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

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.

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Evaluation of the Rapidec Carba NP Test for Detection of Carbapenemases in Enterobacteriaceae

Journal of Clinical Microbiology ◽

10.1128/jcm.02327-15 ◽

2015 ◽

Vol 53 (12) ◽

pp. 3828-3833 ◽

Cited By ~ 35

Author(s):

Michael Hombach ◽

Barbara von Gunten ◽

Claudio Castelberg ◽

Guido V. Bloemberg

Keyword(s):

Positive Predictive Value ◽

Broad Spectrum ◽

Incubation Time ◽

Predictive Value ◽

False Negative ◽

Content Type ◽

Negative Results ◽

False Negative Results ◽

Bacterial Inoculum ◽

Sensitivity Specificity

This study evaluated the performance of the Rapidec Carba NP test, which was introduced recently into the market for the detection of carbapenemase production in a broad spectrum of β-lactamase-producingEnterobacteriaceaeclinical isolates. In total, 252 clinicalEnterobacteriaceaeisolates that had been genetically characterized with respect to carbapenemase, extended-spectrum β-lactamase (ESBL), and AmpC genes were analyzed; 51/252 isolates (20.2%) were genetically confirmed to be carbapenemase producers, whereas 201/252 isolates (79.8%) were genetically negative for the presence of carbapenemase genes. The Rapidec Carba NP test was applied according to the manufacturer's instructions, and results were read after 30 and 120 min of incubation. The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Rapidec Carba NP test were 90.2%, 100%, 100%, and 97.6%, respectively, when the manufacturer's instructions were followed. Four of 5 false-negative results occurred with OXA-48-like enzymes. After an incubation time of 30 min, the sensitivity was 49%. The sensitivity increased to 100% when the recommended bacterial inoculum was doubled and the test was read strictly after 120 min of incubation. The Rapidec Carba NP test is a useful tool for the reliable confirmation of carbapenemase-producingEnterobacteriaceaeisolates. The test should be read strictly after 120 min of incubation and the inoculum should be larger than recommended by the manufacturer.

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Combined CTP- IGF-1 Score: A New Score for Assessment of Disease Severity in HCV Related Liver Cirrhosis

10.21203/rs.3.rs-1216787/v1 ◽

2022 ◽

Author(s):

Elsayed Ghannam ◽

Salah Rozaik ◽

Ramy Hasan Agwa ◽

Ahmed Marwan ◽

Mervat El-Sayed Mashaly ◽

...

Keyword(s):

Liver Cirrhosis ◽

Negative Predictive Value ◽

Predictive Value ◽

False Negative ◽

The Body ◽

P Value ◽

Study Group ◽

Negative Results ◽

False Negative Results ◽

Ctp Score

Abstract Background: Liver is the largest endocrine organ in the body. It is a key organ in insulin mediated metabolism, growth hormone and insulin like growth factors (IGF) pathway. Liver cirrhosis is the end result of many chronic diseases including hepatitis C virus infection. Child-Turcotte-Pugh (CTP) score is the standard used in assessment of hepatic reserve but it has its drawbacks in the form of subjective variables, hepatic encephalopathy and ascites. The aim of this work is to assess IGF-1 in patients with liver cirrhosis, correlate it with CTP score and assess value of modified combined CTP-IGF-1 score. Patients and Methods: 170 patients with CLD (liver cirrhosis) and 72 healthy controls in the study groups were enrolled in the study. All patients were subjected to thorough history, clinical examination and laboratory assessment. IGF-1 was measured and all patients were evaluated using CTP and CTP-IGF-1 scores. Results: IGF1 showed highly significant low values in the study group in comparison to controls (42.15 ± 27.976 and 66.31 ± 33.084 ng/ml respectively, p <0.001). It showed also highly significant negative correlation to CTP score in the study group (p < 0.001) with progressive decrements with CTP score stage progression where IGF1 levels were 48.32 ± 28.611, 40.28 ± 25.869 and 18.80 ± 15.953 ng/ml (mean ± standard deviation) in relation to CTP score groups A, B and C respectively (p value < 0.001). The combined CTP-IGF-1 score in comparison to the classic CTP score showed improved area under curve (0.848 and 0.854), sensitivity (71.2% and 88%), negative predictive value (41.7% and 53.7%), false negative results (49 and 19) and accuracy (75.73% and 83.98%) but decreased specificity (97.22% and 61.1%), positive predictive value (99.2% and 91.5%) and higher false positive results (1 and 14) respectively. Conclusion: IGF-1 show progressive decrements with progression of liver cirrhosis and is negatively correlated with CTP score. Addition of IGF-1 to CTP score to formulate combined score improves the AUC, sensitivity, negative predictive value and the accuracy of CTP score and decreases the false negative results.

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Intraoperative use of transcranial motor/sensory evoked potential monitoring in the clipping of intracranial aneurysms: evaluation of false-positive and false-negative cases

Journal of Neurosurgery ◽

10.3171/2017.8.jns17791 ◽

2019 ◽

Vol 130 (3) ◽

pp. 936-948 ◽

Cited By ~ 3

Author(s):

Jaewoo Chung ◽

Wonhyoung Park ◽

Seok Ho Hong ◽

Jung Cheol Park ◽

Jae Sung Ahn ◽

...

Keyword(s):

Negative Predictive Value ◽

Predictive Value ◽

False Positive ◽

Intracranial Aneurysms ◽

Evoked Potential ◽

False Negative ◽

Motor Weakness ◽

Negative Results ◽

False Negative Results ◽

Sensory Evoked

OBJECTIVESomatosensory and motor evoked potentials (SEPs and MEPs) are often used to prevent ischemic complications during aneurysm surgeries. However, surgeons often encounter cases with suspicious false-positive and false-negative results from intraoperative evoked potential (EP) monitoring, but the incidence and possible causes for these results are not well established. The aim of this study was to investigate the efficacy and reliability of EP monitoring in the microsurgical treatment of intracranial aneurysms by evaluating false-positive and false-negative cases.METHODSFrom January 2012 to April 2016, 1514 patients underwent surgery for unruptured intracranial aneurysms (UIAs) with EP monitoring at the authors’ institution. An EP amplitude decrease of 50% or greater compared with the baseline amplitude was defined as a significant EP change. Correlations between immediate postoperative motor weakness and EP monitoring results were retrospectively reviewed. The authors calculated the sensitivity, specificity, and positive and negative predictive values of intraoperative MEP monitoring, as well as the incidence of false-positive and false-negative results.RESULTSEighteen (1.19%) of the 1514 patients had a symptomatic infarction, and 4 (0.26%) had a symptomatic hemorrhage. A total of 15 patients showed motor weakness, with the weakness detected on the immediate postoperative motor function test in 10 of these cases. Fifteen false-positive cases (0.99%) and 8 false-negative cases (0.53%) were reported. Therefore, MEP during UIA surgery resulted in a sensitivity of 0.10, specificity of 0.94, positive predictive value of 0.01, and negative predictive value of 0.99.CONCLUSIONSIntraoperative EP monitoring has high specificity and negative predictive value. Both false-positive and false-negative findings were present. However, it is likely that a more meticulously designed protocol will make EP monitoring a better surrogate indicator of possible ischemic neurological deficits.

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Transhepatic forceps biopsy after PTCD for histological assessment of bile duct stenoses or occlusions

Zeitschrift für Gastroenterologie ◽

10.1055/a-0821-7060 ◽

2019 ◽

Vol 57 (02) ◽

pp. 133-138

Author(s):

Eva-Marie Warnken ◽

Michael Uder ◽

Hubert Stein ◽

Michael Wucherer ◽

Michael Lell ◽

...

