Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 19.091
Filtrar
1.
Food Chem ; 368: 130831, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34403999

RESUMO

This research aimed to apply nanotechnology for nanoformulation of Laurus nobilis essential oil (EO) by ultrasonic emulsification method and characterization of nano-form: particle size, viscosity, polydispersity index, thermodynamic stability, and surface tension. The antimicrobial activity of laurel EO nanoemulsion (LEON) and laurel EO was also investigated against a panel of ten food-borne pathogens and fish spoilage bacteria. The GC-MS analysis of EO revealed that 1,8-Cineole was the main volatile compound. According to disc-diffusion results, LEON was more effective against Gram-positive pathogen bacteria of Staphylococcus aureus and Enterococcus faecalis than EO. Laurel oil demonstrated a higher inhibitory effect against fish spoilage bacteria (6.19 to 18.5 mm). The MICs values of LEON and laurel EO ranged from 6.25 to >25 mg/mL and from 1.56 to >25 mg/mL, respectively. Nanoemulsion and oil exhibited the best bactericidal activity against Pseudomonas luteola. Therefore, LEON can be developed as a natural antimicrobial agent in food industry.


Assuntos
Anti-Infecciosos , Óleos Voláteis , Anti-Infecciosos/farmacologia , Bactérias , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Pseudomonas , Sesquiterpenos
2.
Mymensingh Med J ; 30(4): 954-959, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34605462

RESUMO

Biocides, including disinfectants and antiseptics, are used for a variety of topical and hard surface applications in health care facilities. Biocides play a significant role for preventing and controlling nosocomial infections. However, failures in the antimicrobial activities of biocides have been reported. The resistance mechanism to disinfectants is usually determined by genes which are related to resistance to quaternary ammonium compounds, namely, qacE, qacΔE1 that are found in Gram-negative bacteria. The aim of this study is to detect the prevalence of Biocides resistance genes, qacE and qacΔE1, in clinical isolates of Pseudomonas spp. It was carried out from March 2017 to July 2018 in the department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh. Samples were collected from Outpatient of ENT department, MMCH. In this study, 300 clinical samples of CSOM cases were tested by the PCR method. The present study shows detection of biocide resistance genes (qacE, qacΔE1) among 87 isolated Pseudomonas spp by uniplex PCR. Among 72 clinical isolates of Pseudomonas aeruginosa 67(93.05%) had the gene qacEΔ1 and 25(34.72%) had the gene qacE. In addition other 15 Pseudomonas spp 3(20%) isolates had the qacEΔ1 gene and 2(13.33%) isolates had the qacE gene. In this study there is a marked difference in detection of the qacEΔ1 gene between the MDR and non MDR P. aeruginosa isolates. The qacEΔ1 was identified in 50 of 54(92.59%) MDR isolates and 7 of 18(38.89%) non MDR strains respectively. While gene qacE was detect 25(46.29%) MDR isolates and did not show any qacEΔ1gene in non MDR isolates. This study shows that the genes, qacE, qacΔE1 are widespread among Pseudomonas aeruginosa, they are higher in MDR strains than non MDR strains.


Assuntos
Desinfetantes , Antibacterianos/farmacologia , Bangladesh/epidemiologia , Hospitais , Humanos , Testes de Sensibilidade Microbiana , Pseudomonas/genética
3.
Int J Mol Sci ; 22(19)2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34639082

RESUMO

Pseudomonas donghuensis HYS is more virulent than P. aeruginosa toward Caenorhabditis elegans but the mechanism underlying virulence is unclear. This study is the first to report that the specific gene cluster gtrA/B/II in P. donghuensis HYS is involved in the virulence of this strain toward C. elegans, and there are no reports of GtrA, GtrB and GtrII in any Pseudomonas species. The pathogenicity of P. donghuensis HYS was evaluated using C. elegans as a host. Based on the prediction of virulence factors and comparative genomic analysis of P. donghuensis HYS, we identified 42 specific virulence genes in P. donghuensis HYS. Slow-killing assays of these genes showed that the gtrAB mutation had the greatest effect on the virulence of P. donghuensis HYS, and GtrA, GtrB and GtrII all positively affected P. donghuensis HYS virulence. Two critical GtrII residues (Glu47 and Lys480) were identified in P. donghuensis HYS. Transmission electron microscopy (TEM) showed that GtrA, GtrB and GtrII were involved in the glucosylation of lipopolysaccharide (LPS) O-antigen in P. donghuensis HYS. Furthermore, colony-forming unit (CFU) assays showed that GtrA, GtrB and GtrII significantly enhanced P. donghuensis HYS colonization in the gut of C. elegans, and glucosylation of LPS O-antigen and colonization in the host intestine contributed to the pathogenicity of P. donghuensis HYS. In addition, experiments using the worm mutants ZD101, KU4 and KU25 revealed a correlation between P. donghuensis HYS virulence and the TIR-1/SEK-1/PMK-1 pathways of the innate immune p38 MAPK pathway in C. elegans. In conclusion, these results reveal that the specific virulence gene cluster gtrA/B/II contributes to the unique pathogenicity of HYS compared with other pathogenic Pseudomonas, and that this process also involves C. elegans innate immunity. These findings significantly increase the available information about GtrA/GtrB/GtrII-based virulence mechanisms in the genus Pseudomonas.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Imunidade Inata/imunologia , Família Multigênica , Pseudomonas/patogenicidade , Fatores de Virulência/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/microbiologia , Proteínas de Caenorhabditis elegans/genética , Virulência , Fatores de Virulência/genética
4.
F1000Res ; 10: 526, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381593

RESUMO

Pseudomonas aeruginosa ( P. aeruginosa) is an aerobic Gram-negative bacterium that is implicated in the development of severe systemic infections among pediatric patients.  It is identified in hospitalized chronically ill pediatric patients in association with genitourinary, respiratory tract, and skin or soft tissue infections as well as severe and life-threating infection including sepsis.  A variety of immunologic mechanisms play a vital role in the host defense mechanisms against invasive infections with P. aeruginosa. Rarely, specific inborn errors of immune function are implicated in deficiencies that predispose to invasive infections with P. aeruginosa.  Innate immune function including germ-line encoded pattern recognition receptors such as toll-like receptors (TLRs) and their downstream signaling is vital in the host defense against P. aeruginosa through the generation of antimicrobial peptides, cytokines/chemokines, and shaping of adaptive immune responses. Herein, we describe a previously healthy two-year-old female with an invasive skin, soft tissue, and central nervous system infection secondary to P. aeruginosa.  The invasive nature of this infection prompted a careful evaluation for an inborn error of immunity. Decreased cytokine response to agonists of TLRs was documented. Targeted sequencing of interleukin-1 receptor-associated kinase (IRAK)-4 documented a homozygous deletion of exons 8-13 consistent with IRAK-4 deficiency.  This report provides a vital educative message in the existing scientific literature by underscoring the importance of considering inborn errors of immunity in all patients with severe P. aeruginosa infections.  Functional assessments of immune function often in combination with sequencing can accurately assign a diagnosis in a timely fashion allowing for definitive treatment and the use of necessary supportive care.


Assuntos
Infecções por Pseudomonas , Pseudomonas , Criança , Pré-Escolar , Feminino , Homozigoto , Humanos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa , Deleção de Sequência
5.
Vestn Oftalmol ; 137(5. Vyp. 2): 238-247, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34669333

RESUMO

The preoperative and postoperative use of antiseptics can be an alternative to antibiotics in repeated courses of anti-VEGF therapy for reducing the risk of developing antibiotic resistance in eye microflora. Among gram-negative bacteria, the most frequently isolated pathogen that causes eye infections is Pseudomonas aeruginosa, which is characterized by reduced sensitivity to antibiotics and disinfectants. PURPOSE: To study the effect of the antiseptic picloxydine dihydrochloride on the gram-negative bacteria Escherichia coli, Pseudomonas luteola and P. aeruginosa isolated from the conjunctiva. MATERIAL AND METHODS: The identification of bacterial isolates and study of their sensitivity to antibiotics were carried out using the automated bacteriological analyzer BD Phoenix 100. To determine the bactericidal concentration, the method of serial dilutions of the antiseptic in a liquid nutrient medium was used. The binding of cationic molecules of picloxydine dihydrochloride to bacterial cells was detected by neutralizing the bacterial surface with increasing amounts of antiseptic, and measuring the zeta potential on the Zetasizer Nano ZS analyzer. The ultrastructure of bacterial cells was studied using the two-beam scanning ion-electron microscope Quanta 200 3D. RESULTS: The most resistant was P. aeruginosa. The interaction mechanism of picloxydine dihydrochloride with bacterial cells includes electrostatic binding of positively charged antiseptic molecules to negatively charged cell walls. Picloxydine dihydrochloride has a destructive effect on the bacterial cell wall and plasma membrane, which leads to cell lysis and release of intracellular components. CONCLUSION: Picloxydine dihydrochloride exhibits bactericidal activity against gram-negative conjunctival isolates and is promising for preventive use during repeated courses of intravitreal injections.


Assuntos
Anti-Infecciosos Locais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos Locais/farmacologia , Túnica Conjuntiva , Testes de Sensibilidade Microbiana , Piperazinas , Pseudomonas
6.
Water Res ; 204: 117593, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34482094

RESUMO

Reconditioning of food processing water streams for reuse is an increasingly common water management practice in the food industry and UV disinfection is often employed as part of the water treatment. Several factors may impact the effect of UV radiation. Here, we aim to assess the impact of cell aggregation on UV inactivation kinetics and investigate if UV exposure induces aggregation. Three strains, isolated from food processing water reuse lines (Raoultella ornithinolytica, Pseudomonas brenneri, Rothia mucilaginosa) and both an aggregating and a non-aggregating strain of Staphylococcus aureus were exposed to UVC light at 255 nm using UV LED equipment. Total Viable Count and phase-contrast microscopy, coupled with image analysis, were used to compare the UV inactivation kinetics with the average particle size for a range of UV doses. Tailing effect, seen as a strong reduction in inactivation rate, was observed for all strains at higher UV doses (industrial strains ≥ 50 or 120 mJ/cm2, S. aureus strains  ≥ 40 or 60 mJ/cm2). The naturally aggregating strains were more UV tolerant, both within and between species. When aggregates of S. aureus were broken, UV tolerance decreased. For the processing water isolates, the lowest applied UV dose (25 mJ/cm2) significantly increased the average particle size. Application of higher UV doses obtained with longer exposure times did not further increase the particle size compared with untreated samples. For the S. aureus strains, however, no consistent change in average particle size was observed due to UV. Our results demonstrate that aggregating strains have a higher degree of protection and that UV radiation induces aggregation in some, but not all bacteria. A better understanding of the mechanisms governing microbial aggregation and survival during UV treatment could help to improve UV applications and predictions of microbial inactivation.


Assuntos
Staphylococcus aureus , Raios Ultravioleta , Bactérias , Desinfecção , Enterobacteriaceae , Cinética , Micrococcaceae , Pseudomonas
7.
Curr Microbiol ; 78(11): 3924-3935, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34522981

RESUMO

Caffeine, a xenobiotic compound, is continuously released into the environment. Fifteen psychrotolerant bacterial strains, isolated from the Indian Himalayan region, were screened for their caffeine degradation capacity. The medium for the growth of bacteria was optimized using Box-Behnken method. Among these bacteria, Pseudomonassp. (GBPI_Hb5), showing the best response, was further used for caffeine degradation in batch mode. The culture medium, having caffeine as a sole source of carbon, was used for analyzing the effect of pH, agitation speed, temperature, inoculum volume, and caffeine concentration on bacterial growth and its caffeine degradation potential. The bacterium GBPI_Hb5 showed approx. 93% caffeine degradation up to 96 h under controlled conditions. The compounds produced during the degradation of caffeine were also studied. The study is likely to have implications in the bioremediation of caffeine from polluted environments.


