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Respiratory Medicine Oct 2017Altered composition of airway microbiota has been reported in subjects suffering from asthma but its relation to eosinophilic phenotype is unclear.
BACKGROUND
Altered composition of airway microbiota has been reported in subjects suffering from asthma but its relation to eosinophilic phenotype is unclear.
OBJECTIVE
To examine the relationship between sputum microbiota, asthma severity and inflammatory type in asthmatic subjects from Guangzhou, China.
METHODS
Induced sputum samples were obtained from 49 non-smoking asthma patients, 25 severe and 24 non-severe, and 15 healthy subjects. Total DNA was amplified using primers specific for the V3-V5 hypervariable region of bacterial 16s rRNA and sequenced using the 454 GS FLX sequencer. Sequences were assigned to bacterial taxa by comparing them with 16s rRNA sequences in the Ribosomal Database Project.
RESULTS
Sputum eosinophil counts were higher and FEV (% predicted) was lower in severe compared to non-severe asthmatics. There were no significant differences in operational taxonomic unit (OTU) numbers at the phylum level and in diversity scores between non-severe asthmatics and severe asthmatics, and healthy subjects. At the family level, Porphyromonadaceae was most abundant in healthy subjects whereas Pseudomonadaceae and Enterobacteriaceae were higher in severe asthmatics compared to non-severe asthmatics (p < 0.05). Actinomycetaceae was particularly abundant in eosinophilic asthma patients compared to non-eosinophilic asthma (p = 0.011). Bacteroidaceae was positively correlated with FEV in all subjects (r = 0.335, p < 0.01), whereas body mass index was negatively associated with the number of species observed (r = -0.3, p < 0.05). Principal component analysis confirmed the positive association of Actinomycetaceae and Enterobacteriaceae abundance with eosinophilic asthma.
CONCLUSION
Patients with asthma have an altered airway microbiota, with specific bacteria associated with severe asthma and the eosinophilic inflammatory phenotype.
Topics: Actinomycetaceae; Adult; Asthma; Bacteroidaceae; Case-Control Studies; China; Enterobacteriaceae; Eosinophils; Female; Forced Expiratory Volume; Humans; Inflammation; Leukocyte Count; Male; Microbiota; Middle Aged; Phenotype; Porphyromonas; Principal Component Analysis; Pseudomonadaceae; Pulmonary Eosinophilia; RNA, Ribosomal, 16S; Severity of Illness Index; Sputum
PubMed: 28947029
DOI: 10.1016/j.rmed.2017.08.016 -
Microbes and Environments 2010Over the past few decades, degradative plasmids have been isolated from bacteria capable of degrading a variety of both natural and man-made compounds. Degradative... (Review)
Review
Over the past few decades, degradative plasmids have been isolated from bacteria capable of degrading a variety of both natural and man-made compounds. Degradative plasmids belonging to three incompatibility (Inc) groups in Pseudomonas (IncP-1, P-7, and P-9) have been well studied in terms of their replication, maintenance, and capacity for conjugative transfer. The host ranges of these plasmids are determined by replication or conjugative transfer systems. The host range of IncP-1 is broad, that of IncP-9 is intermediate, and that of IncP-7 is narrow. To understand the behavior of these plasmids and their hosts in various environments, the survivability of inocula, stability or transferability, and efficiency of biodegradation in environments and microcosms have been monitored. The biodegradation and plasmid transfer in various environments have been observed for all three groups, although the kinds of transconjugants differed with the Inc groups. In some cases, the deletion and amplification of catabolic genes acted to reduce the production of toxic catabolic intermediates, or to increase the activity on a particular catabolic pathway. The combination of degradative genes, the plasmid backbone of each Inc group, and the host of the plasmids is key to the degraders adapting to various hosts or to heterogeneous environments.
Topics: Biodegradation, Environmental; Environmental Microbiology; Environmental Pollutants; Host Specificity; Plasmids; Pseudomonas
PubMed: 21576880
DOI: 10.1264/jsme2.me10155 -
Journal of Bacteriology Oct 2021Pseudomonas aeruginosa strains PA14 and PAO1 are among the two best-characterized model organisms used to study the mechanisms of biofilm formation while also...
