Background
Methods
Bacterial isolates and screening for ST131
Susceptibility testing
Molecular characterization of ST131
Detection of blaCTX-M gene and fluoroquinolone resistance genes
Pulsed-field gel electrophoresis analysis (PFGE) and dendrogram construction
Statistical analysis
Results
Prevalence of ST131 and its subclones
Characteristics | ST131 subclones, number of isolates (%) |
P
a
| |||||
---|---|---|---|---|---|---|---|
Total | H30Rx | H30 non-Rx | H41 | H41 vs H30 non -Rx | H41 vs H30-Rx | H30 Rx vs H30 non-Rx | |
N = 83 (%) |
n = 13 |
n = 40 |
n = 30 | ||||
PCR O type | |||||||
O25b | 55(66.3%) | 12(92.3%) | 40(100%) | 3(10.0%) | < 0.001 | < 0.001 | |
O16 | 28(33.7%) | 1(7.7%) | 0 | 27(90.0%) | |||
Antimicrobial resistance | |||||||
ATM | 30(36.1%) | 12(92.3%) | 11(27.5%) | 7(23.3%) | < 0.001 | < 0.001 | |
CAZ | 22(26.5%) | 10(76.9%) | 5(12.5%) | 7(23.3%) | 0.002 | < 0.001 | |
CTX | 59(71.1%) | 12(92.3%) | 28(70%) | 19(63.3%) | |||
FEP | 26(31.3%) | 11(84.6%) | 10(25.0%) | 5(16.7%) | < 0.001 | < 0.001 | |
TZP | 1(1.2%) | 0 | 0 | 1(3.3%) | |||
CIP | 58(69.9%) | 13(100%) | 40(100%) | 5(16.7%) | < 0.001 | < 0.001 | |
LEV | 58(69.9%) | 13(100%) | 40(100%) | 5(16.7%) | < 0.001 | < 0.001 | |
AMK | 7(8.4%) | 3(23.1%) | 1(2.50%) | 3(10.0%) | 0.042 | ||
SXT | 56(67.5%) | 10(76.9%) | 24(60.0%) | 22(73.3%) | |||
bla
CTX-M type | |||||||
CTX-M-14 | 37(44.6%) | 0 | 22(55.0%) | 15(50.0%) | 0.001 | < 0.001 | |
CTX-M-15 | 22(26.5%) | 12(92.3%) | 7(17.5%) | 3(10.0%) | < 0.001 | < 0.001 | |
CTX-M-14,15 | 2(2.40%) | 0 | 2(5.0%) | 0 | |||
CTX-M-123 | 1(1.2%) | 0 | 0 | 1(3.3%) | |||
No ESBLb
| 21(25.3%) | 1(7.7%) | 11(27.5%) | 9(30.0%) | |||
FQR genesc
| |||||||
5 gyrA, parC and parE mutationsd
| 51(61.4%) | 13(100%) | 35(87.5%) | 3(10.0%) | < 0.001 | < 0.001 | |
aac(6′)-Ib-cr
| 14(16.9%) | 10(76.9%) | 0 | 4(13.3%) | 0.012 | < 0.001 | < 0.001 |
qnr
| 4(4.8%) | 0 | 2(5.0%) | 2(6.70%) | |||
Adhesins | |||||||
papAH
| 22 (26.5%) | 12(92.3%) | 6 (15.0%) | 4(13.3%) | < 0.001 | < 0.001 | |
papC
| 23 (27.7%) | 13(100%) | 6 (15.0%) | 4(13.3%) | < 0.001 | < 0.001 | |
papEF
| 22 (26.5%) | 12(92.3%) | 7(17.5%) | 3(10.0%) | < 0.001 | < 0.001 | |
papG allele I
| 0 | 0 | 0 | 0 | |||
papG allele II
| 21 (25.3%) | 12(92.3%) | 6 (15.0%) | 3(10.0%) | < 0.001 | < 0.001 | |
sfa/focDE
| 1 (1.2%) | 0 | 1(2.50%) | 0 | |||
focG
| 0 | 0 | 0 | 0 | |||
afa/draBC
| 7 (8.4%) | 0 | 2(5.0%) | 5(16.7%) | |||
fimH
| 82 (98.8%) | 13(100%) | 39(97.5%) | 30(100%) | |||
gafD
| 0 | 0 | 0 | 0 | |||
sfaS
| 7 (8.4%) | 3(23.1%) | 3(7.5%) | 1(3.3%) | |||
Toxins | |||||||
hlyA
| 14 (16.9%) | 11(84.6%) | 1(2.50%) | 2(6.70%) | < 0.001 | < 0.001 | |
cnf1
| 10 (12.0%) | 8(61.5%) | 1(2.50%) | 1(3.3%) | 0.002 | < 0.001 | |
cdtB
| 0 | 0 | 0 | 0 | |||
cvaC
| 3 (3.6%) | 0 | 0 | 3(10.0%) | 0.042 | ||
Siderophores | |||||||
fyuA
| 81 (97.6%) | 13(100%) | 38(95.0%) | 30(100%) | |||
iutA
| 77 (92.8%) | 13(100%) | 38(95.0%) | 26(86.7%) | |||
Capsules | |||||||
kpsMT II
| 62 (74.7%) | 9(69.2%) | 33(82.5%) | 20(66.7%) | |||
kpsMT III
| 0 | 0 | 0 | 0 | |||
kpsMT K1
| 10 (12.0%) | 2(15.4%) | 5(12.5%) | 3(10.0%) | |||
kpsMT K5
