Characterization of IS 18 , an Element Capable of Activating the Silent aac(6′)-Ij Gene of Acinetobacter sp. 13 Strain BM2716 by Transposition

Abstract

Insertion sequence IS18 was detected by analysis of the spontaneous aminoglycoside resistant mutant Acinetobactersp. 13 strain BM2716-1. Insertion of the element upstream from the silent acetyltransferase gene aac(6′)-Ij created a hybrid promoter that putatively accounts for the expression of the aminoglycoside resistance gene. The 1,074-bp IS18 element contained partially matched (20 out of 26 bases) terminal inverted repeats, one of which overlapped the 3′ end of a 935-bp open reading frame potentially encoding a protein related to the transposases of the IS30 family. IS18 was found in 6 out of 29 strains of Acinetobacter sp. 13 but not in 10 strains each of A. baumannii and A. haemolyticus.

Transposition and target specificity of the typical IS30 family element IS1655 from Neisseria meningitidis

“…IS 30 and certain other family members (IS 18 : Rudant et al ., 1998; IS 4351 : Hwa et al ., 1988; IS 1470 : Brynestad and Granum, 1999) have previously been shown to generate an IRL–IRR junction and, in the case of IS 30 , an active circular intermediate possessing such a structure has been described (Kiss and Olasz, 1999). It was therefore of interest to determine whether IS 1655 also uses the abutted IRs as a transposition intermediate.…”

“…IS 30 family members are distributed throughout the Gram‐positive and Gram‐negative bacteria (ISFinder: http://www-is.biotoul.fr) and an example has also been found in the Archaea (ISC 1041 , Ammendola et al ., 1998). With few exceptions (IS 4351 : Hwa et al ., 1988; IS 1070 : Vaughan and de Vos, 1995; IS 18 : Rudant et al ., 1998; IS 1470 : Brynestad and Granum, 1999) only the sequence of the element and that of the putative Tpase have been published but no experimental data on their transposition behaviour are available.…”

“…Similar transpositionally active IR-IR junctions have been described for members of several IS families including IS1, IS3, IS21, IS110 and IS256 (Chandler and Mahillon, 2002). IR-IR junctions have also been detected in some other IS30 family members such as IS18 (Rudant et al, 1998), IS4351 (Hwa et al, 1988) and IS1470 (Brynestad and Granum, 1999); however, their role in transposition has not been analysed.…”

Prevalence and Characteristics ofnimGenes Encoding 5-Nitroimidazole Resistance amongBacteroidesStrains Isolated in Morocco

“…The activation of silent antibiotic resistance genes by insertion sequences elements was also detected in other bacteria like Pseudomonas 27 and Acinetobacter. 26 This might be of clinical significance because the activation of the silent gene could lead to a resistance phenotype.…”

Prevalence of ISAba1in epidemiologically unrelatedAcinetobacter baumanniiclinical isolates

“…In Acinetobacter spp., other IS elements associated with activation of aminoglycoside-modifying enzymes have been described (Rudant et al, 1998). The resistance to this b-lactam antibiotic in these three strains may be due to a mechanism of b-lactam resistance other than the overexpression of the bla ADC -like gene.…”