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Journal of Cardiology Cases Jul 2021Late prosthetic valve endocarditis (PVE) is a life-threatening condition, commonly caused by bacterial organisms such as staphylococci, streptococci, or enterococci....
Late prosthetic valve endocarditis (PVE) is a life-threatening condition, commonly caused by bacterial organisms such as staphylococci, streptococci, or enterococci. Infrequently, it can be caused by rare organisms. We hereby report a case of late PVE of the aortic valve, due to a rare gram-negative bacterium It is the first reported case of PVE caused by this particular organism. The patient had infective endocarditis-induced prosthetic valve dehiscence, severe aortic regurgitation, and shock, which was managed with appropriate antibiotics and supportive medical treatment. < Late prosthetic valve infective endocarditis should always be an important differential diagnosis in patients with artificial valve presenting with congestive cardiac failure. This case report is about aortic valve dehiscence and acute aortic regurgitation because of prosthetic valve infective endocarditis due to a rare bacterium .
PubMed: 34257757
DOI: 10.1016/j.jccase.2020.12.003 -
International Microbiology : the... Feb 2024Polymyxin B is considered a last-line therapeutic option against multidrug-resistant gram-negative bacteria, especially in COVID-19 coinfections or other serious...
BACKGROUND
Polymyxin B is considered a last-line therapeutic option against multidrug-resistant gram-negative bacteria, especially in COVID-19 coinfections or other serious infections. However, the risk of antimicrobial resistance and its spread to the environment should be brought to the forefront.
METHODS
Pandoraea pnomenusa M202 was isolated under selection with 8 mg/L polymyxin B from hospital sewage and then was sequenced by the PacBio RS II and Illumina HiSeq 4000 platforms. Mating experiments were performed to evaluate the transfer of the major facilitator superfamily (MFS) transporter in genomic islands (GIs) to Escherichia coli 25DN. The recombinant E. coli strain Mrc-3 harboring MFS transporter encoding gene FKQ53_RS21695 was also constructed. The influence of efflux pump inhibitors (EPIs) on MICs was determined. The mechanism of polymyxin B excretion mediated by FKQ53_RS21695 was investigated by Discovery Studio 2.0 based on homology modeling.
RESULTS
The MIC of polymyxin B for the multidrug-resistant bacterial strain P. pnomenusa M202, isolated from hospital sewage, was 96 mg/L. GI-M202a, harboring an MFS transporter-encoding gene and conjugative transfer protein-encoding genes of the type IV secretion system, was identified in P. pnomenusa M202. The mating experiment between M202 and E. coli 25DN reflected the transferability of polymyxin B resistance via GI-M202a. EPI and heterogeneous expression assays also suggested that the MFS transporter gene FKQ53_RS21695 in GI-M202a was responsible for polymyxin B resistance. Molecular docking revealed that the polymyxin B fatty acyl group inserts into the hydrophobic region of the transmembrane core with Pi-alkyl and unfavorable bump interactions, and then polymyxin B rotates around Tyr43 to externally display the peptide group during the efflux process, accompanied by an inward-to-outward conformational change in the MFS transporter. Additionally, verapamil and CCCP exhibited significant inhibition via competition for binding sites.
CONCLUSIONS
These findings demonstrated that GI-M202a along with the MFS transporter FKQ53_RS21695 in P. pnomenusa M202 could mediate the transmission of polymyxin B resistance.
Topics: Polymyxin B; Escherichia coli; Genomic Islands; Molecular Docking Simulation; Sewage; Membrane Transport Proteins; Anti-Bacterial Agents; Microbial Sensitivity Tests; Burkholderiaceae
PubMed: 37316617
DOI: 10.1007/s10123-023-00384-8 -
Chemosphere Oct 2018The present study delineated the dehydrogenation mechanism of cis-2,3-dihydro-2,3-dihydroxybiphenyl (2,3-DDBPH) and cis-2,3-dihydro-2,3-dihydroxy-4,4'-dichlorobiphenyl...
