HR: 16:45h
AN: B24A-06    [Abstracts]
TI: Indirect Selection for Antibiotic Resistance in Multiple Stream Microhabitats
AU: * Wright, M S
EM: mswright@uga.edu
AF: Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802 United States
AU: * Wright, M S
EM: mswright@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: Peltier, G L
EM: loeffler@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: McArthur, J
EM: mcarthur@srel.edu
AF: Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802 United States
AB: One aspect challenging public health efforts to minimize the spread of antibiotic resistance (AR) is the prevalence of resistant bacteria in the environment. Anthropogenic-derived sources of selection are typically implicated as mechanisms for maintaining AR in the environment. Here we report an additional mechanism for maintaining AR in the environment through co- or cross-resistance to heavy metals. Using culture-independent techniques, bacteria isolated from heavy-metal contaminated sites were more tolerant of antibiotics and metals compared to those bacteria from a reference site. This evidence supports our hypothesis that metal contamination directly selects for metal tolerant bacteria while indirectly selecting for antibiotic tolerant bacteria. Additionally, to assess how antibiotic- and metal-tolerance may be transported through a stream network, we studied antibiotic and metal-tolerance patterns over four months in bacteria collected from multiple stream microhabitats including water column, biofilm, sediment, and Corbicula fluminea (Asiatic clam) digestive tracts. Sediment bacteria were the most tolerant to antibiotics and metals, while bacteria from Corbicula were the least tolerant. Differences between these microhabitats may be important for predicting antibiotic resistance transfer and transport in stream environments. Further, temporal dynamics suggest that tolerance patterns within microhabitats are linked to physico-chemical characteristics of the stream.
UR: http://arches.uga.edu/~mswright
DE: 1845 Limnology
DE: 4803 Bacteria
DE: 4840 Microbiology
DE: 4857 Pollution
DE: 9901 NABS Student Award - Basic Research
SC: Biogeosciences [B]
MN: 2005 Joint Assembly