Multi-site analysis reveals widespread antibiotic resistance in the marine pathogen Vibrio vulnificus.
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.
Baker-Austin
Craig
C
Savannah River Ecology Laboratory, Drawer E, Aiken, SC, USA. craig.baker-austin@cefas.co.uk
McArthur
J V
JV
Lindell
Angela H
AH
Wright
Meredith S
MS
Tuckfield
R Cary
RC
Gooch
Jan
J
Warner
Liza
L
Oliver
James
J
Stepanauskas
Ramunas
R
D000890:Anti-Infective Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005838:Genotype; D019015:Geologic Sediments / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D012623:Seawater / Q000382:microbiology*; D014735:Vibrio Infections / Q000382:microbiology*; D041261:Vibrio vulnificus / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D000890:Anti-Infective Agents