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Frontiers in Cellular and Infection... 2023Water distribution systems in hotels have been related to outbreaks caused by spp. Certain measures, including disinfection by chlorination, maintaining increased...
INTRODUCTION
Water distribution systems in hotels have been related to outbreaks caused by spp. Certain measures, including disinfection by chlorination, maintaining increased temperatures are usually undertaken to prevent outbreaks. However, these preventive strategies are not always effective, since there are several factors (e.g., synergistic interactions with other microbes, physico-chemical factors, biofilm formation, availability of nutrients) that promote survival and proliferation of the pathogen in water pipes., Accordingly, there is a need of a holistic approach in development of preventive models for outbreaks associated with water distribution systems.
METHODS
Water samples were collected from hotel water systems and were tested for the presence of , , total coliforms, total mesophilic count and . In each sample, temperature and chlorine were also tested. Other epidemiological factors were additionally recorded including number of rooms, stars, proximity of sampling point to the boiler, etc. Data were processed by generalized linear analysis, and modeling based on logistic regression analysis to identify independent predictive factors associated with the presence of in hotel water systems.
RESULTS
According to the generalized linear model, temperature affected (p<0.05) the presence of regardless of the species or the water supply (hot or cold). Additionally, opportunistic () or non-opportunistic (, coliforms) pathogens were significantly associated (p<0.05) with the presence of all species. Temperature also exhibited a positive effect to all pathogens tested except for according to the linear model. Multivariate analysis showed that , total coliforms, HPC and temperature had a statistically significant effect on the presence of . Based on a binomial model, cold water had a positive effect on . Type of sampling and proximity of the sample to the boiler seemed to pose different effect on depending on the cfu/L. The number of hotel stars and rooms did not appear to have any effect in all tested models.
DISCUSSION
Collectively, these results indicate the need for development of individualized water safety plans tailored by the presence of other microbiological agents, and unique physico-chemical factors, which could facilitate the survival of .in hotel water systems.
Topics: Legionella; Greece; Escherichia coli; Cold Temperature; Temperature; Pseudomonas; Pseudomonas aeruginosa
PubMed: 38188625
DOI: 10.3389/fcimb.2023.1214717 -
BioTechniques Feb 2002Gram-negative bacteria are extraordinarily diverse microorganisms that present a wide variety of characteristics worthy of genetic investigation. For historical reasons,... (Review)
Review
Gram-negative bacteria are extraordinarily diverse microorganisms that present a wide variety of characteristics worthy of genetic investigation. For historical reasons, the application of recombinant DNA technology to gram-negative bacteria in general has always lagged behind that of E. coli and its close relatives. However, the past 10 years have seen dramatic advances in the development of new tools and vectors for genetic analysis in non-E. coli hosts. Applications include various kinds of genetic manipulation, conjugation, transposition, site-specific recombination, protein secretion, protein purification, cell suicide, microbial ecology, biodegradation, and plant and animal pathogenicity.
Topics: Cloning, Molecular; DNA Probes; DNA Transposable Elements; DNA, Bacterial; DNA, Recombinant; Escherichia coli; Genes, Reporter; Genetic Techniques; Genetic Vectors; Gram-Negative Bacteria; Mutagenesis; Promoter Regions, Genetic; Pseudomonadaceae; Rhizobiaceae
PubMed: 11848415
DOI: 10.2144/02322rv02 -
World Journal of Microbiology &... Sep 2023Pseudomonas spp are considered a common milk-associated psychotropic bacteria, leading to milk deterioration during storage; therefore, our study aimed to study the...
Pseudomonas spp are considered a common milk-associated psychotropic bacteria, leading to milk deterioration during storage; therefore, our study aimed to study the distribution of Pseudomonas aeruginosa in raw milk and its associated products then studying the growth behavior of P. aeruginosa in milk after employing chitosan nanoparticles (CsNPs 50, 25, and 15 mg/100ml) and selenium nanoparticles (SeNPs 0.5, 0.3 and 0.1 mg/100ml) as a trial to control the bacterial growth in milk during five days of cooling storage. Our study relies on the ion gelation method and green synthesis for the conversion of chitosan and selenium to nanosized particles respectively, we subsequently confirmed their shape using SEM and TEM. We employing Pseudomonas selective agar medium for monitoring the bacterial growth along the cooling storage. Our findings reported that high prevalence of Pseudomonas spp count in raw milk and kareish cheese and high incidence percent of P. aeruginosa in ice cream and yogurt respectively. Both synthesized nanoparticles exhibited antibacterial activity in a dose-dependent manner. Moreover, CsNPs50 could inhibit the P. aeruginosa survival growth to a mean average of 2.62 ± 1.18 logcfu/ml in the fifth day of milk cooling storage; also, it was noted that the hexagonal particles SeNPs0.5 could inhibit 2.49 ± 11 logcfu/ml in comparison to the control P. aeruginosa milk group exhibited growth survival rate 7.24 ± 2.57 logcfu/ml under the same conditions. In conclusion, we suggest employing chitosan and selenium nanoparticles to improve milk safety and recommend future studies for the fate of nanoparticles in milk.
Topics: Animals; Selenium; Pseudomonas aeruginosa; Milk; Chitosan; Pseudomonas
PubMed: 37733086
DOI: 10.1007/s11274-023-03757-3 -
Genome Biology and Evolution Dec 2019Many of the soil-dwelling Pseudomonas species are known to produce secondary metabolite compounds, which can have antagonistic activity against other microorganisms,...
Many of the soil-dwelling Pseudomonas species are known to produce secondary metabolite compounds, which can have antagonistic activity against other microorganisms, including important plant pathogens. It is thus of importance to isolate new strains of Pseudomonas and discover novel or rare gene clusters encoding bioactive products. In an effort to accomplish this, we have isolated a bioactive Pseudomonas strain DTU12.1 from leaf-covered soil in Denmark. Following genome sequencing with Illumina and Oxford Nanopore technologies, we generated a complete genome sequence with the length of 5,943,629 base pairs. The DTU12.1 strain contained a complete gene cluster for a rare thioquinolobactin siderophore, which was previously described as possessing bioactivity against oomycetes and several fungal species. We placed the DTU12.1 strain within Pseudomonas gessardii subgroup of fluorescent pseudomonads, where it formed a distinct clade with other Pseudomonas strains, most of which also contained a complete thioquinolobactin gene cluster. Only two other Pseudomonas strains were found to contain the gene cluster, though they were present in a different phylogenetic clade and were missing a transcriptional regulator of the whole cluster. We show that having the complete genome sequence and establishing phylogenetic relationships with other strains can enable us to start evaluating the distribution and evolutionary origins of secondary metabolite clusters.
Topics: Biosynthetic Pathways; Metabolomics; Phylogeny; Pseudomonas; Quinolines; Soil Microbiology; Whole Genome Sequencing
PubMed: 31800028
DOI: 10.1093/gbe/evz267 -
Microbiology (Reading, England) Oct 2000
Review
Topics: Animals; Ecosystem; Evolution, Molecular; Genetic Variation; Genome, Bacterial; Humans; Mutation; Pseudomonas; Recombination, Genetic
PubMed: 11021911
DOI: 10.1099/00221287-146-10-2345 -
Bioresource Technology Apr 2019This research work has succeeded in recovering energy from glucose by generating H with the aid of a Clostridium beijerinckii strain and obtaining electrical energy from...
This research work has succeeded in recovering energy from glucose by generating H with the aid of a Clostridium beijerinckii strain and obtaining electrical energy from compounds present in the H fermentation effluent in a microbial fuel cell (MFC) seeded with native port drainage sediment. In the fermentation step, 49.5% of the initial glucose concentration (56 mmol/L) was used to produce 104 mmol/L H; 5, 33, 3, and 1 mmol/L acetate, butyrate, lactate, and ethanol also emerged, respectively. MFC tests by feeding the anodic compartment with acetate, butyrate, lactate (individually or as a mixture), or the H fermentation effluent provided power density values ranging between 0.6 and 1.2 W/m. Acetate furnished the highest power density with a nanowire-rich biofilm despite the lowest anode bacterial concentration (10 16S gene copies/g of sediment). Non-conventional exoelectrogenic microbial communities were observed in the acetate-fed MFC; e.g., Pseudomonadaceae (Pseudomonas) and Clostridia (Acidaminobacter, Fusibacter).
Topics: Bioelectric Energy Sources; Clostridium; Drainage; Electricity; Electrodes; Fermentation; Hydrogen; Pseudomonas
PubMed: 30660066
DOI: 10.1016/j.biortech.2019.01.031 -
ACS Nano Feb 2014Understanding the molecular mechanisms of bacterial adhesion and biofilm formation is an important topic in current microbiology and a key in nanomedicine for developing...
