The polymerase chain reaction (PCR) amplification technique was investigated as a tool for direct detection of Listeria monocytogenes in soft cheeses. Different sets of oligonucleotide primers were used, and parts of the L. monocytogenes Dth 18-gene could be amplified specifically when either a plasmid vector carrying the cloned gene or chromosomal DNA was used a template. The detection limit for L. monocytogenes in dilutions of pure cultures was between 1 and 10 colony-forming units. In extracts from soft cheeses containing L. monocytogenes DNA, the amplification was strongly inhibited. This inhibition could be reduced by an additional purification step. Despite this the detection limit showed a large variation, depending on the brand of cheese used. In some cheeses 10(3) cfu/0.5g could be visualized whereas in others the presence of 10(8) cfu/0.5 g did not yield a detectable quantity of amplified product.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1365-2672.1991.tb04437.xDOI Listing

Publication Analysis

Top Keywords

polymerase chain
8
chain reaction
8
direct detection
8
detection listeria
8
listeria monocytogenes
8
monocytogenes soft
8
soft cheeses
8
detection limit
8
monocytogenes
5
reaction direct
4

Similar Publications

Background: Whether a detected virus or bacteria is a pathogen that may require treatment, or is merely a commensal 'passenger', remains confusing for many infections. This confusion is likely to increase with the wider use of multi-pathogen PCR.

Objectives: To propose a new statistical procedure to analyse and present data from case-control studies clarifying the probability of causality.

View Article and Find Full Text PDF

Introduction: This study investigated the role of fibroblast growth factor 23 (FGF23)/Klotho in the mortality of patients hospitalized with coronavirus disease 2019 (COVID-19), excluding those with chronic kidney disease (CKD).

Methodology: A prospective cross-sectional study was conducted from April 2021 to May 2022. Patients who tested positive for COVID-19 via polymerase chain reaction and were hospitalized, were classified into two groups (survivors and non-survivors) at the end of their hospital follow-up.

View Article and Find Full Text PDF

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted public transportation systems worldwide. In this study, we evaluated the rate of COVID-19 positivity and its associated factors among users of public transportation in socioeconomically disadvantaged regions of Brazil during the pre-vaccination phase of the pandemic.

Methodology: This ecological study, conducted in Aracaju city in Northeast Brazil, is a component of the TestAju Program.

View Article and Find Full Text PDF

Introduction: China implemented a dynamic zero-COVID strategy to curb viral transmission in response to the coronavirus disease 2019 (COVID-19) pandemic. This strategy was designed to inhibit mutation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19. This study explores the dynamics of viral evolution under stringent non-pharmaceutical interventions (NPIs) through real-world observations.

View Article and Find Full Text PDF

Background: Fibrosis of the connective tissue in the vaginal wall predominates in pelvic organ prolapse (POP), which is characterized by excessive fibroblast-to-myofibroblast differentiation and abnormal deposition of the extracellular matrix (ECM). Our study aimed to investigate the effect of ECM stiffness on vaginal fibroblasts and to explore the role of methyltransferase 3 (METTL3) in the development of POP.

Methods: Polyacrylamide hydrogels were applied to create an ECM microenvironment with variable stiffness to evaluate the effects of ECM stiffness on the proliferation, differentiation, and expression of ECM components in vaginal fibroblasts.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!