Tatavarthy Aparna, Peak Kealy, Veguilla William, Reeves Frank, Cannons Andrew, Amuso Philip, Cattani Jacqueline
Center for Biological Defense, College of Public Health, University of South Florida, Tampa 33612, USA.
J Food Prot. 2006 Apr;69(4):749-56. doi: 10.4315/0362-028x-69.4.749.
The genus Salmonella is composed of more than 2,400 serotypes, many of which cause enteric diseases in humans and animals. Several Salmonella serotypes are multidrug resistant, and there is evidence of the clonal spread of these strains from animals to humans. Salmonella enterica serotype Newport is one of the serotypes that increasingly present a multidrug-resistant phenotype. Source tracking and antibiotic resistance testing are important considerations for identifying the outbreak strain. The first goal of this study was to examine the antibiotic susceptibility patterns of clinical and environmental Salmonella Newport isolates from various geographic locations and to compare the discriminatory ability of two DNA fingerprinting techniques. The second goal was to determine whether the antibiotic resistance profiles and typing patterns correlated. Thirty Salmonella Newport isolates, including environmental and human clinical strains, were subjected to pulsed-field gel electrophoresis (PFGE), ribotyping, and antibiotic susceptibility testing. Eighty percent of the isolates showed total or intermediate resistance to one or more drugs; 75% of the isolates were multidrug resistant. Ribotyping with the EcoRI enzyme and PFGE with the XbaI enzyme each divided the isolates into 14 groups. Cluster analysis based on antibiotic susceptibility patterns generated 23 profiles. The susceptible and resistant isolates were not differentiated on the basis of either of the molecular typing techniques. Hence, no correlation was observed between the antibiotic resistance profiles and the DNA subtyping patterns. In conclusion, ribotyping is as discriminatory as PFGE and, when used in combination with antibiotic resistance profiles, provides a powerful tool for the source tracking of Salmonella Newport.
沙门氏菌属由2400多种血清型组成，其中许多会导致人类和动物的肠道疾病。几种沙门氏菌血清型具有多重耐药性，并且有证据表明这些菌株可从动物克隆传播至人类。肠炎沙门氏菌新港血清型是越来越多地呈现多重耐药表型的血清型之一。溯源追踪和抗生素耐药性检测是识别暴发菌株的重要考虑因素。本研究的首要目标是检测来自不同地理位置的临床和环境新港沙门氏菌分离株的抗生素敏感性模式，并比较两种DNA指纹技术的鉴别能力。第二个目标是确定抗生素耐药谱与分型模式是否相关。对30株新港沙门氏菌分离株，包括环境和人类临床菌株，进行了脉冲场凝胶电泳（PFGE）、核糖体分型和抗生素敏感性检测。80%的分离株对一种或多种药物表现出完全或中度耐药；75%的分离株具有多重耐药性。用EcoRI酶进行核糖体分型和用XbaI酶进行PFGE均将分离株分为14组。基于抗生素敏感性模式的聚类分析产生了23种谱型。根据两种分子分型技术均无法区分敏感和耐药分离株。因此，未观察到抗生素耐药谱与DNA亚型分型模式之间存在相关性。总之，核糖体分型与PFGE的鉴别能力相当，并且与抗生素耐药谱结合使用时，可为新港沙门氏菌的溯源追踪提供有力工具。
