Open AccessCharacterization of pRAS1‐like plasmids from atypical North American psychrophilic Aeromonas salmonicida
Author(s) -
Casas Christina,
Anderson Elizabeth C.,
Ojo Kayode K.,
Keith Ian,
Whelan Daryl,
Rainnie Don,
Roberts Marilyn C.
Publication year - 2005
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 - 10.1016/j.femsle.2004.10.039
Subject(s) - psychrophile , aeromonas salmonicida , plasmid , microbiology and biotechnology , aeromonas , vibrionaceae , biology , bacteria , genetics , gene
Atypical psychrophilic Aeromonas salmonicida isolates were obtained from farmed and wild fish in Northeastern North America. These bacteria were isolated between 1992 and 2001 and carried tetracycline resistance (Tc r ) plasmids of approximately 58 kb. The nine isolates had plasmids which could be divided into four groups based on the specific tetracycline resistance ( tet ) gene carried [ tet (A) or tet (B)], incompatibility of the plasmid [IncU or other], whether the plasmid carried the IS 6100 sequences, the sul1 gene, coding for sulfonamide resistance, the dfrA16 gene, coding for trimethoprim resistance, and/or carried a complete Tn 1721 , and their ability to transfer their Tc r plasmids to an Escherichia coli recipient at 15 °C. Five of the isolates, with genetically related Tc r plasmids, were able to transfer their plasmids to an E. coli recipient at frequencies ranging from 5.7 × 10 −4 to 2.8 × 10 −6 per recipient. The 1992 isolate carried a genetically distinct plasmid, which transferred at a slightly higher rate. The three remaining isolates carried one of two genetically different plasmids, which were unable to transfer to an E. coli recipient. Conjugal transfer at 15 °C is the lowest temperature that has been documented in bacteria.