Distribution of NDM1 Carbapenemase-Producing Proteeae Strains on High-Risk Hospital Wards

Figures & data

Table 1 Distribution of Samples by Clinical Wards

Department	Total	Bronchial Aspirates		Sputum		Blood Cultures		Catheter Tips		Urine Cultures		Wound Swabs		Other Samples
		N	%	N	%	N	%	N	%	N	%	N	%	N	%
ICU	3831	1513	39.49	57	1.48	1192	31.11	303	7.9	209	5.45	353	9.21	204	5.33
General surgery	781	0	0	10	1.28	21	2.68	12	1.54	33	4.23	466	59.67	239	30.6
Neurosurgery	217	14	6.45	0	0	20	9.22	10	4.61	39	17.97	69	31.79	65	29.95
Vascular surgery	925	1	0.11	0	0	5	0.54	4	0.43	12	1.3	894	96.65	9	0.97
Plastic surgery	824	3	0.36	1	0.12	11	1.33	6	0.73	12	1.46	787	95.51	4	0.49
Urology	1095	0	0	5	0.45	31	2.83	8	0.73	991	90.5	43	3.92	17	1.55
Orthopaedics	497	5	1	1	0.201	13	2.61	3	0.6	76	15.29	375	75.45	24	4.83
Polytrauma	147	5	3.4	0	0	15	10.2	19	12.93	19	12.93	82	55.78	7	4.76
Total	8317	1541	18.53	74	0.89	1308	15.73	365	4.39	1391	16.72	3069	36.9	569	6.84

Table 2 Phenotypic and Molecular Profile of Carbapenem-Resistant Proteeae Strains

Species	N=400	KPC	OXA-48	MBL			blaCTX-M	blaCTX-M +KPC	blaCTX-M +blaNDM	Molecularly Analyzed Strains
				blaNDM	blaVIM	blaNDM+blaVIM
P. mirabilis [n, %]	245 (61.25)	1 (6.25)*	0(0)	12 (75.00)	1 (6.25)	0(0)	1 (6.25)	0(0)	1 (6.25)	16 (100)
Proteus vulgaris [n, %]	10 (2.50)	/	/	/	/	/	/	/	/	0(0)
Proteus penneri [n, %]	1 (0.25)	/	/	/	/	/	/	/	/	0(0)
P. rettgeri [n, %]	13 (3.25)	0(0)*	0(0)	1 (100)	0(0)	0(0)	0(0)	0(0)	0(0)	1 (100)
P. stuartii [n, %]	94 (23.50)	3 (6.25)*	2 (4.17)*	37 (77.08)	0(0)	1 (2.08)	1 (2.08)	1 (2.08)	3 (6.25)	48 (100)
Morganella morganii [n, %]	35 (8.75)	/	/	/	/	/	/	/	/	0(0)
Morganella sibonii [n, %]	2 (0.50)	/	/	/	/	/	/	/	/	0(0)
Total [n, %]	400 (100)	4 (6.15)*	2 (3.08)	50 (76.92)	1 (1.54)	1 (1.54)	2 (3.08)	1 (1.54)	4 (6.15)	65 (100)

Note: *Percentages reported to the total number of strains, of the same species, molecularly analyzed.

Figure 1 Distribution of Proteeae strains in samples.

Figure 2 Evolution of the multidrug resistance of Proteeae strains per month in parallel with the monthly share of the two species.

Table 3 Comparative Analysis of the Origin of Proteeae Strains*

Sample	Subgroup of CRP Strains		Total Group of Proteeae Strains		p
	n=65	%	N=400	%
Bronchial aspirates	21	32.31	80	20.00	0.025
Blood cultures	20	30.77	34	8.50	<0.001
Wound swabs	7	10.77	158	39.50	<0.001

Note: *For the rest of the samples, there were no statistically significant differences.

Table 4 Antimicrobial Susceptibilities of Proteeae Strains

Antimicrobial Agent	Proteus mirabilis (n=16)						Providencia stuartii (n=48)						Providencia rettgeri (n=1)
	MIC*	N	MIC*	N	MIC*	N	MIC*	N	MIC*	N	MIC*	N	MIC*	N	MIC*	N
Piperacillin	≥128(R)	16					≥128(R)	48					≥128(R)	1
Piperacillin–tazobactam	≥128/4(R)	14	32/-64/4(I)	2			≥128/4(R)	47	32/-64/4(I)	1			≥128/4(R)	1
Ceftazidime	≥64(R)	16					≥64(R)	48					≥64(R)	1
Cefepime	≥16(R)	11	4–8(SDD)	5			≥16(R)	31	4–8(SDD)	11	≤2(S)	6	≥16(R)	1
Imipenem	≥4(R)	16					≥4(R)	48					≥4(R)	1
Meropenem	≥4(R)	16					≥4(R)	48					≥4(R)	1
Amikacin	≥64(R)	4			≤16(S)	12	≥64(R)	31			≤16(S)	17	≥64(R)	1
Gentamicin	≥16(R)	13			≤4(S)	3	≥16(R)	41	≤8(I)	4	≤4(S)	3	≥16(R)	1
Ciprofloxacin	≥1(R)	15			≤0.25(S)	1	≥1(R)	46			≤0.25(S)	2	≥1(R)	1
Levofloxacin	≥2(R)	12	1(I)	2	≤0.5(S)	2	≥2(R)	44	1(I)	3	≤0.5(S)	1			≤0.5(S)	1
Trimethoprim–sulfamethoxazole	≥4/76(R)	15			≤2/38(S)	1	≥4/76(R)	48					≥4/76(R)	1

Note: *Breakpoints (µg/mL).

