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Cureus Oct 2020is an uncommon pathogen in humans and there are no documented cases of infection associated with central venous catheters. Here we describe a 72-year-old man on...
is an uncommon pathogen in humans and there are no documented cases of infection associated with central venous catheters. Here we describe a 72-year-old man on hemodialysis who presented with a fever and was found to have bacteremia. The only obvious source of infection was the hemodialysis catheter. The isolate was susceptible to all antibiotics tested and he was successfully treated with ciprofloxacin and central venous catheter removal. Patients with chronic medical conditions and vascular devices are at risk for invasive infections with rare Pseudomonas species. As laboratory pathogen detection advances arise, it is possible that additional cases of infections in humans will be identified. Our case provides one example of the successful treatment of bacteremia in a 72-year-old man with a line-associated infection.
PubMed: 33178507
DOI: 10.7759/cureus.10853 -
Tropical Medicine and Infectious Disease May 2020is a Gram-negative, rod-shaped, aerobic bacterium that belongs in the family Pseudomonadaceae and has been isolated from water and soil. Even though it is thought to... (Review)
Review
is a Gram-negative, rod-shaped, aerobic bacterium that belongs in the family Pseudomonadaceae and has been isolated from water and soil. Even though it is thought to cause infections quite rarely in humans, it can cause severe infections even in immunocompetent individuals. The aim of this study was to systemically review all cases of human infection by in the literature and describe their epidemiology, microbiology, antimicrobial susceptibility, treatment and outcomes. Thus, a systematic review of PubMed for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of infections was conducted. In total, 12 studies, containing data of 16 patients, were included. The commonest infections were infective endocarditis, central nervous system infections and skin and soft tissue infections (SSTIs). Fever was the main presenting symptom, while sepsis was evident in almost half the patients. was susceptible to most antibiotics tested. Mortality was low in all different infection types. Third or fourth generation cephalosporins and quinolones are the commonest agents used for treatment, irrespectively of the infection site.
PubMed: 32375225
DOI: 10.3390/tropicalmed5020071 -
Journal of Functional Biomaterials Apr 2020A medium chain-length polyhydroxyalkanoate (PHA) was produced by CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was...
A medium chain-length polyhydroxyalkanoate (PHA) was produced by CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was achieved. Chemical analysis confirmed that the polymer produced was a medium chain-length PHA, a copolymer of 3-hydroxyoctanoate and 3-hydroxydecanoate, P(3HO--3HD). Lime oil, an essential oil with known antimicrobial activity, was used as an additive to P(3HO--3HD) to confer antibacterial properties to this biodegradable polymer. The incorporation of lime oil induced a slight decrease in crystallinity of P(3HO-co-3HD) films. The antibacterial properties of lime oil were investigated using ISO 20776 against 6538P and 8739, showing a higher activity against the Gram-positive bacteria. The higher activity of the oil against 6538P defined the higher efficiency of loaded polymer films against this strain. The effect of storage on the antimicrobial properties of the loaded films was investigated. After one-year storage, the content of lime oil in the films decreased, causing a reduction of the antimicrobial activity of the materials produced. However, the films still possessed antibacterial activity against 6538P.
PubMed: 32290046
DOI: 10.3390/jfb11020024 -
Ecotoxicology and Environmental Safety Jan 2020Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low...
Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low bioavailability to soil microorganisms affects their rate of biodegradation. This study was performed on samples of soil that were (for over forty years) subjected to contamination with creosote oil, and their metagenome and physicochemical properties were characterized. Moreover, the study was undertaken to evaluate the biodegradation of PAHs by autochthonous consortia as well as by selected bacteria strains isolated from long-term contaminated industrial soil. From among the isolated microorganisms, the most effective in biodegrading the contaminants were the strains Pseudomonas mendocina and Brevundimonas olei. They were able to degrade more than 60% of the total content of PAHs during a 28-day test. The biodegradation of these compounds using AT7 dispersant was enhanced only by Serratia marcescens strain. Moreover, the addition of AT7 improved the effectiveness of fluorene and acenaphthene biodegradation by Serratia marcescens 6-fold. Our results indicated that long-term contact with aromatic compounds induced the bacterial strains to use the PAHs as a source of carbon and energy. We observed that supplementation with surfactants does not increase the efficiency of hydrocarbon biodegradation.
Topics: Biodegradation, Environmental; Caulobacteraceae; Creosote; Environmental Monitoring; Industry; Poland; Polycyclic Aromatic Hydrocarbons; Pseudomonas mendocina; Soil; Soil Microbiology; Soil Pollutants
PubMed: 31678701
DOI: 10.1016/j.ecoenv.2019.109843 -
3 Biotech Nov 2019was identified as a novel endophytic isolate of with squalene cyclase activity. The PCR amplification of squalene hopene cyclase () gene from the isolate with the...
was identified as a novel endophytic isolate of with squalene cyclase activity. The PCR amplification of squalene hopene cyclase () gene from the isolate with the primers PA1/PA2 showed a band at 1980 bp specific for the enzyme squalene hopene cyclase. The in silico translation of the squalene hopene cyclase gene showed 96% sequence similarity with squalene hopene cyclase of (WP-060782422). Docking studies of the template and the modeled protein with the ligand squalene showed that the main interacting residues were Asp376 and Asp377. Squalene hopene cyclase template 1 sqc.1A sequence from was used as the template for docking experiments. The gene coding for squalene hopene cyclase from has been cloned in pET-28a vector to produce recombinant vector and was expressed in BL21 (DE3) expression system. Squalene hopene cyclase enzyme was isolated, purified and the molecular weight was confirmed by SDS-PAGE as 75 KDa.