The present study delineated the dehydrogenation mechanism of cis-2,3-dihydro-2,3-dihydroxybiphenyl (2,3-DDBPH) and cis-2,3-dihydro-2,3-dihydroxy-4,4'-dichlorobiphenyl (2,3-DD-4,4'-DBPH) by Pandoraea pnomenusa strain B-356 cis-2,3-dihydro-2,3-dihydroxybiphenyl dehydrogenase (BphB) in atomistic detail. The enzymatic process was investigated by a combined quantum mechanics/molecular mechanics (QM/MM) approach. Five different snapshots were extracted and calculated, which revealed that the Boltzmann-weighted average barriers of 2,3-DDBPH and 2,3-DD-4,4'-DBPH dehydrogenation processes are 10.7 and 11.5 kcal mol, respectively. The established dehydrogenation mechanism provides new insight into the degradation processes of other chlorinated 2,3-DDBPH. In addition to Asn115, Ser142, and Lys149, the importance of Ile 89, Asn143, Pro184, Met 187, Thr189, and Lue 191 during the dehydrogenation process of 2,3-DDBPH and 2,3-DD-4,4'-DBPH were also highlighted to search for promising mutation targets for improving the catalytic efficiency of BphB.
Topics: Burkholderiaceae; Catalysis; Oxidoreductases Acting on CH-CH Group Donors; Quantum Theory; Substrate Specificity
PubMed: 29860146
DOI: 10.1016/j.chemosphere.2018.05.063 -
Bioinformatics (Oxford, England) Sep 2018Long-reads, point-of-care and polymerase chain reaction-free are the promises brought by nanopore sequencing. Among various steps in nanopore data analysis, the...
MOTIVATION
Long-reads, point-of-care and polymerase chain reaction-free are the promises brought by nanopore sequencing. Among various steps in nanopore data analysis, the end-to-end mapping between the raw electrical current signal sequence and the reference expected signal sequence serves as the key building block to signal labeling, and the following signal visualization, variant identification and methylation detection. One of the classic algorithms to solve the signal mapping problem is the dynamic time warping (DTW). However, the ultra-long nanopore sequencing and an order of magnitude difference in the sampling speed complexify the scenario and make the classical DTW infeasible to solve the problem.
RESULTS
Here, we propose a novel multi-level DTW algorithm, continuous wavelet DTW (cwDTW), based on continuous wavelet transforms with different scales of the two signal sequences. Our algorithm starts from low-resolution wavelet transforms of the two sequences, such that the transformed sequences are short and have similar sampling rates. Then the peaks and nadirs of the transformed sequences are extracted to form feature sequences with similar lengths, which can be easily mapped by the original DTW. Our algorithm then recursively projects the warping path from a lower-resolution level to a higher-resolution one by building a context-dependent boundary and enabling a constrained search for the warping path in the latter. Comprehensive experiments on two real nanopore datasets on human and on Pandoraea pnomenusa demonstrate the efficiency and effectiveness of the proposed algorithm. In particular, cwDTW can gain remarkable acceleration with tiny loss of the alignment accuracy. On the real nanopore datasets, cwDTW can finish an alignment task in few seconds, which is about 3000 times faster than the original DTW. By successfully applying cwDTW on the tasks of signal labeling and ultra-long sequence comparison, we further demonstrate the power and applicability of cwDTW.
AVAILABILITY AND IMPLEMENTATION
Our program is available at https://github.com/realbigws/cwDTW.
SUPPLEMENTARY INFORMATION
Supplementary data are available at Bioinformatics online.
Topics: Algorithms; Humans; Nanopores; Sequence Analysis; Time Factors
PubMed: 30423085
DOI: 10.1093/bioinformatics/bty555 -
Journal of Environmental Science and... Jul 2017This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica,...
