TY - JOUR
T1 - Class 1 integrons in benthic bacterial communities
T2 - Abundance, association with Tn402-like transposition modules and evidence for coselection with heavy-metal resistance
AU - Rosewarne, Carly P.
AU - Pettigrove, Vincent
AU - Stokes, Hatch W.
AU - Parsons, Yvonne M.
PY - 2010/4
Y1 - 2010/4
N2 - The integron/gene cassette system contributes to lateral gene transfer of genetic information in bacterial communities, with gene cassette-encoded proteins potentially playing an important role in adaptation to stress. Class 1 integrons are a particularly important class as they themselves seem to be broadly disseminated among the Proteobacteria and have an established role in the spread of antibiotic resistance genes. The abundance and structure of class 1 integrons in freshwater sediment bacterial communities was assessed through sampling of 30 spatially distinct sites encompassing different substrate and catchment types from the Greater Melbourne Area of Victoria, Australia. Real-time PCR was used to demonstrate that the abundance of intI1 was increased as a result of ecosystem perturbation, indicated by classification of sample locations based on the catchment type and a strong positive correlation with the first principal component factor score, comprised primarily of the heavy metals zinc, mercury, lead and copper. Additionally, the abundance of intI1 at sites located downstream from treated sewage outputs was associated with the percentage contribution of the discharge to the basal flow rate. Characterization of class 1 integrons in bacteria cultured from selected sediment samples identified an association with complete Tn402-like transposition modules, and the potential for coselection of heavy-metal and antibiotic resistance mechanisms in benthic environments.
AB - The integron/gene cassette system contributes to lateral gene transfer of genetic information in bacterial communities, with gene cassette-encoded proteins potentially playing an important role in adaptation to stress. Class 1 integrons are a particularly important class as they themselves seem to be broadly disseminated among the Proteobacteria and have an established role in the spread of antibiotic resistance genes. The abundance and structure of class 1 integrons in freshwater sediment bacterial communities was assessed through sampling of 30 spatially distinct sites encompassing different substrate and catchment types from the Greater Melbourne Area of Victoria, Australia. Real-time PCR was used to demonstrate that the abundance of intI1 was increased as a result of ecosystem perturbation, indicated by classification of sample locations based on the catchment type and a strong positive correlation with the first principal component factor score, comprised primarily of the heavy metals zinc, mercury, lead and copper. Additionally, the abundance of intI1 at sites located downstream from treated sewage outputs was associated with the percentage contribution of the discharge to the basal flow rate. Characterization of class 1 integrons in bacteria cultured from selected sediment samples identified an association with complete Tn402-like transposition modules, and the potential for coselection of heavy-metal and antibiotic resistance mechanisms in benthic environments.
KW - Adaptation
KW - Freshwater sediment
KW - Heavy-metal pollution
KW - IntI1
KW - Lateral gene transfer
UR - http://www.scopus.com/inward/record.url?scp=77949280154&partnerID=8YFLogxK
U2 - 10.1111/j.1574-6941.2009.00823.x
DO - 10.1111/j.1574-6941.2009.00823.x
M3 - Article
C2 - 20132306
AN - SCOPUS:77949280154
VL - 72
SP - 35
EP - 46
JO - FEMS Microbiology Ecology
JF - FEMS Microbiology Ecology
SN - 0168-6496
IS - 1
ER -