Recombinations in staphylococcal cassette chromosome mec elements compromise the molecular detection of methicillin resistance in Staphylococcus aureus
| Autor: | Arnab Pain, Mridul Nair, Olaf Piepenburg, Moataz Abd El Ghany, Matthew S. Forrest, Lyndsey O. Hudson, Andrew Dodgson, Taane G. Clark, Grant A. Hill-Cawthorne |
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| Rok vydání: | 2014 |
| Předmět: |
Staphylococcus
Gene Transfer lcsh:Medicine Recombinase Polymerase Amplification medicine.disease_cause law.invention law lcsh:Science Polymerase chain reaction Genetics Recombination Genetic Horizontal Gene Transfer 0303 health sciences Multidisciplinary Bacterial Genomics Microbial Mutation Genomics Chromosomes Bacterial Bacterial Genomes Medical microbiology 3. Good health Gene cassette Molecular Diagnostic Techniques Chromosomal region Research Article Methicillin-Resistant Staphylococcus aureus Staphylococcus aureus Evolutionary Processes Molecular Sequence Data Microbial Genomics Biology Sensitivity and Specificity Microbiology Bacterial Genes 03 medical and health sciences medicine 030304 developmental biology Whole genome sequencing Evolutionary Biology Base Sequence Biology and life sciences 030306 microbiology SCCmec lcsh:R Bacteriology biochemical phenomena metabolism and nutrition bacterial infections and mycoses Methicillin-resistant Staphylococcus aureus Microbial pathogens Multilocus sequence typing lcsh:Q Methicillin Resistance Bacterial pathogens Multiplex Polymerase Chain Reaction |
| Zdroj: | PLoS ONE PLoS ONE, Vol 9, Iss 6, p e101419 (2014) |
| ISSN: | 1932-6203 |
| Popis: | Clinical laboratories are increasingly using molecular tests for methicillin-resistant Staphylococcus aureus (MRSA) screening. However, primers have to be targeted to a variable chromosomal region, the staphylococcal cassette chromosome mec (SCCmec). We initially screened 726 MRSA isolates from a single UK hospital trust by recombinase polymerase amplification (RPA), a novel, isothermal alternative to PCR. Undetected isolates were further characterised using multilocus sequence, spa typing and whole genome sequencing. 96% of our tested phenotypically MRSA isolates contained one of the six orfX-SCCmec junctions our RPA test and commercially available molecular tests target. However 30 isolates could not be detected. Sequencing of 24 of these isolates demonstrated recombinations within the SCCmec element with novel insertions that interfered with the RPA, preventing identification as MRSA. This result suggests that clinical laboratories cannot rely solely upon molecular assays to reliably detect all methicillin-resistance. The presence of significant recombinations in the SCCmec element, where the majority of assays target their primers, suggests that there will continue to be isolates that escape identification. We caution that dependence on amplification-based molecular assays will continue to result in failure to diagnose a small proportion (∼4%) of MRSA isolates, unless the true level of SCCmec natural diversity is determined by whole genome sequencing of a large collection of MRSA isolates. |
| Databáze: | OpenAIRE |
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