This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica, Veracruz, Mexico. The identified bacteria were Ochrobactrum intermedium, Pandoraea pnomenusa and Ochrobactrum sp., but SA2-09 strain was not identified. The ability of the isolates to degrade polycyclic aromatic hydrocarbons (PAHs) was evaluated at 31.61 and 54.52 mg/kg PAHs in soil, when used as crude oil in soil microcosm during 80 days of incubation at 30°C. The results demonstrated that O. intermedium biodegraded many PAHs, including the high molecular weight (HMW) PAHs fluoranthene (100% equivalent 0.24 mg/kg), benzo [b] fluoranthene (81.8% equal 0.18 mg/kg), Benzo[a]pyrene (87.0%, 0.20 mg/kg) and Benzo[g,h,i]perylene (52.7%, 0.39 mg/kg). P. pnomenusa had a degradation profile of HMW PAHs, which was similar to O. intermedium, while Ochrobactrum sp. and the strain SA-09 exhibited lower degradation rates of HMW.
Topics: Biodegradation, Environmental; Burkholderia; Mexico; Ochrobactrum; Petroleum; Phylogeny; Polycyclic Aromatic Hydrocarbons; RNA, Ribosomal, 16S; Soil Pollutants
PubMed: 28463567
DOI: 10.1080/10934529.2017.1316170 -
Journal of Hazardous Materials Sep 2021Azoles are an emerging class of contaminants with a growing ubiquitous presence in the environment. This study investigates the aerobic microbial degradation of four...
Azoles are an emerging class of contaminants with a growing ubiquitous presence in the environment. This study investigates the aerobic microbial degradation of four azoles, pyrazole (PA), 1,2,4-triazole (TA), benzotriazole (BTA) and 5-methylbenzotriazole (5-MBTA), with return activated sludge and microbial enrichment cultures. Slow degradation of PA was observed in the presence of glucose and NH with a peak degradation rate of 0.5 mg d gVSS. TA was found to be highly persistent, with no significant degradation observed in 6-8 months under any incubation condition. In contrast, the benzotriazoles were readily degraded at faster rates in all incubation conditions. The degradation rates observed for BTA and 5-MBTA, when provided as the sole substrates, were 8.1 and 16.5 mg d gVSS, respectively. Two enrichment cultures, one degrading BTA and the other degrading 5-MBTA, were developed from the activated sludge. Mass balance studies revealed complete mineralization of 5-MBTA and partial breakdown of BTA by the enrichment cultures. Nocardioides sp. and Pandoraea pnomenusa were the most abundant bacteria in the BTA and 5-MBTA degrading enrichment cultures, respectively. The research shows large differences in the biodegradability of various azoles, ranging from complete mineralization of 5-MBTA to complete persistence for TA.
Topics: Azoles; Biodegradation, Environmental; Burkholderiaceae; Sewage
PubMed: 34229401
DOI: 10.1016/j.jhazmat.2021.126151 -
Microbiology Resource Announcements Jan 2020strain TF-18 was isolated from the roots of rice seedlings on selective medium containing four classes of antibiotics for isolation of Using Pacific Biosciences...
strain TF-18 was isolated from the roots of rice seedlings on selective medium containing four classes of antibiotics for isolation of Using Pacific Biosciences (PacBio) single-molecule real-time (SMRT) sequencing technology, we report here a complete genome of 5,499,432 bases, a GC content of 64.8%, and 4,849 coding sequences.
PubMed: 31896624
DOI: 10.1128/MRA.01008-19 -
Transplantation Dec 2021Uncontrolled donation after circulatory death (DCD) donors are an extraordinary resource to increase the number of lungs available for transplantation. However, the risk...
BACKGROUND
Uncontrolled donation after circulatory death (DCD) donors are an extraordinary resource to increase the number of lungs available for transplantation. However, the risk of the warm ischemia resulting from cardiac arrest to irreversibly damage the organs is considerable. Moreover, graft preservation issues and organizational problems often worsen the dangerous effects of warm ischemia. Ex vivo lung perfusion (EVLP) enables us to evaluate and recondition lungs whose functionality is doubtful, as well as to overcome the difficulties related to time and logistics.
