Table 3.
Diversity of cassette arrays detected among class 1 and class 2 integrons
| |
Distribution [number, (%)] of cassette arrays of cassette arrays in different types of integrons |
||||
|---|---|---|---|---|---|
| Resistance to selected antimicrobials in randomly selected strains carrying a given integron array | Classes of antimicrobials to which the host strain was resistanta | Prevalence among isolates with integrons (n = 464) | Integrons containing 3’-CS | Integrons lacking 3’-CS | |
|
Class 1 integrons arrays |
|
|
|
|
|
|
dfrA1 |
TRIM, SUL, TET, |
2 to 4 |
60 (13) |
53 (88) |
7 (12) |
|
dfrA1/aadA1 |
TRIM, STP, AMP, C, CTX, CAZ, CIP, NA |
5 to 8 |
51 (11) |
42 (82) |
9 (18) |
|
dfrA17/aadA5 |
TRIM, STP, C, AMP, C, CTX, CAZ, CIP, NA, FOX, AMC |
5 to 8 |
42 (9) |
34 (81) |
8 (19) |
|
dfrA7 |
TRIM, SMX, TET |
2 to 8 |
42 (9) |
35 (83) |
7 (17) |
|
aadA1 |
STP, C, TET, SUL |
2 to 6 |
23 (5) |
19 (83) |
4 (17) |
|
dfrA12/aadB |
TRIM, STRP, CN, K, TOB, AMP, C, CTX, AMC |
4 to 8 |
23 (5) |
19 (83) |
4 (17) |
|
dfrA16/aadA2 |
TRIM, STP, K, TOB, AMP, C, CTX, AMC |
6 to 8 |
23 (5) |
22 (96) |
1 (4) |
|
aadA2/dfrA12 |
STP, TRIM, TET, C, SUL, AMP, CTX, AMC, |
3 to 6 |
28 (6) |
26 (93) |
2 (7) |
|
dfrA12/aadA2 |
TRIM, STP, TET, C, SUL |
3 to 8 |
23 (5) |
22 (96) |
1 (4) |
|
aadA5 |
STP, AMP, SUL, TET |
7 to 8 |
23 (5) |
22 (96) |
1(4) |
|
blaoxa-1/aadA1 |
STP, AMP, C, TET, CTX, CAZ, CIP, NA, FOX, AMC |
8 |
23 (5) |
22 (94) |
1 (4) |
|
blaoxa-1/aadA2 |
STP, AMP, C, TET, CTX, CAZ, CIP, NA, FOX, AMC |
7 to 8 |
9 (2) |
8 (88) |
1 (12) |
|
dfrA12/orfF/aadA2 |
TRIM, STP, C, TET, CTX, NA, AMC |
6 to 8 |
9 (2) |
8 (88) |
1 (12) |
|
aac(6')Ib/catB1/dfrA1 |
CN, TOB, C, TRIM, K, AMP, C, TET, CTX, CAZ, CIP, NA, |
5 to 8 |
9 (2) |
7 (78) |
2 (22) |
|
aadA1/dfrA1 |
STP, TRIM, AMP, C, TET, CTX, NA, AMC |
3 to 8 |
9 (2) |
9 (100) |
0 |
|
aac(6')Ib/blaoxa-1/catB3/arr2 |
CN,TOB, K, C, RIF, AMP, C, TET, CTX, CAZ, CIP, NA, FOX, AMC |
8 |
9 (2) |
2 (22) |
7 (78) |
|
aadA2/orfF/dfrA12 |
STP, AMP, TRIM, SUL, TET |
7 to 8 |
5 (1) |
4 (80) |
1 (20) |
|
cmlA1 |
C,, TET, CTX, NA, AMP |
3 to 8 |
3 (<1) |
3 (100) |
0 |
|
orf5/dfrB/orfA |
TRIM, CN,TOB, C, AMP, C, TET, CTX, CAZ, CIP, NA, AMC |
6 |
3 (<1) |
0 |
3 (100) |
|
dfrA12/aadA1/blaoxa1 |
TRIM, STP, CN,TOB, AMP, C, TET, CTX, CAZ, CIP, NA, |
8 |
5 (1) |
0 |
5 (100) |
|
aac(6')-lb-cr |
CN, K, TOB, C, AMP, C, TET, CTX, CAZ, CIP, NA, AMC |
8 |
42 (9) |
15 (36) |
27 (64) |
|
Class 2 Integron arrays |
|
|
|
|
|
| drfA1/sat2/aadA1 | TRIM, STRP, CN, K, TOB, AMP, C, CTX, AMC | 6 to 8 | 3 (<1) | NA | NA |
The integron cassette arrays are indicated in the order they appear within class 1 and 2 integron variable cassette region (in the 5’-3’ orientation).
The resistance phenotype associated with a given array is indicated in bold.
a: Different antimicrobials tested in this study were conveniently grouped into 8 groups:- β-lactams and β-lactamase inhibitors, aminoglycosides, (fluoro)quinolones, nitrofurantoin, chloramphenicol, sulphonamides, trimethoprim, and tetracyclines.
b: These integrons carried a sul3 gene at the 3’-end or lacked this gene or 3’-CS comprising the qacEΔ1-sul1 genes.