TABLE 2.

Mechanisms of resistance in Acinetobacter baumannii

Antimicrobial class and resistance mechanismEnzyme(s)aReference(s)
β-Lactams
    β-LactamasesTEM148, 387
SHV248, 387
ADCs49, 249, 250, 427, 468
VEB71, 381, 382, 417, 442
PER250, 381, 385, 417, 439, 565, 611
CTX-M76, 386
OXAThis study
IMP89, 104, 113, 179, 246, 265, 298, 316, 402, 471, 506, 530, 544, 618
VIM316, 335, 551, 606, 615
SIM320
    OMPsCarO (29 kDa)336, 380, 511
47-, 44-, and 37-kDa OMPs446
22- and 33-kDa OMPs47
HMP-AB209
33- to 36-kDa OMPs94, 119
43-kDa OMP141
OmpW510
    EffluxAdeABC232, 236, 347, 420
    Altered penicillin-binding proteinsAltered penicillin-binding proteins165, 188, 405, 510
Aminoglycosides
    Aminoglycoside-modifying enzymesAcetyltransferases, nucleotidyltransferases, phosphotransferases246, 250, 320, 395, 458, 503, 551, 556, 618
    Ribosomal (16S rRNA) methylation129, 314, 608
    EffluxAdeABC347
AdeM525
Quinolones
    Modification to target binding siteGyrA, ParC220, 236, 504, 581, 582
    EffluxAdeABC236, 347
AdeM525
Tetracyclines and glycylcyclines
    Tetracycline-specific effluxTet(A), Tet(B)217, 455, 457
    Ribosomal protectionTet(M)457
    Multidrug effluxAdeABC347, 420, 469
  • a ADCs, Acinetobacter-derived cephalosporinases; HMP-AB, heat-modifiable protein in Acinetobacter baumannii.