomonas species.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Adenina/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Fluxo de Trabalho
17.
Arch Microbiol ; 204(5): 247, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35397008

RESUMO

Genomes of three strains-phenazine producers-Pseudomonas chlororaphis subsp. aurantiaca (B-162 (wild type), mutant strain B-162/255, and its derivative B-162/17) were sequenced and compared. Comparison of a wild-type strain and B-162/255 mutant genomes revealed 32 mutations. 19 new mutations were detected in the genome of B-162/17. Further bioinformatics analysis allowed us to predict mutant protein functions and secondary structures of five gene products, mutations which might potentially influence phenazine synthesis and secretion in Pseudomonas bacteria. These genes encode phenylalanine hydroxylase transcriptional activator PhhR, type I secretion system permease/ATPase, transcriptional regulator MvaT, GacA response regulator, and histidine kinase. Amino acid substitutions were found in domains of studied proteins. One deletion in an intergenic region could affect a potential transcription factor binding site that participates in the regulation of gene that encodes ABC transporter.


Assuntos
Fenazinas , Pseudomonas , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fenazinas/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo
18.
Food Res Int ; 155: 111075, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35400453

RESUMO

Zoning is typically adopted by food manufacturers and classified into three different zones including Zone 1 (food contact surface), Zone 2 (proximity to food and food contact surfaces) and Zone 3 (remote surfaces from processing). In this study, environmental surfaces belonging to these three zones were sampled during food processing in a fresh-cut vegetables (FVs) processing facility located in Beijing, China. Bacterial loads in terms of aerobic plate count and coliform count were evaluated by culture-dependent techniques. The profile and diversity of bacterial community in these three zones were investigated by high-throughput sequencing. Zone 1 showed similar microbiota and predominated by Pseudomonas and Acinetobacter, while the predominant genera on Zone 2 or 3 were quite varied among different processing steps. The SourceTracker analysis showed that most of the bacteria (above 80%) on surfaces were from unknown sources, while sorting and disinfection & cleaning steps contributed equally to the bacterial community of cutting areas. Microbial association network analysis revealed strong positive interactions of Comamonas and Janthinobacterium with Myroides and Serratia, respectively, whereas Pseudomonas showed no significant correlation with other genera. The function of microbial communities was predicted based on BugBase 16S rRNA database, and the results indicated that the proportions of potential biofilm-forming bacteria were above 70% in all samples, and species of Pseudomonas, Comamonas, Chryseobacterium and Janthinobacterium were opportunistic pathogens or spoilage bacteria. This study evaluated the bacteria risks including bacterial load, composition, as well as potential bacterial interaction, function and microbial transfer on food processing surfaces, which will facilitate our better understanding on the cross-contaminations and preventions of harmful microorganism in FVs processing industry.


Assuntos
Microbiota , Verduras , Bactérias/genética , Microbiologia de Alimentos , Pseudomonas , RNA Ribossômico 16S/genética , Verduras/microbiologia
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