Tancos K A, Cox K D
Department of Plant Pathology and Plant-Microbe Biology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456.
Plant Dis. 2016 Jul;100(7):1307-1313. doi: 10.1094/PDIS-01-16-0088-RE. Epub 2016 Apr 27.
Streptomycin is the most effective and widely used chemical control in the eastern United States for blossom blight of apple caused by Erwinia amylovora; however, resistance to this antibiotic has been a concern in New York since 2002. From 2011 to 2014, statewide collections of E. amylovora were conducted resulting in the isolation of streptomycin-resistant (SmR) E. amylovora from several commercial orchards. Further genetic analysis of isolates was necessary to understand the origins and the diversity of these bacteria. Clustered regularly interspaced short palindromic repeat (CRISPR) spacer sequencing was employed to explore the diversity and possible origins of New York SmR E. amylovora isolates. The spacer array CR1, CR2, and CR3 regions of 27 SmR E. amylovora isolates and 76 streptomycin-sensitive (SmS) E. amylovora isolates were amplified and subsequently sequenced, revealing 19 distinct CRISPR spacer profiles for New York isolates. The majority of SmR E. amylovora isolates had the same CRISPR profile as SmR E. amylovora isolates discovered in 2002. This may infer that eradication efforts in 2002 failed and the bacterial populations continued to spread throughout the state. Several CRISPR profiles for SmR E. amylovora were identical to SmS E. amylovora collected from the same orchards, leading to the hypothesis that resistance may be developing within New York. Profiles not unique to New York were identical to many isolates from the Midwestern, eastern, and western United States, implying that streptomycin resistance may be due to the introduction of SmR E. amylovora from other regions of the United States. The increased understanding as to how SmR E. amylovora isolates are introduced, evolve, or have become established afforded by CRISPR profiling has been useful for disease management and restricting the movement of streptomycin resistance in New York.
链霉素是美国东部防治由解淀粉欧文氏菌引起的苹果花腐病最有效且应用最广泛的化学防治药剂；然而，自2002年以来，纽约州对这种抗生素的抗性一直令人担忧。2011年至2014年期间，在全州范围内收集了解淀粉欧文氏菌，结果从几个商业果园中分离出了对链霉素具有抗性（SmR）的解淀粉欧文氏菌。有必要对分离株进行进一步的基因分析，以了解这些细菌的起源和多样性。利用成簇规律间隔短回文重复序列（CRISPR）间隔区测序来探究纽约州对链霉素具有抗性的解淀粉欧文氏菌分离株的多样性和可能的起源。对27株对链霉素具有抗性的解淀粉欧文氏菌分离株和76株对链霉素敏感（SmS）的解淀粉欧文氏菌分离株的间隔序列阵列CR1、CR2和CR3区域进行了扩增，随后进行了测序，揭示了纽约分离株有19种不同的CRISPR间隔区图谱。大多数对链霉素具有抗性的解淀粉欧文氏菌分离株与2002年发现的对链霉素具有抗性的解淀粉欧文氏菌分离株具有相同的CRISPR图谱。这可能意味着2002年的根除工作失败了，细菌种群继续在全州范围内传播。一些对链霉素具有抗性的解淀粉欧文氏菌的CRISPR图谱与从同一果园收集的对链霉素敏感的解淀粉欧文氏菌相同，这导致了一种假设，即抗性可能正在纽约州内形成。纽约州不独有的图谱与来自美国中西部、东部和西部的许多分离株相同，这意味着链霉素抗性可能是由于从美国其他地区引入了对链霉素具有抗性的解淀粉欧文氏菌。通过CRISPR图谱分析对如何引入、进化或已建立对链霉素具有抗性的解淀粉欧文氏菌分离株有了更多了解，这对纽约州的病害管理和限制链霉素抗性的传播很有用。
