Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
Med Clin North Am. 2012 Nov;96(6):1067-78. doi: 10.1016/j.mcna.2012.08.005. Epub 2012 Sep 27.
In the setting of infectious disease emergencies, rapid and accurate identification of the causative agent is critical to optimizing antimicrobial therapy in a timely manner. It is clearly evident that the age of molecular diagnostics is now upon us, with real-time PCR becoming the standard of diagnosis for many infectious disease emergencies in either monoplex or multiplex format. Other molecular techniques such as whole or partial genome sequencing, microarrays, broad-range PCR, restriction fragment length polymorphisms, and molecular typing are also being used. However, for most small clinical laboratories, implementation of these advanced molecular techniques is not feasible owing to the high cost of instrumentation and reagents. If these tests are not available in-house, samples can be sent to national reference laboratories (eg, Mayo Medical Laboratories and Quest Diagnostics) for real-time PCR assays that can be completed in 1 day. It is anticipated that over time commercial real-time PCR tests and instrumentation will become more standardized and affordable, allowing individual laboratories to conduct tests locally, thus further reducing turnaround time. Although real-time PCR has been proved to expand our diagnostic capability, it must be stressed that such molecular methodology constitutes only an additional tool in the diagnosis of infectious diseases in emergency situations. Phenotypic methodologies (staining, cultures, biochemical tests, and serology) still play a critical role in identifying, confirming, and providing antibiotic susceptibility testing for many microbial pathogens. As multiplex assays become increasingly available, there will be even greater temptation for taking a “shotgun” approach to diagnostic testing. These new technologies will not substitute for a proper history and physical examination leading to a thoughtful differential diagnosis. None the less, these new molecular tests increase the capability of the diagnostician to rapidly identify the microbiological etiology of an infection. An added advantage of rapid diagnostic tests often not emphasized is the capability to rule out certain diagnoses for which unnecessary antimicrobial therapy may otherwise be instituted and/or continued.
在传染病突发事件中，快速准确地确定病原体对于及时优化抗菌治疗至关重要。显然，分子诊断学的时代已经到来，实时 PCR 已成为许多传染病突发事件的诊断标准，无论是单重还是多重格式。其他分子技术，如全基因组或部分基因组测序、微阵列、广谱 PCR、限制性片段长度多态性和分子分型也正在使用中。然而，对于大多数小型临床实验室来说，由于仪器和试剂的成本高昂，实施这些先进的分子技术是不可行的。如果这些测试在内部不可用，样本可以送到国家参考实验室（例如梅奥医学实验室和 Quest 诊断公司）进行实时 PCR 检测，这些检测可以在 1 天内完成。预计随着时间的推移，商业实时 PCR 测试和仪器将变得更加标准化和负担得起，允许各个实验室在当地进行测试，从而进一步缩短周转时间。尽管实时 PCR 已被证明扩大了我们的诊断能力，但必须强调的是，这种分子方法只是在紧急情况下诊断传染病的另一种工具。表型方法（染色、培养、生化测试和血清学）在识别、确认和提供许多微生物病原体的抗生素敏感性测试方面仍然起着关键作用。随着多重检测方法的日益普及，人们将更倾向于采用“霰弹枪”方法进行诊断检测。这些新技术不会替代适当的病史和体格检查，从而导致深思熟虑的鉴别诊断。尽管如此，这些新的分子测试增加了诊断医生快速识别感染的微生物病因的能力。快速诊断测试的一个额外优势通常不被强调，即能够排除不必要的抗菌治疗可能被实施和/或继续的某些诊断。
