Comparison of Xpert Norovirus and RidaGene Norovirus assays for the detection of noroviruses in clinical fecal specimens.

The purpose of this study was to investigate the usability and performance of the Xpert Norovirus and RidaGene Norovirus assays for the detection of noroviruses in fecal specimens. Of the 186 stool specimens, 53 (28.5%) were considered true-positive for norovirus (NoV). Of the true-positive specimens, Xpert detected 53 and RidaGene detected 52. The respective sensitivity and specificity were 100% and 94.7% [95% confidence interval (CI), 91.0-98.5%] for the Xpert assay, and 98.1% (95% CI, 94.4-100%) and 97.0% (95% CI, 94.1-99.9%) for the RidaGene assay. Positive and negative predictive values (PPVs and NPVs) were 88.3% and 100% for the Xpert assay, and 92.9% and 99.2% for the RidaGene assay, respectively. Based on this study, it can be concluded that there were no significant differences (p-value > 0.5) between the results of the Xpert and RidaGene Norovirus assays. We found that both assays are useful for the detection of noroviruses in clinical stool samples.

Novel portable platform for molecular detection of toxigenic Clostridium difficile in faeces: a diagnostic accuracy study.

BACKGROUND: A novel portable platform for nucleic acid amplification enables rapid detection of diarrhoea causing toxigenic Clostridium difficile directly from faeces, even in resource-limited settings. We evaluated the accuracy and precision of the new commercial molecular test system. METHODS: One thousand one hundred and sixty faecal samples from patients suspected of having Clostridium difficile infection (CDI) were analysed using the Orion GenRead C. difficile test system (Orion Diagnostica Oy, Espoo, Finland) and comparative methods in three teaching hospital laboratories in Finland and France. The precision of the Orion GenRead C. difficile test system was evaluated in a reproducibility study with a set of blind-coded samples. The test system is based on a new isothermal amplification technology (Strand Invasion Based Amplification, SIBA®) and detection of the tcdB gene of C. difficile. We calculated the sensitivity, specificity, and the overall agreement according to Clinical and Laboratory Standards Institute recommendations. FINDINGS: The overall agreement of the Orion GenRead C. difficile test when compared to the comparative methods in routine use in the participating laboratories was between 96.7% and 98.8%. In the reproducibility study; the total percent agreement between three laboratories was 99.8%. INTERPRETATION: The identification of toxigenic C. difficile from faeces with the light-weight portable Orion GenRead test system was highly sensitive and specific, and the results were reproducible in the participating laboratories. This platform could enable fast and accurate molecular pathogen detection even in resource-limited or point-of-care settings.

In vivo dual-delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 (DPP4) inhibitor through composites prepared by microfluidics for diabetes therapy.

Oral delivery of proteins is still a challenge in the pharmaceutical field. Nanoparticles are among the most promising carrier systems for the oral delivery of proteins by increasing their oral bioavailability. However, most of the existent data regarding nanosystems for oral protein delivery is from in vitro studies, lacking in vivo experiments to evaluate the efficacy of these systems. Herein, a multifunctional composite system, tailored by droplet microfluidics, was used for dual delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 inhibitor (iDPP4) in vivo. Oral delivery of GLP-1 with nano- or micro-systems has been studied before, but the simultaneous nanodelivery of GLP-1 with iDPP4 is a novel strategy presented here. The type 2 diabetes mellitus (T2DM) rat model, induced through the combined administration of streptozotocin and nicotinamide, a non-obese model of T2DM, was used. The combination of both drugs resulted in an increase in the hypoglycemic effects in a sustained, but prolonged manner, where the iDPP4 improved the therapeutic efficacy of GLP-1. Four hours after the oral administration of the system, blood glucose levels were decreased by 44%, and were constant for another 4 h, representing half of the glucose area under the curve when compared to the control. An enhancement of the plasmatic insulin levels was also observed 6 h after the oral administration of the dual-drug composite system and, although no statistically significant differences existed, the amount of pancreatic insulin was also higher. These are promising results for the oral delivery of GLP-1 to be pursued further in a chronic diabetic model study.

Comprehensive real-time epidemiological data from respiratory infections in Finland between 2010 and 2014 obtained from an automated and multianalyte mariPOC® respiratory pathogen test.

Respiratory viruses cause seasonal epidemics every year. Several respiratory pathogens are circulating simultaneously and typical symptoms of different respiratory infections are alike, meaning it is challenging to identify and diagnose different respiratory pathogens based on symptoms alone. mariPOC® is an automated, multianalyte antigen test which allows the rapid detection of nine respiratory infection pathogens [influenza A and B viruses, respiratory syncytial virus (RSV), human metapneumovirus, adenovirus, parainfluenza 1-3 viruses and pneumococci] from a single nasopharyngeal swab or aspirate samples, and, in addition, can be linked to laboratory information systems. During the study period from November 2010 to June 2014, a total of 22,485 multianalyte respi tests were performed in the 14 participating laboratories in Finland and, in total, 6897 positive analyte results were recorded. Of the tested samples, 25 % were positive for one respiratory pathogen, with RSV (9.8 %) and influenza A virus (7.2 %) being the most common findings, and 0.65 % of the samples were multivirus-positive. Only small geographical variations in seasonal epidemics occurred. Our results show that the mariPOC® multianalyte respi test allows simultaneous detection of several respiratory pathogens in real time. The results are reliable and give the clinician a picture of the current epidemiological situation, thus minimising guesswork.

Comparison of BD Max Cdiff and GenomEra C. difficile molecular assays for detection of toxigenic Clostridium difficile from stools in conventional sample containers and in FecalSwabs.

