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Virulence Jan 2018Non-fermenting Gram-negative bacteria are problematic in clinical locations, being one of the most prevalent causes of nosocomial infections. Many of these... (Review)
Review
Non-fermenting Gram-negative bacteria are problematic in clinical locations, being one of the most prevalent causes of nosocomial infections. Many of these non-fermenting Gram-negative bacteria are opportunistic pathogens that affect patients that are suffering with underlying medical conditions and diseases. Brevundimonas spp., in particular Brevundimonas diminuta and Brevundimonas vesicularis, are a genus of non-fermenting Gram-negative bacteria considered of minor clinical importance. Forty-nine separate instances of infection relating to Brevundimonas spp were found in the scientific literature along with two pseudo-infections. The majority of these instances were infection with Brevundimonas vesicularis (thirty-five cases - 71%). The major condition associated with Brevundimonas spp infection was bacteraemia with seventeen individual cases/outbreaks (35%). This review identified forty-nine examples of Brevundimonas spp. infections have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Brevundimonas spp outbreaks if these bacteria are clinically isolated in more than one patient.
Topics: Bacteremia; Caulobacteraceae; Communicable Diseases, Emerging; Disease Outbreaks; Global Health; Gram-Negative Bacterial Infections; Humans; Opportunistic Infections
PubMed: 29484917
DOI: 10.1080/21505594.2017.1419116 -
Microbiology Spectrum Sep 2021is a genus of Gram-negative bacteria widely distributed in nature and is also an opportunistic pathogen causing health care-associated infections. strain 090558 was...
is a genus of Gram-negative bacteria widely distributed in nature and is also an opportunistic pathogen causing health care-associated infections. strain 090558 was recovered from a blood culture of a cancer patient and was subjected to genome sequencing and analysis. The average nucleotide identity and DNA-DNA hybridization values between 090558 and type strains of species were 78.76% to 93.94% and 19.8% to 53.9%, respectively, below the cutoff to define bacterial species. Detailed phenotypic tests were performed, suggesting that 090558 can be differentiated from other species by its ability to assimilate sodium acetate but not to utilize glucose, trypsin, or β-glucosidase. Strain 090558 (GDMCC 1.1871 or KCTC 82165) therefore represents a novel species, for which the name Brevundimonas huaxiensis sp. nov. is proposed. All genomes available in GenBank (accessed on 25 January 2021) were retrieved, discarding those labeled "excluded from RefSeq" by GenBank, and included 82 genomes for precise species curation. In addition to the 21 species with genomes of type strains available, we identified 29 taxa that either belong to the 12 species without available genomes of type strains or represent novel species. We found that more than half (57.3%) of the 82 genomes need to be corrected for species assignation, including species mislabeling of a type strain. Our analysis highlights the complexity of taxonomy. We also found that only some species are associated with human infections, and more studies are warranted to understand their pathogenicity and epidemiology. is a genus of the family and comprises 33 species. can cause various infections but remains poorly studied. In this study, we reported a novel species, , based on genome and phenotype studies of strain 090558 recovered from human blood. We then examined the species assignations of all genomes ( = 82) in GenBank and found that in addition to the known species with genome sequences of type strains available, there are 29 taxa based on genome analysis, which need to be further studied using phenotype-based methods to establish their species status. Our study significantly updates the taxonomy of and enhances our understanding of this genus of clinical relevance. The findings also encourage future studies on the characterization of novel species.
Topics: Caulobacteraceae; Genome, Bacterial; Glucose; Phenotype; Phylogeny; Sodium Acetate; Trypsin
PubMed: 34232096
DOI: 10.1128/Spectrum.00111-21 -
Microbiology Spectrum Jun 2023To increase knowledge on pathogens, we conducted in-depth genomic and phenotypic characterization of a strain isolated from the cerebrospinal fluid of a patient...
