Format

Send to

Choose Destination
J Clin Microbiol. 2006 Mar;44(3):909-15.

Detection and genotyping of SHV beta-lactamase variants by mass spectrometry after base-specific cleavage of in vitro-generated RNA transcripts.

Author information

1
Institut für Infektionsmedizin, Universitätsklinikum Hamburg-Eppendorf, Germany. stuerenburg@ladr.de

Abstract

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) after base-specific cleavage of PCR-amplified and in vitro-transcribed bla(SHV) genes was used for the identification and genotyping of SHV beta-lactamases. For evaluation, bla(SHV) stretches of 21 clinical Enterobacteriaceae isolates were PCR amplified using T7 promoter-tagged forward and reverse primers, respectively. In vitro transcripts were generated with T7 RNA and DNA polymerase in the presence of modified analogues replacing either CTP or UTP. Using RNase A, the in vitro transcripts were base-specifically cleaved at every "T" or "C" position. Resulting cleavage products were analyzed by MALDI-TOF MS, generating a characteristic signal pattern based on the fragment masses. All 21 individual SHV genes were identified unambiguously using reference sequences, and the results were in perfect concordance with those obtained by fluorescent dideoxy sequencing, which represents the current standard method. As multiple point mutations can be detected in a single assay and newly emerged mutations which are not yet described in public databases can be identified too, MALDI-TOF MS appears to be an ideal tool for analysis of sequence polymorphisms in resistance-associated gene loci.

PMID:
16517875
PMCID:
PMC1393099
DOI:
10.1128/JCM.44.3.909-915.2006
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center