METHODS: Isolates of V. parahaemolyticus from clinical specimens (n = 77) and oysters (n = 224) were identified by biochemical testing, polymerase chain reaction (PCR) assays, and serotyping. The toxin genes, antimicrobial resistance, and β-lactamase production were determined.
RESULTS: A total of 301 isolates were confirmed as V. parahaemolyticus by PCR using specific primers for the toxR gene. The majority of clinical isolates carried the tdh+/trh- genotype (82.1%), and one of each isolate was tdh-/trh+ and tdh+/trh+ genotypes. One isolate from oyster contained the tdh gene and another had the trh gene. Twenty-six serotypes were characterized among these isolates, and O3:K6 was the most common (37.7%), followed by OUT:KUT, and O4:K9. In 2010, most clinical and oyster isolates were susceptible to antibiotics, with the exception of ampicillin. In 2012, clinical isolates were not susceptible to cephalothin (52.4%), streptomycin (95.2%), amikacin (66.6%), kanamycin (61.9%), and erythromycin (95.2%), significantly more frequently than in 2010. More than 95% of isolates that were not susceptible to ampicillin produced β-lactamase enzymes.
CONCLUSIONS: We found toxin genes in two oyster isolates, and the clinical isolates that were initially determined to be resistant to several antibiotics. Toxin genes and antimicrobial susceptibility profiles of V. parahaemolyticus from seafood and environment should be continually monitored to determine the spread of toxin and antimicrobial resistance genes.
方法:通过生化检测鉴定了临床标本(n=77)和牡蛎(n=224)中的副溶血性弧菌。聚合酶链反应(PCR)测定,和血清分型。毒素基因,抗菌素耐药性,并测定β-内酰胺酶的产量。
结果:使用toxR基因的特异性引物通过PCR确认了总共301个分离株为副溶血性弧菌。大多数临床分离株携带tdh+/trh-基因型(82.1%),每个分离株中的一个是tdh-/trh+和tdh+/trh+基因型。一种来自牡蛎的分离物含有tdh基因,另一种具有trh基因。在这些分离株中表征了26种血清型,和O3:K6是最常见的(37.7%),其次是OUT:KUT,和O4:K9。2010年,大多数临床和牡蛎分离株对抗生素敏感,除了氨苄青霉素。2012年,临床分离株对头孢菌素不敏感(52.4%),链霉素(95.2%),阿米卡星(66.6%),卡那霉素(61.9%),和红霉素(95.2%),比2010年更频繁。超过95%对氨苄青霉素不敏感的分离株产生β-内酰胺酶。
结论:我们在两个牡蛎分离物中发现了毒素基因,以及最初确定对几种抗生素具有耐药性的临床分离株。应持续监测来自海产品和环境的副溶血性弧菌的毒素基因和抗菌敏感性,以确定毒素和抗菌抗性基因的传播。