Open AccessIdentification of a truncated, but functionally active tet (H) tetracycline resistance gene in Pasteurella aerogenes and Pasteurella multocida
Author(s) -
Kehrenberg Corinna,
Schwarz Stefan
Publication year - 2000
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/j.1574-6968.2000.tb09192.x
Subject(s) - pasteurella multocida , plasmid , tetracycline , biology , microbiology and biotechnology , pasteurella , gene , escherichia coli , genetics , bacteria , antibiotics
Molecular analysis of Pasteurella isolates of animal origin for plasmid‐encoded tetracycline resistance genes identified a common tet (H)‐carrying plasmid of 5.5 kbp in a single isolate of Pasteurella aerogenes and six isolates of Pasteurella multocida . This plasmid carried a truncated Tn 5706 element in which one of the IS elements, IS 1596 , was lost completely and of the other, IS 1597 , only a relic of 84 bp was left. Sequencing of the resistance gene region and the flanking areas revealed the presence of a deletion in the 3′ end of the tet (H) gene which shortened the tet (H) reading frame by 24 bp. The amino acid sequence of the respective TetH protein comprised only 392 amino acids. Despite this deletion, the tet (H) gene conferred high level tetracycline resistance not only to the original Pasteurella isolates but also to the respective Escherichia coli JM107 and C600 transformants as confirmed by MIC determination. The deletion was probably the result from recombinational events. Two possible recombination sites involved in the deletion of tet (H) and that of IS 1597 were identified. Macrorestriction analysis of the Pasteurella isolates carrying plasmid pPAT1 confirmed horizontal and vertical transfer of this plasmid.