Vitek® 2 MICs as first-line phenotypic screening method for carbapenemase-producing Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Elske Sieswerda ◽  
Thijs Bosch ◽  
Jacqueline M Lankelma ◽  
Leo M Schouls ◽  
Karin van Dijk
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sensitivity And Specificity ◽  
Screening Method ◽  
Screening Strategy ◽  
Phenotypic Screening ◽  
First Line ◽  
Test Characteristics ◽  
Confirmatory Tests ◽  
Surveillance Database

Aim: To define sensitivity and specificity of Vitek® 2 MICs as phenotypic screening method for carbapenemase-producing Pseudomonas aeruginosa. Materials & methods: We determined Vitek® 2 MICs of antipseudomonal antimicrobials in 130 unrelated carbapenemase-producing P. aeruginosa and 129 carbapenemase-negative P. aeruginosa isolates within a Dutch carbapenemase-surveillance database. We calculated test characteristics of single and combined antimicrobial MICs for carbapenemase production. Results: Vitek® 2 MIC above epidemiological cutoff of both imipenem and tobramycin or ciprofloxacin and tobramycin displayed a sensitivity of 96.2% and specificity of 89.6% for carbapenemase production in P. aeruginosa. Conclusion: Vitek® 2 MIC> epidemiological cut-off values seem sensitive and specific as a phenotypic screening strategy for carbapenemase-producing P. aeruginosa. Combining imipenem and tobramycin or ciprofloxacin and tobramycin performed best as a screening strategy for defining which P. aeruginosa isolates should undergo confirmatory tests for carbapenemase production.

scholarly journals Rapidec Carba NP Test for Rapid Detection of Carbapenemase Producers

2015 ◽  
Vol 53 (9) ◽  
pp. 3003-3008 ◽  
Author(s):  
Laurent Poirel ◽  
Patrice Nordmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sample Preparation ◽  
Acinetobacter Baumannii ◽  
Sensitivity And Specificity ◽  
Rapid Detection ◽  
Content Type

Performances of the Rapidec Carba NP test (bioMérieux) were evaluated for detection of all types of carbapenemases inEnterobacteriaceae,Acinetobacter baumannii, andPseudomonas aeruginosa. In less than 2 h after sample preparation, it showed a sensitivity and specificity of 96%. This ready-to-use test is well adapted to the daily need for detection of carbapenemase producers in any laboratory worldwide.

scholarly journals Immunodiagnosis of human neurocysticercosis by using semi-purified scolex antigens from Taenia solium cysticerci

2007 ◽  
Vol 40 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Francesco Iudici Neto ◽  
Geraldo Pianetti-Filho ◽  
Ricardo Nascimento Araújo ◽  
Evaldo Nascimento
Keyword(s):  
Sensitivity And Specificity ◽  
Excellent Agreement ◽  
Taenia Solium ◽  
Polyacrylamide Gel ◽  
Parasitic Diseases ◽  
Serum Samples ◽  
Serological Screening ◽  
Crude Antigen ◽  
Normal Individuals ◽  
Confirmatory Tests

Crude antigen and semi-purified proteins from scolices of Taenia solium cysticerci were evaluated for the immunodiagnosis of human neurocysticercosis neurocysticercosis. Semi-purified proteins obtained by electrophoresis on polyacrylamide gel and by electroelution were tested by means of the immunoenzymatic reaction against sera from normal individuals and from patients with neurocysticercosis or other parasitic diseases. The 100kDa protein provided 100% sensitivity and specificity in the immunodiagnosis. When 95 or 26kDa proteins were used, 95 and 100% sensitivity and specificity were obtained, respectively. The assays involving crude antigen and sera from normal individuals or from patients with neurocysticercosis, diluted to 1:256, gave excellent agreement with those in which 100, 95 or 26kDa proteins were tested against the same serum samples diluted to 1:64. (Kappa: 0.95 to 1.00). Crude scolex antigen may be useful for serological screening, while 100, 95 or 26kDa protein can be used in confirmatory tests on neurocysticercosis-positive cases.

scholarly journals A Rapid Phenotypic Whole-Cell Screening Approach for the Identification of Small-Molecule Inhibitors That Counter β-Lactamase Resistance in Pseudomonas aeruginosa

2017 ◽  
Vol 23 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Deanna Collia ◽  
Thomas D. Bannister ◽  
Hao Tan ◽  
Shouguang Jin ◽  
Taimour Langaee ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Laboratory Strain ◽  
Multidrug Resistant ◽  
First Line ◽  
Strain Pao1 ◽  
Whole Cell ◽  
Bacterial Sensitivity ◽  
Opportunistic Human Pathogen