In this study, the usability and performance of GenomEra™ C. difficile and BD Max™ Cdiff nucleic acid amplification tests (NAATs) for the detection of toxigenic Clostridium difficile were investigated in comparison with toxigenic culture and C. difficile toxin A- and toxin B-detecting immunochromatographic antigen (IA) test, the Tox A/B QuikChek®. In total, 302 faecal specimens were collected, 113 of which were in parallel to conventional sample containers and FecalSwab liquid-based microbiology (LBM) tubes. Seventy-nine specimens were considered true-positives for toxigenic C. difficile. The sensitivity and specificity were 97.5 % and 99.6 % and 93.7 % and 98.7 % for the GenomEra and BD Max assays respectively. Toxigenic culture and Tox A/B QuikChek had sensitivity and specificity of 91.1 % and 100 % and 34.2 % and 100 % respectively. Hands-on time for analysing 1 to 24 specimens using NAATs was 1 to 15 min. The rate of PCR inhibition was 0 % for both NAATs with faeces in LBM tubes, while with faeces in conventional sample containers the respective inhibition rates were 5.3 % and 4.4 % for the GenomEra and the BD Max assays. The NAATs demonstrated an excellent analytical performance, reducing significantly the overall workload of laboratory personnel compared with culture and IA test.

Outbreak analysis and typing of MRSA isolates by automated repetitive-sequence-based PCR in a region with multiple strain types causing epidemics.

The usefulness and performance of repetitive-sequence-based polymerase chain reaction (rep-PCR), the DiversiLab system, in the epidemiological surveillance for methicillin-resistant Staphylococcus aureus (MRSA) strain typing was assessed. MRSA isolates from five distinct outbreaks with precise epidemiological data (n = 69) and from the culture collection of well-characterized MRSA strains (n = 132) consisting of 35 spa and 23 pulsed-field gel electrophoresis (PFGE) types were analyzed. The typing results of the DiversiLab system in outbreak analysis were compared to the spa and PFGE typing methods. The DiversiLab system proved to be a reliable tool for the rapid first-line typing of MRSA isolates, showing a good reliability in distinguishing MRSA strains in an area where several MRSA types were causing epidemics. This, however, required that the automatic clustering was combined with manual interpretation using the pattern overlay function when the strain types showing high similarity were clustered together. All outbreaks were distinguished with the DiversiLab system and the PFGE method, but not with the spa typing method. The overall discriminatory power of the DiversiLab system in differentiating diverse MRSA strains proved to be good. We also demonstrated that, in addition to the genetic relatedness analysis of MRSA strains, it is important to obtain accurate epidemiological information in order to perform reliable epidemiological surveillance studies.

One-step sample preparation of positive blood cultures for the direct detection of methicillin-sensitive and -resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci within one hour using the automated GenomEra CDX™ PCR system.

A method for the rapid detection of methicillin-sensitive and -resistant Staphylococcus aureus (MSSA and MRSA, respectively) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) with a straightforward sample preparation protocol of blood cultures using an automated homogeneous polymerase chain reaction (PCR) assay, the GenomEra™ MRSA/SA (Abacus Diagnostica Oy, Turku, Finland), is presented. In total, 316 BacT/Alert (bioMérieux, Marcy l'Etoile, France) and 433 BACTEC (Becton Dickinson, Sparks, MD, USA) blood culture bottles were analyzed, including 725 positive cultures containing Gram-positive cocci in clusters (n = 419) and other Gram stain forms (n = 361), as well as 24 signal- and growth-negative bottles. Detection sensitivities for MSSA, MRSA, and MRCoNS were 99.4 % (158/159), 100.0 % (9/9), and 99.3 % (132/133), respectively. One false-positive MRSA result was detected from a non-staphylococci-containing bottle, yielding a specificity of 99.8 %. The lowest detectable amount of viable cells in the blood culture sample was 4 × 10(4) CFU/mL. The results were available within one hour after microbial growth detection and the two-step, time-resolved fluorometric (TRF) measurement mode employed by the GenomEra CDX™ instrument showed no interference from blood, charcoal, or culture media. The method described lacks all sample purification steps and allows reliable and simplified pathogen detection also in clinical microbiology laboratory settings without specialized molecular microbiology competence.

Rapid confirmation of suspected methicillin-resistant Staphylococcus aureus colonies on chromogenic agars by a new commercial PCR assay, the GenomEra MRSA/SA Diagnose.

A new automated closed tube PCR assay, the GenomEra(™) MRSA/SA Diagnose (Abacus Diagnostica Oy, Finland) was evaluated for rapid confirmation of methicillin-resistant Staphylococcus aureus (MRSA) from cultured screening specimens. The ability of the assay to detect genotypically different MRSA strains was studied with a collection of 304 MRSA isolates covering 68 spa types. The specificity was investigated with a collection of 146 non-MRSA staphylococcus isolates. The usefulness of the assay for clinical purposes was assessed by a sequential combination of MRSA screening culture and confirmation of the colonies with the GenomEra MRSA/SA Diagnose assay. A total of 145 suspected MRSA colonies on chromogenic plates were analyzed this way. All MRSA isolates from the culture collection and from the clinical screening specimens were confirmed as MRSA with the GenomEra MRSA/SA Diagnose assay and none of the non-MRSA staphylococci caused false-positive results, which indicates both sensitivity and specificity of 100%. The combination of GenomEra MRSA/SA Diagnose with preceding culture on selective MRSA agar permitted MRSA confirmation within 24 h. This practice offers a reliable and quick detection of MRSA that is also suitable in areas where several strain types cause epidemics.