Bacteriological Profile and Antimicrobial Susceptibility Patterns of Gram-Negative Bloodstream Infection and Risk Factors Associated with Mortality and Drug Resistance: A Retrospective Study from Shanxi, China

Figures & data

Figure 1 The distribution of BSI pathogens by year.

Table 1 The Department Distribution of GNBSI Cases

Department	GNBSI
	n	Percentage (%)
Hematology	242	23.77%
Intensive care unit	89	8.74%
Oncology	75	7.37%
Respiratory and Critical Care	74	7.27%
Emergency	71	6.97%
Gynaecology and obstetrics	69	6.78%
Rheumatology	59	5.80%
Gastroenterology	48	4.72%
Orthopedics	47	4.62%
General surgery	31	3.05%
Nephrology	30	2.95%
Urinary surgery	30	2.95%
Cardiology	25	2.46%
Endocrinology	24	2.36%
Neurology	16	1.57%
Comprehensive	13	1.28%
Infectious Disease	12	1.18%
Vascular surgery	11	1.08%
Interventional therapy	11	1.08%
Geriatric	8	0.79%
Other	24	2.36%

Notes: Other department included ophthalmology department, stomatology department, otolaryngology department, neurosurgery department, cardiothoracic surgery department, breast surgery department, traditional Chinese medicine department and mental health unit.

Abbreviation: GNBSI, gram-negative bacterial blood stream infection.

Figure 2 The age distribution of GNBSI cases. Sum means the total number of patients of each age group over five years.

Figure 3 The mortality of GNBSI cases by year.

Figure 4 The number and isolation rate of the top six GNBSI strains.

Abbreviations: EC, Escherichia coli; KP, Klebsiella pneumoniae; BM, Brucella melitensis; PA, Pseudomonas aeruginosa; AB, Acinetobacter baumannii; ECL, Enterobacter cloacae.

Figure 5 The variation trend of MDR, ESBLs-producing and carbapenem-resistant strains. (A) The quantity variation trend of MDR, ESBLs-producing and carbapenem-resistant strains. (B) The variation trend of isolation rate of MDR, ESBLs-producing and carbapenem-resistant strains. *p < 0.05.

Table 2 Antibiotic Resistance Results for the Most Common Isolated Bacteria

	Escherichia coli		Klebsiella pneumoniae		Pseudomonas aeruginosa		Acinetobacter baumannii		Enterobacter cloacae
	n	%	n	%	n	%	n	%	n	%
1st or 2nd generation cephalosporins	418	82.28%	118	73.75%	–	–	–	–	26	76.47%
3rd or 4th generation cephalosporins	284	55.91%	51	31.88%	1	1.56%	31	81.58%	22	64.71%
Cephamycin	23	4.53%	10	6.25%	–	–	–	–	24	70.59%
β-Lactam/β-lactamase inhibitor combinations	62	12.20%	15	9.38%	20	31.25%	28	73.68%	15	44.12%
Carbapenems	5	0.98%	8	5.00%	4	6.25%	29	76.32%	7	20.59%
Aztreonam	277	54.53%	46	38.33%	6	9.38%	6	15.79%	15	44.12%
Aminoglycosides	67	13.19%	11	6.88%	2	3.13%	27	71.05%	1	2.94%
Quinolones	286	56.30%	25	15.63%	3	4.69%	31	81.58%	6	17.65%
Tigecycline	0	0.00%	0	0.00%	–	–	3	7.89%	0	0.00%
Polymyxin	0	0.00%	0	0.00%	0	0.00%	3	7.89%	0	0.00%