PubMed: 31588405
DOI: 10.1007/s13205-019-1901-7 -
3 Biotech Sep 2019This study aimed to investigate the effects of cytoskeleton protein MreB on bacterial cell morphology and the synthesis of alginate oligosaccharides (AO) and...
This study aimed to investigate the effects of cytoskeleton protein MreB on bacterial cell morphology and the synthesis of alginate oligosaccharides (AO) and polyhydroxyalkanoate (PHA) by NK-01. To overexpress the gene, an expression vector encoding MreB-GFP fusion protein was constructed. The scanning electron microscope (SEM) showed that cells expressing MreB were longer than the wild ones, which agrees with MreB's relationship with the synthesis of peptidoglycan. Cells expressing the MreB-GFP fusion protein emitted green fluorescence under a fluorescence microscope, suggesting that MreB was functionally expressed in strain NK-01. Under a confocal laser scanning microscope, MreB was observed as located around the cell membrane. Furthermore, the recombinant strain could synthesize 0.961 g/L AO, which was 5.86-fold higher than wild-type strain. Through the medium optimization test, we finally selected the addition of 20 g/L glucose as the optimal glycogen addition for AO fermentation based on a high AO yield and high substrate transformation efficiency. The results indicated that overexpression of MreB affected the cell morphology, the activity of AO polymerase, and the efficiency of AO secretion. However, the synthesis of PHA for recombinant strain was slightly reduced. The results suggested that the overexpression of this cytoskeleton protein affected the yield of specific intracellular and extracellular products.
PubMed: 31497462
DOI: 10.1007/s13205-019-1873-7 -
The American Journal of Case Reports Apr 2019BACKGROUND Pseudomonas mendocina is a Gram-negative, aerobic, rod-shaped bacterium belonging to the family Pseudomonadaceae. In nature, P. mendocina has been isolated... (Review)
Review
BACKGROUND Pseudomonas mendocina is a Gram-negative, aerobic, rod-shaped bacterium belonging to the family Pseudomonadaceae. In nature, P. mendocina has been isolated from water and soil samples. The species rarely causes disease in humans though severe infections resulting in hospitalization and intensive care have been documented. This case is perhaps the second reported case in the United States of a P. mendocina related infection. In this case report, we analyze the clinical and laboratory features of P. mendocina infection in a severely immunocompromised acquired immunodeficiency syndrome (AIDS) patient and review the available literature. CASE REPORT A 64-year-old white male with past medical history significant for human immunodeficiency virus (HIV)/AIDS (CD⁴ count on admission <10 cells/mm³) diagnosed in 1988 and on antiretroviral therapy since 1992, was admitted to our facility for acute management of a suspected invasive mold infection. On hospital day 20 the patient developed a fever of 39.9°C, had an elevated lactate of 2.6 mmol/L and absolute neutrophil count greater than 1000 cells/mm³. On hospital day 22, both blood culture sets were positive for Pseudomonas mendocina. Antibiotic therapy was de-escalated to ceftazidime and after a total treatment course of 10 days the was successfully discharged. CONCLUSIONS There have been 14 reported cases of P. mendocina in the world. Four cases presented with meningitis and 5 with endocarditis. Beyond typical anti-pseudomonal agents, 2 of the reported cases show susceptibility of P. mendocina antibiotics such as sulfamethoxazole/trimethoprim and ceftriaxone. All documented case reports of P. mendocina infection resulted in successful treatment with antibiotics and survival of the patient.
Topics: Anti-Bacterial Agents; Bacteremia; Ceftazidime; HIV Infections; Humans; Immunocompromised Host; Male; Middle Aged; Pseudomonas Infections; Pseudomonas mendocina
PubMed: 30948701
DOI: 10.12659/AJCR.914360 -
Biotechnology Reports (Amsterdam,... Mar 2019Wastewater environment is a rich source of microorganisms with the capability for the degradation of malicious aromatic pollutants. Although wastewater could be regarded...