To increase knowledge on pathogens, we conducted in-depth genomic and phenotypic characterization of a strain isolated from the cerebrospinal fluid of a patient admitted in a neonatal intensive care unit. The strain was identified as a member of the genus based on Vitek 2 system results and 16S rRNA gene sequencing and presented a multidrug resistance profile (MDR). Several molecular and biochemical tests were used to characterize and identify the species for in-depth results. The draft genome assembly of the isolate has a total length of 3,261,074 bp and a G+C of 66.86%, similar to other species of the genus. Multilocus sequence analysis, Type (Strain) Genome Server, digital DNA-DNA hybridization, and average nucleotide identity confirmed that the sp. studied represents a distinct species, for which we propose the name sp. nov. analysis detected antimicrobial resistance genes (AMRGs) mediating resistance to β-lactams (, , and ) and aminoglycosides [, , , and ]. We also found AMRGs encoding the AcrAB efflux pump that confers resistance to a broad spectrum of antibiotics. Colistin and quinolone resistance can be attributed to mutation in and/or and GyrA/GyrB, respectively. The sp. nov. genome contained copies of type IV secretion system (T4SS)-type integrative and conjugative elements (ICEs); integrative mobilizable elements (IME); and Tn-type and IS, IS, IS, and IS families, suggesting an important role in the development and dissemination of antibiotic resistance. The isolate presented a range of virulence-associated genes related to biofilm formation, adhesion, and invasion that can be relevant for its pathogenicity. Our findings provide a wealth of data to hinder the transmission of MDR and highlight the need for monitoring and identifying new bacterial species in hospital environments. species is considered an opportunistic human pathogen that can cause multiple types of invasive and severe infections in patients with underlying pathologies. Treatment of these pathogens has become a major challenge because many isolates are resistant to most antibiotics used in clinical practice. Furthermore, there are no consistent therapeutic results demonstrating the efficacy of antibacterial agents. Although considered a rare pathogen, recent studies have provided evidence of the emergence of in clinical settings. Hence, we identified a novel pathogenic bacterium, sp. nov., that presented a multidrug resistance (MDR) profile and carried diverse genes related to drug resistance, virulence, and mobile genetic elements. Such data can serve as a baseline for understanding the genomic diversity, adaptation, evolution, and pathogenicity of MDR
Topics: Infant, Newborn; Humans; RNA, Ribosomal, 16S; Brazil; Anti-Bacterial Agents; Colistin; DNA
PubMed: 37067439
DOI: 10.1128/spectrum.04415-22 -
International Journal of Systematic and... Jan 2020A Gram-stain-negative, rod-shaped, motile, facultatively aerobic and ivory-pigmented bacterium (designated strain LA-55) was isolated from a river in the Republic of...
A Gram-stain-negative, rod-shaped, motile, facultatively aerobic and ivory-pigmented bacterium (designated strain LA-55) was isolated from a river in the Republic of Korea. On the basis of 16S rRNA gene sequencing, strain LA-55 clustered with species of the genus and was closely related to KSL-102 (97.3 %), DSM 4731 (97.1 %), NHI-13 (97.0 %), FDRGB2b (97.0 %) and DSM 17977 (97.0 %). The average nucleotide identity value between strain LA-55 and its closest-related strain was 74.1 %, indicating that strain LA-55 represents a novel species of the genus . Growth occurred at 15-40 °C on Reasoner's 2A medium in the presence of 0-2 % NaCl (w/v) and at pH 6.0-8.0. The genomic DNA G+C content was 70.5 mol% and ubiquinone 10 (Q-10) was the major respiratory quinone. The major cellular fatty acids (>5 %) were C 6 and/or C 7 (summed feature 8), C, C 6 and/or C 7 (summed feature 3) and C 7 11-methyl. The polar lipids consisted of phosphatidylglycerol, 1,2-di--acyl-3--[d-glucopyranosyl-(1→4)--d-glucopyranuronosyl]glycerol, 1,2-di--acyl-3--d-glucopyranuronosyl glycerol, unidentified aminolipid, unidentified phosphoglycolipid and unidentified lipids. Physiological and biochemical characteristics indicated that strain LA-55 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is LA-55 (=KACC 19639=LMG 30850).
Topics: Bacterial Typing Techniques; Base Composition; Caulobacteraceae; DNA, Bacterial; Fatty Acids; Nucleic Acid Hybridization; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Republic of Korea; Rivers; Sequence Analysis, DNA; Ubiquinone; Water Microbiology
PubMed: 31596194
DOI: 10.1099/ijsem.0.003736 -
International Journal of Molecular... Nov 2023Drought stress is a significant threat to agricultural productivity and poses challenges to plant survival and growth. Research into microbial plant biostimulants faces...
Drought stress is a significant threat to agricultural productivity and poses challenges to plant survival and growth. Research into microbial plant biostimulants faces difficulties in understanding complicated ecological dynamics, molecular mechanisms, and specificity; to address these knowledge gaps, collaborative efforts and innovative strategies are needed. In the present study, we investigated the potential role of (S1T13) as a microbial plant biostimulant to enhance drought tolerance in . We assessed the impact of S1T13 on Col-0 wild-type (WT) and mutant plants under drought conditions. Our results revealed that the inoculation of S1T13 significantly contributed to plant vigor, with notable improvements observed in both genotypes. To elucidate the underlying mechanisms, we studied the role of ROS and their regulation by antioxidant genes and enzymes in plants inoculated with S1T13. Interestingly, the inoculation of S1T13 enhanced the activities of GSH, SOD, POD, and PPO by 33, 35, 41, and 44% in WT and 24, 22, 26, and 33% in , respectively. In addition, S1T13 upregulated the expression of antioxidant genes. This enhanced antioxidant machinery played a crucial role in neutralizing ROS and protecting plant cells from oxidative damage during drought stress. Furthermore, we investigated the impact of S1T13 on ABA and drought-stress-responsive genes. Similarly, S1T13 modulated the production of ABA and expression of , , , and by 31, 42, 37, 41, and 42% in WT and 20, 29, 27, 38, and 29% in . The improvement in plant vigor, coupled with the induction of the antioxidant system and modulation of ABA, indicates the pivotal role of S1T13 in enhancing the drought stress tolerance of the plants. Conclusively, the current study provides valuable insights for the application of multitrait S1T13 as a novel strain to improve drought stress tolerance in plants and could be added to the consortium of biofertilizers.
Topics: Arabidopsis; Antioxidants; Droughts; Reactive Oxygen Species; Stress, Physiological; Arabidopsis Proteins; Plants, Genetically Modified; Gene Expression Regulation, Plant; Abscisic Acid; Plant Proteins
PubMed: 38068913
DOI: 10.3390/ijms242316590 -
Eye & Contact Lens Jan 2012To report the first documented case of keratitis secondary to the gram-negative bacillus Brevundimonas diminuta.
PURPOSE
To report the first documented case of keratitis secondary to the gram-negative bacillus Brevundimonas diminuta.
METHODS
A 66-year-old woman with an ocular history of bilateral soft contact lens wear presented with a large, 6×9-mm, culture-positive Pseudomonas aeruginosa-induced corneal ulcer. After weeks of therapy, she developed secondary keratitis. Repeat cultures grew a rare, gram-negative bacillus, B. diminuta.
RESULTS
Targeted therapy followed by adjustments based on repeat bacterial cultures with sensitivities resulted in slow resolution of the ulcer. After months of therapy, the cornea recovered leaving only a minimal corneal scar. Visual acuity improved from a low of Hand Motions to a final 20/40.
CONCLUSIONS
This is the first reported case of ocular infection with B. diminuta. This case demonstrates the need to be aware of potential rare secondary infections in corneas compromised by an initial infection and to adjust pharmacotherapy based on sensitivities and clinical signs.
Topics: Aged; Anti-Bacterial Agents; Caulobacteraceae; Female; Gram-Negative Bacterial Infections; Humans; Keratitis; Visual Acuity
PubMed: 21617535
DOI: 10.1097/ICL.0b013e31821c04f7 -
Chemosphere Jan 2021Natural occurring metal-tolerant microbial population have replaced conventional expensive metal remediation approach since the last few years. The present study focuses...
