A	alanine
AmpC	ampicillin chromosomal cephalosporinase
BSBL	broad-spectrum β-lactamase
C	cysteine
CARBA	carbapenemase
CTX-M	cefotaxime-hydrolyzing β-lactamase–Munich
E	glutamic acid
ESBLs	extended-spectrum β-lactamases
F	phenylalanine
G	glycine
GES	Guiana extended-spectrum β-lactamase
H	histidine
I	isoleucine
K	lysine
KPC	Klebsiella pneumoniae carbapenemase
L	leucine
M	methionine
MBLs	metallo- β-lactamases
NDM	New Delhi metallo- β-lactamase
NSBL	narrow-spectrum β-lactamase
OXA	oxacillinases
P	proline
Q	glutamine
R	arginine
S	serine
SHV	sulfhydryl variant of the TEM enzyme
T	threonine
TEM	Temoneira class A extended-spectrum β-lactamase
V	valine
W	tryptophan