Ambler Classification of β-lactamases

February 28, 2020

The Ambler Classification system, based on amino acid homology, is the most commonly used method to classify β-lactamases. β-lactamases are the primary cause of bacterial resistance to β-lactam antibiotics. The Ambler Classification system is considered the simplest classification scheme of β-lactamases:

Class A

  • TEM-1, 2
  • SHV-1
  • ESBLs, KPC

Class B

  • MBLs

Class C

  • ampC
  • CMY

Class D

  • OXA

Did you know?

Widespread use of extended-spectrum antibiotics has led to the emergence of extended-spectrum β-lactamases (ESBLs) including CTX-M-14, CTX-M-15, GES, TEM and SHV-type enzymes.

Who was R.P. Ambler? In his research, Ambler, Head of the Department of Molecular Biology, University of Edinburgh, employed protein sequencing to cast light on evolutionary relationships between organisms, an approach that is now known as ‘molecular taxonomy’. He played a key role in 1978 in validating one of the first published nucleic sequences, and thus symbolically marking the beginning of the transition to the current era of microbiology.

In 1980, Ambler divided β-lactamases into the four classes based on their sequence similarity. Classes A, C and D function by the serine ester hydrolysis mechanism, whereas class B β-lactamases, also known as metallo β-lactamases, have a zinc ion participating in catalysis.

Did you know?

Carbapenem-resistant Enterobacteriaceae (CRE) is an urgent threat for public health. Some of the most common carbapenemases include KPC, NDM, IMP, OXA and VIM-type enzymes.

Streck offers a free AMR Gene Target Index card deck that features facts on the Class A, B, C and D β-lactamase gene families and trivia about antimicrobial resistance.

GES - Ambler Classification Class A ß-lactamase confers anitbiotic resistance to carbapenem, penam, cephalosporin. GES was named after French Guinea where the first isolate was discovered
FOX Ambler Classification Class C ß-lactamase. Confers resistance to cephalosporin, cephamycin

NDM Ambler Classification Class B ß-lactamase confers resistance to carbapenem, cephalosporin, cephamycin, penam. NDM genes are part of a group of superbug bacteria that are extremely hard to treat and can spread easily in hospitals. Found in Acinetobacter, E. Coli, Salmonella, Enterobacter

The cards complement Streck’s antibiotic resistance monitoring and detection (ARM-D) kits, which allow lab personnel to detect the most clinically important β-lactamases for current and emerging threats and can be used as part of a hospital surveillance program.

For more information about Streck ARM-D® Kits and to get your free set of Gene Target Index cards, click here.

Streck ARM-D Kits are for Research Use Only. Not for use in diagnostic procedures.


A link between AMR and COVID-19

Several recent publications and communications from infectious disease experts have illustrated what has been called the hidden threat behind COVID-19…
Read More

Antimicrobial resistance in pets

Antimicrobial resistance (AMR) has become a significant public health issue globally, including in the United States. The issue is a worsening problem…
Read More

AMR in the food chain

The food supply chain in the United States is among the safest in the world, but keeping it safe has become more challenging due to the rapidly evolvi…
Read More