TABLE 6.

Performance of culture methods on rectal/perirectal swabs^a

Method	No. of positive swabs/total no. of swabs	Sensitivity (%)	Specificity (%)	Enzyme, distribution (%)	Reference standard(s)	Reference
MacConkey agar with IPM	33/139	84.9	94.3	KPC, 100	PCR for KPC	80
MacConkey agar with IPM/MEM/ETP disks		75.8	89.6
CHROMagar KPC		84.9	88.7
chromID Carba	86/177	96.5	91.2	KPC, 98; VIM, 1	qPCR for KPC or VIM, mHT, aminophenyl-boronic acid–meropenem, and EDTA-meropenem testing	139
MacConkey agar with IPM		89.5	31.9
CDC protocol		98.8	80.2
MacConkey agar with ETP disk	97/189	96.9	98.9	KPC, 61.9; VIM, 9.3; KPC + VIM, 26.8; OXA-48, 3	Colony PCR for KPC, VIM, OXA-48, IMP, and NDM; negative isolates confirmed with a mHT	111
MacConkey agar + MEM alone or MEM + PBA, MEM + EDTA, and MEM + PBA		94.8	100
MacConkey agar with MEM	92/200	89.1	85.2	KPC, 68; VIM, 31	PCR for KPC, IMP, NDM, VIM, and OXA-48; Vitek susceptibility testing and mHT	140
CDC protocol		89.1	86.4
Enriched brain heart (BH) culture with ertapenem replated onto chromID ESBL agar		92.4	93.3
chromID Carba		92.4	96.9
chromID ESBL		92.4	84.7
chromID Carba	32/175c	100	98	NDM, 100	NDM PCR, disks with meropenem, boronic acid, cloxacillin, and dipicolinic acid (Rosco KPC/MBL Confirm kit)	157
Brilliance CRE		59	34		Agar dilution MICs for carbapenems, negative Rosco KPC/MBL test
CDC protocol	33/149	65.6	49.6	KPC, 100	KPC PCR; broth microdilution susceptibilities for ertapenem, imipenem, and meropenem; mHT	150
MacConkey agar with ETP disk with a 27-mm breakpoint		97	90.5
MacConkey agar with IPM, MEM, and ETP disks	41/122	92.7	95.9	KPC, 100	Direct KPC PCR on swab	151
CHROMagar KPC		100	98.4
MacConkey agar with MEM and ETP disks	54/187f	87	100	KPC, 100	qPCR on swab and isolates followed by gel electrophoresis and sequencing	152
MacConkey agar with IPM	64/755	87.5	99.4	KPC, 100	KPC PCR, KPC PCR, mHT, repeat culture, repeat PCR	153
chromID Carba (prototype)	64/37,200c	100	93	NDM, 100	PCR for IMP, VIM, GIM, SPM, SIM, and NDM; mHT	158
Colorex KPC		97	96
CHROMagar KPC	46/126	97.8	98.7	KPC, 72.5; VIM, 27.5	Phoenix susceptibility; EDTA/IMI confirmatory disks; PCR for KPC and VIM	159
MacConkey agar with IPM		78.3	97.5		Negative result not confirmed if negative by both methods
HardyChrom	46/126	76.1	100b	KPC, 100	qPCRe for KPC and NDM; PCR for SME, VIM, IMP, GES, OXA-48, and AmpC	141
CDC protocol		78.3	100b
Supercarba	10/77	80	98.5b	OXA-48, 100	For positive and negative results, PCRe for KPC, NDM, VIM, IMP, NDM, OXA-48, and ESBL panel	160
Supercarba with enrichment step		100
chromID ESBL		90	68.6
chromID ESBL with enrichment step		100
Brilliance CRE		80	86.6
Brilliance CRE with enrichment step		100
CHROMagar KPC	66/95	77.3	100	KPC, 100	Positive results confirmed with PCRe; negative results had negative qPCRe and PCR results	155
VAN/AMB/CAZ/CLI plate		77.3	100
CHROMagar KPC	47/150d	76	75.7	KPC (presumed)	Confirmed with KPC qPCR and Microscan susceptibility testing	156
SpectraCRE		97.8	86.4
MacConkey agar with ETP disk		83	73.8
CDC protocol	33/302	57.6	95.2	OXA-48, 100	Initial screen with inhibition disk synergy testing followed by PCR and sequencing of samples with positive results	165
chromID OXA-48		75.8	99.3
chromID Carba		57.6	98.9
chromID Carba + chromID OXA-48		75.8	94.4

^aAbbreviations: MEM, meropenem; IPM, imipenem; ETP, ertapenem; VAN, vancomycin; CLI, clindamycin; CAZ, ceftazidime; AMB, amphotericin B; mHT, modified Hodge test.

^bNonfermenting bacteria were excluded.

^cStool specimens.

^dPerirectal swabs.

^ePCR was done directly on the specimen. If not noted, PCR was performed on pure cultures derived from the sample.

^fIncludes both perianal and perirectal swabs.