Keyword(s):

Predictive Value ◽

False Negative ◽

Short Term ◽

Microsoft Excel ◽

Ct Guided ◽

Forceps Biopsy ◽

Negative Results ◽

False Negative Results ◽

Pet Ct ◽

Ct Guided Biopsy

Abstract Purpose The goal of this study was to evaluate the experience of 11 years of wire-guided forceps biopsy via PTCD in patients with obstructive jaundice. Materials and methods In a retrospective approach, 56 biopsies in 51 patients were analyzed (22 female, 29 male). Data was collected from 2006 to 2016. Mean age was 71 years (range: 34 – 86 years). Data was extracted from dig. Patients’ records (KIS, PACS, RIS) to be analyzed in Microsoft Excel. Results All 56 procedures were technically successful. Stenosis in anastomoses were benign due to scarring in 7 patients and in 9 due to papillitis or others. In 4 patients, results in anastomosis were malignant. In 19 patients without anastomosis, CCC was the diagnosis, thereof 10 klatskin, 9 stenosis in other locations, followed by gastric, pancreatic, and colon carcinoma in 5, 3, and 2 patients. Three patients had a CUP (multimetering in case of more than 1 related category). Overall results were 35 mal. and 16 benign, 76.8 % of all proc. had a correct histopathologic result, and 23.2 % were false negative. Sensitivity was 65.8 %, which results in negative predictive value of 58.1 %. There was no false positive and so specificity was 100 %, as was the positive predictive value. False negative results (no malignancy but clinically and imaging suspect) were corrected by rerunning the procedure, by CT-guided biopsy or by 1 PET-CT. In 1 case the surg. sample brought the result. Minor complications occurred in 8 patients: shivering in 1 case, distinct but hemodynamically not relevant hemobilia in 5 cases, 2 portovenal bleedings. All bleedings were short-term and self-limiting. Conclusion Despite good feasibility, low peri- and post-interv. risk and high validity the forceps biopsy via PTCD is not widely used. For experienced interventionalists, it is an effective method for obtaining histology.

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2 × 2 Contingency table

10.1093/med/9780198765875.003.0064 ◽

2017 ◽

Author(s):

Mark Harrison

Keyword(s):

Emergency Medicine ◽

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Contingency Table ◽

Likelihood Ratios ◽

Negative Results ◽

Sensitivity Specificity

This chapter describes the 2 × 2 contingency table as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratios for positive and negative results, and the 2 × 2 contingency table. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.

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Development and Multicentric Validation of a Lateral Flow Immunoassay for Rapid Detection of MCR-1-Producing Enterobacteriaceae

Journal of Clinical Microbiology ◽

10.1128/jcm.01454-18 ◽

2019 ◽

Vol 57 (5) ◽

Cited By ~ 6

Author(s):

Hervé Volland ◽

Laurent Dortet ◽

Sandrine Bernabeu ◽

Hervé Boutal ◽

Marisa Haenni ◽

...

Keyword(s):

Rapid Detection ◽

False Negative ◽

Cost Effective ◽

Resistance Mechanisms ◽

Lateral Flow ◽

Colistin Resistance ◽

Multicentric Study ◽

Bacterial Colony ◽

Content Type ◽

Negative Results

ABSTRACT Colistin has become a last-resort antibiotic for the treatment of infections caused by highly drug-resistant Gram-negative bacteria. Moreover, it has been widely used in the livestock sector. As a consequence, colistin resistance is emerging worldwide. Among the colistin resistance mechanisms, the spread of the plasmid-encoded colistin resistance gene mcr-1 (mostly in Escherichia coli) is of particular concern due to its increased transferability compared to that of chromosome-encoded resistance. The early detection of MCR-1-producing bacteria is essential to prevent further spread and provide appropriate antimicrobial therapy. Lateral flow immunoassays (LFIAs) were manufactured with selected monoclonal antibodies. A collection of 177 human and 121 animal enterobacterial isolates was tested in a multicentric study. One bacterial colony grown on agar plates was suspended in extraction buffer and dispensed on the cassette. Migration was allowed for 15 min, and the results were monitored by the appearance of a specific band. The positive results showed a pink line resulting in an unambiguous interpretation. All MCR-1-producing isolates were found to be positive by the LFIA, and no false-negative results were observed. Three out of four MCR-2-producing isolates were also found to be positive. Our test does not detect MCR-3-, MCR-4-, or MCR-5-producing isolates. LFIA allows the detection of MCR-1 with 100% sensitivity and 98% specificity. This test is fast, sensitive, specific, easy to use, and cost-effective and can therefore be implemented in any microbiology laboratory worldwide. LFIA is a major tool for the rapid detection and monitoring of MCR-1 producers in humans and animals.

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Development of an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Ringworm Infection in Cattle

Clinical and Vaccine Immunology ◽

10.1128/cvi.00243-13 ◽

2013 ◽

Vol 20 (8) ◽

pp. 1150-1154 ◽

Cited By ~ 6

Author(s):

Elena Tatiana Băguţ ◽

Ludivine Cambier ◽

Marie-Pierre Heinen ◽

Vasile Cozma ◽

Michel Monod ◽

...

Keyword(s):

Positive Predictive Value ◽

Negative Predictive Value ◽

Immunosorbent Assay ◽

Predictive Value ◽

Skin Lesions ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Predictive Values ◽

Content Type ◽

Ringworm Infection

ABSTRACTThe aim of this study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of ringworm infection in cattle. We used available recombinant forms ofTrichophyton rubrumdipeptidyl peptidase V (TruDppV) andT. rubrumleucin aminopeptidase 2 (TruLap2), which are 98% identical toTrichophyton verrucosumorthologues. Field serum samples from 135 cattle with ringworm infection, as confirmed by direct microscopy, fluorescence microscopy, and PCR, and from 55 cattle without any apparent skin lesions or history of ringworm infection that served as negative controls were used. Sensitivities, specificities, and positive and negative predictive values were determined to evaluate the diagnostic value of our ELISA. Overall, the ELISAs based on recombinant TruDppV and TruLap2 discriminated well between infected animals and healthy controls. Highly significant differences (P< 0.0001, Mann-Whitney U test) were noted between optical density values obtained when sera from infected versus control cattle were tested. The ELISA developed for the detection of specific antibodies against DppV gave 89.6% sensitivity, 92.7% specificity, a 96.8% positive predictive value, and a 78.4% negative predictive value. The recombinant TruLap2-based ELISA displayed 88.1% sensitivity, 90.9% specificity, a 95.9% positive predictive value, and a 75.7% negative predictive value. To the best of our knowledge, this is the first ELISA based on recombinant antigens for assessing immune responses to ringworm infection in cattle; it is particularly suitable for epidemiological studies and also for the evaluation of vaccines and/or vaccination procedures.

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Evaluation of the QiagenartusC. difficile QS-RGQ Kit for Detection of Clostridium difficile Toxins A and B in Clinical Stool Specimens

Journal of Clinical Microbiology ◽

10.1128/jcm.00613-15 ◽

2015 ◽

Vol 53 (6) ◽

pp. 1942-1944 ◽

Cited By ~ 8

Author(s):

Nathalie Jazmati ◽

Pia Wiegel ◽

Božica Ličanin ◽

Georg Plum

Keyword(s):

Nucleic Acid ◽

Clostridium Difficile ◽

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Nucleic Acid Amplification Test ◽

Nucleic Acid Amplification ◽

Content Type ◽

Stool Specimens ◽

Sensitivity Specificity

We compared the QiagenartusC. difficile QS-RGQ kit, a new nucleic acid amplification test for the detection ofClostridium difficiletoxins in stool specimens, with the Cepheid XpertC. difficiletest. The sensitivity, specificity, positive predictive value, and negative predictive value for the QiagenartusC. difficile QS-RGQ test were 100%, 89.5%, 60.9%, and 100%, and those for the Cepheid XpertC. difficiletest were 100%, 90%, 62.2%, and 100%, respectively.

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C-reactive protein, as a marker for predicting acute appendicitis and its severity in KVG medical college and hospital, Sullia

International Surgery Journal ◽

10.18203/2349-2902.isj20213984 ◽

2021 ◽

Vol 8 (10) ◽

pp. 3002

Author(s):

Abhirup H. Ramu ◽

Priyanka Kenchetty ◽

Aishwarya K. Chidananda

Keyword(s):

Acute Appendicitis ◽

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

False Negative ◽

Clinical Suspicion ◽

C Reactive Protein ◽

Common Procedure ◽

Medical College ◽

Reactive Protein

Background: Appendicectomy for suspected acute appendicitis is a common procedure. The rate of normal appendices unnecessarily removed remains high despite several techniques and investigations used to improve the diagnostic accuracy. This study emphasizes the value of C reactive protein (CRP) in three groups of patients operated for clinical suspicion of acute appendicitis with different finding at appendicectomy namely an un-inflamed appendix, uncomplicated acute appendicitis or complicated acute appendicitis.Methods: This prospective study was performed on 100 consecutive patients who were operated on for treatment of acute appendicitis in KVG medical college and hospital between 01 August 2019 to 01 February 2021. Clinically proven by a surgeon, patients underwent appendicectomy. Serum CRP results of all patients were determined. Sensitivity, specificity, positive predictive value and negative predictive value were calculated. Statistical analysis will be made using descriptive statistic and SPSS version 21 was used for analysis.Results: The percentage of negative laparotomies was 13% and surgeon ‘s clinical suspicion was true in 87%. Preoperative CRP values were false negative in 21 patients with appendicitis and false positive in 2 patients with normal appendix. The difference of true and false results between CRP tests and surgeon’s diagnosis was statistically significant (p=0.001). Present study revealed, sensitivity=76%, specificity=87.5%, positive predictive value=96% and negative predictive value=41%.Conclusions: Serum C reactive protein when elevated supports the surgeon’s clinical diagnosis of acute appendicitis. It can be used frequently to diagnosis the acute appendicitis, so that the complication rate and negative laparotomies can be avoided.

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Study of ascitic fluid cytology in ovarian tumors

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20175382 ◽

2017 ◽

Vol 5 (12) ◽

pp. 5227 ◽

Cited By ~ 1

Author(s):

Chandralekha Janagam ◽

Bhagyalakshmi Atla

Keyword(s):

Ascitic Fluid ◽

Predictive Value ◽

False Positive ◽

False Negative ◽

Ovarian Tumors ◽

Peritoneal Cytology ◽

Negative Results ◽

Benign Ovarian Tumours ◽

False Negative Results ◽

Fluid Cytology

Background: The objectives of this study were to examine the validity of ascitic fluid cytology in the detection of pathological findings, to examine the percentage of false positive and false negative results in the cytology of ascitic fluid and to determine the validity of peritoneal cytology in relation to the histopathological type of the ovarian tumour.Methods: This retrospective study, over a period of 6 months, included 106 peritoneal cytology findings. The experimental group included 106 cytology findings obtained from patients who presented with an abdominal lump/mass with ascites and diagnosed with ovarian tumors clinically. They included 88 benign ovarian tumours (83%) and 18 malignant ovarian tumors (17%). Patients with other causes of ascites were excluded from the study.Results: The sensitivity of peritoneal cytology is 90%, specificity is 96.5%, positive predictive value is 85.7%, and negative predictive value is 97.6%. In 1.8% of patients, the peritoneal cytology showed false negative results, while in 2.8%, the results were false positive. False negative results were found in one case of teratoma with squamous cell carcinoma and one case of yolk sac tumor. False positive results were found in 2 cases of tuberculous-salpingo- oophoritis and one case of chronic salpingo-oophoritis due to reactive mesothelial proliferation, mistaken for adenocarcinoma.Conclusions: Peritoneal cytology of ascitic fluid is highly specific and sensitive for detection of ovarian malignancies, particularly in grade 3 and grade 4 disease, since most of the patients with ovarian malignancies present to us at advanced stage of the disease.

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