title: [Genetic environments of bla(CTX-M) genes located on conjugative plasmids of Enterobacteriaceae nosocomial isolates collected in Russia within 2003-2007].
abstract: The study showed that bla(CTX-M) genes were present in the genomes of 71% of cephalosporin resistant Enterobacteriaceae nosocomial isolates (n=833) collected in Russian hospitals within 2003-2007, including 91% of E.coli, 90% of Klebsiella spp., 38% of Enterobacter spp., 31% of Citrobacter spp. (n=9), and 36% of the other Enterobacteriaceae species. The genes belonging to the following subtypes (clusters) were identified: bla(CTX-M-1) (529 bla(CTX-M-15) genes; 25 bla(CTX-M-3) genes; 1 bla(CTX-M-22) gene, 1 bla(CTX-M-23) gene, and 1 bla(CTX-M-34) gene); bla(CTX-M-2) (1 bla(CTX-M-2) gene, and 4 bla(CTX-M-5) genes), and bla(CTX-M-9) (2 bla(CTX-M-9) genes, and 28 bla(CTX-M-14) genes). It was shown that bla(CTX-M) genes were located on high-molecular weight (60-160 bp) conjugative plasmids belonging mainly to the incompatibility groups IncF, IncL/M and IncA/C (bla(CTX-M-15) gene); IncL/M(bla(CTX-M-3) gene); and IncF, IncL/Mand IncI1-ly (CTX-M-14 gene). The gene environments of bla(CTX-M) genes were shown specific for the subtype of the genes. A mobile genetic element ISEcp1 (in some cases deleted or inserted by IS26, IS1, IS10, resTn2, or resTn3 sequences, in direct or reverse position) were detected upstream of bla(CTX-M-3), bla(CTX-M-14), and bla(CTX-M-15) genes. A special characteristic was the sequence between ISEcp1 and bla(CTX-M) gene: 48 bp for bla(CTX-M-15) (except 1 E.coli isolate having such a sequence deleted by 3 bp); 127 bp for bla(CTX-M-3); 42 bp for bla(CTX-M-14). Downstream of bla(CTX-M) and bla(CTX-M-15) genes in the major bacterial isolates orf477 mucA and Delta orf477-Delta mucA sequences were detected respectively. Two isolates had additional Delta orf3 insertion inside of Delta orf477-Delta mucA sequence. Insertion sequence IS903 (intact or deleted) was detected downstream of bla(CTX-M-14) gene. Unlike the others, bla(CTX-M-2) and bla(CTX-M-9) genes were located inside of ISCR1 mobile element, downstream of class 1 integron and orf513 sequence.
authors.forename: N K
authors.initials: NK
authors.lastname: Fursova
authors.forename: S D
authors.initials: SD
authors.lastname: Pryamchuk
authors.forename: I V
authors.initials: IV
authors.lastname: Abaev
authors.forename: Yu N
authors.initials: YN
authors.lastname: Kovalev
authors.forename: N A
authors.initials: NA
authors.lastname: Shishkova
authors.forename: E I
authors.initials: EI
authors.lastname: Pecherskikh
authors.forename: O V
authors.initials: OV
authors.lastname: Korobova
authors.forename: E I
authors.initials: EI
authors.lastname: Astashkin
authors.forename: D M
authors.initials: DM
authors.lastname: Pachkunov
authors.forename: E A
authors.initials: EA
authors.lastname: Svetoch
authors.forename: S V
authors.initials: SV
authors.lastname: Sidorenko
mesh_terms: D018550:Cephalosporin Resistance / Q000235:genetics*; D002511:Cephalosporins / Q000494:pharmacology; D004251:DNA Transposable Elements / Q000235:genetics*; D004754:Enterobacter / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006761:Hospitals; D006801:Humans; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D012426:Russia; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D002511:Cephalosporins; D004251:DNA Transposable Elements; C071167:beta-lactamase CTX-2; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases