Diverse class 2 integrons in bacteria from beef cattle sources.
OBJECTIVE
The purpose of this study was to determine the diversity of class 2 integrons in bacteria isolated from beef cattle sources.


METHODS
The variable regions of a subset of 11 class 2 integron-containing bacteria were analysed by PCR and DNA sequencing for the presence of novel rearrangements.


RESULTS
A total of six different class 2 integron arrays were identified and four of these were fully characterized. Three of the four arrays characterized have been previously described; however the remaining array is unlike previously described class 2 integrons. The novel class 2 integron was found in Providencia stuartii and contains an apparently functional class 2 integrase. Examination of the variable region of the P. stuartii integron identified nine open reading frames, mostly of unknown function, and represents the first report of a class 2 integron without inserted antibiotic resistance gene cassettes.


CONCLUSIONS
This study has identified a novel class 2 integron found in P. stuartii that contains an apparently functional naturally occurring class 2 integrase. Further investigation of this novel class 2 integron is required to determine the impact of a functional class 2 integrase upon the evolution of class 2 integrons.
Barlow
Robert S
RS
Food Science Australia, PO Box 3312, Tingalpa DC, Queensland 4173, Australia. Robert.Barlow@csiro.au
Gobius
Kari S
KS
D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D002417:Cattle / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D023061:Gene Order; D014644:Genetic Variation; D016680:Genome, Bacterial; D032023:Integrons / Q000235:genetics*; D008460:Meat / Q000382:microbiology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D011532:Providencia / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial