scholarly journals Molecular detection methods and serotyping performed directly on clinical samples improve diagnostic sensitivity and reveal increased incidence of invasive disease by Streptococcus pneumoniae in Italian children

2008 ◽  
Vol 57 (10) ◽  
pp. 1205-1212 ◽  
Author(s):  
Chiara Azzari ◽  
Maria Moriondo ◽  
Giuseppe Indolfi ◽  
Cristina Massai ◽  
Laura Becciolini ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Detection ◽  
Invasive Disease ◽  
Diagnostic Sensitivity ◽  
Detection Methods ◽  
Clinical Samples ◽  
Italian Children

scholarly journals Automated Broad-Range Molecular Detection of Bacteria in Clinical Samples

2016 ◽  
Vol 54 (4) ◽  
pp. 934-943 ◽  
Author(s):  
Andries E. Budding ◽  
Martine Hoogewerf ◽  
Christina M. J. E. Vandenbroucke-Grauls ◽  
Paul H. M. Savelkoul
Keyword(s):  
Clinical Microbiology ◽  
Molecular Detection ◽  
Bacterial Species ◽  
Added Value ◽  
Detection Methods ◽  
23S Rrna ◽  
Clinical Samples ◽  
Clinical Microbiology Laboratory ◽  
Rrna Gene ◽  
Culture Negative

Molecular detection methods, such as quantitative PCR (qPCR), have found their way into clinical microbiology laboratories for the detection of an array of pathogens. Most routinely used methods, however, are directed at specific species. Thus, anything that is not explicitly searched for will be missed. This greatly limits the flexibility and universal application of these techniques. We investigated the application of a rapid universal bacterial molecular identification method, IS-pro, to routine patient samples received in a clinical microbiology laboratory. IS-pro is a eubacterial technique based on the detection and categorization of 16S-23S rRNA gene interspace regions with lengths that are specific for each microbial species. As this is an open technique, clinicians do not need to decide in advance what to look for. We compared routine culture to IS-pro using 66 samples sent in for routine bacterial diagnostic testing. The samples were obtained from patients with infections in normally sterile sites (without a resident microbiota). The results were identical in 20 (30%) samples, IS-pro detected more bacterial species than culture in 31 (47%) samples, and five of the 10 culture-negative samples were positive with IS-pro. The case histories of the five patients from whom these culture-negative/IS-pro-positive samples were obtained suggest that the IS-pro findings are highly clinically relevant. Our findings indicate that an open molecular approach, such as IS-pro, may have a high added value for clinical practice.

DiiA is a novel dimorphic cell wall protein of Streptococcus pneumoniae involved in invasive disease

2016 ◽  
Vol 73 (1) ◽  
pp. 71-81 ◽  
Author(s):  
María S. Escolano-Martínez ◽  
Arnau Domenech ◽  
José Yuste ◽  
María I. Cercenado ◽  
Carmen Ardanuy ◽  
...  
Keyword(s):  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Invasive Disease ◽  
Cell Wall Protein

scholarly journals Prevalence of metallo-β-lactamase genes among Pseudomonas aeruginosa isolated from various clinical samples in China

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wei Wang ◽  
Xiaoya Wang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Ethylenediaminetetraacetic Acid ◽  
Carbapenem Resistance ◽  
Opportunistic Pathogen ◽  
Detection Methods ◽  
Clinical Samples ◽  
Routine Practice ◽  
Carbapenem Resistant ◽  
High Prevalence

AbstractBackgroundPseudomonas aeruginosa is an opportunistic pathogen which is associated with nosocomial infections and causes various diseases including urinary tract infection, pneumonia, soft-tissue infection and sepsis. The emergence of P. aeruginosa-acquired metallo-β-lactamase (MBL) is most worrisome and poses a serious threat during treatment and infection control. The objective of this study was to identify antibiotic susceptibility, phenotypic detection of MBL production and to determine the prevalence of MBL genes in carbapenem-resistant P. aeruginosa isolated from different clinical samples.MethodsA total of 329 non-duplicate P. aeruginosa isolated from various clinical samples from two hospitals in China between September 2017 and March 2019 were included in this study. Phenotypic detection of MBL was performed by the combined detection method using imipenem and imipenem-ethylenediaminetetraacetic acid (EDTA) discs. MBL-encoding genes including blaVIM-1, blaVIM-2, blaIMP-1, blaIMP-2, blaSPM-1, blaSIM, blaNDM-1 and blaGIM were detected by polymerase chain reaction (PCR).ResultsOf the 329 P. aeruginosa, majority of the isolates were resistant to imipenem (77.5%) followed by meropenem (64.7%). Of the 270 P. aeruginosa isolates tested, 149 (55.2%) isolates were found to be positive for MBL detection. Of the different samples, 57.8% (n = 26) of P. aeruginosa isolated from blood were found to be positive for MBL production. Of the various MBL genes, blaIMP-1 (28.2%) was the most predominant gene detected followed by blaVIM-2 (18.8%), blaVIM-1 (16.1%), blaNDM-1 (9.4%), blaIMP-2 (6.7%), blaSIM (6.0%), blaSPM-1 (4.0%) and blaGIM (1.3%) genes.ConclusionsThe high resistance of P. aeruginosa toward imipenem and meropenem and the high prevalence of blaIMP-1 and blaVIM-2 set the alarm on the increasing, perhaps the increased, carbapenem resistance. In addition to routine antibiotic susceptibility testings, our results emphasize the importance of both the phenotypic and genotypic MBL detection methods in routine practice for early detection of carbapenem resistance and to prevent further dissemination of this resistant pathogen.