| 47 (56.6%) | 11(84.6%) | 29(72.5%) | 7(23.3%) | < 0.001 | 0.001 | |
Miscellaneous | |||||||
nfaE
| 0 | 0 | 0 | 0 | |||
rfc
| 0 | 0 | 0 | 0 | |||
malX
| 76 (91.6%) | 13(100%) | 37(92.5%) | 26(86.7%) | |||
traT
| 73 (88.0%) | 13(100%) | 32(80.0%.) | 28(93.3%) | |||
Virulence scorese
| 7 | 9 | 7 | 6 | 0.001 | 0.001 |
Characteristics | Clonal groups, number of isolates (%) |
P
a
| ||
---|---|---|---|---|
All isolates (n = 83) | O25b (n = 55) | O16 (n = 28) | O25b vs O16 | |
Source | ||||
Urine | 55 (66.3%) | 36 (65.5%) | 19 (67.9%) | |
Blood | 12 (14.5%) | 10 (18.2%) | 2 (7.1%) | |
Other | 16 (19.3%) | 9 (16.4%) | 7 (25.0%) | |
Antimicrobial resistance | ||||
ATM | 30 (36.1%) | 24 (43.6%) | 6 (21.4%) | |
CAZ | 22 (26.5%) | 16 (29.1%) | 6 (21.4%) | |
CTX | 59 (71.1%) | 41 (74.5%) | 18 (64.3%) | |
FEP | 26 (31.3%) | 22 (40.0%) | 4 (14.3%) | 0.024 |
TZP | 1 (1.2%) | 0 | 1 (3.6%) | |
CIP | 58 (69.9%) | 49 (89.1%) | 9 (32.1%) | < 0.001 |
LEV | 58 (69.9%) | 49 (89.1%) | 9 (32.1%) | < 0.001 |
AMK | 7 (8.4%) | 4 (7.3%) | 3 (10.7%) | |
SXT | 56 (67.5%) | 36 (65.5%) | 20 (71.4%) | |
Adhesins | ||||
papAH
| 22 (26.5%) | 19 (34.5%) | 3 (10.7%) | 0.034 |
papC
| 23 (27.7%) | 21 (38.2%) | 2 (7.1%) | 0.004 |
papEF
| 22 (26.5%) | 19 (34.5%) | 3 (10.7%) | 0.034 |
papG allele I
| 0 | 0 | 0 | |
papG allele II
| 21 (25.3%) | 18 (32.7%) | 3 (10.7%) | 0.034 |
sfa/focDE
| 1 (1.2%) | 1 (1.8%) | 0 | |
focG
| 0 | 0 | 0 | |
afa/draBC
| 7 (8.4%) | 2 (3.6%) | 5 (17.9%) | 0.040 |
fimH
| 82 (98.8%) | 54 (98.2%) | 28 (100%) | |
gafD
| 0 | 0 | 0 | |
sfaS
| 7 (8.4%) | 6 (10.9%) | 1 (3.6%) | |
Toxins | ||||
hlyA
| 14 (16.9%) | 11 (20.0%) | 3 (10.7%) | |
cnf1
| 10 (12.0%) | 8 (14.5%) | 2 (7.1%) | |
cdtB
| 0 | 0 | 0 | |
cvaC
| 3 (3.6%) | 1 (1.8%) | 2 (7.1%) | |
Siderophores | ||||
fyuA
| 81 (97.6%) | 53 (96.4%) | 28 (100%) | |
iutA
| 77 (92.8%) | 52 (94.5%) | 25 (89.3%) | |
Capsules | ||||
kpsMTII
| 62 (74.7%) | 43 (78.2%) | 19 (67.9%) | |
kpsMTIII
| 0 | 0 | 0 | |
kpsMT K1
| 10 (12.0%) | 8 (14.5%) | 2 (7.1%) | |
kpsMT K5
| 47 (56.6%) | 40 (72.7%) | 7 (25.0%) | < 0.001 |
Miscellaneous | ||||
nfaE
| 0 | 0 | 0 | |
rfc
| 0 | 0 | 0 | |
malX
| 76 (91.6%) | 51 (92.7%) | 25 (89.3%) | |
traT
| 73 (88.0%) | 46 (83.6%) | 27 (96.4%) | |
Virulence scoresb
| 7 (3 to 11) | 7 (3 to 11) | 6 (4 to 10) |
Antimicrobial susceptibility
CTX-M ESBL and fluoroquinolone resistance mechanisms
CIPa
|
fimH type (n) | O type (n) | N | gyrA | parC | parE | aac(6′)-Ib-cr | qnr (n) |
---|---|---|---|---|---|---|---|---|
R | H30 | O25b | 48 | S83 L, D87N | S80I, E84V | I529L | 9 |
qnrS1(1) |
R | H41 | O16 | 3 | S83 L, D87N | S80I, E84V | I529L | 1 |
qnrB1(1) |
R | H30 | O25b | 1 | S83 L, D87N | S80I | P415L | – | – |
R | H41 | O16 | 1 | S83 L, D87N | S80I | I529L | – | – |
R | H41 | O16 | 1 | S83 L, D87N | S80I | S458A | 1 | – |
R | H41 | O16 | 3 | S83 L, D87N | S80I | L445H | 1 | – |
R | H41 | O25b | 1 | S83 L, D87N | S80I | L445H | – | – |
I | H41 | O25b | 1 | NDb
| ND | ND | 1 |
qnrB1(1) |
S | H41 | O16 | 19 | ND | ND | ND | 1 | – |
S | H41 | O25b | 2 | ND | ND | ND | – |
qnrS1(1)c
|
S | H30 | O25b | 3 | ND | ND | ND | – | – |