Table 4.
Mechanisms of resistance of enterotoxigenic Escherichia coli (ETEC) isolates from Peruvian children
| Antimicrobial | Mechanism of resistance | No. of isolates with indicated mechanism of resistance/total no. of resistant isolates (%) |
||||
|---|---|---|---|---|---|---|
| Cohort 1 | Cohort 2 | Diarrhoea | Control | All strains | ||
| Ampicillina | blaTEM-like | 31/59 (53)b | 60/72 (83)b | 53/78 (68) | 38/53 (72) | 91/131 (69) |
| blaOXA1-like | 3/59 (5) | 8/72 (11) | 7/78 (9) | 4/53 (8) | 11/131 (8) | |
| blaCARB-like | 0/59 (0) | 2/72 (3) | 1/78 (1) | 1/53 (2) | 2/131 (2) | |
| Non determined | 25/59 (42)c | 6/72 (8)c | 20/78 (26) | 11/53 (21) | 31/131 (24) | |
| Chloramphenicol | cat | 3/5 (60) | 7/9 (78) | 6/7 (86) | 4/7 (57) | 10/14 (71) |
| floR | 1/5 (20) | 1/9 (11) | 1/7 (14) | 1/7 (14) | 2/14 (14) | |
| Non determined | 1/5 (20) | 1/9 (11) | 0/7 (0) | 2/7 (29) | 2/14 (14) | |
| Tetracyclined | tet(A) | 15/34 (44) | 22/42 (52) | 21/42 (50) | 16/34 (47) | 37/76 (49) |
| tetB | 8/34 (24)e | 22/42 (52)e | 17/42 (40) | 13/34 (38) | 30/76 (39) | |
| Non determined | 11/34 (32)c | 0/52 (0)c | 5/42 (12) | 6/34 (18) | 11/76 (14) | |
| Sulfamethoxazolef | sul2 | 30/51 (59)g | 43/56 (77)g | 44/64 (69) | 29/43 (67) | 73/107 (68) |
| sul1 | 13/51 (25) | 13/56 (23) | 14/64 (22) | 12/43 (28) | 26/107 (24) | |
| sul3 | 1/51 (2) | 0/56 (0) | 1/64 (2) | 0/43 (0) | 1/107 (1) | |
| Non determined | 9/51 (18) | 5/56 (9) | 7/64 (11) | 7/43 (16) | 14/107 (13) | |
| Trimethoprimh | dfrA1 | 4/51 (8) | 7/56 (13) | 8/64 (13) | 3/43 (7) | 11/107 (10) |
| dfrA15 | 8/51 (16) | 6/56 (11) | 8/64 (13) | 6/43 (14) | 14/107 (13) | |
| dfrA7 | 2/51 (4) | 5/56 (9) | 4/64 (6) | 3/43 (7) | 7/107 (7) | |
| dfrA5 | 0/51 (0) | 2/56 (4) | 2/64 (3) | 2/43 (5) | 4/107 (4) | |
| dfrA14 | 0/51 (0) | 3/56 (5) | 2/64 (3) | 1/43 (2) | 3/107 (3) | |
| dfrA17 | 0/51 (0) | 2/56 (4) | 0/64 (0) | 2/43 (5) | 2/107 (2) | |
| Non determined | 38/51 (75)c | 31/56 (55)c | 41/64 (64) | 27/43 (63) | 68/107 (64) | |
| Azithromycin | mph(A) | 1/42 (2) | 3/31 (10) | 2/29 (7) | 2/44 (5) | 4/73 (5) |
| Non determined | 41/42 (98) | 28/31 (90) | 27/29 (93) | 42/44 (95) | 69/73 (95) | |
a Two isolates from Cohort 2 presented blaTEM-like and blaOXA1-like concomitantly, also both blaCARB-like were found concomitantly with blaTEM-like.
b p<0.001.
c p=0.0001.
d Two isolates from Cohort 2 possessed both the tet(A) and tet(B) genes.
e p<0.05.
f Seven isolates (2 from Cohort 1, and 5 from Cohort 2) presented the sul1 and sul2 genes concomitantly.
g p=0.061.
h the dfrA7 gene was found concomitantly with dfrA1 gene (1 case) and dfrA15 gene (1 case).