title: Molecular characterization of multidrug-resistant avian pathogenic Escherichia coli isolated from septicemic broilers.
abstract: Avian pathogenic Escherichia coli (APEC) causes extensive mortality in poultry flocks, leading to extensive economic losses. To date, little information is available on the molecular basis of antimicrobial resistance in APEC in Africa. Therefore, the objective of this study was to characterize the virulence and antimicrobial resistance of multidrug-resistant APEC isolated from septicemic broilers in Egypt at the molecular level. Among 91 non-repetitive E. coli isolates, 73 (80.2%) carried three or more of the APEC virulence genes iroN, ompT, iss, iutA, and hlyF. All 73 APEC isolates showed multidrug resistance phenotypes, particularly against ampicillin, tetracycline, spectinomycin, streptomycin, kanamycin, and trimethoprim/sulfamethoxazole. PCR and DNA sequencing identified class 1 and class 2 integrons in 34 (46.6%) and seven (9.6%) isolates, respectively. The β-lactamase-encoding genes, bla(TEM-1), bla(TEM-104), bla(CMY-2), bla(OXA-30), bla(CTX-M-15), and bla(SHV-2); tetracycline resistance genes, tet(A), tet(B), tet(C), tet(D), and tet(E); the plasmid-mediated quinolone resistance genes, qnrA1, qnrB2, qnrS1, and aac(6')-Ib-cr, and florfenicol resistance gene, floR, were also identified in 69 (94.5%), 67 (91.8%), 47 (64.4%), and 13 (17.8%) isolates, respectively. To the best of our knowledge, this is the first report of molecular characterization of antimicrobial resistance in APEC strains from Africa.
authors.affiliation: Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt.
authors.forename: Ashraf M
authors.initials: AM
authors.lastname: Ahmed
authors.forename: Toshi
authors.initials: T
authors.lastname: Shimamoto
authors.forename: Tadashi
authors.initials: T
authors.lastname: Shimamoto
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004534:Egypt; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D005838:Genotype; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000382:microbiology*; D018805:Sepsis / Q000382:microbiology / Q000662:veterinary*; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D037521:Virulence Factors
keywords: APEC; Integrons; Septicemic broilers; Virulence; β-Lactamase