Assuntos
Cafeína , Pseudomonas , Carbono , Meios de Cultura , Pseudomonas/genética , Temperatura
8.
Rev Chilena Infectol ; 38(3): 324-332, 2021 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-34479287

RESUMO

BACKGROUND: Indoor air quality in health centers is essential to protect the health of people. In Chile, the Community Family Health Centers (CECOSF) are places with large attendance of people, favoring the dissemination of microorganisms, and there are no reports of the microbial air loading these health centers. AIM: To evaluate the microbiological indoor air quality in CECOSF-Centinela in Talcahuano, Biobío Region. METHODS: Air samples were taken in 6 rooms of the CECOSF, every 15 days between July 2018 and June 2019, with the MAS-100 NT equipment using trypticase and Sabouraud agars. Different morphotypes of bacteria and fungi were identified by PCR. RESULTS: The bacterial and fungal counts varied between 9.1 × 101 - 2.4 × 103 cfu/m3 and 10 - 1.5 × 102 cfu/m3, respectively. The air in the waiting room presented the highest counts, both for bacteria and fungi (P < 0.05). Staphylococcus, Enterococcus, Pseudomonas, Acinetobacter were identified, highlighting the species Staphylococcus aureus and Pseudomonas oryzihabitans, the latter described as a nosocomial pathogen. Among the fungi, Aspergillus, Meyerozyma and Rhodotorula were identified. CONCLUSION: The indoor air of the CECOSF-Centinela presents microorganisms of importance in human health. Therefore, it is necessary to formulate more regular monitoring programs for the control of air quality inside these health centers.


Assuntos
Poluição do Ar em Ambientes Fechados , Saúde da Família , Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Chile , Contagem de Colônia Microbiana , Monitoramento Ambiental , Fungos , Humanos , Pseudomonas
9.
Food Res Int ; 148: 110618, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507762

RESUMO

The biofilm formation ability of a collection of thirty-three Pseudomonas spp. isolates from food processing facilities was investigated in order to find biomarkers of strong biofilm production, a characteristic that can determine persistence in food processing environments. The strains were classified according to the colony pigmentation on solid media as green, brown or not pigmented. The biofilm production on stainless steel and polystyrene was assessed by spectrometric determination of the fixed crystal violet, and the biofilm formed on glass, through confocal laser scanning microscopy. Besides, pyoverdine production, catalase activity, RpoS status and cellular hydrophobicity were also monitored. A significantly higher biofilm production level on stainless steel and polystyrene was observed for green-pigmented strains as compared to brown or not pigmented strains. The influence of iron availability on biofilm formation on stainless steel was studied through the addition of the iron scavenger 2,2-bipyridine resulting in a decrease of 40 % in biofilm formation for the not pigmented strains. For most of the potential biomarkers studied (i.e., pyoverdine production, catalase activity, cellular hydrophobicity), the phenotypic heterogeneity observed among strains was mainly dependent on the Pseudomonas species and no strong associations with the biofilm formation capacity were detected. However, the green colony pigmentation on solid media showed good potential as a biomarker of strong biofilm formation on stainless steel and polystyrene both in P. aeruginosa and Pseudomonas spp.


Assuntos
Pseudomonas , Aço Inoxidável , Biofilmes , Biomarcadores , Manipulação de Alimentos
10.
Artigo em Inglês | MEDLINE | ID: mdl-34546867

RESUMO

The evolutionary relationships among species of the family Pseudomonadaceae were examined based on 255 available genomes representing >85 % of the species from this family. In a phylogenetic tree based on concatenated sequences of 118 core proteins, most species of the genus Pseudomonas grouped within one large cluster which also included members of the genera Azotobacter and Azomonas. Within this large cluster 18-30 clades/subclades of species of the genus Pseudomonas consisting of between 1 and 36 species, were observed. However, a number of species of the genus Pseudomonas branched outside of this main cluster and were interspersed among other genera of the family Pseudomonadaceae. This included a strongly supported clade (Pertucinogena clade) consisting of 19 mainly halotolerant species. The distinctness of this clade from all other members of the family Pseudomonadaceae is strongly supported by 24 conserved signature indels (CSIs) in diverse proteins that are exclusively found in all members of this clade. Nine uncharacterized members of the genus Pseudomonas also shared these CSIs and they branched within the Pertucinogena clade, indicating their affiliation to this clade. On the basis of the strong evidence supporting the distinctness of the Pertucinogena clade, we are proposing transfer of species from this clade into a novel genus Halopseudomonas gen. nov. Pseudomonas caeni also branches outside of the main cluster and groups reliably with Oblitimonas alkaliphila and Thiopseudomonas denitrificans. Six identified CSIs are uniquely shared by these three species and we are proposing their integration into the emended genus Thiopseudomonas, which has priority over the name Oblitimonas. We are also proposing transfer of the deep-branching Pseudomonas hussainii, for which 22 exclusive CSIs have been identified, into the genus Atopomonas gen. nov. Lastly, we present strong evidence that the species Pseudomonas cissicola and Pseudomonas geniculata are misclassified into the genus Pseudomonas and that they are specifically related to the genera Xanthomonas and Stenotrophomonas, respectively. In addition, we are also reclassifying 'Pseudomonas acidophila' as Paraburkholderia acidicola sp. nov. (Type strain: G-6302=ATCC 31363=BCRC 13035).


Assuntos
Ácidos Graxos , Genômica , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , Pseudomonadaceae , Pseudomonas/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Xanthomonas
11.
J Environ Manage ; 299: 113641, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479150

RESUMO

Aerobic denitrifying bacteria have the potential to remove the co-pollutants Ni(II) and nitrate in industrial wastewater. In this study, aerobic denitrifying bacteria with significant Ni(II) removal efficiency was isolated from the biological reaction tank and named as Pseudomonas hibiscicola L1 strain after 16 S rRNA identification analysis. The removal of ever-increasing Ni(II) and NO3--N wastewater under aerobic conditions by strain L1 was discussed. The experimental results showed that strain L1 removed 84% of Ni(II) and 81% of COD, with the use of 34.8 mg L-1 of nitrogen source and without nitrite accumulation yet. Strain L1 had remarkable activity (OD600 = 0.51-0.56 (p < 0.05)) at 20 mg L-1 of Ni(II) and 100 mg L-1 of NO3--N. It was found that high Ni(II) gradients (2-10 mg L-1) had little effect on nitrate removal ratio (35-34% (p > 0.05), and the removal ratios of Ni(II) was enhanced (from 42% to 83% (p < 0.05)) by increasing nitrate (25-100 mg L-1). Also, the results indicated that strain L1 could reduce Ni(II) and nitrate under different pH (6-9); electron donor-glucose, sodium acetate, sodium succinate and trisodium citrate; C/N (5-20) and coexisting ions (Cu(II) and Zn(II)). Notably, the nitrogen balance analysis showed 32.4% of TN was lost nitrogen and 19.7% of TN was assimilated for cell growth, which indicated aerobic denitrification process of strain L1. Meanwhile, characterization technology (SEM, FTIR, and XRD) showed Ni(II) was bioadsorbed in the form of Ni(NH2)2, NiCO3, and Ni(OH)2·2H2O through surface functional groups. This research provides new microbial method for the simultaneous removal of nitrate and Ni(II) in wastewater.


Assuntos
Desnitrificação , Nitratos , Aerobiose , Nitrificação , Nitritos , Nitrogênio , Pseudomonas/genética , Stenotrophomonas
12.
J Hazard Mater ; 416: 125914, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492848

RESUMO

A simultaneous denitrifying and mineralizing bacterium, Pseudomonas sp. WZ39 was isolated for fluoride (F-), nitrate (NO3--N), and calcium (Ca2+) removal. Strain WZ39 exhibited a remarkable defluoridation efficiency of 87.49% under a pH of 6.90, F- and Ca2+ concentration of 1.99 and 201.88 mg L-1, respectively. EEM, SEM-EDS, XRD, and FTIR analyses elucidated the chemical adsorption and co-precipitation with calcium salt contributed to the removal of F-. The mechanisms of biomineralization were also investigated by determining the role of bound and unbound extracellular polymeric substances (EPS), cell wall, and calcium channel in nucleation. The results showed that bacteria can promote nucleation on the templates of cell walls or EPS through the electrostatic effect. The presence of the calcium channel blocker inhibited the transport of intracellular Ca2+ to the extracellular environment. The outcome of the present research can provide a theoretical basis for the understanding of MICP phenomenon and the efficient treatment of F- containing groundwater.


Assuntos
Fluoretos , Nitratos , Cálcio , Desnitrificação , Pseudomonas
13.
J Hazard Mater ; 416: 126239, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492990

RESUMO

Polystyrene (PS), a major plastic waste, is difficult to biodegrade due to its unique chemical structure that comprises phenyl moieties attached to long linear alkanes. In this study, we investigated the biodegradation of PS by mesophilic bacterial cultures obtained from various soils in common environments. Two new strains, Pseudomonas lini JNU01 and Acinetobacter johnsonii JNU01, were specifically enriched in non-carbonaceous nutrient medium, with PS as the only source of carbon. Their growth after culturing in basal media increased more than 3-fold in the presence of PS. Fourier transform infrared spectroscopy analysis, used to confirm the formation of hydroxyl groups and potentially additional chemical bond groups, showed an increase in the amount of oxidized PS samples. Moreover, field emission scanning electron microcopy analysis confirmed PS biodegradation by biofilms of the screened microbes. Water contact angle measurement additionally offered insights into the increased hydrophilic characteristics of PS films. Bioinformatics and transcriptional analysis of A. johnsonii JNU01 revealed alkane-1-monooxygenase (AlkB) to be involved in PS biodegradation, which was confirmed by the hydroxylation of PS using recombinant AlkB. These results provide significant insights into the discovery of novel functions of Pseudomonas sp. and Acinetobacter sp., as well as their potential as PS decomposers.


Assuntos
Poliestirenos , Solo , Acinetobacter , Bactérias , Biodegradação Ambiental , Pseudomonas
14.
Artigo em Inglês | MEDLINE | ID: mdl-34424837

RESUMO

Three phytopathogenic bacterial strains (Pc19-1T, Pc19-2 and Pc19-3) were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper (Capsicum annuum) leaves in Georgia, USA. Upon isolation on King's medium B, light cream-coloured colonies were observed and a diffusible fluorescent pigment was visible under ultraviolet light. Analysis of their 16S rRNA gene sequences showed that they belonged to the genus Pseudomonas, with the highest similarity to Pseudomonas cichorii ATCC 10857T (99.7 %). The fatty acid analysis revealed that the majority of the fatty acids were summed feature 3 (C16  :  1 ω7c/C16  :  1 ω6c), C16  :  0 and summed feature 8 (C18  :  1 ω7c/C18  :  1 ω6c). Phylogenomic analyses based on whole genome sequences demonstrated that the pepper strains belonged to the Pseudomonas syringae complex with P. cichorii as their closest neighbour, and formed a separate monophyletic clade from other species. Between the pepper strains and P. cichorii, the average nucleotide identity values were 91.3 %. Furthermore, the digital DNA-DNA hybridization values of the pepper strains when compared to their closest relatives, including P. cichorii, were 45.2 % or less. In addition, biochemical and physiological features were examined in this study and the results indicate that the pepper strains represent a novel Pseudomonas species. Therefore, we propose a new species Pseudomonas capsici sp. nov., with Pc19-1T (=CFBP 8884T=LMG 32209T) as the type strain. The DNA G+C content of the strain Pc19-1T is 58.4 mol%.


Assuntos
Capsicum/microbiologia , Filogenia , Pseudomonas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Georgia , Hibridização de Ácido Nucleico , Folhas de Planta/microbiologia , Pseudomonas/classificação , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
J Glob Antimicrob Resist ; 26: 330-334, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34363995

RESUMO

OBJECTIVES: Antibiotic therapy for Pseudomonas infections is becoming increasingly difficult. In this study, the transposons from two multidrug-resistant (MDR) clinical Pseudomonas strains containing related transposons responsible for giving rise to resistance determinants were characterised. METHODS: Two MDR clinical Pseudomonas isolates were obtained from a medical facility in Cyprus. The strains were identified as Pseudomonas putida C54 and Pseudomonas aeruginosa C69. DNA was extracted from both strains and was sequenced. Transposons were identified, annotated and compared with DNA sequences in GenBank. RESULTS: Two related nested transposons, here named Tn6608 (from P. putida C54) and Tn6609 (from P. aeruginosa C69), were characterised. The transposons are built on an ancestral Tn1403 base element (here named Tn1403A) that contains only the transposition module (tnpA and tnpR) and the associated cargo gene module (orfA, orfB, orfC and orfD) flanked by a 38-bp inverted repeat. The nested transposons identified in this study have evolved via acquisition of multiple transposons, adding multiple resistance genes to an ancestral transposon that originally lacked any resistance determinants. CONCLUSION: Transposons related to Tn6608 and Tn6609 have evolved and are globally disseminated. Of particular interest is that most of these nested transposons are located within the same site in a genomic island, providing alternative avenues for dissemination.


Assuntos
Infecções por Pseudomonas , Pseudomonas , Chipre , Resistência Microbiana a Medicamentos , Humanos , Pseudomonas/genética , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa
16.
Bioresour Technol ; 340: 125679, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34364084

RESUMO

Pseudomonas citronellolis SJTE-3 was isolated as a highly efficient microorganism for biodegradation and valorization of drilling fluids (DF) wastewater. The strain metabolised DF and oily mud exhibiting up to 93%, 86%, 85% and 88% of chemical oxygen demand (COD), n-dodecane, n-tetradecane and naphthalene removal efficiency respectively. Enhanced bioconversion was enabled through production of biosurfactants that reduced the surface tension of water by 53% and resulted in 43.3% emulsification index (E24), while synthesizing 24% of dry cell weight (DCW) as medium-chain-length polyhydroxyalkanoates (PHA). Expression from the main pathways for alkanes and naphthalene biodegradation as well as biosurfactants and PHA biosynthesis revealed that although the alkanes and naphthalene biodegradation routes were actively expressed even at stationary phase, PHA production was stimulated at late stationary phase and putisolvin could comprise the biosurfactant synthesized. The bioconversion of toxic petrochemical residues to added-value thermoelastomers and biosurfactants indicate the high industrial significance of P. citronellolis SJTE-3.


Assuntos
Poli-Hidroxialcanoatos , Biodegradação Ambiental , Pseudomonas , Tensoativos , Águas Residuárias
17.
Water Res ; 203: 117511, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34375932

RESUMO

Efficient and sustainable removal of phosphate ions from an aqueous solution is of great challenge. Herein we demonstrated a greener route for phosphate recovery through struvite formation by using bacterial siderophore. This method was efficient for removal of phosphate as low as 1.3 mM with 99% recovery efficiency. The siderophore produced by Pseudomonas taiwanensis R-12-2 act as template for the nucleation of struvite crystals and was found sustainable for recycling the phosphorous efficiently after twenty cycles. The formation of struvite crystals is driven by surrounding pH (9.0) and presence of Mg2+ and NH4+ ions along with PO43- and siderophore which was further validated by computational studies. The morphology of struvite was characterized by scanning electron microscopy, followed by elemental analysis. Furthermore, our results revealed that the siderophore plays an important role in struvite biomineralization. We have successfully demonstrated the phosphate sequestration by using industrial waste samples, as possible application for environmental sustainability and phosphate conservation. For the first time electrochemical super-capacitance performance of the struvite was studied. The specific capacitance value for the struvite was found to be 320 F g-1 at 1.87 A g-1 and retained 92 % capacitance after 250 cycles. The study revealed the potential implications of siderophore for the phosphate recycling and the new mechanism for biomineralization by sequestering into struvite.