Understanding the molecular mechanisms of bacterial adhesion and biofilm formation is an important topic in current microbiology and a key in nanomedicine for developing new antibacterial strategies. There is growing evidence that the production of extracellular polymeric substances at the cell-substrate interface plays a key role in strengthening bacterial adhesion. Yet, because these adhesive polymers are available in small amounts and are localized at interfaces, they are difficult to study using traditional techniques. Here, we use single-molecule atomic force microscopy (AFM) to functionally analyze the biophysical properties (distribution, adhesion, and extension) of bacterial footprints, that is, adhesive macromolecules left on substrate surfaces after removal of the attached cells. We focus on the large adhesin protein LapA from Pseudomonas fluorescens, which mediates cell attachment to a wide diversity of surfaces. Using AFM tips functionalized with specific antibodies, we demonstrate that adhesion of bacteria to hydrophobic substrates leads to the active accumulation of the LapA protein at the cell-substrate interface. We show that single LapA proteins left on the substrate after cell detachment localize into microscale domains corresponding to the bacterial size and exhibit multiple adhesion peaks reflecting the adhesion and extension of adsorbed LapA proteins. The mechanical behavior of LapA-based footprints makes them ideally suited to function as multipurpose bridging polymers, enabling P. fluorescens to attach to various surfaces. Our experiments show that single-molecule AFM offers promising prospects for characterizing the biophysics and dynamics of the cell-substrate interface in the context of bacterial adhesion, on a scale that was not accessible before.
Topics: Bacterial Adhesion; Biofilms; Microscopy, Atomic Force; Pseudomonas fluorescens
PubMed: 24456070
DOI: 10.1021/nn4060489 -
The Journal of General Physiology May 2017A new study explains 's strong resistance to osmotic down-shock.
A new study explains 's strong resistance to osmotic down-shock.
Topics: Pseudomonas; Pseudomonas aeruginosa
PubMed: 28424228
DOI: 10.1085/jgp.201711799 -
Genome Biology 2009Pseudomonas fluorescens are common soil bacteria that can improve plant health through nutrient cycling, pathogen antagonism and induction of plant defenses. The genome...
BACKGROUND
Pseudomonas fluorescens are common soil bacteria that can improve plant health through nutrient cycling, pathogen antagonism and induction of plant defenses. The genome sequences of strains SBW25 and Pf0-1 were determined and compared to each other and with P. fluorescens Pf-5. A functional genomic in vivo expression technology (IVET) screen provided insight into genes used by P. fluorescens in its natural environment and an improved understanding of the ecological significance of diversity within this species.
RESULTS
Comparisons of three P. fluorescens genomes (SBW25, Pf0-1, Pf-5) revealed considerable divergence: 61% of genes are shared, the majority located near the replication origin. Phylogenetic and average amino acid identity analyses showed a low overall relationship. A functional screen of SBW25 defined 125 plant-induced genes including a range of functions specific to the plant environment. Orthologues of 83 of these exist in Pf0-1 and Pf-5, with 73 shared by both strains. The P. fluorescens genomes carry numerous complex repetitive DNA sequences, some resembling Miniature Inverted-repeat Transposable Elements (MITEs). In SBW25, repeat density and distribution revealed 'repeat deserts' lacking repeats, covering approximately 40% of the genome.
CONCLUSIONS
P. fluorescens genomes are highly diverse. Strain-specific regions around the replication terminus suggest genome compartmentalization. The genomic heterogeneity among the three strains is reminiscent of a species complex rather than a single species. That 42% of plant-inducible genes were not shared by all strains reinforces this conclusion and shows that ecological success requires specialized and core functions. The diversity also indicates the significant size of genetic information within the Pseudomonas pan genome.
Topics: Ecosystem; Genome, Bacterial; Plants; Pseudomonas fluorescens
PubMed: 19432983
DOI: 10.1186/gb-2009-10-5-r51 -
PloS One 2016Contact-dependent inhibition (CDI) toxins, delivered into the cytoplasm of target bacterial cells, confer to host strain a significant competitive advantage. Upon cell...
Contact-dependent inhibition (CDI) toxins, delivered into the cytoplasm of target bacterial cells, confer to host strain a significant competitive advantage. Upon cell contact, the toxic C-terminal region of surface-exposed CdiA protein (CdiA-CT) inhibits the growth of CDI- bacteria. CDI+ cells express a specific immunity protein, CdiI, which protects from autoinhibition by blocking the activity of cognate CdiA-CT. CdiA-CT are separated from the rest of the protein by conserved peptide motifs falling into two distinct classes, the "E. coli"- and "Burkholderia-type". CDI systems have been described in numerous species except in Pseudomonadaceae. In this study, we identified functional toxin/immunity genes linked to CDI systems in the Pseudomonas genus, which extend beyond the conventional CDI classes by the variability of the peptide motif that delimits the polymorphic CdiA-CT domain. Using P. aeruginosa PAO1 as a model, we identified the translational repressor RsmA as a negative regulator of CDI systems. Our data further suggest that under conditions of expression, P. aeruginosa CDI systems are implicated in adhesion and biofilm formation and provide an advantage in competition assays. All together our data imply that CDI systems could play an important role in niche adaptation of Pseudomonadaceae.
Topics: Bacterial Adhesion; Bacterial Proteins; Biofilms; Escherichia coli; Pseudomonas; Real-Time Polymerase Chain Reaction
PubMed: 26808644
DOI: 10.1371/journal.pone.0147435