SREL Reprint #3144

Multi-site Analysis Reveals Widespread Antibiotic Resistance in the Marine Pathogen Vibrio vulnificus

Craig Baker-Austin1, J. V. McArthur1, Angela H. Lindell1, Meredith S. Wright1, R. Cary Tuckfield2, Jan Gooch3, Liza Warner4, James Oliver4, and Ramunas Stepanauskas5

1Savannah River Ecology Laboratory, Drawer E, Aiken, SC, USA
2Savannah River National Laboratory, Bldg. 773-42A, Aiken, SC, USA
3National Oceanographic and Atmospheric Administration, Charleston, SC, USA
4Department of Biology, University of North Carolina at Charlotte, Charlotte, NC, USA
5Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME, USA

Abstract: Vibrio vulnificus is a serious opportunistic human pathogen commonly found in subtropical coastal waters, and is the leading cause of seafood-borne mortality in the USA. This taxon does not sustain prolonged presence in clinical or agricultural settings, where it would undergo human-induced selection for antibiotic resistance. Therefore, few studies have verified the effectiveness of commonly prescribed antibiotics in V. vulnificus treatment. Here we screened 151 coastal isolates and 10 primary septicaemia isolates against 26 antimicrobial agents representing diverse modes of action. The frequency of multiple resistances to antibiotics from all sources was unexpectedly high, particularly during summer months, and a substantial proportion of isolates (17.3%) were resistant to eight or more antimicrobial agents. Numerous isolates demonstrated resistance to antibiotics routinely prescribed for V. vulnificus infections, such as doxycycline, tetracycline, aminoglycosides and cephalosporins. These resistances were detected at similar frequencies in virulent and non-virulent strains (PCR-based virulence typing) and were present in septicaemia isolates, underlying the public health implications of our findings. Among environmental isolates, there were no consistent differences in the frequency of resistance between pristine and anthropogenically impacted estuaries, suggesting natural rather than human-derived sources of resistance traits. This report is the first to demonstrate prevalent antibiotic resistance in a human pathogen with no clinical reservoirs, implying the importance of environmental studies in understanding the spread, evolution and public health relevance of antibiotic resistance factors.

SREL Reprint #3144

Baker-Austin, C., J. V. McArthur, A. H. Lindell, M. S. Wright, R. C. Tuckfield, J. Gooch, L. Warner, J. Oliver, and R. Stepanauskas. 2009. Multi-site Analysis Reveals Widespread Antibiotic Resistance in the Marine Pathogen Vibrio vulnificus. Microbial Ecology 2009(57): 151-159.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).