Table 2.
Antibiotic resistance patterns observed among E. coli isolates from broiler breeder/broiler chicks reported worldwide.
| Location | E. coli Isolated from | Antibiotic Resistance Genes Identified | Resistant Antibiotics Identified by Susceptibility Testing | Multi-Drug Resistance Percentage/% | Source |
|---|---|---|---|---|---|
| Algeria | Broiler breeders | blaCTX-M-1, blaSHV-12, blaTEM-1 | NAL, UB, CIP, LVX, AMP, AMC, XNL, TET, TPM, SXT, NEO, CHL | 89.18 | [17] |
| United States | Broiler breeders | blaTEM, blaCTX-M-1, aph3IA, aadA, tetA, sul1 | TET, STM, KAN, GEN, SXT | 10.7 | [20] |
| Italy | Broiler breeder | - | AMX, ENR, TET, SXT | 100 | [45] |
| Belgium | Broiler breeder (roosters) | - | CTX, XNL, AMX, CFM, TMP, NAL, CZM | N/A | [56] |
| Thailand | Broiler breeder | - | AMX, CEF, CHL, CIP, ENR, FLO, GEN, NAL, SXT, TET | 60.71 | [60] |
| Australia | Broiler breeder | - | AMX, CEF, CHL, CIP, ENR, FLO, GEN, NAL, SXT, TET | 10.71 | [60] |
| Korea | Broiler breeder | blaTEM-1, blaTEM-135, blaTEM-176, blaCTX-M-1, blaCTX-M-55, qnrS, qnrB, qnrA, cmlA, catA1, aac(6’)-Ib, aac(3)-II, tetA, tetB, tetC | TET, NAL, AMP, CEP, SXT, CHL, CZN, GEN, LVX | 81.6 | [61] |
| Egypt | Broiler chicks—first week | - | AMP, AUG, CTX, CST, TET, DOX, GEN, NEO, OFX, ENR, CIP, FLO | N/A | [75] |
| Algeria | Broiler breeder | blaCTX-M-1, qnrS1 * | AMP, TET, PRL, CZN, CXM, NAL | 89 | [79] |
| Denmark | Broiler breeder/Broiler | - | AMP, NAL, CIP | N/A | [80] |
| Algeria | Broiler breeder | - | TET, NAL, AUG, AMP, SXT, ENR, NIT, NEO, CHL, GEN | 100 | [81] |
| Switzerland | Broiler breeder | GyrA, ParC * | ENR | N/A | [82] |
| Sweden | Broiler breeder | blaCMY-2 | - | N/A | [83] |
| Indonesia | Broiler breeder/Layer breeder | tetA, tetB | AMP, NAL, TET, OTC, GEN, CHL | 69 | [84] |
| France | Broiler chicks—first week | - | TET, AMX, SXT, NAL, GEN | N/A | [85] |
TET, tetracycline; NAL, nalidixic acid; AUG, amoxicillin–clavulanic acid; AMP, ampicillin; SXT, sulfamethoxazole and trimethoprim; ENR, enrofloxacin; NIT, nitrofurantoin; NEO, neomycin; CHL, chloramphenicol; GEN, gentamycin; CTX, cefotaxime; CST, colistin; DOX, doxycycline; OFX, ofloxacin; CIP, ciprofloxacin; FLO, florfenicol; CEF, cefalexin; PRL, piperacillin; CZN, cefazolin; CXM, cefuroxime; CEP, cephalothin; OTC, oxytetracycline; UB, flumequine; LVX, levofloxacin; AMC, amoxicillin; XNL, ceftiofur; TPM, trimethoprim; CZM, ceftazidime; STM, streptomycin; KAN, kanamycin. N/A, data not available. * Vertically transmitted.