Assuntos
Fosfatos , Sideróforos , Magnésio , Fósforo , Pseudomonas , Estruvita , Águas Residuárias
18.
BMC Infect Dis ; 21(1): 868, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433417

RESUMO

BACKGROUND: Pseudomonas otitidis is a novel species of Pseudomonas bacteria that has been isolated from patients with otic infections. CASE PRESENTATION: In this report, we describe a case of a 59-year-old known with moderate chronic obstructive pulmonary disease with bronchiectasis and recurrent pneumonia where blood cultures revealed the growth of P. otitidis. CONCLUSIONS: This case describes the first report of bacteraemia to P. otitidis and raises questions regarding the misdiagnosis and underestimation of the incidence of infections caused by this novel pathogen.


Assuntos
Bacteriemia , Pneumonia , Doença Pulmonar Obstrutiva Crônica , Bacteriemia/diagnóstico , Humanos , Pessoa de Meia-Idade , Pseudomonas , Doença Pulmonar Obstrutiva Crônica/complicações
19.
Molecules ; 26(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34443401

RESUMO

The dinitrotoluene isomers 2,4 and 2,6-dinitrotoluene (DNT) represent highly toxic, mutagenic, and carcinogenic compounds used in explosive manufacturing and in commercial production of polyurethane foam. Bioremediation, the use of microbes to degrade residual DNT in industry wastewaters, represents a promising, low cost and environmentally friendly alternative technology to landfilling. In the present study, the effect of different bioremediation strategies on the degradation of DNT in a microcosm-based study was evaluated. Biostimulation of the indigenous microbial community with sulphur phosphate (2.3 g/kg sludge) enhanced DNT transformation (82% transformation, from 300 g/L at Day 0 to 55 g/L in week 6) compared to natural attenuation over the same period at 25 °C. The indigenous microbial activity was found to be capable of transforming the contaminant, with around 70% transformation of DNT occurring over the microcosm study. 16S rDNA sequence analysis revealed that while the original bacterial community was dominated by Gammaproteobacteria (30%), the addition of sulphur phosphate significantly increased the abundance of Betaproteobacteria by the end of the biostimulation treatment, with the bacterial community dominated by Burkholderia (46%) followed by Rhodanobacter, Acidovorax and Pseudomonas. In summary, the results suggest biostimulation as a treatment choice for the remediation of dinitrotoluenes and explosives waste.


Assuntos
Biodegradação Ambiental , Substâncias Explosivas/toxicidade , Microbiota/genética , Esgotos/microbiologia , Burkholderia/química , Burkholderia/genética , Burkholderia/isolamento & purificação , Burkholderia/metabolismo , Dinitrobenzenos/química , Dinitrobenzenos/toxicidade , Substâncias Explosivas/química , Humanos , Pseudomonas/química , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RNA Ribossômico 16S/genética
20.
Bioresour Technol ; 341: 125785, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34455248

RESUMO

The nitrogen metabolic pathways of Pseudomonas taiwanensis J488 have not been confirmed from genomic function analysis and its divalent metal ion resistance remains poorly understood. In this study, the key denitrifying gene of Pseudomonas taiwanensis J488, nirB, was determined by draft genome sequencing. The nitrification of ammonium was insensitive to high concentrations of Ca(II), Mn(II), Zn(II), and Cd(II). Similarly, complete nitrite removal was achieved despite Mn(II) and Zn(II) reaching concentrations up to 30 mg/L. Furthermore, the efficiency of nitrate removal was significantly enhanced by 1.33%, 3.33%, 5.99%, and 1.53% with the addition of 0.5 mg/L Ca(II), 20 mg/L Mn(II), 5 mg/L Zn(II), and 2 mg/L Cd(II), respectively, comparison with the control. The bacterial growth in both nitrifying and denitrifying processes was substantially promoted by various dosages of divalent metal ions. These results indicate that divalent metal ions would not severely limit the capacity of strain J488 to purify nitrogen-polluted wastewater.


Assuntos
Compostos de Amônio , Hipotermia , Aerobiose , Desnitrificação , Processos Heterotróficos , Humanos , Nitrificação , Nitritos , Nitrogênio , Pseudomonas , Águas Residuárias
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...