Pulsed-field gel electrophoresis and ribotype profiles of clinical and environmental Vibrio vulnificus isolates

Abstract

Vibrio vulnificus belongs to the autochthonous bacterial flora of warm estuarine waters. It can cause lifethreatening extraintestinal disease in persons who have underlying illness and who consume raw shellfish or contact wounds with estuarine water. Currently, very little is known about genetic diversity within this species. In this report, we describe high-level variation in restriction fragment length polymorphism profiles among 53 clinical and 78 environmental isolates, as determined by pulsed-field gel electrophoresis. In contrast, ribotype profiles showed greater similarity. When combined ribotype profiles of clinical and environmental isolates were analyzed, four predominant clusters were observed. Interestingly, a low number (16%) of clinical isolates were found in cluster C, compared with clusters A, B, and D (range, 50 to 83%). In addition, 83% of all Hawaiian isolates were located in a single cluster, indicating a possible relationship between geography and genotype. We also report that spontaneous translucent colonial morphotypes were distinct by both restriction fragment length polymorphism and biochemical profiles, compared with opaque parent strains.

Cluster analysis of AP-PCR generated DNA fingerprints of Vibrio vulnificus isolates from patients fatally infected after consumption of raw oysters

“…Examination of the DNA ¢ngerprints from the clinical isolates used in this study (all of which caused fatality after consumption of raw oysters) using gel analysis and cluster analysis, revealed signi¢cant genetic diversity among these strains known to be fatal in susceptible human individuals. This result is consistent with data from several other studies (Aznar et al 1993;Buchrieser et al 1995;Tamplin et al 1996;Vickery et al 1996Vickery et al , 1998 which demonstrated that V. vulni¢cus strains isolated from environmental samples had a diverse genomic organization. To the best of our knowledge, this is the ¢rst study to examine AP-PCR DNA ¢ngerprints produced only from strains of V. vulni¢cus con¢rmed to be virulent in humans.…”

“…vulni¢cus ¢ngerprints, the scored molecular weight data were exported to the statistical analysis program NTSYS-pc2 (Exeter Software, Setaukey, NY, USA) in a binary matrix format. The data were formatted so that the presence or absence of bands of speci¢c molecular weights was indicated either as a 0 (absence) or a1 (presence) (Go et al 1995;Tamplin et al 1996).The matrix was analysed ¢rst using the SIMQUAL algorithm of NTSYS-pc, which generated a similarity matrix for the data, comparing individual ¢ngerprints and assigning them similarity values. Cluster analysis was then performed on the similarity matrix data using the SAHN CLUSTERING (sequential, agglomerative, hierarchical and nested clustering), UPGMA (unweighted pairgroup method, arithmetic average) method algorithm in order to group the ¢ngerprints according to their similarity.…”

“…Despite the collective e¡orts of multiple investigators, only limited progress has been made in determining the genetic and biochemical factor(s) that are responsible for the virulence of this human pathogen. Restriction fragment length polymorphism (RFLP) and ribotype pro¢les among environmental isolates have revealed a high degree of genomic heterogeneity (Buchrieser et al 1995;Tamplin et al 1996).…”

Use of a marker plasmid to examine differential rates of growth and death between clinical and environmental strains of Vibrio vulnificus in experimentally infected mice

“…We studied two clinical isolates of V. vulnificus (LL728, and M06-24/O) obtained from patients who died of sepsis following ingestion of contaminated oysters and two environmental V. vulnificus strains isolated from seawater (MLT365 and MLT367) (Wright et al, 1990;Tamplin et al, 1996;Jackson et al, 1997;Starks et al, 2000). These clinical and environmental strains were selected from a collection based on their relative virulence and attenuation respectively (Wright et al, 1990;Starks et al, 2000).…”

Genetic and quantitative assessment of Vibrio vulnificus populations in oyster (Crassostrea virginica) tissues

“…Vibrio vulnificus is an autochthonous inhabitant of estuarine environments that is found at high population densities and diversities in oysters (Buchrieser et al, 1995;Tamplin et al, 1996;Jackson et al, 1997). This opportunistic pathogen is the leading cause of reported deaths associated with shellfish consumption (Hlady et al, 1993;DePaola et al, 2003), and it caused approximately 14.5% of the Vibrio infections reported by Foodborne Diseases Active Surveillance Network.…”