Wastewater environment is a rich source of microorganisms with the capability for the degradation of malicious aromatic pollutants. Although wastewater could be regarded as both a resource and a problem, we intended to elucidate its beneficial aspect in this study sourcing for laccase-producing proteobacteria. Different wastewater samples, from selected wastewater treatment plants (WWTPs), were selectively enriched with some model compounds (vanillin, lignin and potassium hydrogen phthalate) to screen out bacterial isolates that possess excellent degradation potentials. Thereafter, positive isolates were screened for the production of laccase and degradation on phenolic (guaiacol, α-naphthol and syringaldazine) and non-phenolic (ABTS; 2,2 azino-bis -(3-ethylbenzothiazoline 6 sulphonic acid) and PFC; potassium ferrocyanoferrate) substrates characteristic of laccase oxidation. Remarkable laccase producers were identified based on their 16 S rRNA sequences and their secreted enzymes were subjected to substrate specificity test, employing laccase substrates; ABTS, PFC, guaiacol, α-naphthol, 2,6-dimethoxyphenol and pyrogallol. Results showed that wastewater and selective enrichment, in tandem, produced the gammaproteobacteria aeruginosa DEJ16, mendocina AEN16 and maltophila BIJ16, which preferably oxidized the non-phenolic substrates. Units of extracellular laccase activity ranging between cca. 490 and cca. 600 U/mL were recorded for ABTS whereas outputs recorded from PFC catalysis ranged from cca. 320 to cca. 430 U/mL. BIJ16 presented an unparalleled high laccase activity and had a responsive substrate specificity to aromatic and inorganic substrates, thereby suggesting its employment for in situ biodegradation studies. In conclusion, wastewater serves as an ideal milieu for the isolation of laccase producing bacteria.
PubMed: 30899681
DOI: 10.1016/j.btre.2019.e00320 -
Journal of Biosciences Mar 2019Biofilm genesis by sp is associated with biofouling in natural settings. D-Tryptophan (D-Trp) inhibits bacterial biofilms and have been proposed for biofouling control...
Biofilm genesis by sp is associated with biofouling in natural settings. D-Tryptophan (D-Trp) inhibits bacterial biofilms and have been proposed for biofouling control applications. In this study, D-Trp significantly inhibited and attachment (biofilm formation) rates on polystyrene96-well microtiter plates in comparison with L-Tryptophan (L-Trp) and mixtures of D-/L-Tryptophan (D-/L-Trp). Theinhibitory effect was greater on P. mendocina,where the rate of cell adherence was declined to 8.79105cells/h from8.09106cells/h (control) inP. mendocina.InS. aureusit was declined to 4.29107cells/h from 9.29107cells/h(control) at 1 mM concentration. It hindered the intracellular communication and adherence in both the strains, as con-firmed by SEM and real time PCR analysis. Addition of D-Trp to preformed biofilms also caused partial disassembly. Intraand interbacterial aggregation were decreased subsequently upon treatment with D-Trp. It repressed the genes involved incell-cell communication, which could be responsible for the diminished biofilm formation of the selected strains. HenceD-Tryptophan has proved to be an effective strategy to control biofilm and may support in the development of surfacecoating technologies.
Topics: Anti-Bacterial Agents; Bacterial Infections; Biofilms; Humans; Pseudomonas mendocina; Staphylococcus aureus; Tryptophan
PubMed: 30837355
DOI: No ID Found -
Scientific Reports Feb 2019Polyhydroxyalkanoate (PHA) can be produced by microorganisms from renewable resources and is regarded as a promising bioplastic to replace petroleum-based plastics....
Polyhydroxyalkanoate (PHA) can be produced by microorganisms from renewable resources and is regarded as a promising bioplastic to replace petroleum-based plastics. Pseudomonas mendocina NK-01 is a medium-chain-length PHA (mcl-PHA)-producing strain and its whole-genome sequence is currently available. The yield of mcl-PHA in P. mendocina NK-01 is expected to be improved by applying a promoter engineering strategy. However, a limited number of well-characterized promoters has greatly restricted the application of promoter engineering for increasing the yield of mcl-PHA in P. mendocina NK-01. In this work, 10 endogenous promoters from P. mendocina NK-01 were identified based on RNA-seq and promoter prediction results. Subsequently, 10 putative promoters were characterized for their strength through the expression of a reporter gene gfp. As a result, five strong promoters designated as P4, P6, P9, P16 and P25 were identified based on transcriptional level and GFP fluorescence intensity measurements. To evaluate whether the screened promoters can be used to enhance transcription of PHA synthase gene (phaC), the three promoters P4, P6 and P16 were separately integrated into upstream of the phaC operon in the genome of P. mendocina NK-01, resulting in the recombinant strains NKU-4C1, NKU-6C1 and NKU-16C1. As expected, the transcriptional levels of phaC1 and phaC2 in the recombinant strains were increased as shown by real-time quantitative RT-PCR. The phaZ gene encoding PHA depolymerase was further deleted to construct the recombinant strains NKU-∆phaZ-4C1, NKU-∆phaZ-6C1 and NKU-∆phaZ-16C1. The results from shake-flask fermentation indicated that the mcl-PHA titer of recombinant strain NKU-∆phaZ-16C1 was increased from 17 to 23 wt% compared with strain NKU-∆phaZ. This work provides a feasible method to discover strong promoters in P. mendocina NK-01 and highlights the potential of the screened endogenous strong promoters for metabolic engineering of P. mendocina NK-01 to increase the yield of mcl-PHA.
Topics: Acyltransferases; Bacterial Proteins; Metabolic Engineering; Polyhydroxyalkanoates; Promoter Regions, Genetic; Pseudomonas mendocina; Real-Time Polymerase Chain Reaction
PubMed: 30755729
DOI: 10.1038/s41598-019-39321-z