Phenotypic and Genotypic Characterization of Extended Spectrum β-Lactamase-producing (ESBL) Salmonella species isolated from poultry and human in Egypt

Abstract

This study was carried out in Alexandria Province for a period of 12 months from July 2022 to June 2023 for isolation and molecular identification of extended - spectrum β-Lactamase producing (ESBL) Salmonella isolated from human and poultry. A total of 125 cloacal swabs were collected by sterile swabs from 25 poultry farms (5 samples / farm) located in Behera province including broilers, layers, breeder chicken and ducks. In addition, 50 human stool samples have been obtained from diarrheal individuals. It was recorded that the overall rate of isolation of Salmonella from poultry after molecular detection of invA gene in biochemically identified Salmonella isolates was 10.4% and it was 8, 6, 20 and 25 % in flocks of broilers, layers, breeders and ducks, respectively. Also, serological identification of 13 Salmonella strains revealed the presence of S. Kentucky (9 isolates), S. Anatum (2 isolates) and S. Bloomsbury (2 isolates). Distribution of antibiogram pattern of Salmonella isolates obtained from poultry samples using β -lactam antibiotics revealed that the highest resistance rate was recorded in Ceftazimide (100%), followed by Cephalexin and Cefadroxil (92.31% for each) then Ceftriaxone and Imipeneme (84.62% for each) then Piperacillin and Cefotaxime (76.92 % for each) while the least resistance rate was recorded in using Amoxicillin + Clavulanate (69.23%) and ESBLs resistant genes were identified in Salmonella strains where CTX gene was detected in 9 isolates, AmpC gene was detected in 10 isolates and IMP gene was detected in 11 isolates. On the other hand, it was recorded that the overall rate of isolation of Salmonella from diarrheic human stools was 6% (3 isolates) after detection of invA gene and serological identification revealed the presence of S. Kentucky (2 isolates) and S. Bloomsbury (1 isolate). Distribution of antibiogram pattern of Salmonella isolates (n=3) obtained from human using β -lactam antibiotics revealed that the highest resistance rate was recorded in Ceftazimide and Piperacillin (100%), followed by Ticarcillin, Amoxicillin + Clavulanate, Piperacillin/Tazobactam, Ticarcillin/clavulinic acid and Cefotaxime (66.67%) while the least resistance rate was recorded in using Cefepime, Aztreonam, Imipenem, Meropenem and Cefoxitin and ESBLs resistant genes were identified in Salmonella strains where CTX, AmpC and IMP gene was detected in 2 isolates while they could not be detected in the remained isolate.