Pseudomonas aeruginosa is an opportunistic human pathogen that is prevalent in hospitals and continues to develop resistance to multiple classes of antibiotics. Historically, β-lactam antibiotics have been the first line of therapeutic defense. However, the emergence of multidrug-resistant (MDR) strains of P. aeruginosa, such as AmpC β-lactamase overproducing mutants, limits the effectiveness of current antibiotics. Among AmpC hyperproducing clinical isolates, inactivation of AmpG, which is essential for the expression of AmpC, increases bacterial sensitivity to β-lactam antibiotics. We hypothesize that inhibition of AmpG activity will enhance the efficacy of β-lactams against P. aeruginosa. Here, using a highly drug-resistant AmpC-inducible laboratory strain PAO1, we describe an ultra-high-throughput whole-cell turbidity assay designed to identify small-molecule inhibitors of the AmpG. We screened 645,000 compounds to identify compounds with the ability to inhibit bacterial growth in the presence of cefoxitin, an AmpC inducer, and identified 2663 inhibitors that were also tested in the absence of cefoxitin to determine AmpG specificity. The Z′ and signal-to-background ratio were robust at 0.87 ± 0.05 and 2.2 ± 0.2, respectively. Through a series of secondary and tertiary studies, including a novel luciferase-based counterscreen, we ultimately identified eight potential AmpG-specific inhibitors.

scholarly journals Optimising the mutation screening strategy in Marfan syndrome and identifying genotypes with more severe aortic involvement

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Roland Stengl ◽  
András Bors ◽  
Bence Ágg ◽  
Miklós Pólos ◽  
Gabor Matyas ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Single Gene ◽  
Mutation Screening ◽  
Screening Method ◽  
Connective Tissue Disorder ◽  
Screening Strategy ◽  
Gene Panel ◽  
Dominant Negative ◽  
Second Phase ◽  
High Detection Rate

Abstract Background Marfan syndrome (MFS) is a systemic connective tissue disorder with life-threatening manifestations affecting the ascending aorta. MFS is caused by dominant negative (DN) and haploinsufficient (HI) mutations of the FBN1 gene. Our aim was to identify mutations of MFS patients with high detection rate and to investigate the use of a gene panel for patients with Marfanoid habitus. We also aimed to examine correlations between genotype and cardiovascular manifestations to predict “malignant” mutations. Methods 136 individuals were enrolled. In the first phase, next-generation sequencing (NGS) and Sanger sequencing were performed for 57 patients to screen the FBN1 gene, followed by multiplex ligation-dependent probe amplification (MLPA) in negative cases. For repeated negative results, NGS gene panel involving 9 genes was used. In the second phase, 79 patients were tested primarily with the same gene panel, negative samples were tested by MLPA. Results 84 pathogenic mutations were detected, out of which 78 affected FBN1, 6 non-FBN1 mutations (2 TGFB2, 1 TGFBR2, 2 TGFBR1, 1 SMAD3) are associated with Loeys-Dietz syndrome (LDS). LDS patients had lower systemic score and they were younger, but their aortic involvement did not differ. MLPA detected 4 multi-exon deletions of FBN1 gene, which could not be identified by our first-step screening method. Aortic involvement (aortic dissection and/or dilation) did not differ significantly among HI and DN mutations (p = 0.061). Combined group of HI and DN mutations eliminating a disulphide-bonding cysteine (DN Cys) had significantly higher aortic involvement rate than DN mutations not eliminating a disulphide-bonding cysteine (DN non-Cys) (p < 0.001). Patients with DN Cys required significantly more aortic surgeries than HI and DN non-Cys mutations (p = 0.042 and p = 0.015, respectively). Conclusions Due to the relevant number of mutations affecting genes other than FBN1, preferred approach for testing individuals with Marfanoid habitus is using a gene panel rather than single-gene analysis, followed by MLPA for negative samples. DN Cys and HI mutations should be considered as risk factors for aortic involvement. Genetic testing for patients with Marfanoid features and a systemic score under 7 is recommended, as LDS patients may have lower scores, but they may have severe cardiovascular manifestations.

scholarly journals A study of the sensitivity and specificity of the Magnetic Resonance Imaging (MRI) technique used in the diagnosis of endometriosis versus the intraoperative appearance considered the reference standard in the diagnosis of endometriosis

2021 ◽  
Vol 28 (1) ◽  
pp. 55-61
Author(s):  
Alexandra RADU ◽  
◽  
Elvira BRATILA ◽  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sensitivity And Specificity ◽  
Reference Standard ◽  
Resonance Imaging ◽  
First Line ◽  
Magnetic Resonance Imaging Mri ◽  
Asymptomatic Women ◽  
Bladder Invasion