Table 5 Analysis of Associated Factors Involved in Infections with CR Proteeae Strains

Variables	CRP Group n1=65	P-S Group n2=222	p	OR [95% CI]	p	HR [95% CI]
Age [median, IQR]	60 [50.00–68.00]	64.00 [54.00–72.00]	0.005	0.975 [0.96–0.99]
Days of hospital stay [median, IQR]	45.00 [32.00–69.00]	23.00 [8.00–53.00]	<0.001	1.00 [1.00–1.01]
Days of antibiotherapy [median, IQR]	35.00 [16.00–52.00]	9.00 [4.00–24.00]	<0.001	1.01 [1.00–1.02]	0.033	1.01 [1.00–1.02]
Number of antibiotics [median, IQR]	5.00 [4.00–7.00]	2.00 [1.00–3.00]	<0.001	1.57 [1.38–1.79]
Days of CVC [median, IQR]	28.00 [16.00–48.00]	2.00 [0.00–12.00]	<0.001	1.03 [1.02–1.04]
Days of urinary catheter [median, IQR]	31.00 [20.00–55.00]	0.00 [0.00–12.00]	<0.001	1.03 [1.02–1.04]
Female [n, %]	21 (32.31)	82 (36.94)	0.493	0.81 [0.42–1.52]
Male [n, %]	44 (67.69)	140 (63.04)
Previous antibiotherapy Yes/No [n, %]	22 (33.85)	28 (12.61)	<0.001	3.54 [1.76–7.13]
	43 (66.15)	194 (87.39)
Mechanical ventilation Yes/No [n, %]	61 (93.85)	56 (25.23)	<0.001	45.21 [15.51–176.26]
	4 (6.15)	166 (77.77)
Length of mechanical ventilation>96 h [n, %]	59 (90.77)	47 (21.17)	<0.001	36.61 [14,42–108.45]	<0.001	40.51 [13.65–120.25]
CVC Yes/No [n, %]	61 (93.85)	129 (58.11)	<0.001	10.99 [3.85–42.83]
	4 (6.15)	93 (41.89)
Urinary catheter D Yes/No [n, %]	61 (93.85)	87 (39.19)	<0.001	23.66 [8.26–91.93]
	4 (6.15)	135 (60.81)
Hemodialysis Yes/No [n, %]	7 (10.77)	8 (3.60)	0.049	3.23 [1.00–10.32]
	58 (89.23)	214 (96.40)
Tracheostomy Yes/No [n, %]	41 (63.08)	28 (12.61)	<0.001	12.35 [6.18–24.91]	0.024	2.65 [1.14–6.17
	23 (35.38)	194 (87.39)
Gastrostomy Yes/No [n, %]	2(3.08)	7 (3.15)	1.00	0.98 [0.10–5.30]
	63 (96.92)	215 (96.85)
Vasoactive therapy Yes/No [n, %]	46 (70.77)	43 (19.37)	<0.001	10.08 [5.14–19.92]
	19 (29.23)	179 (80,63)
Surgical wound Yes/No [n, %]	52 (80.00)	189 (85.14)	0.321	0.70 [0.33–1.51]
	13 (20.00)	33 (14.86)
Pressure sores Yes/No [n, %]	9 (13.85)	23 (10.36)	0.432	1.39 [0.56–3.38]
	56 (86.15)	199(89.64)
Transfusions Yes/No [n, %]	47 (72.31)	48 (21.62)	<0.001	9.47 [4.83–18.72]
	18 (27.69)	174 (78.38)
Nasogastric nutrition Yes/No [n, %]	57 (87.69)	53 (23.87)	<0.001	22.72 [9.68–55.26]
	8 (12.31)	169 (76.13)
Immunosuppressive pathology Yes/No [n, %]	5 (7.69)	12 (5.41)	0.549	1.46 [0.39–4.66]
	60 (92.31)	210 (94.59)
Chemotherapy Yes/No [n, %]	0 (0.00)	6 (2.70)	0.342	0.00 [0.00–2.90]
	65 (100)	216 (97.30)
Radiotherapy Yes/No [n, %]	0 (0.00)	1 (0.45)	1.00	0.00 [0.00–133.20]
	65 (100)	221 (99.55)

Notes: P-S group, subsample with carbapenem-sensitive Proteeae strains; CVC, central venous catheter; Nagelkerke R²=0.534; Hosmer and Lemeshow test=0.929; CI, confidence interval.