Genomic characterization of carbapenem-non-susceptible Pseudomonas aeruginosa in Singapore

Figures & data

Table 1. Antimicrobial susceptibility patterns of 222 CNPA isolates.

Antibiotic	S (%)	I/SDD (%)	R (%)	MIC data (mg L^−1)
				MIC50	MIC90	Range
Doripenem	12.2	11.2	76.6	32	≥ 64	≤ 0.25–≥ 64
Imipenem	2.7	7.2	90.1	32	≥ 64	2–≥ 64
Meropenem	8.1	7.7	84.2	≥ 64	≥ 64	≤ 0.25–≥ 64
Aztreonam	12.6	28.8	58.6	32	≥1 28	4–≥ 128
Cefepime	15.8	9.9	74.3	≥ 128	≥ 128	≤ 1–≥ 128
Piperacillin/tazobactam	11.8	8.6	79.6	≥ 256/4	≥ 256/4	4/4–≥ 256/4
Levofloxacin	14.4	7.7	77.9	32	≥ 64	≤ 0.25–64
Amikacin	55.0	6.7	38.3	16	≥ 128	≤ 1–≥ 128
Gentamicin	30.6	2.7	66.7	–	–	–
Polymyxin B	–	95.0	5.0	1	2	≤ 0.25–4
Ceftazidime/avibactam^a	67.0	–	33.0	4	≥ 128/4	1–≥ 128/4
Ceftolozane/tazobactam^a	64.2	9.2	26.6	2	≥ 128/4	1–≥ 128/4

Notes: I, intermediate; S, susceptible; SDD, susceptible dose-dependent; R, resistant.

^a Only assessed for 109 non-metallo-β-lactamases producing CNPA isolates (inclusive of 108 carbapenemase-negative + 1 KPC-producing isolates).

Figure 1. Prevalence of ARGs by antimicrobial classes. Percentages on the bar represent the proportion of isolates which harboured at least one ARG mediating resistance to that antimicrobial class.

Table 2. Sub-types of 94 isolates with non-disrupted full-length OprD.

OprD type	No of isolates, n
	100% Identity	Amino acid substitutions
PAO1	6	7
PA14	44	2
LESB58	16	4
MTB-1	4	4
PA-VAP-4	7	0

Table 3. Distribution of STs among non-carbapenase producing and carbapenemase-producing CNPA.

ST	Non-carbapenemase producer (n = 108)	Carbapenemase producer (n = 114)
		IMP	NDM	VIM	GES-5	KPC
179	10
235	5	39		7	11
244	10			1	1
274	7
308	1		40
357	6	2		2
Other STs	11(1); 27(2); 111(2); 115(1); 207(1); 245(1); 252(2); 266(1); 282(1); 292(2); 298(1); 313(2); 314(1); 316(1); 389(1); 399(1); 446(2); 463(1); 471(1); 485(2); 534(1); 553(1); 560(1); 564(1); 569(1); 606(2); 620(1); 664(3); 697(1); 708(1); 792(1); 815(2); 840(1); 882(1); 1076(2); 1247(1); 1342(1); 1666(1); 1930(2); 2013(1); 2021(1); 2033(1); 2069(1); 2326(1); 2476(1); 2651(1); 2651(1); Novel(10)	233(1); 497(1); 621(2); 964(1)	316(1)	773(1); 823(2)		Novel(1)

Bold text denotes that ST was observed in both carbapenemase and non-carbapenemase producers.

Figure 2. Rooted phylogenetic tree of the 222 P. aeruginosa strains in this study inferred from an alignment of 22,810 SNP positions obtained after mapping the genomes to the PAO1 reference genome (highlighted in red and indicated with “ref”) and masking of recombination sites. Isolates are labelled with the sequence types (ST) and year of isolation. The tree tips are coloured by the STs. The colour-coded rings denote the carbapenemase, exo genes, and O-serotype. The scale bar represents the number of nucleotide substitution per site.