Endometriosis is a gynecological pathology with chronic symptoms, which negatively affects the patient’s quality of life. The prevalence of endometriosis in asymptomatic women is between 2% and 50%, depending on the populations studied and the method of diagnosis. The severity of the symptoms as well as the probability of diagnosing endometriosis increases with age9. Because endometriosis is a gynecological condition with a nonspecific clinical picture, sometimes even asymptomatic, imaging technology can be considered the first line of diagnosis for this pathology. The main objective of this study is to evaluate the sensitivity and specificity of nuclear magnetic resonance imaging (MRI) used in the diagnosis of endometriotic lesions depending on their location, and compare the results obtained with the intraoperative appearance considered a reference standard in the diagnosis of endometriosis. Our study revealed the highest specificity for MRI in the case of endometriotic bladder invasion, respectively the highest sensitivity for endometriotic rectal nodules.

scholarly journals Effectiveness of the toxin-degrading strain screening strategy: Deficiency and improvement in screening the gossypol-degrading microorganism Aspergillus niger

2021 ◽  
Author(s):  
Chen Zhang ◽  
Gangqin Shu ◽  
Hui Wang ◽  
Daojie Li ◽  
Yuan Xü ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Free Gossypol ◽  
Screening Method ◽  
Screening Strategy ◽  
Gossypol Content ◽  
Control Group ◽  
Total Gossypol ◽  
Screening Strategies ◽  
Free Gossypol Content ◽  
Degrading Microorganism

Abstract The effectiveness of the classic screening strategy was verified, by duplicating and verifying the degradation of gossypol by the Aspergillus niger. It can reduce the free gossypol content through biosorption but has no effect on the total gossypol content and cannot effectively degrade gossypol. And the most interesting thing we found the strain can secrete agarase, utilise agar as carbon source. In this case, that will mislead researchers and lead them to make wrong judgments. That turns out the usual methods of previous screening strategies are not rigorous enough, the classic screening method has defect in screening toxin-degrading strain, so agar control group should be added. In this study, some suggestions are put forward to optimise the same type of experiments and broaden the idea of detoxification by microorganisms and provide reference for screening effective toxin-degrading microorganisms.

scholarly journals Challenges in microbiological diagnosis of invasive Aspergillus infections

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 157 ◽  
Author(s):  
Alexandre Alanio ◽  
Stéphane Bretagne
Keyword(s):  
Current Trend ◽  
Screening Strategy ◽  
Consensus Methods ◽  
Real Time Quantitative Pcr ◽  
Genetic Risks ◽  
Confirmatory Tests ◽  
Polymerase Chain ◽  
Defined Culture ◽  
Diagnostic Criterion ◽  
Respiratory Specimens

Invasive aspergillosis (IA) has been increasingly reported in populations other than the historical hematology patients and there are new questions about the performance of microbiological tools. Microscopy and culture have been completed by biomarkers, either antigens or DNA, and in blood or respiratory specimens or both. First studied in hematology, the antigen galactomannan performance in serum is low in other patient populations where the pathophysiology of the infection can be different and the prevalence of IA is much lower. DNA detection with polymerase chain reaction (PCR) in blood or serum (or both) has reached a certain level of acceptance thanks to consensus methods based on real-time quantitative PCR (qPCR). When used on respiratory specimens, galactomannan and qPCR depend on standardization of the sampling and the diverse mycological procedures. Thus, culture remains the main diagnostic criterion in critically ill patients. The current trend toward more effective anti-mold prophylaxis in hematology hampers the yield of a screening strategy, as is usually performed in hematology. Therefore, circulating biomarkers as confirmatory tests should be considered and their performance should be reappraised in each new setting. The use of azole prophylaxis also raises the issue of selecting azole-resistanceAspergillus fumigatusisolates. Ideally, the biomarkers will be more efficient when individual genetic risks of IA are defined. Culture, though not standardized, remains a key element for the diagnosis of IA and has the advantage to easily detect molds other thanA. fumigatus. It is still unclear whether next-generation sequencing will replace culture in the future.

EVALUATION OF THE SENSITIVITY AND SPECIFICITY OF THE PEDIATRIC BLEEDING QUESTIONNAIRE IN VARIOUS HEMORRHAGIC DISORDERS

2021 ◽  
Vol 100 (3) ◽  
pp. 35-41
Author(s):  
T.U. Yafoshkina ◽  
◽  
D.B. Florinskiy ◽  
A.V. Pshonkin ◽  
D.V. Fedorova ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Screening Method ◽  
Threshold Value ◽  
Discriminatory Ability ◽  
Pediatric Hematology ◽  
National Medical ◽  
Single Center Study ◽  
History Of ◽  
Laboratory Examinations

Determination of significant bleeding in the anamnesis is quite difficult, since mild mucocutaneous bleeding can occur both in patients with hereditary bleeding disorders and in healthy people. As a result, there is a growing interest among researchers and clinicians in accurate and objective quantification of hemorrhage symptoms. Objective of the study: to evaluate the effectiveness of the Pediatric bleeding questionnaire as a tool for identifying a group of children requiring further laboratory examination. Materials and methods of research: the study was a retrospective, uncontrolled, comparative, nonrandomized, single-center study. Based on the analysis of the database of the Consultive department of the Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology from January 2017 to December 2019, out of the total number of visits to doctors, patients under 18 years old who complained of increased bleeding were selected. The manifestations of hemorrhagic syndrome were evaluated using the pediatric bleeding scale – PBQ (Pediatric Bleeding Questionnaire), followed by a series of laboratory examinations to verify the diagnosis in all children. The sensitivity and specificity of this questionnaire was assessed at various threshold values using the ROC AUC curve, and a comparison of the scores on the scale in patients with different nosologies was made. Results: the study included 346 people, 174 were diagnosed, 172 had no data for coagulopathy/thrombocytopathy found – the patients were considered healthy. The discriminatory ability of the scale under study, studied using the ROC-AUC, was 0,815 (95% CI 0,772–0,858) – satisfactory. With a threshold value of pathological bleeding of 2 points, the sensitivity of the method was 98%, specificity – 12%. The best ratio of sensitivity and specificity (69% and 79%, respectively) was achieved when the threshold value was increased to 4 points. Conclusion: this questionnaire is a convenient addition, with the help of which it is easy to collect a history of bleeding, to assess the severity of bleeding, but it cannot be used as a screening method due to the large number of falsepositive results.

scholarly journals LO76: Can emergency physicians perform carotid artery ultrasound to detect severe stenosis in patients with TIA and stroke?

CJEM ◽  
2018 ◽  
Vol 20 (S1) ◽  
pp. S34-S34
Author(s):  
R. Suttie ◽  
M.Y. Woo ◽  
J.J. Perry ◽  
L. Park ◽  
G. Stotts
Keyword(s):  
Carotid Artery ◽  
Sensitivity And Specificity ◽  
Tertiary Care ◽  
Stroke Patients ◽  
Convenience Sample ◽  
Test Characteristics ◽  
Urgent Surgery ◽  
Ica Stenosis ◽  
Mean Time ◽  
Rule Out

Introduction: Carotid artery stenosis (CAS) is a common cause of stroke. Patients with severe, symptomatic CAS can have their subsequent stroke risk reduced by carotid endarterectomy or stenting when completed soon after a TIA or non-disabling stroke. Patients presenting to a peripheral ED with TIA/stroke, may require transfer to another hospital for imaging to rule-out CAS. The purpose of this study was to determine the test characteristics of carotid artery POCUS in detecting greater than 50% stenosis in patients presenting with TIA/stroke. Methods: We conducted a prospective cohort study on a convenience sample of adult patients presenting to a tertiary care academic ED with TIA/stroke between June and October 2017. Carotid POCUS was performed by a trained medical student or a trained emergency physician. Our outcome measure, CAS >50% was determined by the final radiology report of CTA imaging by a trained radiologist, blinded to our study. A blinded POCUS expert reviewed the carotid POCUS scans. We calculated the sensitivity and specificity for CAS >50% using carotid POCUS versus the gold standard of CTA. Results: We enrolled 75 patients of which 5 did not meet inclusion criteria. The mean age was 70.4 years, 57% were male. 16% were diagnosed with greater than 50% CAS. 47% were stroke codes and 37% were admitted to hospital. Carotid POCUS had a sensitivity and specificity of 72% (46%-99%) and 88% (80%-96%) respectively. There were three false negatives of which two were exactly 50% ICA stenosis on CTA and the other was 100% occlusion of the distal ICA. Kappa coefficient for inter-rater reliability between standard and expert interpretation was 0.68 for moderate agreement. The scan took a mean time of 6.2 minutes to complete. Conclusion: Carotid POCUS has moderate correlation with CTA for detection of CAS greater than 50%. Carotid POCUS identified all the critical 70-99% stenosis lesions that would need urgent surgery. Further research is needed to confirm these findings.

scholarly journals CYP51 as drug targets for fungi and protozoan parasites: past, present and future

Parasitology ◽  
2018 ◽  
Vol 145 (14) ◽  
pp. 1820-1836 ◽  
Author(s):  
Galina I. Lepesheva ◽  
Laura Friggeri ◽  
Michael R. Waterman
Keyword(s):  
Cell Growth ◽  
Drug Targets ◽  
Mortality Rates ◽  
Phenotypic Screening ◽  
Protozoan Parasites ◽  
First Line ◽  
Fungal Cell ◽  
History Of ◽  
Actual Target ◽  
Human Infections

AbstractThe efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.

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