Background
Methods
Patients and bacterial isolates
Clinical parameters
Identification of K. variicola and K. quasipneumoniae from K. pneumoniae isolates
Detection of virulence genes and serotyping
String test
Statistical analysis
Results
Bacterial characteristics
Total = 119 | K. pneumoniae = 87 | K. variicola = 21 | K. quasipneumoniae = 11 | p-value | ||||||
---|---|---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | n | % | |||
K1 | 16 | (13.5) | 15 | (17.2) | 0 | (0) | 1 | (9.1) | 0.09 | |
K2 | 13 | (10.9) | 12 | (13.8) | 1 | (4.8) | 0 | (0) | 0.32 | |
rmpA | 29 | (24.4) | 29 | (33.3) | 0 | (0) | 0 | (0) | <0.001 | * |
iutA | 32 | (26.9) | 32 | (36.8) | 0 | (0) | 0 | (0) | < 0.001 | * |
ybtS | 45 | (37.8) | 41 | (47.1) | 4 | (19.0) | 0 | (0) | <0.001 | * |
entB | 108 | (90.8) | 85 | (97.7) | 19 | (90.5) | 4 | (36.4) | < 0.001 | * |
kfu | 45 | (37.8) | 26 | (29.9) | 19 | (90.5) | 0 | (0) | < 0.001 | * |
allS | 28 | (23.5) | 21 | (24.1) | 1 | (4.8) | 6 | (54.5) | < 0.01 | * |
mrkD | 118 | (99.2) | 86 | (98.9) | 21 | (100.0) | 11 | (100.0) | 1.00 | |
Hypermucoviscous phenotype | 25 | (21.0) | 22 | (25.3) | 2 | (9.5) | 1 | (9.1) | 0.24 | |
ESBL-producing | 3 | (2.5) | 2 | (2.3) | 1 | (4.8) | 0 | (0) | 0.61 |
Clinical characteristics
Characteristics of patients | Total = 106 | K. pneumoniae = 78 | K. variicola = 19 | K. quasipneumoniae = 9 | p-value | |||||
---|---|---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | n | % | |||
Age, median, years | 74 | 72 | 81 | 77 | ||||||
Age > 80 years | 29 | (27.4) | 15 | (19.2) | 11 | (57.9) | 3 | (33.3) | <0.005 | * |
Male sex | 74 | (69.8) | 53 | (67.9) | 15 | (78.9) | 6 | (66.7) | 0.68 | |
Comorbidities | 0.0 | |||||||||
Diabetes mellitus | 29 | (27.4) | 20 | (25.6) | 7 | (36.8) | 2 | (22.2) | 0.61 | |
Malignancy | 45 | (42.5) | 29 | (37.2) | 9 | (47.4) | 7 | (77.8) | <0.05 | * |
Liver cirrhosis | 11 | (10.4) | 9 | (11.5) | 2 | (10.5) | 0 | (0) | 0.87 | |
Collagen disease | 8 | (7.5) | 8 | (10.3) | 0 | (0) | 0 | (0) | 0.36 | |
Chronic kidney disease | 4 | (3.8) | 4 | (5.1) | 0 | (0) | 0 | (0) | 0.71 | |
Pulmonary disease | 4 | (3.8) | 4 | (5.1) | 0 | (0) | 0 | (0) | 0.71 | |
Mental disorder | 7 | (6.6) | 5 | (6.4) | 2 | (10.5) | 0 | (0) | 0.80 | |
Immunosuppressive drug | 14 | (13.2) | 12 | (15.4) | 2 | (10.5) | 0 | (0) | 0.64 | |
Neutropenia | 7 | (6.6) | 5 | (6.4) | 1 | (5.3) | 1 | (11.1) | 0.80 | |
Source of infection | ||||||||||
Pneumonia | 6 | (5.7) | 5 | (6.4) | 1 | (5.3) | 0 | (0) | 1.00 | |
Skin and soft tissue | 4 | (3.8) | 4 | (5.1) | 0 | (0) | 0 | (0) | 0.70 | |
Abdominal | 39 | (36.8) | 27 | (34.6) | 9 | (47.4) | 3 | (33.3) | 0.40 | |
Urinary tract | 31 | (29.2) | 26 | (33.3) | 2 | (10.5) | 3 | (33.3) | 0.14 | |
Liver abscess | 7 | (6.6) | 5 | (6.4) | 2 | (10.5) | 0 | (0) | 0.79 | |
Others | ||||||||||
Hospital-acquired infection | 56 | (52.8) | 41 | (52.6) | 10 | (52.6) | 5 | (55.6) | 1.00 | |
Appropriate antibiotic therapy within 24 h | 101 | (95.3) | 75 | (96.2) | 17 | (89.5) | 9 | (100) | 0.52 |
Differences in clinical characteristics of bacterial species
Differences in clinical characteristics between community-acquired and hospital-acquired infections
Characteristics of patients | Total = 106 | Hospital = 56 | Community = 50 | p-value | ||||
---|---|---|---|---|---|---|---|---|
n | % | N | % | n | % | |||
Age, median, years | 74 | 72 | 75.5 | |||||
Male sex | 74 | (69.8) | 43 | (76.8) | 31 | (62.0) | 0.14 | |
Age > 80 years | 29 | (27.4) | 12 | (21.4) | 17 | (34.0) | 0.19 | |
Comorbidities | ||||||||
Diabetes mellitus | 29 | (27.4) | 13 | (23.2) | 16 | (32.0) | 0.38 | |
