title: Genetic analysis of antimicrobial resistance in Escherichia coli isolated from diarrheic neonatal calves.
abstract: This study was carried out to screen and analyze the genetic basis of antimicrobial resistance in Escherichia coli strains isolated from neonatal calf diarrhea in Egypt. A total of 182 isolates of E. coli recovered from 91 diarrheic neonatal calves were analyzed for antimicrobial susceptibilities, the presence of class 1 and class 2 integrons and antimicrobial resistance genes. Nineteen isolates (10.4%) showed multidrug resistance phenotypes and harbored at least three antimicrobial resistance genes. PCR screening detected class 1 integrons in 19 isolates (10.4%) and class 2 integrons in 2 isolates (1.1%). The identified antimicrobial resistance genes within class 1 integrons were dihydrofolate reductase types: dfrA1, dfrA12, dfrA15 and dfrA17, which confer resistance to trimethoprim; aminoglycoside adenyltransferase types: aadA1, aadA2, aadA5, aadA7 and aadA23, which confer resistance to streptomycin and spectinomycin; and aminoglycoside acetyltransferase gene, aac(3)-Id, which confers resistance to gentamicin and sisomicin. Furthermore, many beta-lactamases encoding genes, plasmid-mediated quinolone resistance genes and florfenicol resistance gene were identified in this study. To the best of our knowledge, this is the first report for molecular characterization of antimicrobial resistance in E. coli isolated from diarrheic neonatal calves in Africa.
authors.affiliation: Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafr El-Sheikh University, Kafr El-Sheikh 33516, Egypt. ashrafa5@yahoo.com
authors.forename: Ashraf M
authors.initials: AM
authors.lastname: Ahmed
authors.forename: Emad E A
authors.initials: EE
authors.lastname: Younis
authors.forename: Salama A
authors.initials: SA
authors.lastname: Osman
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Ishida
authors.forename: Sabry A
authors.initials: SA
authors.lastname: El-Khodery
authors.forename: Tadashi
authors.initials: T
authors.lastname: Shimamoto
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D024901:Drug Resistance, Multiple, Bacterial; D004534:Egypt; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D032023:Integrons; D016133:Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial