scholarly journals Recent Advances in Aptamer-Based Biosensors for Detection of Pseudomonas aeruginosa

2020 ◽  
Vol 11 ◽  
Author(s):  
Xin Zheng ◽  
Shunxiang Gao ◽  
Jihong Wu ◽  
Xiaobo Hu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogen Detection ◽  
Environmental Safety ◽  
Clinical Diagnostics ◽  
Future Trends ◽  
Negative Results ◽  
Spot Detection ◽  
Recognition Elements ◽  
Detection Technologies ◽  
Conventional Detection

Increasing concerns about nosocomial infection, food and environmental safety have prompted the development of rapid, accurate, specific and ultrasensitive methods for the early detection of critical pathogens. Pseudomonas aeruginosa is one of the most common pathogens that cause infection. It is ubiquitous in nature, being found in water, soil, and food, and poses a great threat to public health. The conventional detection technologies are either time consuming or readily produce false positive/negative results, which makes them unsuitable for early diagnosis and spot detection of P. aeruginosa. To circumvent these drawbacks, many efforts have been made to develop biosensors using aptamers as bio-recognition elements. Various aptamer-based biosensors for clinical diagnostics, food, and environmental monitoring of P. aeruginosa have been developed in recent years. In this review, we focus on the latest advances in aptamer-based biosensors for detection of P. aeruginosa. Representative biosensors are outlined according to their sensing mechanisms, which include optical, electrochemical and other signal transduction methods. Possible future trends in aptamer biosensors for pathogen detection are also outlined.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

scholarly journals Characterization of the New Metallo-β-Lactamase VIM-13 and Its Integron-Borne Gene from a Pseudomonas aeruginosa Clinical Isolate in Spain

2008 ◽  
Vol 52 (10) ◽  
pp. 3589-3596 ◽  
Author(s):  
Carlos Juan ◽  
Alejandro Beceiro ◽  
Olivia Gutiérrez ◽  
Sebastián Albertí ◽  
Margalida Garau ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pcr Amplification ◽  
Class 1 Integron ◽  
Negative Results ◽  
New Variant ◽  
Class B ◽  
Class 1 ◽  
Encoding Gene ◽  
Good Agreement

ABSTRACT During a survey conducted to evaluate the incidence of class B carbapenemase (metallo-β-lactamase [MBL])-producing Pseudomonas aeruginosa strains from hospitals in Majorca, Spain, five clinical isolates showed a positive Etest MBL screening test result. In one of them, strain PA-SL2, the presence of a new bla VIM derivative (bla VIM-13) was detected by PCR amplification with bla VIM-1-specific primers followed by sequencing. The bla VIM-13-producing isolate showed resistance to all β-lactams (except aztreonam), gentamicin, tobramycin, and ciprofloxacin. VIM-13 exhibited 93% and 88% amino acid sequence identities with VIM-1 and VIM-2, respectively. bla VIM-13 was cloned in parallel with bla VIM-1, and the resistance profile conferred was analyzed both in Escherichia coli and in P. aeruginosa backgrounds. Compared to VIM-1, VIM-13 conferred slightly higher levels of resistance to piperacillin and lower levels of resistance to ceftazidime and cefepime. VIM-13 and VIM-1 were purified in parallel as well, and their kinetic parameters were compared. The k cat/K m ratios for the antibiotics mentioned above were in good agreement with the MIC data. Furthermore, EDTA inhibited the activity of VIM-13 approximately 25 times less than it inhibited the activity of VIM-1. VIM-13 was harbored in a class 1 integron, along with a new variant (Ala108Thr) of the aminoglycoside-modifying enzyme encoding gene aacA4, which confers resistance to gentamicin and tobramycin. Finally, the VIM-13 integron was apparently located in the chromosome, since transformation and conjugation experiments consistently yielded negative results and the bla VIM-13 probe hybridized only with the genomic DNA.

scholarly journals Antimicrobial Activity of Ceftazidime-Avibactam Tested against Multidrug-Resistant Enterobacteriaceae and Pseudomonas aeruginosa Isolates from U.S. Medical Centers, 2013 to 2016

