Table 4.

Synergy of activity of iron withdrawal agents combined with antibiotics for both antibiotic-sensitive and antibiotic-resistant microbes

Microbe	Antibiotic characteristic	Antibiotic tested	Fe withdrawal agent tested	Agent synergy by: 24 h ∆Log10 CFUa or FICIb	References
A. baumannii ATCC 17978	Sensitive	CIP	DIBI	Yes, ∆Log10 = − 2.58	c
A. baumannii ATCC 17978	Sensitive	GEN	DIBI	Yes, ∆Log10 = − 9.10	c
A. baumannii ATCC 17978	Sensitive	TGC	DIBI	Yes, ∆Log10 = − 4.78	c
A. baumannii ATCC 17978	Sensitive	CST	DIBI	Yes, ∆Log10 = − 7.52	c
A. baumannii LAC-4	CIP resistant	CIP	DIBI	Yes, ∆Log10 = − 2.16	c
A. baumannii LAC-4	GEN resistant	GEN	DIBI	Yes, ∆Log10 = − 2.20	c
S. aureus LAC300	MRSA	VAN	DEF	Yes, ∆Log10 = − 3.20	d
S. aureus Mu50	VAN resistant	VAN	DEF	Yes, ∆Log10 = − 3.70	d
S. aureus ATCC 6538	Sensitive	VAN	DIBI	Mild, ∆Log10 = − 1.70	e
S. aureus ATCC 43300	MRSA	MUP	DIBI	Mild, ∆Log10 = − 1.45	f
V. vulnificus ATCC 27562	Sensitive	CIP	DEF	Yes, ∆Log10 = − 2.80	g
V. vulnificus ATCC 33815	Sensitive	CIP	DEF	Yes, ∆Log10 = − 6.10	g
V. vulnificus CUH 42–14	Sensitive	CIP	DEF	Yes, ∆Log10 = − 2.30	g
K pneumoniae KP4	Sensitive	CIP	Apo-Tf	Yes, ∆Log10 = − 5.1	h
C. albicans 96113	Sensitive	FLU	DIBI	Yes, FICI = 0.38	i
C. albicans SC5314	Sensitive	AMB	Apo-Lf	Yes, FICI = 0.38	j

CFU—Colony Forming Units; CIP (ciprofloxacin); GEN (gentamicin); CST (colistin); TGC (tigecycline); MUP (mupirocin); VAN (vancomycin); DEF (deferasirox); DIBI (hydroxypyridinone containing copolymer) MDR multiple drug resistant; MRSA Methicillin resistant S aureus; AMB (amphotericin B); FLU (fluconazole) Apo-Tf (iron-free transferrin); Apo-Lf (iron-free lactoferrin)

^a± Log10 CFU change of combination over the higher of either antibiotic or Fe withdrawal agent alone; Synergy if change of combination ≥ − 2log10 CFU; weak synergy at < − 2 but > − 1 log10CFU

^bSynergy if Fractional Inhibition Concentration Index (FICI) < 0.5

^cParquet et al. (2019)

^dEstimated from Luo et al. (2014)

^eParquet et al. (2018)

^fAllan et al. (2020)

^gEstimated from Neupane and Kim (2010)

^hEstimated from Ambrose et al. (2019)

^jFernandes et al. (2020)