Distribution of Vibrio vulnificus and Other Lactose-Fermenting Vibrios in the Marine Environment

Abstract

negative vibrios were isolated from seawater, sediment, plankton, and animal samples taken from 80 sites from Miami, Fla., to Portland, Maine. Of these, 4.2% were able to ferment lactose. The lactose-positive strains isolated from the various samples correlated positively with pH and turbidity of the water, vibrios in the sediment and oysters, and total bacterial counts in oysters. Negative correlations were obtained for water salinity. Numerical taxonomy was performed on 95 of the lactose-fermenting environmental isolates and 23 reference strains. Five clusters resulted, with the major cluster containing 33 of the environmental isolates and all of the Vibrio vulnificus reference strains. The 33 isolates, which produced an acid reaction in lactose broth within hours of initial inoculation, represented 20% of all lactose-fermenting vibrios studied. These isolates were nearly identical phenotypically to clinical strains of V. vulnificus studied by the Centers for Disease Control, Atlanta, Ga., and by our laboratory, and their identification was confirmed by DNA-DNA hybridization studies. V. vulnificus was isolated from all sample types and from Miami to Cape Cod, Mass., and comparison of the environmental parameters of the eight subsites yielding this species with those of all 80 subsites revealed no significant differences. The majority of the isolates were obtained from animals, with clams providing most (84%) of these. On injection into mice, 82% of the V. vulnificus isolates resulted in death. Members of the remaining four clusters contained strains which differed from V. vulnificus in such phenotypic traits as luminescence and in urease or H2S production. None of the other reference cultures, including nine other Vibrio species, were contained in the remaining clusters, and these isolates could not be identified. Most of these were also lethal for mice. Phenotypic differences, potential pathogenicity, and geographic distribution of the five clusters were examined. It is concluded that V. vulnificus is a ubiquitous organism, both geographically and in a variety of environmental sources, although it occurs in relatively low numbers. The public health significance of this organism and of the other unidentified lactose-fermenting Vibrio species is discussed. Vibrio vulnificus is a lactose-fermenting, opportunistic human pathogen capable of causing death in mice within 2.5 h (3, 19) and in humans within 2 or 3 days (2, 6). Although infections apparently can occur in otherwise healthy individuals (11), human disease typically results from ingestion of contaminated seafood or from infection of a wound, frequently of crab or oyster origin (2). Studies from our laboratory and from case histories suggest that persons with elevated serum iron levels (owing to, e.g., chronic alcoholism, hepatitis, thalassemia major, or hemochromatosis) are especially vulnerable to infection by this organism (2, 27). The organism is able to cause massive damage to the intestinal wall, which probably allows its penetration to the circulator...

First record of Vibrio vulnificus biotype 2 from diseased European eel, Anguilla anguilla L.

“…The present authors' strains, as well as the Japanese ones, are sensitive to a broad spectrum of antimicrobial compounds, being resistant to amoxicillin, penicillin, streptomycin, sulphonamides, fosphomycin and polymyxin B. Oxolinic acid, one of the drugs most currently employed in aquaculture (Austin & Austin 1987), gave the strongest inhibition on the Mueller-Hinton plates, and was therefore chosen to control the disease. Tison et al, (1982) described biotype 2 of the species only with three strains originally isolated from diseased eels in Japan by Muroga et al (1976a), whereas V. vulnificus biotype 1 has been isolated from sea water and shellfish (Tamplin, Rodrick, Blake & Cuba 1982;Oliver, Warner & Cleland 1983;Kaysner, Abeyta, Wekell, DePaola, Stott & Leicht 1987). In the present study, the diseased eels had different origins; therefore, it is impossible to ascertain the source of the microorganism.…”

“…* G, green colonies on TCBS; Y, yellow colonies on TCBS; +, > 80% strains possess character; -, > 80% do not possess character; d, 21-79% of the strains possess character; NT, not tested. Data obtained from: Tison et al (1982), Oliver et al (1983), Baumann et al (1984), Lee & Donovan (1985) and Ortigosa et al (1989). *• Test positive after 72 h of incubation at 28°C.…”

Improved specific detection of Vibrio cholerae in environmental water samples by culture on selective medium and colony hybridization assay with an oligonucleotide probe

“…In aquatic environments, V. cholerae is frequently isolated together with other Vibrio species, such as V. parahaemolyticus, V. mimicus, V. vulni¢cus, V. alginolyticus, and with a variety of indigenous bacteria [36]. The detection of any bacterial species in an environmental sample depends on the ability of that species to grow on the culture media used for isolation.…”

North Atlantic Vibrio vulnificus surveillance from postharvest oysters at a US shellfish processing facility

“…vulnificus follows a consistent fluctuation pattern throughout the year. The highest concentrations are observed during the warmer summer months (July-August), decline through the fall and winter (October-February), and begin to increase as the spring (March-June) temperatures rise (Kelly 1982;Oliver et al 1983;Tamplin 1990;O'Neill et al 1990;O'Neill et al 1992;Wright et al 1996). As a result of this oscillation, the overwhelming majority of vibrio oyster consumption-related infections occur during the summer months when the organisms are at peak abundance (Shapiro et al 1998).…”