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Helio S. Sader ◽  
Mariana Castanheira ◽  
Dee Shortridge ◽  
Rodrigo E. Mendes ◽  
Robert K. Flamm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Large Collection ◽  
Content Type ◽  
Negative Results ◽  
Medical Centers ◽  
Extensively Drug Resistant ◽  
Genes Encoding

ABSTRACT The in vitro activity of ceftazidime-avibactam and many comparator agents was determined against various resistant subsets of organisms selected among 36,380 Enterobacteriaceae and 7,868 Pseudomonas aeruginosa isolates. The isolates were consecutively collected from 94 U.S. hospitals, and all isolates were tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories). Enterobacteriaceae isolates resistant to carbapenems (CRE) and/or ceftazidime-avibactam (MIC ≥ 16 μg/ml) were evaluated for the presence of genes encoding extended-spectrum β-lactamases and carbapenemases. Ceftazidime-avibactam inhibited >99.9% of all Enterobacteriaceae at the susceptible breakpoint of ≤8 μg/ml and was active against multidrug-resistant (MDR; n = 2,953; MIC50/90, 0.25/1 μg/ml; 99.2% susceptible), extensively drug-resistant (XDR; n = 448; MIC50/90, 0.5/2 μg/ml; 97.8% susceptible), and CRE (n = 513; MIC50/90, 0.5/2 μg/ml; 97.5% susceptible) isolates. Only 82.2% of MDR Enterobacteriaceae (n = 2,953) and 64.2% of ceftriaxone-nonsusceptible Klebsiella pneumoniae (n = 1,063) isolates were meropenem susceptible. Among Enterobacter cloacae (22.2% ceftazidime nonsusceptible), 99.8% of the isolates, including 99.3% of the ceftazidime-nonsusceptible isolates, were ceftazidime-avibactam susceptible. Only 23 of 36,380 Enterobacteriaceae (0.06%) isolates were ceftazidime-avibactam nonsusceptible, including 9 metallo-β-lactamase producers and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. Ceftazidime-avibactam showed potent activity against P. aeruginosa (MIC50/90, 2/4 μg/ml; 97.1% susceptible), including MDR (MIC50/90, 4/16 μg/ml; 86.5% susceptible) isolates, and inhibited 71.8% of isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n = 628). In summary, ceftazidime-avibactam demonstrated potent activity against a large collection (n = 44,248) of contemporary Gram-negative bacilli isolated from U.S. patients, including organisms resistant to most currently available agents, such as CRE and meropenem-nonsusceptible P. aeruginosa.

Future Trends in Management of Hazardous Envhionments - Panel Summary

2000 ◽  
Vol 44 (12) ◽  
pp. 2-602-2-605
Author(s):  
Thomas J. Smith
Keyword(s):  
Large Scale ◽  
New Technologies ◽  
Systems Approach ◽  
Environmental Safety ◽  
Future Trends ◽  
Psychological Consequences ◽  
Hazard Management ◽  
Musculoskeletal Problems ◽  
To Come ◽  
Panel Summary

Coming decades almost certainly will see a continuing process of change in the nature and distribution of workplace and environmental safety hazards and risks. This session discusses future trends in the management of hazardous environments, particularly in terms of how such management can benefit from the application of macroergonomic principles and methods, Thomas Albin points out that although the application of ergonomics will remain a key strategy for abating musculoskeletal problems in the workplace, there is need for a broader systems approach to ergonomics program design. Michael Smith deals with new types and patterns of hazards and risks related to the emergence of new technologies. Markku Mattila addresses future trends in management of workplace hazards from a Scandinavian and European perspective, including the integration of ergonomics and quality management. Victor Koscheyev and Gloria Leon discuss future needs and trends in systems management of large-scale disasters and in the psychological consequences of human exposure to such disasters. Thomas Smith notes that a number of prevailing concepts and practices in the safety profession remain contrary to the principle of ‘fitting the job to the worker,’ and that perhaps the greatest challenge facing the safety and hazard management field in the decades to come will be to broaden the acceptance and application of this principle to enhance safety performance in the workplace.

