Study of Antibiotic Resistance of Escherichia coli strains isolated from livestock in the province of Guelma
| dc.contributor.author | KIRAT, Hassina | |
| dc.contributor.author | CHEKROUD, Zohra | |
| dc.date.accessioned | 2026-03-15T08:02:29Z | |
| dc.date.available | 2026-03-15T08:02:29Z | |
| dc.date.issued | 2025 | |
| dc.description.abstract | Antibiotic resistance is a global health concern, threatening both human and veterinary medicine, with livestock acting as a major reservoir for the dissemination and persistence of resistant bacteria particularly third-generation cephalosporin-resistant (3GC-R) and colistinresistant (CL-R) Enterobacterales. This thesis investigated the dissemination of 3GC-R and CL-R Escherichia coli among poultry, bovine and ovine farms in Guelma province, northeastern Algeria. A longitudinal surveillance was further performed in order to assess the persistence of CL-R isolates in poultry farms over production cycles. A total of 919 animal and environmental samples were collected from 38 farms in Guelma. Samples were screened for 3GC-R and CL-R E. coli in selective media. The screened isolates were identified then subjected to susceptibility tests, including the disc diffusion test, the determination of colistin minimum inhibitory concentration, and the phenotypic detection of extended spectrum β- lactamase and carbapenemase enzymes. Afterwards, standard PCR was performed to the 3GCR isolates to investigate the presence of antibiotic resistance genes and integrons, whereas the CL-R were submitted to whole genome sequencing. Overall, 112 isolates were collected from 21 farms, including 58 3GC-R and 54 CL-R E. coli strains. The 3GC-R isolates were detected in poultry, bovine and ovine farms, while CL-R strains were only found in poultry farms. Phenotypic tests revealed that the majority of the isolates were multidrug resistant and displayed high resistance rates against β-lactams, tetracyclines, fluoroquinolones and sulfonamides. The molecular analysis identified critical resistance genes including mcr-1, blaCTX-M, blaNDM, blaOXA-181, blaCMY and blaDHA. The MLST analysis identified 28 different Sequence Types (STs), mainly ST162 and ST93, and provided evidence on the clonal dissemination and the potential persistence of several STs within the farms. These findings underscore the major role of livestock as a reservoir for resistant bacteria and their genes and emphasize the urgent need for targeted strategies within a “One Health” framework to mitigate the spread of these isolates and preserve the effectiveness of critical antibiotic agents | |
| dc.identifier.uri | http://dspace.univ-skikda.dz:4000/handle/123456789/5909 | |
| dc.language.iso | en | |
| dc.publisher | University of 20 August 1955 Skikda | |
| dc.subject | Antibiotic Resistance | |
| dc.subject | Escherichia coli strains | |
| dc.title | Study of Antibiotic Resistance of Escherichia coli strains isolated from livestock in the province of Guelma | |
| dc.type | Thesis |