Emergence of an Extensive Drug Resistant Citrobacter portucalensis Clinical Strain Harboring bla_SFO-1, bla_KPC-2, and bla_NDM-1

Figures & data

Table 1 The MIC Values of L2724hy, L2724hy-KPC-EC600, L2724hy-NDM-EC600 and EC600

Antimicrobials	MIC Values (mg/L)			EC600
	L2724hy	L2724hy-KPC-EC600	L2724hy-NDM-EC600
Aztreonam	>128 (R)	>128 (R)	>128 (R)	0.125 (S)
Imipenem	16 (R)	4 (R)	4 (R)	0.5 (S)
Meropenem	>32 (R)	4 (R)	4 (R)	0.06 (S)
Ceftriaxone	>128 (R)	64 (R)	128 (R)	0.06 (S)
Cefotaxime	>128 (R)	16 (R)	128 (R)	0.03 (S)
Ceftazidime	>128 (R)	64 (R)	>128 (R)	0.5 (S)
Levofloxacin	>64 (R)	0.5 (S)	0.25 (S)	1 (I)
Ciprofloxacin	>64 (R)	0.25 (S)	0.25 (S)	0.5 (S)
Amikacin	>128 (R)	1 (S)	2 (S)	2 (S)
Gentamicin	>128 (R)	1 (S)	1 (S)	2 (S)
Piperacillin	>128 (R)	>128 (R)	128 (R)	1 (S)
Fosfomycin	>512 (R)	4 (S)	2 (S)	8 (S)
Chloramphenicol	>128 (R)	8 (S)	8 (S)	8 (S)
Trimethoprim/Sulfamethoxazole	>8 (R)	≤0.125 (S)	≤0.125 (S)	≤2.375 (S)
Amoxicillin/Clavulanic acid	>128 (R)	128 (R)	128 (R)	4 (S)
Cefepime	128 (R)	16 (R)	16 (R)	<0.008 (S)
Ceftazidime-avibactam	64 (R)	1 (S)	64 (R)	0.5 (S)
Tigecycline	0.06 (S)	0.06 (S)	≤0.03 (S)	<0.05 (S)
Polymyxin B	2 (I)	2 (I)	2 (I)	0.5 (I)

Note: The quality control strains were E. coli ATCC 25922 and K. pneumoniae ATCC 700603.

Abbreviations: S, susceptible; R, resistant; I, intermediate.

Figure 1 S1-PFGE profiles and southern blotting hybridization for L2724hy. S1-PFGE determines the number and size of plasmids in the strain. Southern blotting hybridization indicates the location of resistance genes bla_SFO-1, bla_NDM-1, and bla_KPC-2.

Table 2 The Genomic Characteristics of L2724hy

L2724hy	Sizes	Type	G+C%	ARGs
Chromosome	5,031,620 bp	ST85	51.9	blaCMY-46, qnrB18,
p1-L2724hy	365,162 bp	IncH12/lncH12A	46.5
p2-L2724hy-SFO-1	131,226 bp	IncFII	53.7	blaSFO-1, fosA3
p3-L2724hy-NDM-1	54,000 bp	IncX3	49.2	blaSHV-12, blaNDM-1
p4-L2724hy	45,944 bp	IncR	51.9	mph(A)
p5-L2724hy-KPC-2	41,244 bp	Undefined	49.1	blaKPC-2
p6-L2724hy	5,933 bp	Undefined	51.1	aac(6’)-Ib-cr, aac(6’)-Ib-Hangzhou
p7-L2724hy	5,234 bp	Undefined	50.7
p8-L2724hy	5,040 bp	Undefined	50.0
p9-L2724hy	2,182 bp	Undefined	50.1
p10-L2724hy	2,152 bp	Undefined	49.9
p11-L2724hy	2,013 bp	Undefined	49.3

Figure 2 Comparative analysis of plasmids p2-L2724hy-SFO-1, p4-L2724hy-NDM-1, and p5-L2724hy-KPC-2 in L2724hy. The BRIG circle maps show plasmid resistance genes and mobile genetic elements (MGEs). (a) plasmid p2-L2724hy-SFO-1 carrying bla_SFO-1 and fosA3. (b) plasmid p4-L2724hy-NDM-1 harboring bla_NDM-1 and bla_SHV-12. (c) plasmid p5-L2724hy-KPC-2 bearing bla_KPC-2.

Figure 3 Genetic environment of bla_SFO-1, bla_NDM-1, and bla_KPC-2 in L2724hy. (a) bla_SFO-1 (b) bla_NDM-1 (c) bla_KPC-2. Red arrows denote drug resistance genes, green arrows denote transposons, pink arrows denote other genes, and yellow arrows represent hypothetical proteins.

Figure 4 A conjugative plasmid p2-L2724hy-SFO-1. ORF1-57,fosA3; ORF1-60, bla_SFO-1.

Abbreviation: AR (ARGs), acquired antibiotic resistance determinant genes ;ORF, Open Reading Frame