Tn , a novel Tn family transposon coding for temperature-sensitive mercury resistance

Characterization of a marine-isolated mercury-resistant Pseudomonas putida strain SP1 and its potential application in marine mercury reduction

“…Mercury transformation by bacteria is sensitive to important process factors; therefore, factors such as temperature, pH, ion concentrations, and carbon sources that may affect mer-mediated transformation systems have been previously investigated (Kholodii et al 2000;Kholodii and Bogdanova 2002;Oehmen et al 2009). Mortazavi et al (2005) studied the effect of pH on the efficiency of removal of HgCl 2 by a P. putida strain.…”

Tn5041-like transposons: molecular diversity, evolutionary relationships and distribution of distinct variants in environmental bacteria b bThe accession numbers for the nucleotide sequences reported in this work are given in the legends for Figs 1 F1 and 2. c cA comparison of the sequence of INT5041C with other proteins is available as supplementary data on Microbiology Online (http://mic.sgmjournals.org).

“…This system has promoted the integration of various genes, especially those for antibiotic resistance, into these transposons (Stokes et al, 1997 ;Partridge et al, 2000), thus conferring on them a selective advantage. Our studies of bacteria isolated from non-medical sources have suggested that transposons of the Tn21 subgroup are not the sole transposon vehicles responsible for the broad dissemination of mercury resistance in the natural environment (Kholodii et al, 1993a(Kholodii et al, , 2000aHobman et al, 1994 ;Mindlin et al, 2001 ;and our unpublished data). One of the ' new ' mer transposons, Tn5041, was identified in a Pseudomonas strain isolated from a mercury mine in Central Asia .…”

“…These strains were : 3 of 19 examined from Central Asia (Kyrgyzstan), 11 of 25 from the Carpathians (Ukraine), 4 of 15 from the North Caucasus, 1 of 13 from the Kamchatka Peninsula (Far East of Russia), 3 of 77 from Central Russia, 1 of 7 from New Zealand and 1 of 26 from the USA (East Lansing, Bethesda, Chicago, New York). All strains that hybridized to probe 4 were further screened for the presence of active transposons by introduction of the broad-host-range plasmid RP1 and mating out to E. coli AB1456 as previously described (Kholodii et al, 2000a). Eight strains were refractory to RP1 introduction.…”

“…It is 14 907 bp in length and contains a typical Tn3 family transposase gene (tnpA) that is distantly related to tnpA genes found in the Tn21 subgroup transposons, and a mer operon at the right arm of the transposon that is G. Kholodii The genetic/restriction map of Tn5041A together with the Southern hybridization probes 1 to 5 (described in Methods) are at the top. E, EcoRI ; P, PstI ; EV, EcoRV ; Sc, SacII ; orfP, the ORF encoding a porin-like protein ; R', an incomplete merR gene ; κγ, the minitransposon with terminal inverted repeats closely related to those of Tn5044 and Tn5046 (Kholodii et al, 2000a ;Mindlin et al, 2001 ; ACs Y17691 and Y18360) ; 1 and 2, the urf-1 (merE) and urf-2 genes. Other Tn5041 determinants are described in Introduction and Results.…”

Convergent In Vivo and In Vitro Selection of Ceftazidime Resistance Mutations at Position 167 of CTX-M-3 β-Lactamase in Hypermutable Escherichia coli Strains

“…Isolates Irk1224, Irk2320, and Irk2322 were mated in broth with E. coli AB1456 Rif r F Ϫ (20) to determine the transferability of the CTX-M-coding plasmids. Transconjugants were selected on Mueller-Hinton (MH) agar plates containing rifampin (100 g/ml) and CTX (1 g/ml).…”