Genotypic diversity and antimicrobial resistance in asymptomatic Salmonella enterica serotype Typhimurium DT104.
Genotypic diversity and antimicrobial resistance in asymptomatic Salmonella enterica serotype Typhimurium DT104.
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无症状肠沙门氏菌血清型鼠伤寒 DT104 的基因型多样性和抗菌药物耐药性。
DOI：
10.1016/j.meegid.2006.09.003
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
G. Bell
中科院分区：
文献类型：
--
作者：
G. Perron;S. Quessy;A. Letellier;G. Bell
最近出现的多重耐药肠道沙门氏菌肠道亚种血清型鼠伤寒噬菌体型DT 104代表了来自人类和兽医的卫生工作者的挑战。在努力制定有效的控制策略，它是至关重要的，以准确地描述的程度，遗传和表型变异存在于病原体种群。虽然以前的研究主要集中在疾病相关人群，但我们报告了与猪中发现的无症状鼠伤寒沙门氏菌DT 104分离株相关的遗传多样性和抗菌素耐药性多样性。使用脉冲场凝胶电泳（XbaI和SpeI），我们确定了62种不同的基因型与13种不同的抗菌药物耐药表型之间的80个无症状的DT 104分离株从加拿大养猪业。当将无症状分离株的子样本稀疏曲线与来自相似空间和时间尺度的疾病相关分离株的稀疏曲线进行比较时，我们在无症状人群中鉴定出显著更多的基因型，具有27种PFGE模式，而后者为23.0±1.4（95%置信区间）。此外，使用辛普森的多样性指数，我们观察到相当高的遗传和表型多样性在牛群内的无症状的分离株，并检测可能的模式的疾病相关的人口内的周期性选择。因此，我们得出结论，沙门氏菌种群结构和生态的一个重要方面被忽视的疾病相关的菌株的调查。
The recent emergence of multidrug-resistant Salmonella enterica subspecies enterica serotype Typhimurium phage-type DT104 represents a challenge to health workers from both human and veterinary medicine. In an effort to develop effective control strategies, it is vital to characterize accurately the extent of genetic and phenotypic variation present in the pathogen population. While previous studies have focused on disease-associated populations, we report the genetic diversity and the diversity in antimicrobial resistance associated with asymptomatic Salmonella Typhimurium DT104 isolates found in pigs. Using pulsed-field gel electrophoresis (XbaI and SpeI), we identified 62 different genotypes associated to 13 different antimicrobial resistant phenotypes among 80 asymptomatic DT104 isolates collected from the Canadian swine industry. When rarefaction curves of a subsample the asymptomatic isolates were compared to that of disease-associated isolates from a similar spatial and temporal scale, we identified significantly more genotypes among the asymptomatic populations with 27 PFGE patterns against 23.0±1.4 (95% confidence intervals) in the latter. Also, using Simpson's diversity index, we observed considerably higher genetic and phenotypic diversity in the asymptomatic isolates within herds and detected possible patterns of periodic selection within the disease-associated population. We thus concluded that an important aspect of Salmonella population structure and ecology is overlooked in investigations of disease-associated isolates.