Outbreak Of Klebsiella pneumoniae Carbapenemase-Producing Klebsiella aerogenes Strains In A Tertiary Hospital In China

Figures & data

Table 1 In-Vitro Activities Of Antimicrobial Agents Against CRKA Isolates

	Range	MIC50	MIC90	R%	S%	I%
Imipenem	0.125–16	16	>16	100	0	0
Ertapenem	0.125–32	16	32	100	0	0
Meropenem	0.125–16	16	>16	100	0	0
Cefepime	0.25–32	>32	>32	100	0	0
Cefotaxime	0.5–32	>32	>32	100	0	0
Ceftazidime	1–32	>32	>32	92.9	0	7.1
Piperacillin/tazobactam	8/4–256/4	>256	>256	100	0	0
Cefuroxime	4–64	>64	>64	100	0	0
Cefoxitin	4–128	>128	>128	100	0	0
Amikacin	8–128	>128	>128	78.6	21.4	0
Aztreonam	2–64	>64	>64	100	0	0
Ciprofloxacin	0.25–8	2	>8	85.7	0	14.3
Levofloxacin	0.5–16	2	>16	78.6	21.4	0
Gentamicin	2–32	>32	>32	85.8	14.2	0
Fosfomycin	8–512	>512	>512	100	0	0
Colistin	1–16	≤1	2	7.1	92.9	/
Tigecycline	0.25–8	≤0.25	0.5	0	100	/

Note: MIC presented as µg/mL.

Abbreviations: CRKA, carbapenem-resistant Klebsiella aerogenes; R, resistance; S, susceptibility; I, Intermediate; MIC, minimum inhibitory concentration.

Table 2 Carbapenem MICs, β-Lactamase Detection, And bla_KPC-2-Carrying Plasmid Analysis In The Isolates Studied

Isolates	ETP	MEM	IPM	IPM+PAβN	CAZ	LVX	AMK	CT	TGC	β-lactamases In Clinical Isolates	β-lactamases In Transformants	PFGE Type	RFLP Type	Plasmid Size (bp)
A25	>32	>16	>16	>16	32	>16	>128	≤1	≤0.25	KPC-2, SHV-1, CTX-M-14	KPC-2, CTX-M-14	D	III	≈150
A27	32	>16	16	8	>32	8	>128	≤1	≤0.25	KPC-2, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A31	32	>16	16	16	>32	2	>128	≤1	≤0.25	KPC-2, SHV-1, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A32	32	>16	8	8	16	4	≤8	≤1	1	KPC-2	KPC-2	C	Ⅳ	≈85
A33	16	16	8	16	32	2	>128	≤1	≤0.25	KPC-2, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A35	16	16	8	4	32	2	>128	≤1	≤0.25	KPC-2, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A39	8	8	4	2	16	≤0.5	≤8	≤1	≤0.25	KPC-2	KPC-2	A	II	≈95
A40	8	8	16	16	>32	4	>128	≤1	≤0.25	KPC-2	KPC-2	A	II	≈95
A41	16	16	8	16	>32	2	>128	≤1	≤0.25	KPC-2	KPC-2	A	II	≈95
A42	8	8	8	8	8	≤0.5	≤8	8	≤0.25	KPC-2, CTX-M-14	KPC-2, CTX-M-14	A	Ⅴ	≈75
A44	16	>16	8	8	>32	2	>128	≤1	≤0.25	KPC-2, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A47	32	>16	>16	>16	>32	4	>128	≤1	≤0.25	KPC-2, CTX-M-15	KPC-2, CTX-M-15	A	I	≈40
A52	32	16	8	8	>32	≤0.5	>128	≤1	≤0.25	KPC-2, SHV-1	KPC-2	B	Ⅵ	≈50
A61	8	>16	8	4	>32	>16	>128	2	0.5	KPC-2	KPC-2	E	Ⅶ	≈105

Abbreviations: ETP, ertapenem; MEM, meropenem; IPM, imipenem; CAZ, ceftazidime; LVX, levofloxacin; AMK, amikacin; CT, colistin; TGC, tigecycline.

Figure 1 Outer-membrane protein profiles of 14 clinical K. aerogenes isolates on a 12% sodium dodecyl sulfate-polyacrylamide gel.

Abbreviations: K. aerogenes, Klebsiella aerogenes; M, marker.

Figure 2 PFGE patterns for CRKA. Isolates with 85% similarity were considered the same type.

Abbreviations: PFGE, pulsed-field gel electrophoresis; CRKA, carbapenem-resistant Klebsiella aerogenes.

Figure 3 Genetic environment of the bla_KPC-2 gene from clinical isolates. Genes are depicted as arrows according to the direction of transcription. Variant 1 included isolate A25. Variant 2 included isolates A27, A31, A33, A35, A44, and A47. Variant 3 included isolates A32, A39, A40, A41, A42, and A61. Variant 4 included isolate A52.

Table 3 Clinical Characteristics Of Patients Infected With CRKA

Patient	Isolate No.	Sex (Age, Years)	Underlying Condition	Ward	Days Of Hospital Stay Before Infection/total Days	Specimen	Antimicrobial Therapy
1	A27	Female (64)	Craniocerebral trauma	Neurosurgery Department	13/19	Sputum	AMK, TZP, LVX
2	A33	Male (39)	Craniocerebral trauma	Neurosurgery Department	23/66	Sputum	TGC, MEM, FOS, CSL
3	A35	Male (67)	Craniocerebral trauma	Neurosurgery Department	12/50.5	Sputum	MEM, VAN, AMK, TGC
4	A39	Male (34)	Craniocerebral trauma	Neurosurgery Department	13/14.5	Sputum	MEM, VAN
5	A40	Male (14)	Cerebellar hemorrhage	Neurosurgery Department	18/33.5	Sputum	MEM, FOS, TGC
6	A41	Female (61)	Subarachnoid hemorrhage	Neurosurgery Department	23/42	Sputum	CFZ, MEM, VAN, SAM
7	A42	Male (50)	Craniocerebral trauma	Neurosurgery Department	5/18.5	Sputum	TZP
8	A44	Male (62)	Craniocerebral trauma	Neurosurgery Department	5/23.5	Sputum	CSL, VAN, AMK
9	A47	Male (62)	Craniocerebral trauma	Neurosurgery Department	4/24	Sputum	CSL, MEM, VAN
10	A52	Male (55)	Cervical spinal fractures	Intensive Care Unit	5/44	Sputum	CSL, AMK, VAN, IMP, TZP, FOS
11	A61	Female (44)	Craniocerebral trauma	Intensive Care Unit	7/31	Sputum	MEM, FOS, CSL

Abbreviations: AMK, amikacin; TZP, piperacillin/tazobactam; LVX, levofloxacin; TGC, tigecycline; MEM, meropenem; FOS, fosfomycin; CSL, cefoperazone/sulbactam; VAN:vancomycin; CFZ, cefazolin; SAM, ampicillin/sulbactam; IMP, imipenem.