Class 2 Integrons Dissemination Among Multidrug Resistance (MDR) Clones of Acinetobacter baumannii

Abstract

Acinetobacter baumannii has emerged as a serious problem in the hospital environment at a global scale. Previous results from our laboratory showed a high frequency of class 2 integrons in A. baumannii strains from Argentina regarding the low rate of this element in A. baumannii isolates from the rest of the world. To reveal the current epidemiology of class 2 integrons, a molecular surveillance analyzing 78 multidrug resistant (MDR) A. baumannii isolates from Argentina and Uruguay was performed, exposing the presence of class 2 integron in the 36.61% of the isolates. Class 2 integron characterization showed that the typical Tn7::In2-7 array was present in 26 out of 27 intI2 positive isolates. All intI2 positive isolates contained at least one of the Tn7 transposition genes. In addition, we identified that 18 intI2 positive isolates possessed the Tn7::In2-7 within the attTn7 site. The molecular typing evidenced that clones I and IV that do not belong to widespread European clones I and II were found among the intI2 positive isolates. Our results exposed the widely dissemination of class 2 integron among MDR A. baumannii isolates from Argentina and Uruguay, also showing the persistence of two novel clones in our region, which could explain in part the high frequency of class 2 integron found in our region.

Association of Class 1 and 2 Integrons with Multidrug-Resistant Acinetobacter baumannii International Clones and Acinetobacter nosocomialis Isolates

“…In Argentina, this array was also frequently observed (5), and this finding is in line with the report of the CC113/79 spread in this country (14). Similarly, the description of dfrA1, sat2, and aadA1 cassettes in Argentina, Chile, and Uruguay may also be explained by the CC113/79 spread in Latin America (5, 7).…”

“…This finding is possibly related to local clonal groups (6), but a hypothesis has not yet been addressed. The class 2 integron structure seems less diverse than that of class 1 (7) and is usually embedded within transposon Tn7 (5,8).…”

“…The MDR phenotype in Acinetobacter has been related to class 1 and 2 integrons (3,4,5); class 2 integrons predominate in A. baumannii from Latin America (5,6). This finding is possibly related to local clonal groups (6), but a hypothesis has not yet been addressed.…”

Outbreak of Extensively Drug-Resistant Acinetobacter baumannii Indigo-Pigmented Strains

“…Class 2 integrons were also found in all the indigo-pigmented A. baumannii strains, whereas no class 1 integrons were found. These results are in accordance with our previous studies, which showed that class 2 integrons are more abundant than class 1 integrons in A. baumannii strains from Argentina (20,29,30). PCR cartography and sequence analyses revealed that In2-7, which is the common class 2 integron array, was present in the 13 strains studied (20,29).…”

Integron-Mediated Antibiotic Resistance inAcinetobacter baumanniiIsolated from Intensive Care Unit Patients, Babol, North of Iran

“…Also, Kamalbeik et al showed that 7.5% and 67.5% of the strains contained class I and II integrons, respectively [23]. In the studies carried out by Ramírez et al [24] and Martins et al [25], the prevalence of class II Integron was 23% and 41.7%, respectively. In the research conducted by Taherikalani et al (Tehran at 2012) [26] and Moammadi et al (west of Iran at 2012) [27] the frequency of class I, II, and III integrons was 85%, 14%, and 0%, and 97%, 31%, and 0%, respectively.…”