Table 3 Predictors of Mortality with GNBSIs

	Univariable Analysis			Multivariate Analysis
	Non-Survivor (n=108)	Survivor (n=910)	p-value	OR	95% CI	p-value
Male	60 (55.56%)	459 (50.44%)	0.315
Age > 60	54 (50.00%)	377 (41.43%)	0.088
History of smoking	9 (8.33%)	83 (9.12%)	0.787
History of drinking	7 (6.48%)	42 (4.62%)	0.392
Hypoproteinemia	99 (91.67%)	759 (83.41)	0.026
Agranulocytosis	32 (29.63%)	230 (25.27%)	0.328
Diabetes	30 (27.78%)	186 (20.44%)	0.078	1.852	1.109–3.093	0.019
History of hospitalization for 90 days prior to BSI	65 (60.19%)	448 (49.23%)	0.031
Hematologic malignancy	29 (26.85%)	222 (24.40%)	0.576
Solid organ tumor	22 (20.37%)	97 (10.66%)	0.003	3.229	1.840–5.667	<0.001
Enterobacteriales	60 (55.56%)	669 (73.52%)	<0.001
Non-fermentative bacteria	42 (38.89%)	101 (11.10%)	<0.001	2.867	1.665–4.936	<0.001
MDR strain	56 (51.85%)	356 (39.12%)	0.011	1.675	1.047–2.679	0.031
ESBLs-producing strain	33 (30.56%)	314 (34.51%)	0.413
Carbapenem-resistant strain	29 (26.85%)	36 (3.96%)	<0.001
Intubation
Thoracentesis	1 (0.93%)	4 (0.44%)	0.43
Drainage tube	21 (19.44%)	103 (11.32%)	0.015
Lumbar puncture	28 (25.93%)	242 (26.59%)	0.882
Arterial cannula	17 (15.74%)	114 (12.53%)	0.346
Central venous cannula	62 (57.41%)	260 (28.57%)	<0.001	1.878	1.175–3.002	0.008
Trachea cannula	34 (31.48%)	63 (6.92%)	<0.001
Tracheotomy	11 (10.19%)	20 (2.20%)	<0.001
Urinary catheter	53 (49.07%)	207 (22.75%)	<0.001	1.717	1.011–2.917	0.046
Nasogastric tube	41 (37.96%)	86 (9.45%)	<0.001
Therapy with antibiotics prior 30 days of infection
1st or 2nd generation cephalosporins	11 (10.19%)	145 (15.93%)	0.117
3rd or 4th generation cephalosporins	16 (14.81%)	152 (16.70%)	0.617
Cephamycin	8 (7.41%)	53 (5.82%)	0.512
β-Lactam/β-lactamase inhibitor combinations	44 (40.74%)	366 (40.22%)	0.438
Carbapenems	69 (63.89%)	366 (40.22%)	<0.001
Aztreonam	1 (0.93%)	5 (0.55%)	0.629
Quinolones	21 (19.44%)	203 (22.31%)	0.497
Aminoglycosides	8 (7.41%)	100 (10.99%)	0.267
Tigecycline	27 (25.00%)	22 (2.42%)	<0.001	7.254	3.588–14.669	<0.001
Polymyxin	0	0	NA

Note: Bold front: variable included in multivariate analysis.

