Clinical predictors of multidrug-resistant Gram-negative pyogenic liver abscess and nomogram construction: A retrospective analysis

Table 1 Distribution of specific pathogen types among patients co-infected with two or more multidrug-resistant-Gram-negative bacteria

Patients	Pathogenic bacteria
A	Klebsiella pneumoniae	Escherichia coli
B	Klebsiella pneumoniae	Serratia odorifera
C	Escherichia coli	Pseudomonas monteilii
D	Klebsiella pneumoniae	Enterobacter cloacae
E	Escherichia coli	Klebsiella variicola
F	Klebsiella pneumoniae	Escherichia coli	Pseudomonas aeruginosa
G	Klebsiella pneumoniae	Escherichia coli	Pseudomonas monteilii	Pseudomonas aeruginosa

Table 2 Comparison of clinical characteristics, laboratory parameters, comorbidities, and clinical outcomes in patients with pyogenic liver abscesses caused by multidrug-resistant-Gram-negative bacteria vs non-multidrug-resistant-Gram-negative bacteria, n (%)/median (interquartile ranges)

	Total (n = 268)	MDR (n = 105)	Non-MDR (n = 163)	P value
Age ≥ 60 years	136 (50.75)	66 (62.86)	70 (42.94)	0.0011
Male sex	181 (67.54)	67 (63.81)	114 (69.94)	0.2961
BMI	23.83 (21.63, 25.71)	22.99 (20.03, 24.92)	24.22 (22.21, 26.12)	0.0012
Diabetes	159 (59.33)	68 (64.76)	91 (55.83)	0.1461
Hypertension	72 (26.87)	28 (26.67)	44 (26.99)	0.9531
Malignant tumor	48 (17.91)	33 (31.43)	15 (9.20)	< 0.0011
Charlson Comorbidity Index	3.00 (2.00, 5.00)	4.00 (3.00, 6.00)	3.00 (2.00, 4.00)	< 0.0012
Clinical manifestations
Fever	237 (88.43)	87 (82.86)	150 (92.02)	0.0221
Abdominal pain	121 (45.15)	46 (43.81)	75 (46.01)	0.7241
Gastrointestinal symptoms	158 (58.96)	55 (52.38)	103 (63.19)	0.0791
Laboratory examination
White blood cell count (× 109/L)	11.40 (8.70, 16.15)	11.30 (8.70, 16.50)	11.50 (8.85, 16.05)	0.6532
Absolute lymphocyte count (× 109/L)	0.90 (0.60, 1.30)	0.90 (0.60, 1.20)	0.80 (0.50, 1.30)	0.7482
Neutrophil count (× 109/L)	9.43 (7.22, 14.22)	9.61(6.89, 14.57)	9.34 (7.41, 13.97)	0.7602
Neutral-lymphocyte ratio	11.72 (7.02, 20.71)	12.02 (6.89, 20.73)	11.68 (7.25, 20.18)	0.8672
Hemoglobin (g/L)	114.00 (102.00, 129.00)	108.00 (95.00, 119.00)	118.00 (106.00, 133.00)	< 0.0012
Platelet count (× 109/L)	173.50 (89.00, 271.00)	162.00 (91.00, 257.00)	191.00 (89.00, 277.00)	0.5692
CRP (mg/L)	167.66 (97.26, 214.73)	149.20 (72.90, 204.10)	175.60 (113.75, 218.15)	0.0162
ALT (U/L)	58.00 (32.75, 100.00)	48.00 (29.00, 85.00)	66.00 (35.50, 123.50)	0.0072
AST (U/L)	44.00 (25.75, 89.00)	42.00 (25.00, 81.00)	46.00 (26.50, 124.50)	0.2402
GGT (U/L)	119.50 (64.75, 221.25)	137.00 (65.00, 249.00)	114.00 (64.00, 204.00)	0.1702
Albumin (g/L)	29.85 (26.00, 34.18)	29.10 (25.00, 33.00)	30.90 (26.50, 35.35)	0.0472
Total bilirubin (μmol/L)	15.05 (9.70, 26.20)	14.90 (10.10, 26.20)	15.20 (9.15, 25.95)	0.7672
APTT (seconds)	13.20 (12.10, 14.50)	13.70 (12.60, 14.90)	13.10 (11.85, 14.10)	0.0072
PT (seconds)	29.50 (26.60, 32.13)	29.90 (26.90, 32.70)	29.17 (26.45, 31.90)	0.1022
PCT (ng/mL)	6.66 (1.36, 21.38)	5.73 (1.30, 16.82)	7.19 (1.50, 22.66)	0.3252
IL-6 (pg/mL)	118.27 (36.98, 265.14)	153.00 (54.50, 352.26)	89.00 (29.16, 208.60)	0.0032
Imaging results
Abscess size (mm)	65.50 (49.75, 87.00)	63.00 (48.00, 77.00)	68.00 (50.00, 93.50)	0.0382
Abscess location				0.5611
Right lobe	208 (77.61)	84 (80.00)	124 (76.07)
Left lobe	41 (15.30)	13 (12.38)	28 (17.18)
Bilateral	19 (7.09)	8 (7.62)	11 (6.75)
Multiple abscesses	85 (31.72)	40 (38.10)	45 (27.61)	0.0721
Clinical outcomes				0.0183
Clinical resolution	246 (91.79)	91 (86.67)	155 (95.09)
Persistent infection	13 (4.85)	8 (7.62)	5 (3.07)
Death	5 (1.87)	2 (1.90)	3 (1.84)
Relapse	4 (1.49)	4 (3.81)	0 (0.0)
Treatment methods				0.9021
Antimicrobial agents alone	45 (16.79)	18 (17.14)	27 (16.56)
Antimicrobial agents and drainage	223 (83.21)	87 (82.86)	136 (83.44)
Co-existing with other infections
Pulmonary infection	92 (34.33)	31 (29.52)	61 (37.42)	0.1841
Comorbidities
Septic shock	28 (10.45)	12 (11.43)	16 (9.82)	0.6741
Pleural effusion	75 (27.99)	31 (29.52)	44 (26.99)	0.6521
Ascites	18 (6.72)	9 (8.57)	9 (5.52)	0.3301
Biliary tract diseases	92 (34.33)	49 (46.67)	43 (26.38)	< 0.0011
Heart failure	16 (5.97)	5 (4.76)	11 (6.75)	0.5031
Renal insufficiency	15 (5.60)	5 (4.76)	10 (6.13)	0.6331

¹χ² test.

