Increased gene expression and copy number of mutated blaKPC lead to high-level ceftazidime/avibactam resistance in Klebsiella pneumoniae

Table 1 Characteristics of isolates recoverd from the same patients before (A) and after (B) ceftazidime/avibactam exposure

				MIC		Porin sequcence modifications
			KPN clinical isolate		E.coli DH5a(clone)
Strain	KPC^a	β-lactamase	CZA^a	CZA + 25 mg/ml PABN	CZA^a	Ompk35^b	Ompk36^c
1A	KPC-2	TEM,SHV-64,CTX-M-65	2	^d		truncated at 62 aa	GD insertion at 136–137 aa
3A	KPC-2	TEM,SHV-11,CTX-M-65	4			truncated at 62 aa	GD insertion at 136–137 aa
7A	KPC-2	SHV-64,OXA-10,DHA-1	4			truncated at 62 aa	GD insertion at 136–137 aa
8A	KPC-2	SHV-64,DHA-1	4	4	≤0.125	truncated at 62 aa	GD insertion at 136–137 aa
1B	KPC-51	TEM,SHV-64,CTX-M-65	2048	2048	8	truncated at 62 aa	GD insertion at 136–137 aa
3B	KPC-33,KPC-2	TEM,SHV-11,CTX-M-65	256	512	2	truncated at 62 aa	GD insertion at 136–137 aa
7B	KPC-52	SHV-64,OXA-10,DHA-1	256	512	32	truncated at 62 aa	GD insertion at 136–137 aa
8B	KPC-33	SHV-64,DHA-1	128	128	2	truncated at 62 aa	GD insertion at 136–137 aa

Notes
^a Data were from the reported paper [25].
^b Predicted translational modification of Ompk35 were based on the reference sequence (NCBI reference sequence WP_135730820.1) from K. pneumoniae ATCC 13883.
^c Predicted translational modification of Ompk36 were based on the reference sequence (GenBank accession number AEW62399.1) from K. pneumoniae ATCC 13883.
^d The MIC of CZA + 25 mg/mL PABN were not detected in isolates 1A,3A, and 7A.
Abbreviations: CZA ceftazidime/avibactam

ISSN: 1471-2180