Table 4 Risk Factors for MDR in GNBSIs Patients

	Univariable Analysis			Multivariate Analysis
	MDR (n=267)	Non-MDR (n=751)	p-value	OR	95% CI	p-value
Male	188 (495.63%)	331 (54.62%)	0.005
Age > 60	184 (44.66%)	247 (40.76%)	0.216
History of smoking	38 (9.22%)	54 (8.91%)	0.865
History of drinking	21 (5.10%)	28 (4.62%)	0.727
Hypoproteinemia	356 (86.41%)	502 (82.84%)	0.125
Agranulocytosis	106 (25.73%)	156 (25.74%)	0.996
Diabetes	102 (24.76%)	114 (18.81%)	0.023
History of hospitalization for 90 days prior to BSI	232 (56.31%)	281 (46.37%)	0.002
Hematologic malignancy	105 (25.49%)	146 (24.09%)	0.613
Solid organ tumor	57 (13.83%)	62 (10.23%)	0.079
Enterobacteriales	363 (88.11%)	366 (60.40%)	<0.001	20.491	8.906–47.143	<0.001
Non-fermentative bacteria	43 (10.44%)	100 (16.50%)	0.006	6.364	2.540–15.948	<0.001
Intubation
Thoracentesis	3 (0.73%)	2 (0.33%)	0.372
Drainage tube	58 (14.08%)	66 (10.89%)	0.127
Lumbar puncture	104 (25.24%)	166 (27.39%)	0.446
Arterial cannula	57 (13.83%)	74 (12.21%)	0.448
Central venous cannula	154 (37.38%)	168 (27.72%)	0.001	1.401	1.043–1.882	0.025
Trachea cannula	45 (10.92%)	52 (8.58%)	0.212
Tracheotomy	14 (3.40%)	17 (2.81%)	0.589
Urinary catheter	130 (31.55%)	130 (21.45%)	<0.001
Nasogastric tube	63 (15.29%)	64 (10.56%)	0.025
Therapy with antibiotics prior 30 days of infection
1st or 2nd generation cephalosporins	81 (19.66%)	75 (12.38%)	0.002	1.936	1.333–2.812	0.001
3rd or 4th generation cephalosporins	89 (21.60%)	79 (13.04%)	0.058
Cephamycin	30 (7.28%)	31 (5.12%)	0.153
β-Lactam/β-lactamase inhibitor combinations	180 (43.69%)	200 (33.00%)	0.001
Carbapenems	189 (45.87%)	246 (40.59%)	0.095
Aztreonam	2 (0.48%)	4 (0.66%)	0.721
Quinolones	100 (24.27%)	124 (20.46%)	0.15
Aminoglycosides	55 (13.35%)	53 (8.75%)	0.019
Tigecycline	33 (8.01%)	16 (2.64%)	<0.001	3.963	2.025–7.757	<0.001
Polymyxin	0	0	NA

Note: Bold front: variable included in multivariate analysis.

Table 5 Risk Factors for ESBLs-Producing in GNBSIs Patients

	Univariable Analysis			Multivariate Analysis
	ESBLs-Producing (n=347)	Non-ESBLs-Producing (n=671)	p-value	OR	95% CI	p-value
Male	155 (44.67%)	364 (54.25%)	0.004
Age > 60	149 (42.94%)	282 (42.03%)	0.78
History of smoking	33 (9.51%)	59 (8.79%)	0.705
History of drinking	16 (4.61%)	33 (4.92%)	0.828
Hypoproteinemia	292 (84.15%)	566 (84.35%)	0.933
Agranulocytosis	87 (25.07%)	175 (26.08%)	0.727
Diabetes	82 (23.63%)	134 (19.97%)	0.176
History of hospitalization for 90 days prior to BSI	198 (57.06%)	315 (46.94%)	0.002	1.461	1.086–1.963	0.012
Hematologic malignancy	89 (25.65%)	162 (24.14%)	0.597
Solid organ tumor	52 (14.99%)	67 (9.99%)	0.019
Enterobacteriales	336 (96.83%)	393 (58.57%)	<0.001	24.748	12.944–47.315	<0.001
Non-fermentative bacteria	7 (2.02%)	136 (20.27%)	<0.001
Intubation
Thoracentesis	2 (0.58%)	3 (0.45%)	0.782
Drainage tube	40 (11.53%)	84 (12.52%)	0.647
Lumbar puncture	87 (25.07%)	183 (27.27%)	0.451
Arterial cannula	45 (12.97%)	86 (12.82%)	0.945
Central venous cannula	118 (34.01%)	204 (30.40%)	0.241
Trachea cannula	22 (6.34%)	75 (11.18%)	0.013
Tracheotomy	7 (2.02%)	24 (3.58%)	0.17
Urinary catheter	101 (29.11%)	159 (23.70%)	0.061
Nasogastric tube	39 (11.24%)	88 (13.11%)	0.391
Therapy with antibiotics prior 30 days of infection
1st or 2nd generation cephalosporins	70 (20.17%)	86 (12.82%)	0.002	1.964	1.315–2.934	0.001
3rd or 4th generation cephalosporins	69 (19.88%)	99 (14.75%)	0.037	1.548	1.057–2.267	0.025
Cephamycin	25 (7.20%)	36 (5.37%)	0.241
β-Lactam/β-lactamase inhibitor combinations	152 (43.80%)	228 (33.98%)	0.002	1.424	1.055–1.923	0.021
Carbapenems	146 (42.07%)	289 (43.07%)	0.761
Aztreonam	2 (0.58%)	4 (0.60%)	0.969
Quinolones	85 (24.50%)	139 (20.72%)	0.168
Aminoglycosides	46 (13.26%)	62 (9.24%)	0.049
Tigecycline	21 (6.05%)	28 (4.17%)	0.184	3.588	1.664–7.734	0.001
Polymyxin	0	0	NA