²Wilcoxon rank-sum test.

³Fisher’s exact test.

BMI: Body mass index; CRP: C-reactive protein; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; GGT: Gamma-glutamyl transferase; APTT: Activated partial thromboplastin time; PT: Prothrombin time; PCT: Procalcitonin; IL-6: Interleukin-6; MDR: Multidrug-resistant.

Table 3 Univariate logistic regression analysis and multivariate stepwise regression analysis

Variables	Univariate analysis	Multivariate analysis	Variables	Univariate analysis
	OR (95%CI)	P value	OR (95%CI)	P value
Age ≥ 60 years	2.248 (1.360-3.718)	0.002	1.957 (1.099-3.484)	0.023
Female sex	1.320 (0.784-2.220)	0.296
BMI	0.895 (0.830-0.964)	0.003	0.936 (0.866-1.011)	0.092
Diabetes	1.454 (0.877-2.411)	0.147	1.998 (1.089-3.663)	0.025
Hypertension	0.983 (0.565-1.711)	0.953
Malignant tumor	4.522 (2.309-8.857)	< 0.001	3.968 (1.810-8.699)	< 0.001
Charlson Comorbidity Index	1.357 (1.193-1.543)	< 0.001
laboratory examination
White blood cell count (× 109/L)	1.001 (0.964-1.040)	0.961
Absolute lymphocyte count (× 109/L)	0.912 (0.585-1.421)	0.822
Neutrophil count (× 109/L)	1.003 (0.965-1.043)	0.866
Neutral-lymphocyte ratio	1.002 (0.985-1.019)	0.811
Hemoglobin (g/L)	0.970 (0.956-0.983)	< 0.001
Platelet count (× 109/L)	0.999 (0.998-1.001)	0.509
CRP (mg/L)	0.996 (0.993-0.999)	0.013	0.993 (0.990-0.997)	0.001
ALT (U/L)	0.997 (0.994-1.000)	0.036
AST (U/L)	0.998 (0.996-1.000)	0.094	0.998 (0.995-1.000)	0.082
GGT (U/L)	1.001 (1.000-1.003)	0.088	1.002 (1.000-1.004)	0.081
Albumin (g/L)	0.954 (0.915-0.996)	0.030	0.955 (0.907-1.004)	0.073
Total bilirubin	1.000 (0.992-1.008)	0.951
APTT (seconds)	1.016 (0.962-1.074)	0.567	1.058 (0.978-1.145)	0.157
PT (seconds)	1.026 (0.988-1.066)	0.180	1.065 (1.007-1.127)	0.028
PCT (ng/mL)	0.997 (0.988-1.007)	0.550
IL-6 (pg/mL)	1.000 (1.000-1.000)	0.674
Imaging results
Abscess size (mm)	0.992 (0.984-1.001)	0.076
Abscess location
Right lobe
Left lobe	0.685 (0.336-1.399)	0.300
Bilateral	1.074 (0.414-2.781)	0.884
Multiple abscesses	1.614 (0.957-2.721)	0.073
Co-existing with other infections
Pulmonary infection	0.700 (0.414-1.185)	0.185	0.562 (0.303-1.044)	0.068
Comorbidities
Septic shock	1.185 (0.537-2.618)	0.674
Pleural effusion	1.133 (0.658-1.951)	0.653
Ascites	1.604 (0.615-4.183)	0.334
Biliary tract diseases	2.442 (1.455-4.099)	< 0.001
Heart failure	0.691 (0.233-2.048)	0.505
Renal insufficiency	0.765 (0.254-2.304)	0.634

BMI: Body mass index; CRP: C-reactive protein; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; GGT: Gamma-glutamyl transferase; APTT: Activated partial thromboplastin time; PCT: Procalcitonin; PT: Prothrombin time; IL-6: Interleukin-6; CI: Confidence interval; OR: Odds ratio.

Table 4 Correspondence between risk factors and points

Factor	Points
Age ≥ 60 years	26
Diabetes	19
Malignant tumor	53
CRP	11 points per 50 mg/L decrease
PT	7 points per 5 seconds increase

CRP: C-reactive protein; PT: Prothrombin time.

Table 5 Association between total points and the probability of pyogenic liver abscess being caused by multidrug-resistant-Gram-negative bacteria

Total points	Odds of PLA infection being caused by MDR-GNB, %
< 69	< 10
69-97	10-20
97-115	20-30
115-130	30-40
130-144	40-50
144-158	50-60
158-173	60-70
173-191	70-80
> 191	> 80

MDR-GNB: Multidrug-resistant-Gram-negative bacteria; PLA: Pyogenic liver abscess.

Table 6 Variance inflation factors for independent variables

Independent variable	Variance inflation factor
Age ≥ 60 years	1.08
Diabetes	1.13
Malignant tumor	1.09
CRP	1.23
PT	1.48

CRP: C-reactive protein; PT: Prothrombin time.