Open AccessIdentification and characterization of Salmonella enterica subsp. enterica serovar Derby isolates carrying a new aadA26 gene cassette in a class 1 integron obtained at pig slaughterhouses
Author(s) -
Lopes Graciela Volz,
Michael Geovana Brenner,
Cardoso Marisa,
Schwarz Stefan
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12473
Subject(s) - integron , salmonella enterica , biology , gene cassette , serotype , microbiology and biotechnology , salmonella , spectinomycin , tetracycline , genetics , genotype , gene , transposable element , plasmid , escherichia coli , antibiotics , bacteria , mutant
Salmonella enterica subsp. enterica ( S .) serovar Derby is one of the most prevalent serovars in pigs. Twenty‐seven multiresistant S . Derby isolates, obtained at two pig slaughterhouses in Southern Brazil, were investigated for their molecular relationships, genotypic resistance and presence of class 1 and 2 integrons. All isolates shared the same XbaI–macrorestriction pattern and showed a common resistance genotype with resistance to streptomycin/spectinomycin ( aadA variant), sulphonamides ( sul1 ) and tetracycline [ tet (A)]. They carried chromosome‐located class 1 integrons with a new aadA gene variant, designated aadA26 , as part of a gene cassette. The sequence of the flanking regions of this integron and the amplification of the merA gene may indicate the location of the class 1 integron into a Tn 21 ‐related transposon. The close relationships among these isolates and isolates from an earlier study suggest the persistence of a resistant clone of S . Derby in the pig production chain in Southern Brazil.