scholarly journals Molecular detection of Brucella spp. from broth culture of clinical samples in Nigeria: Its role in vaccine quality control

2009 ◽  
Vol 8 (21) ◽  
pp. 5661-5665 ◽  
Author(s):  
F Antiabong J ◽  
Yakubu B ◽  
A Owolodun O ◽  
Bertu W ◽  
A Ocholi R
Keyword(s):  
Quality Control ◽  
Molecular Detection ◽  
Broth Culture ◽  
Clinical Samples

scholarly journals ANTIMICROBIAL SUSCEPTIBILITY AND DETECTION METHODS FOR THE EXTENDED‑SPECTRUM β-LACTAMASES PRODUCING ENTEROBACTERIACEAE FROM CLINICAL SAMPLES

2018 ◽  
Vol 11 (5) ◽  
pp. 139
Author(s):  
Kaviyarasan G ◽  
Rajamanikandan Kcp ◽  
Sabarimuthu M ◽  
Ramya S ◽  
Arvind Prasanth D
Keyword(s):  
Infection Control ◽  
Bacterial Infections ◽  
Control Measures ◽  
Detection Methods ◽  
Clinical Samples ◽  
Healthcare Settings ◽  
Infection Control Measures ◽  
Extended Spectrum ◽  
Drug Choice ◽  
Synergy Test

Objectives: Detection of extended-spectrum β-lactamases (ESBLs) is crucial for the infection control and antibiotic choice in healthcare settings. The aim of this study is to develop a standardized, inexpensive, and simple approach that is able to detect ESBL-producing Enterobacteriaceae isolates.Methods: Isolates those were resistant to at least one of the three indicator cephalosporins (cefotaxime, cefpodoxime, and ceftazidime) were tested for ESBL production using the double disc synergy test (DDST), combined disc synergy test (CDST) test and genotypic detection of the responsible gene for the ESBL.Result: From 64 isolates, 28 were resistant to cephalosporins. In 28 isolates, 23 were positive in CDST but in the DDST 18 were showing ESBL positive. 10 were positive in both CDST and DDST.Conclusion: Resistance to cephalosporins, which are the drug choice to treat mixed bacterial infections by the Enterobacteriaceae of which disseminate rapidly being plasmid mediated. Hence, it is necessary that rapid detection of ESBL should be done and immediate infection control measures should be implemented to prevent their dissemination.

scholarly journals Detection of LytA Genes in Streptococcus pneumoniae Isolated from sputum pneumonia patients

Biomedika ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23-30
Author(s):  
Mustika Sari Hutabarat ◽  
Firdaus Hamid ◽  
Irawaty Djaharuddin ◽  
Alfian Zainuddin ◽  
Rossana Agus ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
False Negative ◽  
Pneumococcal Infection ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Streptococcus pneumoniae (pneumococcus) is a Gram-positive facultative anaerobic bacterium that is a major cause of morbidity and mortality worldwide. But the lack of reporting of disease by this bacterium in Indonesia, one of the causes is because the diagnosis of pneumococcal infection is often clinically not typical and conventional methods which are still the standard gold method often give false-negative results. So the purpose of this study was to evaluate the performance of culture and molecular diagnostic methods using the Polymerase Chain Reaction (PCR) technique in detecting Streptococcus pneumoniae in sputum clinical samples using the Autolysin (LytA) gene which is a virulence factor of this bacterium. 57 isolates from 60 samples were confirmed as Streptococcus sp through microscopic identification, culture, and biochemical tests. Then the sensitivity test with an optochin test of 9 (9%) compared the results descriptively with the PCR technique using the Autolysin A (LytA) gene which was obtained more sensitive by 15 (25%).

scholarly journals A pneumococcal controlled human infection model in Malawi: Transfer of an established pneumococcal carriage model from Liverpool, UK to Blantyre, Malawi – A feasibility study

2020 ◽  
Vol 5 ◽  
pp. 25
Author(s):  
Ben Morton ◽  
Sarah Burr ◽  
Kondwani Jambo ◽  
Jamie Rylance ◽  
Marc Y.R. Henrion ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Feasibility Study ◽  
Invasive Disease ◽  
Community Acquired Pneumonia ◽  
Human Infection ◽  
Infection Model ◽  
Endpoint Detection ◽  
Pneumococcal Carriage ◽  
Sampling Protocols ◽  
Classical Culture

Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement and demonstrate reduced effectiveness against mucosal colonisation.  As asymptomatic colonisation of the human nasopharynx is a prerequisite for pneumococcal disease, this is proposed as a marker for novel vaccine efficacy. Our team established a safe and reproducible pneumococcal controlled human infection model at Liverpool School of Tropical Medicine (LSTM). This has been used to test vaccine induced protection against nasopharyngeal carriage for ten years in over 1000 participants. We will transfer established standardised operating procedures from LSTM to Malawi and test in up to 36 healthy participants. Primary endpoint: detection of the inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: confirmation of robust clinical and laboratory methods for sample capture and processing. Tertiary endpoints: participant acceptability of study and methods. We will test three doses of pneumococcal inoculation (20,000, 80,000 and 160,000 colony forming units [CFUs] per naris) using a parsimonious study design intended to reduce unnecessary exposure to participants. We hypothesise that 80,000 CFUs will induce nasal colonisation in approximately half of participants per established LSTM practice. The aims of the feasibility study are: 1) Establish Streptococcus pneumoniae experimental human pneumococcal carriage in Malawi; 2) Confirm optimal nasopharyngeal pneumococcal challenge dose; 3) Confirm safety and measure potential symptoms; 4) Confirm sampling protocols and laboratory assays; 5) Assess feasibility and acceptability of consent and study procedures. Confirmation of pneumococcal controlled human infection model feasibility in Malawi will enable us to target pneumococcal vaccine candidates for an at-risk population who stand the most to gain from new and improved vaccine strategies.

scholarly journals Multiplexed Detection of Sepsis Markers in Whole Blood using Nanocomposite Coated Electrochemical Sensors

2020 ◽  
Author(s):  
Uroš Zupančič ◽  
Pawan Jolly ◽  
Pedro Estrela ◽  
Despina Moschou ◽  
Donald E. Ingber
Keyword(s):  
Electrochemical Detection ◽  
Whole Blood ◽  
Electrochemical Sensors ◽  
Point Of Care ◽  
Sample Volume ◽  
Nanocomposite Coating ◽  
Cross Reactivity ◽  
Detection Methods ◽  
Clinical Samples ◽  
Undiluted Serum

ABSTRACTSepsis is a leading cause of mortality worldwide that is difficult to diagnose and manage because this requires simultaneous analysis of multiple biomarkers. Electrochemical detection methods could potentially provide a way to accurately quantify multiple sepsis biomarkers in a multiplexed manner as they have very low limits of detection and require minimal sensor instrumentation; however, affinity-based electrochemical sensors are usually hampered by biological fouling. Here we describe development of an electrochemical detection platform that enables detection of multiple sepsis biomarkers simultaneously by incorporating a recently developed nanocomposite coating composed of crosslinked bovine serum albumin containing a network of reduced graphene oxide nanoparticles that prevents biofouling. Using nanocomposite coated planar gold electrodes, we constructed a procalcitonin sensor and demonstrated sensitive PCT detection in undiluted serum and clinical samples, as well as excellent correlation with a conventional ELISA (adjusted r2 = 0.95). Sensors for two additional sepsis biomarkers — C-reactive protein and pathogen-associated molecular patterns — were developed on the same multiplexed platform and tested in whole blood. Due to the excellent antifouling properties of the nanocomposite coating, all three sensors exhibited specific responses within the clinically significant range without any cross-reactivity in the same channel with low sample volume. This platform enables sensitive simultaneous electrochemical detection of multiple analytes in human whole blood, which can be expanded further to any target analyte with an appropriate antibody pair or capturing probe, and thus, may offer a potentially valuable tool for development of clinical point-of-care diagnostics.GRAPHICAL ABSTRACT

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