Natural occurring metal-tolerant microbial population have replaced conventional expensive metal remediation approach since the last few years. The present study focuses on investigating the potential of a copper-tolerant plant growth promoting rhizobacterial strain Brevundimonas diminuta MYS6 for Cu bioremediation, plant growth promotion and Cu uptake in Helianthus annuus L. Box-Behnken Design of response surface methodology optimized the influencing parameters such as pH, temperature and Cu concentration. At optimized conditions of pH (5), temperature (32.5 °C) and Cu concentration (250 mg/L), the rhizobacteria followed a sigmoid growth curve pattern with maximum Cu removal of 94.8% in the stationary phase of growth. Cu exposed Brevundimonas diminuta MYS6 produced increased EPS (18.6%), indicating their role in internal defence against Cu stress. The FTIR analysis suggested the role of carboxylic acids, alcohols and aliphatic amine groups in Cu bioremoval. Furthermore, the results of pot experiments conducted with Helianthus annuus L. var. CO4 and Brevundimonas diminuta MYS6 showed enhanced plant growth and Cu uptake. The rhizobacteria increased root and shoot length, fresh and dry plant biomass and leaf chlorophyll by 1.5, 1.7, 9.9, 15.8 and 2.1 fold. The plant biomass mediate enhanced Cu uptake in roots and shoots was found to be 2.98 and 4.1 folds higher when compared to non-inoculated treatment. Henceforth the results of the study evidence the rhizobacterial strain Brevundimonas diminuta MYS6 as an efficient bio-inoculant for copper remediation.
Topics: Biodegradation, Environmental; Caulobacteraceae; Copper; Helianthus; Plant Roots; Soil Pollutants
PubMed: 33297160
DOI: 10.1016/j.chemosphere.2020.128195 -
Germs Mar 2023spp. are rare and opportunistic pathogens which may cause infections in patients who are immunocompromised or have underlying disease.
INTRODUCTION
spp. are rare and opportunistic pathogens which may cause infections in patients who are immunocompromised or have underlying disease.
CASE REPORT
Two cases with a microbiological diagnosis of and spp. are presented. Both occurred in immunocompromised patients with post-chemotherapy febrile neutropenia for B-type acute lymphoblastic leukemia and hepatoblastoma. Antibiogram findings showed resistance to quinolones, ceftazidime, and intermediate resistance to cefepime, being susceptible to carbapenems and aminoglycosides. The cases responded favorably to the administration of carbapenem.
CONCLUSIONS
The identification of the species and antimicrobial susceptibility profile favor response to infection, denoting the importance of species identification and the performance of an antibiogram to determine the different susceptibility profiles described in the literature on this emerging pathogen.
PubMed: 38023950
DOI: 10.18683/germs.2023.1369 -
Case Reports in Nephrology and Dialysis 2021Gram-negative peritonitis in chronic peritoneal dialysis patients is difficult to treat and may result in catheter loss. is a Gram-negative rod bacterium which rarely...
Gram-negative peritonitis in chronic peritoneal dialysis patients is difficult to treat and may result in catheter loss. is a Gram-negative rod bacterium which rarely causes infections in humans. A 41-year-old male receiving continuous cycling peritoneal dialysis for 5 months developed culture-negative peritonitis. He failed initial empiric treatment with intraperitoneal vancomycin and levofloxacin and thereafter intravenous gentamicin. resistant to levofloxacin was isolated from the peritoneal fluid 21 days after his initial symptoms. Despite treatment with intravenous ceftriaxone and oral amoxicillin-clavulanate, the infection persisted, which required removal of the peritoneal catheter in order to cure this infection. We describe the features of infection in our patient and the rarely reported additional cases.
PubMed: 34901199
DOI: 10.1159/000517140 -
Scandinavian Journal of Infectious... 2004Brevundimonas spp. are infrequently isolated from clinical samples, including blood. The vast majority of reported cases have underlying diseases. Whether these... (Review)
Review
Brevundimonas spp. are infrequently isolated from clinical samples, including blood. The vast majority of reported cases have underlying diseases. Whether these microorganisms represent true pathogens of human disease in all populations remains to be explored. We present 2 cases of bloodstream infection caused by Brevundimonas sp., with one of these individuals immunocompetent, and discuss the possible role of these organisms in different patient populations.
Topics: Adult; Anti-Bacterial Agents; Bacteremia; Drug Therapy, Combination; Follow-Up Studies; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Immunocompetence; Male; Middle Aged; Rare Diseases; Risk Assessment; Severity of Illness Index; Treatment Outcome
PubMed: 15000562
DOI: 10.1080/00365540310018879