Note: Bold front: variable included in multivariate analysis.

Table 6 Risk Factors for Carbapenem-Resistant in GNBSIs Patients

	Univariable Analysis				Multivariate Analysis
	Carbapenem-Resistant (n=65)	Non-Carbapenem-Resistant (n=953)	p-value		OR	95% CI	p-value
Male	47 (72.31%)	472 (49.53%)	<0.001
Age > 60	31 (47.69%)	400 (41.97%)	0.367
History of smoking	11 (16.92%)	81 (8.50%)	0.022
History of drinking	8 (12.31%)	41 (4.30%)	0.004		5.043	1.797–14.154	0.002
Hypoproteinemia	64 (98.46%)	794 (83.32%)	0.001
Agranulocytosis	12 (18.46%)	250 (26.23%)	0.166
Diabetes	13 (20.00%)	203 (21.30%)	0.804
History of hospitalization for 90 days prior to BSI	32 (49.23%)	481 (50.47%)	0.846
Hematologic malignancy	11 (16.92%)	240 (25.18%)	0.135
Solid organ tumor	2 (3.08%)	117 (12.28%)	0.026		0.12	0.018–0.787	0.027
Enterobacteriales	17 (26.15%)	712 (74.71%)	<0.001
Non-fermentative bacteria	47 (72.31%)	96 (10.07%)	<0.001		10.176	5.149–20.111	<0.001
Intubation
Thoracentesis	1 (1.54%)	4 (0.42%)	0.281
Drainage tube	29 (44.62%)	95 (9.97%)	<0.001		3.023	1.339–6.823	0.008
Lumbar puncture	9 (13.85%)	261 (27.39%)	0.017
Arterial cannula	16 (24.62%)	115 (12.07%)	0.003
Central venous cannula	45 (69.23%)	277 (29.07%)	<0.001
Trachea cannula	39 (60.00%)	58 (6.09%)	<0.001		5.68	2.633–12.256	<0.001
Tracheotomy	13 (20.00%)	18 (1.89%)	<0.001
Urinary catheter	44 (67.69%)	216 (22.67%)	<0.001
Nasogastric tube	40 (61.54%)	87 (9.13%)	<0.001
Therapy with antibiotics prior 30 days of infection
1st or 2nd generation cephalosporins	13 (20.00%)	143 (15.01%)	0.279
3rd or 4th generation cephalosporins	13 (20.00%)	155 (16.26%)	0.432
Cephamycin	9 (13.85%)	52 (5.46%)	0.006
β-Lactam/β-lactamase inhibitor combinations	35 (53.85%)	345 (36.20%)	0.004
Carbapenems	48 (73.85%)	387 (40.61%)	<0.001
Aztreonam	2 (3.08%)	4 (0.42%)	0.007		22.434	2.385–211.034	0.007
Quinolones	14 (21.54%)	210 (22.04%)	0.925
Aminoglycosides	9 (13.85%)	99 (10.39%)	0.381
Tigecycline	22 (33.85%)	27 (2.83%)	<0.001		9.222	3.873–21.956	<0.001
Polymyxin	0	0	NA

Note: Bold front: variable included in multivariate analysis.