Malignancy | 45 | (42.5) | 30 | (53.6) | 15 | (30.0) | < 0.05 | * |
Liver cirrhosis | 11 | (10.4) | 7 | (12.5) | 4 | (8.0) | 0.53 | |
Collagen disease | 8 | (7.5) | 3 | (5.4) | 5 | (10.0) | 0.47 | |
Chronic kidney disease | 4 | (3.8) | 1 | (1.8) | 3 | (6.0) | 0.34 | |
Pulmonary disease | 4 | (3.8) | 1 | (1.8) | 3 | (6.0) | 0.34 | |
Mental disorder | 7 | (6.6) | 4 | (7.1) | 3 | (6.0) | 1.00 | |
Immunosuppressive drug | 14 | (13.2) | 6 | (10.7) | 8 | (16.0) | 0.57 | |
Neutropenia | 7 | (6.6) | 5 | (8.9) | 2 | (4.0) | 0.44 | |
Source of infection | ||||||||
Pneumonia | 6 | (5.7) | 1 | (1.8) | 5 | (10.0) | 0.10 | |
Skin and soft-tissue | 4 | (3.8) | 2 | (3.6) | 2 | (4.0) | 1.00 | |
Abdominal | 39 | (36.8) | 18 | (32.1) | 21 | (42.0) | 0.32 | |
Urinary tract | 31 | (29.2) | 15 | (26.8) | 16 | (32.0) | 0.67 | |
Liver abscess | 7 | (6.6) | 3 | (5.4) | 4 | (8.0) | 0.70 | |
Other | ||||||||
Appropriate antibiotic therapy within 24 h | 101 | (95.3) | 52 | (92.9) | 49 | (98.0) | 0.37 | |
Bacterial characteristics | ||||||||
K. pneumoniae | 78 | (73.6) | 41 | (73.2) | 37 | (74.0) | 1.00 | |
K. variicola | 19 | (17.9) | 10 | (17.9) | 9 | (18.0) | 1.00 | |
K. quasipneumoniae | 9 | (8.5) | 5 | (8.9) | 4 | (8.0) | 1.00 | |
K1 serotype | 15 | (14.2) | 7 | (12.5) | 8 | (16.0) | 0.78 | |
K2 serotype | 13 | (12.3) | 6 | (10.7) | 7 | (14.0) | 0.77 | |
Hypermucoviscous phenotype | 23 | (21.7) | 9 | (16.1) | 14 | (28.0) | 0.16 | |
ESBL-producing | 3 | (2.8) | 3 | (3.4) | 0 | (0) | 0.38 |
Risk factor analysis for 30-day mortality
Characteristics of patients | Total = 100 | Fatal = 11 | Survivors = 89 | p-value | ||||
---|---|---|---|---|---|---|---|---|
n | % | N | % | n | % | |||
Age, median, years | 75.0 | 77.0 | 75.0 | |||||
Male sex | 70 | (70.0) | 6 | (54.5) | 64 | (71.9) | 0.30 | |
Age > 80 years | 27 | (27.0) | 4 | (36.4) | 23 | (25.8) | 0.48 | |
Comorbidities | ||||||||
Diabetes mellitus | 29 | (29.0) | 5 | (45.5) | 24 | (27.0) | 0.29 | |
Malignancy | 41 | (41.0) | 3 | (27.3) | 38 | (42.7) | 0.52 | |
Liver cirrhosis | 10 | (10.0) | 3 | (27.3) | 7 | (7.9) | 0.08 | |
Collagen disease | 8 | (8.0) | 1 | (9.1) | 7 | (7.9) | 1.00 | |
Chronic kidney disease | 3 | (3.0) | 1 | (9.1) | 2 | (2.2) | 0.30 | |
Pulmonary disease | 4 | (4.0) | 1 | (9.1) | 3 | (3.4) | 0.38 | |
Mental disorder | 7 | (7.0) | 3 | (27.3) | 4 | (4.5) | < 0.05 | * |
Immunosuppressive drug | 12 | (12.0) | 1 | (9.1) | 11 | (12.4) | 1.00 | |
Neutropenia | 7 | (7.0) | 0 | (0) | 7 | (7.9) | 1.00 | |
Source of infection | ||||||||
Pneumonia | 6 | (6.0) | 0 | (0) | 6 | (6.7) | 1.00 | |
Skin and soft-tissue | 4 | (4.0) | 2 | (18.2) | 2 | (2.2) | < 0.05 | * |
Abdominal | 37 | (37.0) | 3 | (27.3) | 34 | (38.2) | 0.74 | |
Urinary tract | 27 | (27.0) | 2 | (18.2) | 25 | (28.1) | 0.72 | |
Other | ||||||||
Hospital-acquired infection | 52 | (52.0) | 6 | (54.5) | 46 | (51.7) | 1.00 | |
Appropriate antibiotic therapy within 24 h | 96 | (96.0) | 11 | (100.0) | 85 | (95.5) | 1.00 | |
Bacterial characteristics | ||||||||
K. pneumoniae | 73 | (73.0) | 8 | (72.7) | 65 | (73.0) | 1.00 | |
K. variicola | 19 | (19.0) | 2 | (18.2) | 17 | (19.1) | 1.00 | |
K. quasipneumoniae | 8 | (8.0) | 1 | (9.1) | 7 | (7.9) | 1.00 | |
K1 serotype | 14 | (14.0) | 3 | (27.3) | 11 | (12.4) | 0.18 | |
K2 serotype | 13 | (13.0) | 0 | (0) | 13 | (14.6) | 0.35 | |
Hypermucoviscous phenotype | 23 | (23.0) | 3 | (27.3) | 20 | (22.5) | 0.71 |
Odds ratio | 95% CI | p-value | ||
---|---|---|---|---|
Liver cirrhosis | 6.43 | 1.0–37.0 | < 0.05 | * |
Mental disorder | 15.00 | 2.33–97.1 | < 0.005 | * |
Skin and soft-tissue infection | 13.16 | 1.19–145.0 | < 0.05 | * |