Extended-spectrum β-lactamase (ESBL) gene PCR and sequencing
Registry Details
Area | Health Science |
Lab name | Antibiotic Reference Laboratory |
Lab location | Kenepuru Science Centre, Porirua |
Test name | Extended-spectrum β-lactamase (ESBL) gene PCR and sequencing |
Organisms | Enterobacterales |
Requested for surveillance | no |
Notice required | yes |
Routine turnaround time | 20 working days for reference specimens |
Culture requirements | Pure culture |
Media requirements | A slope of any medium that supports the growth of the organism |
Pre-transport requirements | Ambient temperature |
Transport requirements | Ambient temperature |
Unacceptable sample types | Clinical specimens will not be accepted. |
How results reported | The results will state the ESBL type or CTX-M group |
Referral link | Form |
Details
ESBLs belong to three main families of β-lactamases: TEM, SHV and CTX-M. The CTX-M ESBLs are grouped, on the basis of sequence similarity, into five main groups: 1, 2, 8, 9 and 25. To identify a specific ESBL, sets of consensus primers, which amplify all TEM genes, all SHV genes and identify the CTX-M group, are used in separate PCR reactions. Any products of the correct size from the TEM and SHV PCRs are sequenced to identify the specific TEM or SHV β-lactamase. The specific CTX-M type can be identified by sequencing using CTX-M group-specific primers.
Identification of the ESBL type is appropriate for outbreak strains of ESBL-producing Enterobacterales.