| 1. |
- Barisic, Ivan, et al.
(författare)
-
Multiplex detection of antibiotic resistance genes using padlock probes
- 2013
-
Ingår i: Diagnostic microbiology and infectious disease. - : Elsevier BV. - 0732-8893 .- 1879-0070. ; 77:2, s. 118-125
-
Tidskriftsartikel (refereegranskat)abstract
- The elucidation of resistance mechanisms is of central importance to providing and maintaining efficient medical treatment. However, molecular detection methods covering the complete set of resistance genes with a single test are still missing. Here, we present a novel 100-plex assay based on padlock probes in combination with a microarray that allows the simultaneous large-scale identification of highly diverse beta-lactamases. The specificity of the assay was performed using 70 clinical bacterial isolates, recovering 98% of the beta-lactamase nucleotide sequences present. Additionally, the sensitivity was evaluated with PCR products and genomic bacterial DNA, revealing a detection limit of 10(4) DNA copies per reaction when using PCR products as the template. Pre-amplification of genomic DNA in a 25-multiplex PCR further facilitated the detection of beta-lactamase genes in dilutions of 10(7) cells/mL. In summary, we present an efficient, highly specific, and highly sensitive multiplex detection method for any gene.
|
|
| 2. |
- Kreij, Karl, 1975-, et al.
(författare)
-
On-line detection of microbial contaminations in animal cell reactor cultures using an electronic nose device
- 2005
-
Ingår i: Cytotechnology (Dordrecht). - : Springer Science and Business Media LLC. - 0920-9069 .- 1573-0778. ; 48:1-3, s. 41-58
-
Tidskriftsartikel (refereegranskat)abstract
- An electronic nose (EN) device was used to detect microbial and viral contaminations in a variety of animal cell culture systems. The emission of volatile components from the cultures accumulated in the bioreactor headspace, was sampled and subsequently analysed by the EN device. The EN, which was equipped with an array of 17 chemical gas sensors of varying selectivity towards the sampled volatile molecules, generated response patterns of up to 85 computed signals. Each 15 or 20 min a new gas sample was taken generating a new response pattern. A software evaluation tool visualised the data mainly by using principal component analysis. The EN was first used to detect microbial contaminations in a Chinese hamster ovary (CHO) cell line producing a recombinant human macrophage colony stimulating factor (rhM-CSF). The CHO cell culture was contaminated by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida utilis which all were detected. The response patterns from the CHO cell culture were compared with monoculture references of the microorganisms. Second, contaminations were studied in an Sf-9 insect cell culture producing another recombinant protein (VP2 protein). Contaminants were detected from E. coli, a filamentous fungus and a baculovirus. Third, contamination of a human cell line, HEK-293, infected with E. coli exhibited comparable results. Fourth, bacterial contaminations could also be detected in cultures of a MLV vector producer cell line. Based on the overall experiences in this study it is concluded that the EN method has in a number of cases the potential to be developed into a useful on-line contamination alarm in order to support safety and economical operation for industrial cultivation. © Springer 2005.
|
|
