Volume 2 Issue 2
Molecular Characterization of Listeria monocytogenes Isolates from Human and Food Samples in Brazil
Nilma Cintra Leal*, Ana Paula Rocha da Costa, Carina Lucena Mendes-Marques, Natália Regina Souza da Silva, Deyse Christina Vallim, Cristina Barroso Hofer, Ernesto Hofer, Alzira Maria Paiva de Almeida
Listeria monocytogenes is a food-borne disease with high lethality among susceptible individuals. The identification and characterization of the bacterium is required for food industry and commerce microbiology safety, as well as for prevention and control of the disease. In the present study, we performed a molecular characterization of 135 human (47) and food (88) L. monocytogenes isolates from the serotypes 1/2a, 1/2b, 1/2c, and 4b, which are the serotypes that are the principal cause of human listeriosis and are prevalent in food. PCR amplification of the 23S rRNA sequence confirmed the identification of the strains at the genus level; amplification of the 16S-23S rRNA internal spacer region (ITS-typing) clustered the 135 isolates into three ITS profiles (R1-R3); and most of the L. monocytogenes virulence-associated genes assessed by PCR (inlAB, inlC, inlJ, actA, hly, iap, plcA) were amplified in all of the strains.
Detection and Confirmation of Neisseria gonorrhoeae Infections in Genital and Extragenital Samples using Aptima Assays on the Panther™ Instrument
Mark Turra, Trish Hahesy, Sally Dubedat, and Peter Lowe*
The objective of this study was to review the diagnostic accuracy of the Aptima Combo 2 (AC2) assay on the PantherTM system for reporting Neisseria gonorrhoeae (NG) detection from routine clinical samples. Results for samples routinely submitted for the diagnosis of NG infection from two laboratories in Australia were retrospectively reviewed from September 2011 to May 2013. Each sample was initially tested on a Panther instrument with the AC2 assay. Samples positive or equivocal for NG in AC2 were retested with the Aptima Neisseria gonorrhoeae assay (AGC) on the Panther instrument. AC2-NG positive results were considered false positive if the AGC result was negative. AC2 results were available for 91,217 samples, 1,434 of which were initially AC2 non-negative for NG and included an AGC result.
A New Molecular Diagnostic PCR/Microarray Hybridization Prototype Evaluation Compared to Standard PCR/Sequencing for Pneumocystis jirovecii Detection
Jan Weile, Berit Schulte, Ingo B. Autenrieth, Olivier Denis, Ricardo De Mendonça, Catia Cillòniz, Jorge Puig de la Bellacasa, Antoni Torres, Holm Eickmeyer, Cornelius Knabbe, Anne Thews, Matthias Klein, Gerd Lüdke, Alexandra Heininger, Eberhard Straube, Wolfgang Pfister, Peter M. Keller and Matthias Karrasch
Diagnosis of Pneumocystis jirovecii pneumonia (PjP) is challenging. Therefore highly-sensitive and time-efficient new diagnostic tools are needed for early antibiotic treatment start and optimized patient outcome. We evaluated a prototype of a new molecular diagnostic tool using PCR/microarray hybridization for P. jirovecii detection in respiratory samples of hospitalized patients suffering from pneumonia. Prototype results were first compared to established routine PCR results and were set in the context of patients’ immune status and clinical presentation in an overall assessment (true positive, false negative or false positive).