Córdova José Luis, Astorga Josefa, Silva Wally, Riquelme Carlos
Fundación Ciencia para la Vida, Millennium Institute for Fundamental and Applied Biology, Av. Marathón 1943, Nuñoa, Santiago, Chile.
Biol Res. 2002;35(3-4):433-40. doi: 10.4067/s0716-97602002000300017.
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.
1997年11月至1998年4月期间，智利北部城市安托法加斯塔报告了几起人类肠胃炎病例。此次疫情与食用贝类有关，致病病原体被确定为副溶血性弧菌。这是该细菌在智利引发疫情的首次报告。副溶血性弧菌是从患者粪便和贝类样本中分离出的唯一病原菌。通过聚合酶链反应（PCR）扩增物种特异性序列pR72H基因对这些分离株进行了分析。根据pR72H基因扩增模式，发现了至少三种不同的副溶血性弧菌分离株。两种分离株（分别命名为扩增子A和C）分别产生了约400 bp和340 bp的PCR产物，而另一种类型的分离株B无论使用哪种DNA纯化方法都未产生PCR产物。扩增子A和C的序列分析表明，它们在基因的5'端有一个80 bp和183 bp的保守区域。然而，两种分离株在其3'末端具有不同的序列，并且也与最初报道的pR72H序列不同。使用这种PCR检测方法，我们证明在临床样本和贝类中都发现了这三种分离株。气候现象“厄尔尼诺”导致的温暖海水可能有利于当时在安托法加斯塔出现的细菌地理扩散（细菌大量繁殖）。
