title: Characterization by PCR of Vibrio parahaemolyticus isolates collected during the 1997-1998 Chilean outbreak.
abstract: Between November 1997 and April 1998, several human gastroenteritis cases were reported in Antofagasta, a city in the north of Chile. This outbreak was associated with the consumption of shellfish, and the etiologic agent responsible was identified as Vibrio parahaemolyticus. This was the first report of this bacterium causing an epidemic in Chile. V. parahaemolyticus was the only pathogenic bacterium isolated from patient stools and from shellfish samples. These isolates were analyzed by polymerase chain reaction (PCR) amplification of the pR72H gene, a species-specific sequence. Based on the pR72H gene amplification pattern, at least three different isolates of V. parahaemolyticus were found. Two isolates (named amplicons A and C) generated PCR products of approximately 400 bp and 340 bp respectively, while another type of isolate designated B, did not generate a PCR product, regardless of which method of DNA purification was used. Sequence analysis of the amplicons A and C shows that they have an 80 bp and 183 bp conserved region at the 5' end of the gene. However, both isolates have different sequences at their 3' terminus and are also different from the pR72H sequence originally reported. Using this PCR assay we demonstrated that these three isolates were found in clinical samples as well as in shellfish. The warm seawater caused by the climatological phenomena "El Niño" perhaps favored the geographic dispersion of the bacterium (bacterial bloom) occurring in Antofagasta that occurred during that time of year.
authors.affiliation: Fundación Ciencia para la Vida, Millennium Institute for Fundamental and Applied Biology, Av. Marathón 1943, Nuñoa, Santiago, Chile. jcordova@bionova.cl
authors.forename: José Luis
authors.initials: JL
authors.lastname: Córdova
authors.forename: Josefa
authors.initials: J
authors.lastname: Astorga
authors.forename: Wally
authors.initials: W
authors.lastname: Silva
authors.forename: Carlos
authors.initials: C
authors.lastname: Riquelme
mesh_terms: D000818:Animals; D001483:Base Sequence; D002677:Chile / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004196:Disease Outbreaks; D005243:Feces / Q000382:microbiology; D005759:Gastroenteritis / Q000453:epidemiology / Q000382:microbiology*; D005784:Gene Amplification; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012758:Shellfish / Q000382:microbiology*; D014735:Vibrio Infections / Q000453:epidemiology / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial