Resuscitation-Promoting Factors Are Required for β-Lactam Tolerance and the Permeability Barrier in Mycobacterium tuberculosis

DOI: 10.1128/AAC.06027-11

Article Figures & Data

Open in new tab
Download powerpoint
Fig 1
RPF^WT and RPF^null were grown in 3 μM cefotaxime, and surviving bacteria were enumerated at the indicated time points by plating for CFU on 7H10 agar. The result shown is representative of the experiment performed in biological triplicate.
Open in new tab
Download powerpoint
Fig 2
Kinetics of cefamandole hydrolysis. Absorption at 285 nm of H37Rv (●) or H37RvΔrpfACDEB (■). Samples were mechanically lysed (A) or resuspended in phosphate-buffered saline intact (B) and exposed to 20 mM cefamandole nafate. Subsequently, absorption measurements were taken at the indicated times. The illustrated values are averages of two technical replicates for each strain. Parameters v_lysed and v_intact are the slope and error calculated from the aggregated data for each strain.

Table 1
Additional hits from RPF^null screen
a ChemBank is a public cheminformatics resource available at http://chembank.broad.harvard.edu/ (7).

Table 2

IC₉₀s of β-lactams against H37Rv, RPF^null, and related strains

β-Lactam	Strain^a	IC₉₀ (μM)^b
Cefotaxime	H37Rv (RPF^WT)	26
	H37RvΔrpfA	13–26
	H37RvΔrpfB	13–26
	H37RvΔrpfC	26
	H37RvΔrpfD	26
	H37RvΔrpfE	26–52
	H37RvΔrpfAB	26
	H37RvΔrpfACBED::pHrpfCDE	6.5–26
	H37RvΔrpfACBE	6.5
	H37RvΔrpfACBED (RPF^null)	1.6–3.3
	H37RvΔrpfACDEB^c	0.78
Cefamandole	H37Rv (RPF^WT)	390–780
	H37RvΔrpfACBED (RPF^null)	98
With potassium clavulanate (1 μM)	H37Rv (RPF^WT)	24
With potassium clavulanate (1 μM)	H37RvΔrpfACBED (RPF^null)	1.5
Ceftriaxone	H37Rv (RPF^WT)	3.2–6.3
	H37RvΔrpfACBED (RPF^null)	1.6

↵a From reference 5.
↵b Differences in IC₉₀s are representative of at least two independent experiments containing at least four duplicates each; for cefamandole, amounts of clavulanate were varied across duplicates.
↵c RPFs were deleted from this strain in a different order than that for RPF^null.