A new assay design for clinical diagnostics based on alternative recognition elements

2010 ◽  
Vol 25 (10) ◽  
pp. 2302-2308 ◽  
Author(s):  
Christiane Albrecht ◽  
Peter Fechner ◽  
Dmytro Honcharenko ◽  
Lars Baltzer ◽  
Günter Gauglitz
Keyword(s):  
Clinical Diagnostics ◽  
Recognition Elements ◽  
Assay Design

scholarly journals Evaluation of the Xpert Carba-R NxG Assay for Detection of Carbapenemase Genes in a Global Challenge Set of Pseudomonas aeruginosa Isolates

2020 ◽  
Vol 58 (12) ◽  
Author(s):  
Christian M. Gill ◽  
Tomefa E. Asempa ◽  
Isabella A. Tickler ◽  
Caitlin dela Cruz ◽  
Fred C. Tenover ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Negative Control ◽  
Research Use ◽  
Whole Genome ◽  
Content Type ◽  
Global Challenge ◽  
Negative Results ◽  
Carbapenem Resistant ◽  
Detection Capabilities ◽  
Positive Results

ABSTRACT The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and the Carba-R tests per the manufacturer’s instructions. Carba-R NxG testing was completed by Cepheid (Sunnyvale, CA), blinded to genotype. Both assays gave negative results for all non-CP isolates and positive results for all VIM, NDM, and KPC isolates. An improvement in IMP detection among isolates was observed (100% detection by Carba-R NxG versus 58% by Carba-R). All SPM and GES isolates, targets not present in commercially available Carba-R, were positive by Carba-R NxG. Two isolates harbored both VIM and GES, while a third isolate contained VIM and NDM. The Carba-R NxG identified both targets in all 3 isolates, while the Carba-R was negative for both GES-containing isolates. Overall, the Carba-R NxG successfully categorized 100% of isolates tested compared with 68% for its predecessor. The Carba-R NxG will expand the detection spectrum of the current Carba-R assay to include SPM, GES, and expanded IMP variants, increasing the global utility of the test.

Rapid, Automated Nucleic Acid Probe Assays Using Silicon Microstructures for Nucleic Acid Concentration

1999 ◽  
Vol 121 (1) ◽  
pp. 22-27 ◽  
Author(s):  
L. A. Christel ◽  
K. Petersen ◽  
W. McMillan ◽  
M. A. Northrup
Keyword(s):  
Nucleic Acid ◽  
Pathogen Detection ◽  
High Surface ◽  
High Surface Area ◽  
Clinical Diagnostics ◽  
Medium Size ◽  
Point Of Use ◽  
Biowarfare Agent ◽  
Silicon Microstructures ◽  
Pcr Techniques

A system for rapid point-of-use nucleic acid (NA) analysis based on PCR techniques is described. The extraction and concentration of DNA from test samples has been accomplished utilizing silicon fluidic microchips with high surface-area-to-volume ratios. Short (500 bp) and medium size (48,000 bp) DNA have been captured, washed, and eluted using the silicon dioxide surfaces of these chips. Chaotropic (GuHCl) salt solutions were used as binding agents. Wash and elution agents consisted of ethanol-based solutions and water, respectively. DNA quantities approaching 40 ng/cm2 of binding area were captured from input solutions in the 100–1000 ng/mL concentration range. For dilute samples of interest for pathogen detection, PCR and gel electrophoresis were used to demonstrate extraction efficiencies of about 50 percent, and concentration factors of about 10× using bacteriophage lambda DNA as the target. Rapid, multichannel PCR thermal cycling modules with integrated solid-state detection components have also been demonstrated. These results confirm the viability of utilizing these components as elements of a compact, disposable cartridge system for the detection of NA in applications such as clinical diagnostics, biowarfare agent detection, food quality control, and environmental monitoring.

scholarly journals Broad Range Detection of Viral and Bacterial Pathogens in Bronchoalveolar Lavage Fluid of Children to Identify the Cause of Lower Respiratory Tract Infections

2020 ◽  
Author(s):  
Heping Wang ◽  
Jiali Gu ◽  
Xiaonan Li ◽  
Christa E. van der Gaast de Jongh ◽  
Wenjian Wang ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Clinical Diagnosis ◽  
Pathogen Detection ◽  
Bacterial Pathogens ◽  
Clinical Diagnostics ◽  
Large Set ◽  
Detection Rates ◽  
Multiplex Qpcr ◽  
Accurate Treatment ◽  
Tract Infections

Abstract OBJECTIVES: Knowledge on the etiology of LRTIs is essential for improvement of the clinical diagnosis and accurate treatment. Molecular detection methods were applied to identify a broad range of bacterial and viral pathogens in a large set of bronchial alveolar lavage (BAL) fluid samples. The patterns of detected pathogens were correlated to the clinical symptoms.METHODS: BAL fluid samples and clinical data were collected from 573 hospitalized children between 1 month and 14 years of age with LRTIs, enrolled from January to December 2018. Pathogens were detected using standardized clinical diagnostics, with a sensitive, high-throughput GeXP-based multiplex PCR and with multiplex qPCR. Data were analyzed to describe the correlation between the severity of respiratory tract disease and the pathogens identified.RESULTS: The pathogen detection rate with GeXP-based PCR and multiplex qPCR was significantly higher than by clinical routine diagnostics (76.09% VS 36.13%,χ2 = 8.191, P=0.004). The most frequently detected pathogens in the BAL fluid were human adenovirus (HADV)(21.82%), Mycoplasma pneumoniae (20.24%), human rhinovirus (13.96%), Streptococcus pneumoniae (8.90%) and Haemophilus influenzae (8.90%). In 16.4 % of the cases co-infection with two or three different pathogens was found. Viral detection rates declined with age, while atypical pathogen detection rates increased with age. Oxygen supply in the HADV and Influenza H1N1 infected patients was more frequent (49.43%) than in patients infected with other pathogens.CONCLUSION: Broad range detection of viral and bacterial pathogens using molecular methods is a promising and implementable approach to improve clinical diagnosis and accurate treatment of LRTI in children.

scholarly journals Chest physiotherapy enhances detection of Pseudomonas aeruginosa in non-expectorating CF children

2021 ◽  
pp. 00513-2020
Author(s):  
Christophe Marguet ◽  
Véronique Houdouin ◽  
I. Pin ◽  
Philippe Reix ◽  
Frédéric Huet ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogen Detection ◽  
Chest Physiotherapy ◽  
Lung Damage ◽  
Lower Airway ◽  
Prospective Multicentre Study ◽  
Airway Secretion ◽  
Airway Infections ◽  
Oropharyngeal Swab

Lung damage in Cystic Fibrosis (CF) is strongly associated with lower airway infections. Early treatment of Pseudomonas aeruginosa is recommended. Pathogen detection requires sampling of lower airway secretions, which remains a challenge in non-expectorating patients. Our hypothesis was that chest physiotherapy would improve the quality of airway secretion samples and increase the rates of pathogens detected in non-expectorating patients.This prospective multicentre study compared three successive methods for sampling airway secretions applied through a same session: 1) oropharyngeal swab (OP); 2) sputum collected after chest physiotherapy (CP-SP); and 3) oropharyngeal swab 2 performed after chest physiotherapy(CP-SP-CP-OP). Haemophilus influenzae, Staphylococcus aureus and P. aeruginosa (Pa) growth cultures were assessed. Accuracy tests and an equivalence test was performed to compare the three successive methods of collection. Three-hundred non-expectorating children with CF were included. Pa was detected cumulatively in 56 (18.9%) children and according to the collection techniques in 28 (9.8%), 37(12.4%) and 44 (15%) children by using CP-SP and CP-OP, respectively. Compared to OP, the increased detection rate was +22% for CP-OP, p=0029 and +57% for CP-SP, p=0.003. CP-SP had the best positive predictive value (PPV) (86.3%) and negative PV (96%) for Pa compared to the overall detection. The results of this adequately powered study show differences in the rates of pathogens detected according to the sampling method used. Chest physiotherapy enhanced detection of P. aeruginosa in non-expectorating children with CF.

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