title: Identification of a novel metallo-β-lactamase VIM-28 located within unusual arrangement of class 1 integron structure in Pseudomonas aeruginosa isolates from Egypt.
abstract: Two multidrug-resistant Pseudomonas aeruginosa strains harboring blaVIM were isolated from a hospital in Egypt and were indistinguishable by pulsed-field gel electrophoresis. Sequence analysis revealed a novel VIM β-lactamase, VIM-28. Additional sequencing of integron revealed that the blaVIM-28 gene cassette had an unusual arrangement of class 1 integron structure, located directly downstream of the integrase gene "intI1" and oriented divergently from it. The new organization of integron also comprised the aacA7 and smr-2 gene cassettes in that order. A complete ISPa21 containing a tnpA gene flanked by two 13-bp inverted repeats was located directly upstream of the 3'-CS conserved region of the integron containing qacEΔ1/sul1 genes. The blaVIM-28-containing class 1 integron was found to have a chromosomal origin in both strains. In conclusion, the presence of a new variant of blaVIM, blaVIM-28, on a new organization of class 1 integron having ISPa21 increases the possibility of dissemination of resistance genes within the integron in P. aeruginosa among hospitalized patients in Egypt.
authors.affiliation: Faculty of Pharmacy, Helwan University.
authors.forename: Taghrid S
authors.initials: TS
authors.lastname: El-Mahdy
mesh_terms: D024901:Drug Resistance, Multiple, Bacterial; D004534:Egypt; D016521:Electrophoresis, Gel, Pulsed-Field; D023061:Gene Order; D006801:Humans; D032023:Integrons; D008969:Molecular Sequence Data; D058889:Molecular Typing; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001618:beta-Lactamases