Pseudomonas aeruginosa strains PA14 and PAO1 are among the two best-characterized model organisms used to study the mechanisms of biofilm formation while also representing two distinct lineages of P. aeruginosa. Previous work has shown that PA14 and PAO1 use different strategies for surface colonization; they also have different extracellular matrix composition and different propensities to disperse from biofilms back into the planktonic phase surrounding them. We expand on this work here by exploring the consequences of these different biofilm production strategies during direct competition. Using differentially labeled strains and microfluidic culture methods, we show that PAO1 can outcompete PA14 in direct competition during early colonization and subsequent biofilm growth, that they can do so in constant and perturbed environments, and that this advantage is specific to biofilm growth and requires production of the Psl polysaccharide. In contrast, P. aeruginosa PA14 is better able to invade preformed biofilms and is more inclined to remain surface-associated under starvation conditions. These data together suggest that while P. aeruginosa PAO1 and PA14 are both able to effectively colonize surfaces, they do so in different ways that are advantageous under different environmental settings. Recent studies indicate that P. aeruginosa PAO1 and PA14 use distinct strategies to initiate biofilm formation. We investigated whether their respective colonization and matrix secretion strategies impact their ability to compete under different biofilm-forming regimes. Our work shows that these different strategies do indeed impact how these strains fair in direct competition: PAO1 dominates during colonization of a naive surface, while PA14 is more effective in colonizing a preformed biofilm. These data suggest that even for very similar microbes there can be distinct strategies to successfully colonize and persist on surfaces during the biofilm life cycle.
Topics: Biofilms; Cell Death; Lab-On-A-Chip Devices; Pseudomonas aeruginosa; Surface Properties
PubMed: 34516283
DOI: 10.1128/JB.00265-21 -
PloS One 2019Biofilms are microbial communities encased in a protective matrix composed of exopolymeric substances including exopolysaccharides, proteins, lipids, and extracellular...
The Pseudomonas aeruginosa biofilm matrix and cells are drastically impacted by gas discharge plasma treatment: A comprehensive model explaining plasma-mediated biofilm eradication.
Biofilms are microbial communities encased in a protective matrix composed of exopolymeric substances including exopolysaccharides, proteins, lipids, and extracellular DNA. Biofilms cause undesirable effects such as biofouling, equipment damage, prostheses colonization, and disease. Biofilms are also more resilient than free-living cells to regular decontamination methods and therefore, alternative methods are needed to eradicate them. The use of non-thermal atmospheric pressure plasmas is a good alternative as plasmas contain reactive species, free radicals, and UV photons well-known for their decontamination potential against free microorganisms. Pseudomonas aeruginosa biofilms colonize catheters, indwelling devices, and prostheses. Plasma effects on cell viability have been previously documented for P. aeruginosa biofilms. Nonetheless, the effect of plasma on the biofilm matrix has received less attention and there is little evidence regarding the changes the matrix undergoes. The aim of this work was to study the effect plasma exerts mostly on the P. aeruginosa biofilm matrix and to expand the existing knowledge about its effect on sessile cells in order to achieve a better understanding of the mechanism/s underlying plasma-mediated biofilm inactivation. We report a reduction in the amount of the biofilm matrix, the loss of its tridimensional structure, and morphological changes in sessile cells at long exposure times. We show chemical and structural changes on the biofilm matrix (mostly on carbohydrates and eDNA) and cells (mostly on proteins and lipids) that are more profound with longer plasma exposure times. We also demonstrate the presence of lipid oxidation products confirming cell membrane lipid peroxidation as plasma exposure time increases. To our knowledge this is the first report providing detailed evidence of the variety of chemical and structural changes that occur mostly on the biofilm matrix and sessile cells as a consequence of the plasma treatment. Based on our results, we propose a comprehensive model explaining plasma-mediated biofilm inactivation.
Topics: Atmospheric Pressure; Biofilms; Models, Biological; Plasma Gases; Pseudomonas aeruginosa; Time Factors
PubMed: 31233528
DOI: 10.1371/journal.pone.0216817 -
Applied and Environmental Microbiology May 1993Two Pseudomonas isolates, named ES-1 and ES-2, were shown to possess a wide degradative spectrum for haloalkanes in general and bromoalkanes in particular but did not...
Two Pseudomonas isolates, named ES-1 and ES-2, were shown to possess a wide degradative spectrum for haloalkanes in general and bromoalkanes in particular but did not degrade nonsubstituted alkanes. The utilization of water-insoluble haloalkanes, such as 1-bromooctane, appeared to consist of three phases: (i) extracellular emulsification by a constitutively excreted, broad-spectrum surface-active agent, (ii) dehalogenation by an inducible hydrolytic dehalogenase (possibly periplasmic), and (iii) intracellular degradation of the residual carbon skeleton. Several observations suggest the existence of more than one dehalogenase in strain ES-2.
Topics: Alkanes; Biodegradation, Environmental; Excipients; Hydrocarbons, Brominated; Pseudomonas
PubMed: 8517736
DOI: 10.1128/aem.59.5.1403-1409.1993 -
FEMS Immunology and Medical Microbiology Aug 2010Ilya Metchnikoff and Paul Ehrlich were awarded the Nobel price in 1908. Since then, numerous studies have unraveled a multitude of mechanistically different immune... (Review)
Review
Ilya Metchnikoff and Paul Ehrlich were awarded the Nobel price in 1908. Since then, numerous studies have unraveled a multitude of mechanistically different immune responses to intruding microorganisms. However, in the vast majority of these studies, the underlying infectious agents have appeared in the planktonic state. Accordingly, much less is known about the immune responses to the presence of biofilm-based infections (which is probably also due to the relatively short period of time in which the immune response to biofilms has been studied). Nevertheless, more recent in vivo and in vitro studies have revealed both innate as well as adaptive immune responses to biofilms. On the other hand, measures launched by biofilm bacteria to achieve protection against the various immune responses have also been demonstrated. Whether particular immune responses to biofilm infections exist remains to be firmly established. However, because biofilm infections are often persistent (or chronic), an odd situation appears with the simultaneous activation of both arms of the host immune response, neither of which can eliminate the biofilm pathogen, but instead, in synergy, causes collateral tissue damage. Although the present review on the immune system vs. biofilm bacteria is focused on Pseudomonas aeruginosa (mainly because this is the most thoroughly studied), many of the same mechanisms are also seen with biofilm infections generated by other microorganisms.
Topics: Biofilms; Chronic Disease; Humans; Immune Evasion; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 20579098
DOI: 10.1111/j.1574-695X.2010.00706.x -
European Journal of Biochemistry Mar 1994OprB is a glucose-selective porin known to be produced by Pseudomonas aeruginosa and Pseudomonas putida. We have cloned and sequenced the oprB gene of P. aeruginosa and... (Comparative Study)
Comparative Study
OprB is a glucose-selective porin known to be produced by Pseudomonas aeruginosa and Pseudomonas putida. We have cloned and sequenced the oprB gene of P. aeruginosa and obtained expression of OprB in Escherichia coli. The mature protein consists of 423 amino acid residues with a deduced molecular mass of 47597 Da. Several clusters of amino acid residues, potentially involved in the structure or function of the protein, were identified. An area of regional homology with E. coli LamB was also identified. Carbohydrate-inducible proteins, potentially homologous to OprB, were identified in several rRNA homology-group-I pseudomonads by sodium dodecyl sulfate/polyacrylamide gel electrophoresis analysis, Western immunoblotting and N-terminal amino acid sequencing. These species also contained DNA that hybridized to a P. aeruginosa oprB gene probe.
Topics: Amino Acid Sequence; Bacterial Proteins; Base Sequence; Blotting, Western; Cloning, Molecular; Conserved Sequence; DNA, Bacterial; Escherichia coli; Genes, Bacterial; Molecular Sequence Data; Porins; Pseudomonadaceae; Pseudomonas aeruginosa; Recombinant Proteins; Restriction Mapping; Sequence Homology, Amino Acid; Species Specificity
PubMed: 8125108
DOI: 10.1111/j.1432-1033.1994.tb18649.x -
Diagnostic Microbiology and Infectious... Aug 2013The aim of this study was to isolate, quantify, identify, and compare opportunistic microorganisms (Candida and Staphylococcus genera and...
The aim of this study was to isolate, quantify, identify, and compare opportunistic microorganisms (Candida and Staphylococcus genera and Enterobacteriaceae/Pseudomonadaceae families) from prosthesis-fitting surfaces, the hard palate, and mouth rinses of individuals wearing removable maxillary prosthesis with (50) and without (50) lesions of denture stomatitis (DS). The strains were collected and identified using phenotypic, biochemical and molecular tests. The counts of microorganisms were significantly higher in the group of individuals with DS (P < 0.05). C. albicans was the most frequently isolated yeast species in both groups, following by C. tropicalis and C. glabrata. Six isolates were identified as C. dubliniensis. S. aureus and S. epidermidis were the most frequent Staphylococcus species in both groups. Klebsiella pneumoniae was the predominant species in both groups. The association between Candida spp. and bacteria isolated in this study with DS suggests that these microorganisms may play important roles in the establishment and persistence of this disease.
