Antimicrobial resistance in Acinetobacter baumannii: From bench to bedside

Table 1 Antimicrobial resistance mechanisms in Acinetobacter baumannii

Resistancemechanism	Class/family	Protein	Ref.
β-lactamases	Class A	TEM-1	[105,119,121]
		TEM-92	[120]
		SHV-5	[122]
		CTX-M-2	[123]
		CTX-M-15	[124]
		GES-11	[115,125]
		GES-12	[115]
		GES-14	[115]
		SCO-1	[126]
		PER-1	[127,128]
		PER-2	[132]
		PER-7	[129,130]
		VEB-1	[96,105,131-133]
		CARB-4	[135]
		CARB-10	[134]
		KPC-10	[136]
	Class B	VIM-1	[140-142]
		VIM-2	[139,143]
		VIM-3	[143]
		VIM-4	[141,142]
		VIM-11	[143]
		IMP-1	[144]
		IMP-2	[145]
		IMP-4	[146,147]
		IMP-5	[148]
		IMP-6	[149]
		IMP-8	[143]
		IMP-11	[150]
		IMP-19	[150]
		IMP-24	[143]
		SIM-1	[151]
		NDM-1	[152-154]
		NDM-2	[155]
	Class C	AmpC	[156-160]
	Class D
	Narrow- spectrum
	OXA-3 group	OXA-21	[163]
	OXA-20 group	OXA-37	[164]
	OXA-10 group	OXA-128	[387]
	CHDLs
	OXA-23 group	OXA-23	[66,92,105,147,167-183]
		OXA-133	[185]
	OXA-24 group	OXA-40/24	[197,201,204]
		OXA-40	[188,200, 202,203]
		OXA-72	[92,205,206]
		OXA-25, OXA-26, OXA-27	[198]
	OXA-51 group	OXA-51	[105,187-190]
		OXA64, OXA-65, OXA-66, OXA-68, OXA-70, OXA-71	[191]
		OXA-69, OXA-75, OXA-76, OXA-77	[186]
		OXA-79, OXA80, OXA-104, OXA106~OXA-112	[194]
		OXA-82, OXA-83, OXA-84	[192,194]
		OXA-86, OXA-87	[193]
		OXA-88, OXA-91, OXA-93, OXA-94, OXA-95, OXA-96	[147]
		OXA-92	[195]
		OXA-113	[122]
	OXA-58 group	OXA-58	[116,118,207,210,211, 21,5,219]
		OXA-96	[147]
		OXA-97	[220]
	Novel groups	OXA-143	[196]
		OXA-182	[221]
		OXA-235	[222]
Efflux pumps	RND	AdeABC	[235,238]
		AdeFGH	[243]
		AdeIJK	[244]
	MFS	TetA	[248]
		CmlA	[225]
		MdfA	[233]
		CraA	[249]
		AmvA	[250]
	MATE	AbeM	[251]
	SMR	AbeS	[252]
AME	AAC	AAC3 (aacC1, aacC2)	[256]
		AAC (6′) (aacA4)	[17,253,257-259,261]
	ANT	ANT (2′′) (aadB)	[256]
		ANT (3′′) (aadA1)	[17,253,261]
	APH	APH (3′) (aphA1)	[255]
		APH (3′′)	[253]
Permeability defects		CarO	[263-267]
		47-kDa OMP	[91]
		44-kDa OMP	[91]
		37-kDa OMP	[91]
		33-36-kDa OMP	[269]
		22-33-kDa OMP	[268]
		43-kDa OMP	[271]
		Lipopolysaccharide	[64]
		OmpA	[274]
Alteration of target sites	Change of PBP	PBP2	[276]
	DNA gyrase	GyrA/ParC	[237]
	Ribosomal protection	TetM	[280]
	Dihydrofolate	Dfr or Dhfr	[17,281]
	reductase	FolA	[281]
	16S rRNA methylation	ArmA	[253,258,282-286]

TEM: Temoneira; SHV: Sulfhydryl variable; CTX-M: Cefotaxime hydrolyzing capabilities; GES: Guiana extended-spectrum; SCO: Self-transferable plasmid from E. coli; PER: Pseudomonas extended resistant; VEB: Vietnam extended-spectrum β-lactamase; CARB: Carbenicillin hydrolyzing β-lactamase; KPC: K. pneumoniae carbapenemase; VIM: Verona integron-encoded metallo-β-lactamase; IMP: Imipenemase; SIM: Seoul imipenemase; NDM: New Deli metallo-β-lactamase; AmpC: Ampicillin class C β-lactamase; CHDL: Carbapenem-hydrolyzing class D β-lactamase; OXA: Oxacillinase; RND: Resistance-nodulation-division; MFS: Major facilitator superfamily; MATE: Multidrug and toxic compound extrusion; SMR: Small multidrug resistance; Ade: A. baumannii multidrug-resistant efflux pump; TetA: Tetracycline resistant Acinetobacter; CmlA: Chloramphenicol resistance Acinetobacter; MdfA: Multidrug facilitator; CraA: Chloramphenicol resistance Acinetobacter; Amva: A. baumannii Methyl Viologen and antimicrobial resistance protein; AbeM: A. baumannii efflux pump of MATE family; AbeS: A. baumannii efflux pump of SMR family; AME: Aminoglycoside-modifying enzyme; AAC: Aminoglycoside acetyltransferases; ANT: Aminoglycoside adenyltransferases; APH: Aminoglycoside phosphotransferases; CarO: Carbapenem-associated outer membrane protein; OMP: Outer membrane protein; PBP: Penicillin binding protein; GyrA/ParC: DNA Gyrase/partitioning of the nucleoid partition; Dhfr: Dihydrofolate reductase; FolA: Folate; ArmA: Armillaria mellea.