METHODS
We report the case of uncontrolled DCD lungs successfully treated with an exceptionally prolonged EVLP. Because the donor's blood count and liver biopsy showed signs of possible leukemia, EVLP was protracted up to 17 h while waiting for immunohistochemical analyses to rule out this diagnosis; eventually, the results came back negative, and the lungs were judged suitable for transplantation.
RESULTS
The recipient was a 32-y-old male individual with cystic fibrosis, colonized by Pandoraea pnomenusa. Bilateral transplantation required central extracorporeal membrane oxygenation. The patient was extubated after 36 h and was discharged 21 d after the operation. Despite early recolonization by Pandoraea pnomenusa and airway complications requiring pneumatic dilatation, he is alive and has a satisfactory respiratory function 15 mo after transplantation.
CONCLUSIONS
Uncontrolled DCD represents a challenge due to both logistical issues and the complexity of graft evaluation before procurement. EVLP with cellular perfusate could be a valuable tool to overcome these limits. Nonetheless, caution should be exercised when interpreting the effects of this technique on airway healing.
Topics: Extracorporeal Circulation; Humans; Lung; Lung Transplantation; Male; Organ Preservation; Perfusion; Tissue Donors; Warm Ischemia
PubMed: 33496562
DOI: 10.1097/TP.0000000000003646 -
Genome Announcements Feb 2015Pandoraea is an emerging respiratory pathogen capable of causing chronic lung infections in people with cystic fibrosis (CF), but the clinical significance of this...
Pandoraea is an emerging respiratory pathogen capable of causing chronic lung infections in people with cystic fibrosis (CF), but the clinical significance of this infection is ambiguous. We have sequenced and annotated the genomes of two multidrug-resistant Pandoraea pnomenusa isolates recovered 11 months apart from the same CF patient.
PubMed: 25657265
DOI: 10.1128/genomeA.01389-14 -
Ecotoxicology and Environmental Safety Feb 2016A series of toxicity bioassays was conducted to monitor the ecotoxicity of soils in the different phases of bioremediation. Artificially oil-contaminated soil was...
A series of toxicity bioassays was conducted to monitor the ecotoxicity of soils in the different phases of bioremediation. Artificially oil-contaminated soil was inoculated with a petroleum hydrocarbon-degrading bacterial consortium containing Burkholderia cepacia GS3C, Sphingomonas GY2B and Pandoraea pnomenusa GP3B strains adapted to crude oil. Soil ecotoxicity in different phases of bioremediation was examined by monitoring total petroleum hydrocarbons, soil enzyme activities, phytotoxicity (inhibition of seed germination and plant growth), malonaldehyde content, superoxide dismutase activity and bacterial luminescence. Although the total petroleum hydrocarbon (TPH) concentration in soil was reduced by 64.4%, forty days after bioremediation, the phytotoxicity and Photobacterium phosphoreum ecotoxicity test results indicated an initial increase in ecotoxicity, suggesting the formation of intermediate metabolites characterized by high toxicity and low bioavailability during bioremediation. The ecotoxicity values are a more valid indicator for evaluating the effectiveness of bioremediation techniques compared with only using the total petroleum hydrocarbon concentrations. Among all of the potential indicators that could be used to evaluate the effectiveness of bioremediation techniques, soil enzyme activities, phytotoxicity (inhibition of plant height, shoot weight and root fresh weight), malonaldehyde content, superoxide dismutase activity and luminescence of P. phosphoreum were the most sensitive.
Topics: Bacteria; Biodegradation, Environmental; Germination; Hydrocarbons; Magnoliopsida; Malondialdehyde; Petroleum; Plant Development; Plant Roots; Seeds; Soil Microbiology; Soil Pollutants; Superoxide Dismutase
PubMed: 26491984
DOI: 10.1016/j.ecoenv.2015.10.005