Topics: Aged; Bacterial Typing Techniques; Candida; Candidiasis, Oral; Case-Control Studies; Colony Count, Microbial; Denture, Partial, Removable; Enterobacteriaceae; Female; Humans; Male; Middle Aged; Mouth Mucosa; Mycological Typing Techniques; Palate, Hard; Pseudomonadaceae; Staphylococcus; Stomatitis, Denture
PubMed: 23747028
DOI: 10.1016/j.diagmicrobio.2013.05.001 -
Journal of Food Protection Jan 2021Kitfo is a version of beef tartar widely consumed in the Ethiopian community. It is made from raw minced beef and a blend of powdered spice and butter. Although previous...
ABSTRACT
Kitfo is a version of beef tartar widely consumed in the Ethiopian community. It is made from raw minced beef and a blend of powdered spice and butter. Although previous studies have shown that kitfo contains several bacteria that are of public health concern, the status of their antibiotic resistance is not known. In this study, the antibiotic resistance of bacterial isolates from 26 retail kitfo samples obtained from the Washington metropolitan area was analyzed. Characterization and antibiotic sensitivity of the isolates were determined by the Vitek 2 system and pulsed-field gel electrophoresis was used to delineate the intraspecies variations. Of the isolates, 59% were resistant to two or more antibiotics. Acinetobacter calcoaceticus and Pseudomonas luteola were multidrug resistant to the classes of β-lactam, cephalosporins, and nitrofurantoin. The antibiotic susceptibility profile of the isolates was cefazolin (59%), cefoxitin (50%), ampicillin (32%), and nitrofuran (18%). Most isolates (75%) were Enterobacteriaceae, whereas only 3.8 and 2.6% were Pseudomonadaceae and Moraxellaceae, respectively. Of the Enterobacteriaceae, Enterobacter cloacae, Escherichia coli, and Klebsiella spp. were the most predominant. All isolates except Klebsiella spp. showed high genetic variation (>65%). This study implicates for the first time kitfo as a potential reservoir of antibiotic-resistant bacteria.
Topics: Animals; Anti-Bacterial Agents; Cattle; Dental Calculus; Drug Resistance, Bacterial; Drug Resistance, Microbial; Microbial Sensitivity Tests; Prevalence; Pseudomonas; Washington; beta-Lactamases
PubMed: 33411928
DOI: 10.4315/JFP-20-230 -
Molecules (Basel, Switzerland) Oct 2017Materials used in ossicular replacement prostheses must possess appropriate biological properties, such as biocompatibility, stability, no cytotoxicity. Due to the risk...
Materials used in ossicular replacement prostheses must possess appropriate biological properties, such as biocompatibility, stability, no cytotoxicity. Due to the risk of infection (otitis media and chronic otitis media), it is desirable to use an antibacterial agent for illness prevention during the ossicular reconstruction. The goal of this work was to observe biological properties of a new composite prosthesis made of ABS containing silver nanoparticles (AgNPs 45T). Samples for biological tests and then a prototype of middle ear prosthesis were prepared using injection moulding and extrusion techniques. In vitro experiments were carried out to assess bactericidal efficacy against and standard strains, cell proliferation, viability and cytotoxicity, using Hs680.Tr. fibroblast cells. Surface parameters of the samples were evaluated, including roughness and wettability. The silver ions were continually released from the polymer in aqueous solution. The silver ions release was measured as increasing with time and concentration of the silver nanoparticles in the polymer matrix. No cytotoxicity effect was observed, while bactericidal efficacy was noticed for silver nanoparticles. The roughness studies showed an increase in roughness for the samples with silver nanoparticles. All polymer and composite materials containing silver nanoparticles showed hydrophilic properties. The composites were found to release silver ions at a concentration level capable of rendering the antimicrobial efficacy even with the lowest concentration of silver nanoparticles in the material. Our results demonstrate that middle ear prosthesis made of polymer and silver nanoparticles may eliminate bacteria during inflammation in the middle ear.
Topics: Acrylic Resins; Anti-Bacterial Agents; Butadienes; Cell Line; Cell Proliferation; Cell Survival; Fibroblasts; Humans; Metal Nanoparticles; Microbial Sensitivity Tests; Ossicular Prosthesis; Polystyrenes; Prosthesis-Related Infections; Pseudomonadaceae; Silver; Staphylococcus aureus; Surface Properties
PubMed: 28994723
DOI: 10.3390/molecules22101681