Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons.
2009 (English)In: BMC Infectious Diseases, ISSN 1471-2334, Vol. 9, no 1, 7- p.Article in journal (Refereed) Published
BACKGROUND: Plasmid encoded blaCTX-M enzymes represent an important sub-group of class A beta-lactamases causing the ESBL phenotype which is increasingly found in Enterobacteriaceae including Klebsiella spp. Molecular typing of clinical ESBL-isolates has become more and more important for prevention of the dissemination of ESBL-producers among nosocomial environment.
METHODS: Multiple displacement amplified DNA derived from 20 K. pneumoniae and 34 K. oxytoca clinical isolates with an ESBL-phenotype was used in a universal CTX-M PCR amplification assay. Identification and differentiation of blaCTX-M and blaOXY/K1 sequences was obtained by DNA sequencing of M13-sequence-tagged CTX-M PCR-amplicons using a M13-specific sequencing primer.
RESULTS: Nine out of 20 K. pneumoniae clinical isolates had a blaCTX-M genotype. Interestingly, we found that the universal degenerated primers also amplified the chromosomally located K1-gene in all 34 K. oxytoca clinical isolates. Molecular identification and differentiation between blaCTX-M and bla OXY/K1-genes could only been achieved by sequencing of the PCR-amplicons. In silico analysis revealed that the universal degenerated CTX-M primer-pair used here might also amplify the chromosomally located blaOXY and K1-genes in Klebsiella spp. and K1-like genes in other Enterobacteriaceae.
CONCLUSION: The PCR-based molecular typing method described here enables a rapid and reliable molecular identification of blaCTX-M, and blaOXY/K1-genes. The principles used in this study could also be applied to any situation in which antimicrobial resistance genes would need to be sequenced.
Place, publisher, year, edition, pages
2009. Vol. 9, no 1, 7- p.
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-17021DOI: 10.1186/1471-2334-9-7PubMedID: 19161622OAI: oai:DiVA.org:liu-17021DiVA: diva2:201174
Original Publication:Hans-Jurg Monstein, Maria Tärnberg and Lennart Nilsson, Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons., 2009, BMC infectious diseases, (9), 1, 7.http://dx.doi.org/10.1186/1471-2334-9-7Copyright: BioMed Centralhttp://www.biomedcentral.com/2009-03-032009-03-032012-03-28Bibliographically approved